Minor updates

This will allow importing storage.Config without importing every SQL drivers in the known universe

.dockerignore

@@ -1,4 +1,4 @@
-examples
+.examples
 Dockerfile
 .github
 .idea

.examples/docker-compose-postgres-storage/config.yaml

@@ -1,6 +1,6 @@
 storage:
   type: postgres
-  file: "postgres://username:password@postgres:5432/gatus?sslmode=disable"
+  path: "postgres://username:password@postgres:5432/gatus?sslmode=disable"
 
 endpoints:
   - name: back-end

.examples/docker-compose-sqlite-storage/config.yaml

@@ -1,6 +1,6 @@
 storage:
   type: sqlite
-  file: /data/data.db
+  path: /data/data.db
 
 endpoints:
   - name: back-end

.examples/kubernetes/gatus.yaml

@@ -9,14 +9,17 @@ data:
     endpoints:
       - name: website
         url: https://twin.sh/health
-        interval: 1m
+        interval: 5m
         conditions:
           - "[STATUS] == 200"
+          - "[BODY].status == UP"
+
       - name: github
         url: https://api.github.com/healthz
         interval: 5m
         conditions:
           - "[STATUS] == 200"
+
       - name: cat-fact
         url: "https://cat-fact.herokuapp.com/facts/random"
         interval: 5m
@@ -27,11 +30,18 @@ data:
           - "[BODY].text == pat(*cat*)"
           - "[STATUS] == pat(2*)"
           - "[CONNECTED] == true"
+
       - name: example
         url: https://example.com/
         conditions:
           - "[STATUS] == 200"
 ---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: gatus
+  namespace: kube-system
+---
 apiVersion: apps/v1
 kind: Deployment
 metadata:
@@ -41,14 +51,16 @@ spec:
   replicas: 1
   selector:
     matchLabels:
-      k8s-app: gatus
+      app: gatus
   template:
     metadata:
       labels:
-        k8s-app: gatus
+        app: gatus
       name: gatus
       namespace: kube-system
     spec:
+      serviceAccountName: gatus
+      terminationGracePeriodSeconds: 5
       containers:
         - image: twinproduction/gatus
           imagePullPolicy: IfNotPresent
@@ -84,4 +96,4 @@ spec:
       protocol: TCP
       targetPort: 8080
   selector:
-    k8s-app: gatus
+    app: gatus

.github/workflows/build.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.16
+          go-version: 1.17
       - name: Check out code into the Go module directory
         uses: actions/checkout@v2
       - name: Build binary to make sure it works
@@ -25,9 +25,9 @@ jobs:
       - name: Test
         # We're using "sudo" because one of the tests leverages ping, which requires super-user privileges.
         # As for the 'env "PATH=$PATH" "GOROOT=$GOROOT"', we need it to use the same "go" executable that
-        # was configured by the "Set up Go 1.15" step (otherwise, it'd use sudo's "go" executable)
+        # was configured by the "Set up Go" step (otherwise, it'd use sudo's "go" executable)
         run: sudo env "PATH=$PATH" "GOROOT=$GOROOT" go test -mod vendor ./... -race -coverprofile=coverage.txt -covermode=atomic
       - name: Codecov
-        uses: codecov/codecov-action@v1.5.2
+        uses: codecov/codecov-action@v2.1.0
         with:
-          file: ./coverage.txt
+          files: ./coverage.txt

README.md

@@ -19,7 +19,7 @@ core applications: https://status.twin.sh/
 <details>
   <summary><b>Quick start</b></summary>
 
-```
+```console
 docker run -p 8080:8080 --name gatus twinproduction/gatus
 ```
 For more details, see [Usage](#usage)
@@ -235,26 +235,31 @@ Here are some examples of conditions you can use:
 | Parameter          | Description                                                                            | Default        |
 |:------------------ |:-------------------------------------------------------------------------------------- |:-------------- |
 | `storage`          | Storage configuration                                                                  | `{}`           |
-| `storage.file`     | Path to persist the data in. If the type is `memory`, data is persisted on interval.   | `""`           |
-| `storage.type`     | Type of storage. Valid types: `memory`, `sqlite`, `postgres` (ALPHA).                  | `"memory"`     |
+| `storage.path`     | Path to persist the data in. Only supported for types `sqlite` and `postgres`.         | `""`           |
+| `storage.type`     | Type of storage. Valid types: `memory`, `sqlite`, `postgres`.                          | `"memory"`     |
 
-- If `storage.type` is `memory` (default) and `storage.file` is set to a non-blank value.
-  Furthermore, the data is periodically persisted, but everything remains in memory.
-- If `storage.type` is `sqlite`, `storage.file` must not be blank:
+- If `storage.type` is `memory` (default):
+```yaml
+# Note that this is the default value, and you can omit the storage configuration altogether to achieve the same result.
+# Because the data is stored in memory, the data will not survive a restart.
+storage:
+  type: memory
+```
+- If `storage.type` is `sqlite`, `storage.path` must not be blank:
 ```yaml
 storage:
   type: sqlite
-  file: data.db
+  path: data.db
 ```
-See [examples/docker-compose-sqlite-storage](examples/docker-compose-sqlite-storage) for an example.
+See [examples/docker-compose-sqlite-storage](.examples/docker-compose-sqlite-storage) for an example.
 
-- If `storage.type` is `postgres`, `storage.file` must be the connection URL:
+- If `storage.type` is `postgres`, `storage.path` must be the connection URL:
 ```yaml
 storage:
   type: postgres
-  file: "postgres://user:password@127.0.0.1:5432/gatus?sslmode=disable"
+  path: "postgres://user:password@127.0.0.1:5432/gatus?sslmode=disable"
 ```
-See [examples/docker-compose-postgres-storage](examples/docker-compose-postgres-storage) for an example.
+See [examples/docker-compose-postgres-storage](.examples/docker-compose-postgres-storage) for an example.
 
 
 ### Client configuration
@@ -798,29 +803,29 @@ maintenance:
 
 
 ## Deployment
-Many examples can be found in the [examples](examples) folder, but this section will focus on the most popular ways of deploying Gatus.
+Many examples can be found in the [.examples](.examples) folder, but this section will focus on the most popular ways of deploying Gatus.
 
 
 ### Docker
 To run Gatus locally with Docker:
-```
+```console
 docker run -p 8080:8080 --name gatus twinproduction/gatus
 ```
 
-Other than using one of the examples provided in the `examples` folder, you can also try it out locally by 
+Other than using one of the examples provided in the [.examples](.examples) folder, you can also try it out locally by 
 creating a configuration file, we'll call it `config.yaml` for this example, and running the following 
 command:
-```
+```console
 docker run -p 8080:8080 --mount type=bind,source="$(pwd)"/config.yaml,target=/config/config.yaml --name gatus twinproduction/gatus
 ```
 
 If you're on Windows, replace `"$(pwd)"` by the absolute path to your current directory, e.g.:
-```
+```console
 docker run -p 8080:8080 --mount type=bind,source=C:/Users/Chris/Desktop/config.yaml,target=/config/config.yaml --name gatus twinproduction/gatus
 ```
 
 To build the image locally:
-```
+```console
 docker build . -t twinproduction/gatus
 ```
 
@@ -845,7 +850,7 @@ Gatus can be deployed on Terraform by using the following module: [terraform-kub
 
 
 ## Running the tests
-```
+```console
 go test ./... -mod vendor
 ```
 
@@ -937,8 +942,8 @@ endpoints:
       - "[CONNECTED] == true"
 ```
 
-Placeholders `[STATUS]` and `[BODY]` as well as the fields `endpoints[].body`, `endpoints[].insecure`, 
-`endpoints[].headers`, `endpoints[].method` and `endpoints[].graphql` are not supported for TCP endpoints.
+Placeholders `[STATUS]` and `[BODY]` as well as the fields `endpoints[].body`, `endpoints[].headers`, 
+`endpoints[].method` and `endpoints[].graphql` are not supported for TCP endpoints.
 
 **NOTE**: `[CONNECTED] == true` does not guarantee that the endpoint itself is healthy - it only guarantees that there's 
 something at the given address listening to the given port, and that a connection to that address was successfully 
@@ -991,7 +996,7 @@ endpoints:
     url: "starttls://smtp.gmail.com:587"
     interval: 30m
     client:
-        timeout: 5s
+      timeout: 5s
     conditions:
       - "[CONNECTED] == true"
       - "[CERTIFICATE_EXPIRATION] > 48h"
@@ -1006,7 +1011,7 @@ endpoints:
     url: "tls://ldap.example.com:636"
     interval: 30m
     client:
-        timeout: 5s
+      timeout: 5s
     conditions:
       - "[CONNECTED] == true"
       - "[CERTIFICATE_EXPIRATION] > 48h"

alerting/provider/pagerduty/pagerduty.go

@@ -71,15 +71,15 @@ func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, al
     "source": "%s",
     "severity": "critical"
   }
-}`, provider.getPagerDutyIntegrationKeyForGroup(endpoint.Group), resolveKey, eventAction, message, endpoint.Name),
+}`, provider.getIntegrationKeyForGroup(endpoint.Group), resolveKey, eventAction, message, endpoint.Name),
 		Headers: map[string]string{
 			"Content-Type": "application/json",
 		},
 	}
 }
 
-// getPagerDutyIntegrationKeyForGroup returns the appropriate pagerduty integration key for a given group
-func (provider *AlertProvider) getPagerDutyIntegrationKeyForGroup(group string) string {
+// getIntegrationKeyForGroup returns the appropriate pagerduty integration key for a given group
+func (provider *AlertProvider) getIntegrationKeyForGroup(group string) string {
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if group == override.Group {
@@ -87,10 +87,7 @@ func (provider *AlertProvider) getPagerDutyIntegrationKeyForGroup(group string)
 			}
 		}
 	}
-	if provider.IntegrationKey != "" {
-		return provider.IntegrationKey
-	}
-	return ""
+	return provider.IntegrationKey
 }
 
 // GetDefaultAlert returns the provider's default alert configuration

alerting/provider/pagerduty/pagerduty_test.go

@@ -161,7 +161,7 @@ func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlertAndOverride(t *tes
 	}
 }
 
-func TestAlertProvider_getPagerDutyIntegrationKey(t *testing.T) {
+func TestAlertProvider_getIntegrationKeyForGroup(t *testing.T) {
 	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
@@ -217,7 +217,7 @@ func TestAlertProvider_getPagerDutyIntegrationKey(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			if output := scenario.Provider.getPagerDutyIntegrationKeyForGroup(scenario.InputGroup); output != scenario.ExpectedOutput {
+			if output := scenario.Provider.getIntegrationKeyForGroup(scenario.InputGroup); output != scenario.ExpectedOutput {
 				t.Errorf("expected %s, got %s", scenario.ExpectedOutput, output)
 			}
 		})

config/config.go

@@ -43,28 +43,28 @@ var (
 // Config is the main configuration structure
 type Config struct {
 	// Debug Whether to enable debug logs
-	Debug bool `yaml:"debug"`
+	Debug bool `yaml:"debug,omitempty"`
 
 	// Metrics Whether to expose metrics at /metrics
-	Metrics bool `yaml:"metrics"`
+	Metrics bool `yaml:"metrics,omitempty"`
 
 	// SkipInvalidConfigUpdate Whether to make the application ignore invalid configuration
 	// if the configuration file is updated while the application is running
-	SkipInvalidConfigUpdate bool `yaml:"skip-invalid-config-update"`
+	SkipInvalidConfigUpdate bool `yaml:"skip-invalid-config-update,omitempty"`
 
 	// DisableMonitoringLock Whether to disable the monitoring lock
 	// The monitoring lock is what prevents multiple endpoints from being processed at the same time.
 	// Disabling this may lead to inaccurate response times
-	DisableMonitoringLock bool `yaml:"disable-monitoring-lock"`
+	DisableMonitoringLock bool `yaml:"disable-monitoring-lock,omitempty"`
 
 	// Security Configuration for securing access to Gatus
-	Security *security.Config `yaml:"security"`
+	Security *security.Config `yaml:"security,omitempty"`
 
 	// Alerting Configuration for alerting
-	Alerting *alerting.Config `yaml:"alerting"`
+	Alerting *alerting.Config `yaml:"alerting,omitempty"`
 
 	// Endpoints List of endpoints to monitor
-	Endpoints []*core.Endpoint `yaml:"endpoints"`
+	Endpoints []*core.Endpoint `yaml:"endpoints,omitempty"`
 
 	// Services List of endpoints to monitor
 	//
@@ -72,19 +72,19 @@ type Config struct {
 	// XXX: This is not a typo -- not v4.0.0, but v5.0.0 -- I want to give enough time for people to migrate
 	//
 	// Deprecated in favor of Endpoints
-	Services []*core.Endpoint `yaml:"services"`
+	Services []*core.Endpoint `yaml:"services,omitempty"`
 
 	// Storage is the configuration for how the data is stored
-	Storage *storage.Config `yaml:"storage"`
+	Storage *storage.Config `yaml:"storage,omitempty"`
 
 	// Web is the web configuration for the application
-	Web *web.Config `yaml:"web"`
+	Web *web.Config `yaml:"web,omitempty"`
 
 	// UI is the configuration for the UI
-	UI *ui.Config `yaml:"ui"`
+	UI *ui.Config `yaml:"ui,omitempty"`
 
 	// Maintenance is the configuration for creating a maintenance window in which no alerts are sent
-	Maintenance *maintenance.Config `yaml:"maintenance"`
+	Maintenance *maintenance.Config `yaml:"maintenance,omitempty"`
 
 	filePath        string    // path to the file from which config was loaded from
 	lastFileModTime time.Time // last modification time
@@ -149,12 +149,12 @@ func readConfigurationFile(fileName string) (config *Config, err error) {
 	return
 }
 
+// parseAndValidateConfigBytes parses a Gatus configuration file into a Config struct and validates its parameters
 func parseAndValidateConfigBytes(yamlBytes []byte) (config *Config, err error) {
 	// Expand environment variables
 	yamlBytes = []byte(os.ExpandEnv(string(yamlBytes)))
 	// Parse configuration file
-	err = yaml.Unmarshal(yamlBytes, &config)
-	if err != nil {
+	if err = yaml.Unmarshal(yamlBytes, &config); err != nil {
 		return
 	}
 	if config != nil && len(config.Services) > 0 { // XXX: Remove this in v5.0.0
@@ -167,8 +167,6 @@ func parseAndValidateConfigBytes(yamlBytes []byte) (config *Config, err error) {
 	if config == nil || config.Endpoints == nil || len(config.Endpoints) == 0 {
 		err = ErrNoEndpointInConfig
 	} else {
-		// Note that the functions below may panic, and this is on purpose to prevent Gatus from starting with
-		// invalid configurations
 		validateAlertingConfig(config.Alerting, config.Endpoints, config.Debug)
 		if err := validateSecurityConfig(config); err != nil {
 			return nil, err
@@ -197,19 +195,10 @@ func validateStorageConfig(config *Config) error {
 		config.Storage = &storage.Config{
 			Type: storage.TypeMemory,
 		}
-	}
-	err := storage.Initialize(config.Storage)
-	if err != nil {
-		return err
-	}
-	// Remove all EndpointStatus that represent endpoints which no longer exist in the configuration
-	var keys []string
-	for _, endpoint := range config.Endpoints {
-		keys = append(keys, endpoint.Key())
-	}
-	numberOfEndpointStatusesDeleted := storage.Get().DeleteAllEndpointStatusesNotInKeys(keys)
-	if numberOfEndpointStatusesDeleted > 0 {
-		log.Printf("[config][validateStorageConfig] Deleted %d endpoint statuses because their matching endpoints no longer existed", numberOfEndpointStatusesDeleted)
+	} else {
+		if err := config.Storage.ValidateAndSetDefaults(); err != nil {
+			return err
+		}
 	}
 	return nil
 }

config/config_test.go

@@ -20,6 +20,7 @@ import (
 	"github.com/TwiN/gatus/v3/config/ui"
 	"github.com/TwiN/gatus/v3/config/web"
 	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v3/storage"
 )
 
 func TestLoadFileThatDoesNotExist(t *testing.T) {
@@ -44,7 +45,8 @@ func TestParseAndValidateConfigBytes(t *testing.T) {
 	}()
 	config, err := parseAndValidateConfigBytes([]byte(fmt.Sprintf(`
 storage:
-  file: %s
+  type: sqlite
+  path: %s
 maintenance:
   enabled: true
   start: 00:00
@@ -83,6 +85,9 @@ endpoints:
 	if config == nil {
 		t.Fatal("Config shouldn't have been nil")
 	}
+	if config.Storage == nil || config.Storage.Path != file || config.Storage.Type != storage.TypeSQLite {
+		t.Error("expected storage to be set to sqlite, got", config.Storage)
+	}
 	if config.UI == nil || config.UI.Title != "Test" {
 		t.Error("Expected Config.UI.Title to be Test")
 	}
@@ -1297,3 +1302,53 @@ endpoints:
 		t.Error("services should've been merged in endpoints")
 	}
 }
+
+// XXX: Remove this in v4.0.0
+func TestParseAndValidateConfigBytes_backwardCompatibleWithStorageFile(t *testing.T) {
+	file := t.TempDir() + "/test.db"
+	config, err := parseAndValidateConfigBytes([]byte(fmt.Sprintf(`
+storage:
+  type: sqlite
+  file: %s
+
+endpoints:
+  - name: website
+    url: https://twin.sh/actuator/health
+    conditions:
+      - "[STATUS] == 200"
+`, file)))
+	if err != nil {
+		t.Error("expected no error, got", err.Error())
+	}
+	if config == nil {
+		t.Fatal("Config shouldn't have been nil")
+	}
+	if config.Storage == nil || config.Storage.Path != file || config.Storage.Type != storage.TypeSQLite {
+		t.Error("expected storage to be set to sqlite, got", config.Storage)
+	}
+}
+
+// XXX: Remove this in v4.0.0
+func TestParseAndValidateConfigBytes_backwardCompatibleWithStorageTypeMemoryAndFile(t *testing.T) {
+	file := t.TempDir() + "/test.db"
+	config, err := parseAndValidateConfigBytes([]byte(fmt.Sprintf(`
+storage:
+  type: memory
+  file: %s
+
+endpoints:
+  - name: website
+    url: https://twin.sh/actuator/health
+    conditions:
+      - "[STATUS] == 200"
+`, file)))
+	if err != nil {
+		t.Error("expected no error, got", err.Error())
+	}
+	if config == nil {
+		t.Fatal("Config shouldn't have been nil")
+	}
+	if config.Storage == nil || config.Storage.Path != file || config.Storage.Type != storage.TypeMemory {
+		t.Error("expected storage to be set to memory, got", config.Storage)
+	}
+}

controller/handler/badge.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/TwiN/gatus/v3/storage"
+	"github.com/TwiN/gatus/v3/storage/store"
 	"github.com/TwiN/gatus/v3/storage/store/common"
 	"github.com/gorilla/mux"
 )
@@ -40,7 +40,7 @@ func UptimeBadge(writer http.ResponseWriter, request *http.Request) {
 		return
 	}
 	key := variables["key"]
-	uptime, err := storage.Get().GetUptimeByKey(key, from, time.Now())
+	uptime, err := store.Get().GetUptimeByKey(key, from, time.Now())
 	if err != nil {
 		if err == common.ErrEndpointNotFound {
 			writer.WriteHeader(http.StatusNotFound)
@@ -79,7 +79,7 @@ func ResponseTimeBadge(writer http.ResponseWriter, request *http.Request) {
 		return
 	}
 	key := variables["key"]
-	averageResponseTime, err := storage.Get().GetAverageResponseTimeByKey(key, from, time.Now())
+	averageResponseTime, err := store.Get().GetAverageResponseTimeByKey(key, from, time.Now())
 	if err != nil {
 		if err == common.ErrEndpointNotFound {
 			writer.WriteHeader(http.StatusNotFound)

controller/handler/badge_test.go

@@ -9,12 +9,12 @@ import (
 
 	"github.com/TwiN/gatus/v3/config"
 	"github.com/TwiN/gatus/v3/core"
-	"github.com/TwiN/gatus/v3/storage"
+	"github.com/TwiN/gatus/v3/storage/store"
 	"github.com/TwiN/gatus/v3/watchdog"
 )
 
 func TestUptimeBadge(t *testing.T) {
-	defer storage.Get().Clear()
+	defer store.Get().Clear()
 	defer cache.Clear()
 	cfg := &config.Config{
 		Metrics: true,

controller/handler/chart.go

@@ -7,7 +7,7 @@ import (
 	"sort"
 	"time"
 
-	"github.com/TwiN/gatus/v3/storage"
+	"github.com/TwiN/gatus/v3/storage/store"
 	"github.com/TwiN/gatus/v3/storage/store/common"
 	"github.com/gorilla/mux"
 	"github.com/wcharczuk/go-chart/v2"
@@ -42,7 +42,7 @@ func ResponseTimeChart(writer http.ResponseWriter, r *http.Request) {
 		http.Error(writer, "Durations supported: 7d, 24h", http.StatusBadRequest)
 		return
 	}
-	hourlyAverageResponseTime, err := storage.Get().GetHourlyAverageResponseTimeByKey(vars["key"], from, time.Now())
+	hourlyAverageResponseTime, err := store.Get().GetHourlyAverageResponseTimeByKey(vars["key"], from, time.Now())
 	if err != nil {
 		if err == common.ErrEndpointNotFound {
 			writer.WriteHeader(http.StatusNotFound)

controller/handler/chart_test.go

@@ -8,12 +8,12 @@ import (
 
 	"github.com/TwiN/gatus/v3/config"
 	"github.com/TwiN/gatus/v3/core"
-	"github.com/TwiN/gatus/v3/storage"
+	"github.com/TwiN/gatus/v3/storage/store"
 	"github.com/TwiN/gatus/v3/watchdog"
 )
 
 func TestResponseTimeChart(t *testing.T) {
-	defer storage.Get().Clear()
+	defer store.Get().Clear()
 	defer cache.Clear()
 	cfg := &config.Config{
 		Metrics: true,

controller/handler/endpoint_status.go

@@ -10,7 +10,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/TwiN/gatus/v3/storage"
+	"github.com/TwiN/gatus/v3/storage/store"
 	"github.com/TwiN/gatus/v3/storage/store/common"
 	"github.com/TwiN/gatus/v3/storage/store/common/paging"
 	"github.com/TwiN/gocache"
@@ -44,7 +44,7 @@ func EndpointStatuses(writer http.ResponseWriter, r *http.Request) {
 		var err error
 		buffer := &bytes.Buffer{}
 		gzipWriter := gzip.NewWriter(buffer)
-		endpointStatuses, err := storage.Get().GetAllEndpointStatuses(paging.NewEndpointStatusParams().WithResults(page, pageSize))
+		endpointStatuses, err := store.Get().GetAllEndpointStatuses(paging.NewEndpointStatusParams().WithResults(page, pageSize))
 		if err != nil {
 			log.Printf("[handler][EndpointStatuses] Failed to retrieve endpoint statuses: %s", err.Error())
 			http.Error(writer, err.Error(), http.StatusInternalServerError)
@@ -76,7 +76,7 @@ func EndpointStatuses(writer http.ResponseWriter, r *http.Request) {
 func EndpointStatus(writer http.ResponseWriter, r *http.Request) {
 	page, pageSize := extractPageAndPageSizeFromRequest(r)
 	vars := mux.Vars(r)
-	endpointStatus, err := storage.Get().GetEndpointStatusByKey(vars["key"], paging.NewEndpointStatusParams().WithResults(page, pageSize).WithEvents(1, common.MaximumNumberOfEvents))
+	endpointStatus, err := store.Get().GetEndpointStatusByKey(vars["key"], paging.NewEndpointStatusParams().WithResults(page, pageSize).WithEvents(1, common.MaximumNumberOfEvents))
 	if err != nil {
 		if err == common.ErrEndpointNotFound {
 			http.Error(writer, err.Error(), http.StatusNotFound)

controller/handler/endpoint_status_test.go

@@ -8,7 +8,7 @@ import (
 
 	"github.com/TwiN/gatus/v3/config"
 	"github.com/TwiN/gatus/v3/core"
-	"github.com/TwiN/gatus/v3/storage"
+	"github.com/TwiN/gatus/v3/storage/store"
 	"github.com/TwiN/gatus/v3/watchdog"
 )
 
@@ -84,7 +84,7 @@ var (
 )
 
 func TestEndpointStatus(t *testing.T) {
-	defer storage.Get().Clear()
+	defer store.Get().Clear()
 	defer cache.Clear()
 	cfg := &config.Config{
 		Metrics: true,
@@ -153,12 +153,12 @@ func TestEndpointStatus(t *testing.T) {
 }
 
 func TestEndpointStatuses(t *testing.T) {
-	defer storage.Get().Clear()
+	defer store.Get().Clear()
 	defer cache.Clear()
 	firstResult := &testSuccessfulResult
 	secondResult := &testUnsuccessfulResult
-	storage.Get().Insert(&testEndpoint, firstResult)
-	storage.Get().Insert(&testEndpoint, secondResult)
+	store.Get().Insert(&testEndpoint, firstResult)
+	store.Get().Insert(&testEndpoint, secondResult)
 	// Can't be bothered dealing with timezone issues on the worker that runs the automated tests
 	firstResult.Timestamp = time.Time{}
 	secondResult.Timestamp = time.Time{}
@@ -175,37 +175,37 @@ func TestEndpointStatuses(t *testing.T) {
 			Name:         "no-pagination",
 			Path:         "/api/v1/endpoints/statuses",
 			ExpectedCode: http.StatusOK,
-			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":150000000,"errors":null,"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":true},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":true}],"success":true,"timestamp":"0001-01-01T00:00:00Z"},{"status":200,"hostname":"example.org","duration":750000000,"errors":["error-1","error-2"],"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":false},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":false}],"success":false,"timestamp":"0001-01-01T00:00:00Z"}],"events":[]}]`,
+			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":150000000,"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":true},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":true}],"success":true,"timestamp":"0001-01-01T00:00:00Z"},{"status":200,"hostname":"example.org","duration":750000000,"errors":["error-1","error-2"],"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":false},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":false}],"success":false,"timestamp":"0001-01-01T00:00:00Z"}]}]`,
 		},
 		{
 			Name:         "pagination-first-result",
 			Path:         "/api/v1/endpoints/statuses?page=1&pageSize=1",
 			ExpectedCode: http.StatusOK,
-			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":750000000,"errors":["error-1","error-2"],"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":false},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":false}],"success":false,"timestamp":"0001-01-01T00:00:00Z"}],"events":[]}]`,
+			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":750000000,"errors":["error-1","error-2"],"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":false},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":false}],"success":false,"timestamp":"0001-01-01T00:00:00Z"}]}]`,
 		},
 		{
 			Name:         "pagination-second-result",
 			Path:         "/api/v1/endpoints/statuses?page=2&pageSize=1",
 			ExpectedCode: http.StatusOK,
-			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":150000000,"errors":null,"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":true},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":true}],"success":true,"timestamp":"0001-01-01T00:00:00Z"}],"events":[]}]`,
+			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":150000000,"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":true},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":true}],"success":true,"timestamp":"0001-01-01T00:00:00Z"}]}]`,
 		},
 		{
 			Name:         "pagination-no-results",
 			Path:         "/api/v1/endpoints/statuses?page=5&pageSize=20",
 			ExpectedCode: http.StatusOK,
-			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[],"events":[]}]`,
+			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[]}]`,
 		},
 		{
 			Name:         "invalid-pagination-should-fall-back-to-default",
 			Path:         "/api/v1/endpoints/statuses?page=INVALID&pageSize=INVALID",
 			ExpectedCode: http.StatusOK,
-			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":150000000,"errors":null,"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":true},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":true}],"success":true,"timestamp":"0001-01-01T00:00:00Z"},{"status":200,"hostname":"example.org","duration":750000000,"errors":["error-1","error-2"],"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":false},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":false}],"success":false,"timestamp":"0001-01-01T00:00:00Z"}],"events":[]}]`,
+			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":150000000,"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":true},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":true}],"success":true,"timestamp":"0001-01-01T00:00:00Z"},{"status":200,"hostname":"example.org","duration":750000000,"errors":["error-1","error-2"],"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":false},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":false}],"success":false,"timestamp":"0001-01-01T00:00:00Z"}]}]`,
 		},
 		{ // XXX: Remove this in v4.0.0
 			Name:         "backward-compatible-service-status",
 			Path:         "/api/v1/services/statuses",
 			ExpectedCode: http.StatusOK,
-			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":150000000,"errors":null,"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":true},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":true}],"success":true,"timestamp":"0001-01-01T00:00:00Z"},{"status":200,"hostname":"example.org","duration":750000000,"errors":["error-1","error-2"],"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":false},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":false}],"success":false,"timestamp":"0001-01-01T00:00:00Z"}],"events":[]}]`,
+			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":150000000,"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":true},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":true}],"success":true,"timestamp":"0001-01-01T00:00:00Z"},{"status":200,"hostname":"example.org","duration":750000000,"errors":["error-1","error-2"],"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":false},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":false}],"success":false,"timestamp":"0001-01-01T00:00:00Z"}]}]`,
 		},
 	}
 

controller/handler/spa_test.go

@@ -8,12 +8,12 @@ import (
 
 	"github.com/TwiN/gatus/v3/config"
 	"github.com/TwiN/gatus/v3/core"
-	"github.com/TwiN/gatus/v3/storage"
+	"github.com/TwiN/gatus/v3/storage/store"
 	"github.com/TwiN/gatus/v3/watchdog"
 )
 
 func TestSinglePageApplication(t *testing.T) {
-	defer storage.Get().Clear()
+	defer store.Get().Clear()
 	defer cache.Clear()
 	cfg := &config.Config{
 		Metrics: true,

core/condition.go

@@ -80,7 +80,7 @@ const (
 	maximumLengthBeforeTruncatingWhenComparedWithPattern = 25
 )
 
-// Condition is a condition that needs to be met in order for a Endpoint to be considered healthy.
+// Condition is a condition that needs to be met in order for an Endpoint to be considered healthy.
 type Condition string
 
 // evaluate the Condition with the Result of the health check
@@ -283,7 +283,7 @@ func prettifyNumericalParameters(parameters []string, resolvedParameters []int64
 	return prettify(parameters, []string{strconv.Itoa(int(resolvedParameters[0])), strconv.Itoa(int(resolvedParameters[1]))}, operator)
 }
 
-// XXX: make this configurable? i.e. show-resolved-conditions-on-failure
+// prettify returns a string representation of a condition with its parameters resolved between parentheses
 func prettify(parameters []string, resolvedParameters []string, operator string) string {
 	// Since, in the event of an invalid path, the resolvedParameters also contain the condition itself,
 	// we'll return the resolvedParameters as-is.

core/endpoint.go

@@ -79,19 +79,19 @@ type Endpoint struct {
 	Conditions []*Condition `yaml:"conditions"`
 
 	// Alerts is the alerting configuration for the endpoint in case of failure
-	Alerts []*alert.Alert `yaml:"alerts"`
+	Alerts []*alert.Alert `yaml:"alerts,omitempty"`
 
 	// ClientConfig is the configuration of the client used to communicate with the endpoint's target
-	ClientConfig *client.Config `yaml:"client"`
+	ClientConfig *client.Config `yaml:"client,omitempty"`
 
 	// UIConfig is the configuration for the UI
-	UIConfig *ui.Config `yaml:"ui"`
+	UIConfig *ui.Config `yaml:"ui,omitempty"`
 
 	// NumberOfFailuresInARow is the number of unsuccessful evaluations in a row
-	NumberOfFailuresInARow int
+	NumberOfFailuresInARow int `yaml:"-"`
 
 	// NumberOfSuccessesInARow is the number of successful evaluations in a row
-	NumberOfSuccessesInARow int
+	NumberOfSuccessesInARow int `yaml:"-"`
 }
 
 // IsEnabled returns whether the endpoint is enabled or not

core/endpoint_status.go

@@ -17,7 +17,7 @@ type EndpointStatus struct {
 	Results []*Result `json:"results"`
 
 	// Events is a list of events
-	Events []*Event `json:"events"`
+	Events []*Event `json:"events,omitempty"`
 
 	// Uptime information on the endpoint's uptime
 	//

core/result.go

@@ -13,7 +13,7 @@ type Result struct {
 	DNSRCode string `json:"-"`
 
 	// Hostname extracted from Endpoint.URL
-	Hostname string `json:"hostname"`
+	Hostname string `json:"hostname,omitempty"`
 
 	// IP resolved from the Endpoint URL
 	IP string `json:"-"`
@@ -25,7 +25,7 @@ type Result struct {
 	Duration time.Duration `json:"duration"`
 
 	// Errors encountered during the evaluation of the Endpoint's health
-	Errors []string `json:"errors"`
+	Errors []string `json:"errors,omitempty"`
 
 	// ConditionResults results of the Endpoint's conditions
 	ConditionResults []*ConditionResult `json:"conditionResults"`

main.go

@@ -9,7 +9,7 @@ import (
 
 	"github.com/TwiN/gatus/v3/config"
 	"github.com/TwiN/gatus/v3/controller"
-	"github.com/TwiN/gatus/v3/storage"
+	"github.com/TwiN/gatus/v3/storage/store"
 	"github.com/TwiN/gatus/v3/watchdog"
 )
 
@@ -18,6 +18,7 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
+	initializeStorage(cfg)
 	start(cfg)
 	// Wait for termination signal
 	signalChannel := make(chan os.Signal, 1)
@@ -46,8 +47,7 @@ func stop() {
 }
 
 func save() {
-	err := storage.Get().Save()
-	if err != nil {
+	if err := store.Get().Save(); err != nil {
 		log.Println("Failed to save storage provider:", err.Error())
 	}
 }
@@ -62,6 +62,27 @@ func loadConfiguration() (cfg *config.Config, err error) {
 	return
 }
 
+// initializeStorage initializes the storage provider
+//
+// Q: "TwiN, why are you putting this here? Wouldn't it make more sense to have this in the config?!"
+// A: Yes. Yes it would make more sense to have it in the config package. But I don't want to import
+//    the massive SQL dependencies just because I want to import the config, so here we are.
+func initializeStorage(cfg *config.Config) {
+	err := store.Initialize(cfg.Storage)
+	if err != nil {
+		panic(err)
+	}
+	// Remove all EndpointStatus that represent endpoints which no longer exist in the configuration
+	var keys []string
+	for _, endpoint := range cfg.Endpoints {
+		keys = append(keys, endpoint.Key())
+	}
+	numberOfEndpointStatusesDeleted := store.Get().DeleteAllEndpointStatusesNotInKeys(keys)
+	if numberOfEndpointStatusesDeleted > 0 {
+		log.Printf("[config][validateStorageConfig] Deleted %d endpoint statuses because their matching endpoints no longer existed", numberOfEndpointStatusesDeleted)
+	}
+}
+
 func listenToConfigurationFileChanges(cfg *config.Config) {
 	for {
 		time.Sleep(30 * time.Second)

storage/config.go

@@ -1,14 +1,59 @@
 package storage
 
+import (
+	"errors"
+	"log"
+)
+
+var (
+	ErrSQLStorageRequiresFile          = errors.New("sql storage requires a non-empty file to be defined")
+	ErrMemoryStorageDoesNotSupportFile = errors.New("memory storage does not support persistence, use sqlite if you want persistence on file")
+	ErrCannotSetBothFileAndPath        = errors.New("file has been deprecated in favor of path: you cannot set both of them")
+)
+
 // Config is the configuration for storage
 type Config struct {
+	// Path is the path used by the store to achieve persistence
+	// If blank, persistence is disabled.
+	// Note that not all Type support persistence
+	//
+	// XXX: Rename to path for v4.0.0
+	Path string `yaml:"path"`
+
 	// File is the path of the file to use for persistence
 	// If blank, persistence is disabled
 	//
-	// XXX: Rename to path for v4.0.0
+	// Deprecated
 	File string `yaml:"file"`
 
 	// Type of store
 	// If blank, uses the default in-memory store
 	Type Type `yaml:"type"`
 }
+
+// ValidateAndSetDefaults validates the configuration and sets the default values (if applicable)
+func (c *Config) ValidateAndSetDefaults() error {
+	if len(c.File) > 0 && len(c.Path) > 0 { // XXX: Remove for v4.0.0
+		return ErrCannotSetBothFileAndPath
+	} else if len(c.File) > 0 { // XXX: Remove for v4.0.0
+		log.Println("WARNING: Your configuration is using 'storage.file', which is deprecated in favor of 'storage.path'")
+		log.Println("WARNING: storage.file will be completely removed in v4.0.0, so please update your configuration")
+		log.Println("WARNING: See https://github.com/TwiN/gatus/issues/197")
+		c.Path = c.File
+	}
+	if c.Type == "" {
+		c.Type = TypeMemory
+	}
+	if (c.Type == TypePostgres || c.Type == TypeSQLite) && len(c.Path) == 0 {
+		return ErrSQLStorageRequiresFile
+	}
+	if c.Type == TypeMemory && len(c.Path) > 0 {
+		log.Println("WARNING: Your configuration is using a storage of type memory with persistence, which has been deprecated")
+		log.Println("WARNING: As of v4.0.0, the default storage type (memory) will not support persistence.")
+		log.Println("WARNING: If you want persistence, use 'storage.type: sqlite' instead of 'storage.type: memory'")
+		log.Println("WARNING: See https://github.com/TwiN/gatus/issues/198")
+		// XXX: Uncomment the following line for v4.0.0
+		//return ErrMemoryStorageDoesNotSupportFile
+	}
+	return nil
+}

storage/storage.go

@@ -1,91 +0,0 @@
-package storage
-
-import (
-	"context"
-	"log"
-	"time"
-
-	"github.com/TwiN/gatus/v3/storage/store"
-	"github.com/TwiN/gatus/v3/storage/store/memory"
-	"github.com/TwiN/gatus/v3/storage/store/sql"
-)
-
-var (
-	provider store.Store
-
-	// initialized keeps track of whether the storage provider was initialized
-	// Because store.Store is an interface, a nil check wouldn't be sufficient, so instead of doing reflection
-	// every single time Get is called, we'll just lazily keep track of its existence through this variable
-	initialized bool
-
-	ctx        context.Context
-	cancelFunc context.CancelFunc
-)
-
-// Get retrieves the storage provider
-func Get() store.Store {
-	if !initialized {
-		log.Println("[storage][Get] Provider requested before it was initialized, automatically initializing")
-		err := Initialize(nil)
-		if err != nil {
-			panic("failed to automatically initialize store: " + err.Error())
-		}
-	}
-	return provider
-}
-
-// Initialize instantiates the storage provider based on the Config provider
-func Initialize(cfg *Config) error {
-	initialized = true
-	var err error
-	if cancelFunc != nil {
-		// Stop the active autoSaveStore task, if there's already one
-		cancelFunc()
-	}
-	if cfg == nil {
-		cfg = &Config{}
-	}
-	if len(cfg.File) == 0 && cfg.Type != TypePostgres {
-		log.Printf("[storage][Initialize] Creating storage provider with type=%s and file=%s", cfg.Type, cfg.File)
-	} else {
-		log.Printf("[storage][Initialize] Creating storage provider with type=%s", cfg.Type)
-	}
-	ctx, cancelFunc = context.WithCancel(context.Background())
-	switch cfg.Type {
-	case TypeSQLite, TypePostgres:
-		provider, err = sql.NewStore(string(cfg.Type), cfg.File)
-		if err != nil {
-			return err
-		}
-	case TypeMemory:
-		fallthrough
-	default:
-		if len(cfg.File) > 0 {
-			provider, err = memory.NewStore(cfg.File)
-			if err != nil {
-				return err
-			}
-			go autoSaveStore(ctx, provider, 7*time.Minute)
-		} else {
-			provider, _ = memory.NewStore("")
-		}
-	}
-	return nil
-}
-
-// autoSaveStore automatically calls the Save function of the provider at every interval
-func autoSaveStore(ctx context.Context, provider store.Store, interval time.Duration) {
-	for {
-		select {
-		case <-ctx.Done():
-			log.Printf("[storage][autoSaveStore] Stopping active job")
-			return
-		case <-time.After(interval):
-			log.Printf("[storage][autoSaveStore] Saving")
-			err := provider.Save()
-			if err != nil {
-				log.Println("[storage][autoSaveStore] Save failed:", err.Error())
-			}
-		}
-	}
-}

storage/storage_test.go

@@ -1,94 +0,0 @@
-package storage
-
-import (
-	"testing"
-	"time"
-
-	"github.com/TwiN/gatus/v3/storage/store/sql"
-)
-
-func TestGet(t *testing.T) {
-	store := Get()
-	if store == nil {
-		t.Error("store should've been automatically initialized")
-	}
-}
-
-func TestInitialize(t *testing.T) {
-	type Scenario struct {
-		Name        string
-		Cfg         *Config
-		ExpectedErr error
-	}
-	scenarios := []Scenario{
-		{
-			Name:        "nil",
-			Cfg:         nil,
-			ExpectedErr: nil,
-		},
-		{
-			Name:        "blank",
-			Cfg:         &Config{},
-			ExpectedErr: nil,
-		},
-		{
-			Name:        "memory-no-file",
-			Cfg:         &Config{Type: TypeMemory},
-			ExpectedErr: nil,
-		},
-		{
-			Name:        "memory-with-file",
-			Cfg:         &Config{Type: TypeMemory, File: t.TempDir() + "/TestInitialize_memory-with-file.db"},
-			ExpectedErr: nil,
-		},
-		{
-			Name:        "sqlite-no-file",
-			Cfg:         &Config{Type: TypeSQLite},
-			ExpectedErr: sql.ErrFilePathNotSpecified,
-		},
-		{
-			Name:        "sqlite-with-file",
-			Cfg:         &Config{Type: TypeSQLite, File: t.TempDir() + "/TestInitialize_sqlite-with-file.db"},
-			ExpectedErr: nil,
-		},
-	}
-	for _, scenario := range scenarios {
-		t.Run(scenario.Name, func(t *testing.T) {
-			err := Initialize(scenario.Cfg)
-			if err != scenario.ExpectedErr {
-				t.Errorf("expected %v, got %v", scenario.ExpectedErr, err)
-			}
-			if err != nil {
-				return
-			}
-			if cancelFunc == nil {
-				t.Error("cancelFunc shouldn't have been nil")
-			}
-			if ctx == nil {
-				t.Error("ctx shouldn't have been nil")
-			}
-			if provider == nil {
-				t.Fatal("provider shouldn't have been nit")
-			}
-			provider.Close()
-			// Try to initialize it again
-			err = Initialize(scenario.Cfg)
-			if err != scenario.ExpectedErr {
-				t.Errorf("expected %v, got %v", scenario.ExpectedErr, err)
-				return
-			}
-			provider.Close()
-		})
-	}
-}
-
-func TestAutoSave(t *testing.T) {
-	file := t.TempDir() + "/TestAutoSave.db"
-	if err := Initialize(&Config{File: file}); err != nil {
-		t.Fatal("shouldn't have returned an error")
-	}
-	go autoSaveStore(ctx, provider, 3*time.Millisecond)
-	time.Sleep(15 * time.Millisecond)
-	cancelFunc()
-	time.Sleep(50 * time.Millisecond)
-}

storage/store/memory/memory.go

@@ -2,7 +2,11 @@ package memory
 
 import (
 	"encoding/gob"
+	"io/fs"
+	"io/ioutil"
+	"log"
 	"sort"
+	"strings"
 	"sync"
 	"time"
 
@@ -24,6 +28,10 @@ func init() {
 // Store that leverages gocache
 type Store struct {
 	sync.RWMutex
+	// Deprecated
+	//
+	// File persistence will no longer be supported as of v4.0.0
+	// XXX: Remove me in v4.0.0
 	file  string
 	cache *gocache.Cache
 }
@@ -37,9 +45,24 @@ func NewStore(file string) (*Store, error) {
 		file:  file,
 		cache: gocache.NewCache().WithMaxSize(gocache.NoMaxSize),
 	}
+	// XXX: Remove the block below in v4.0.0 because persistence with the memory store will no longer be supported
+	// XXX: Make sure to also update gocache to v2.0.0
 	if len(file) > 0 {
 		_, err := store.cache.ReadFromFile(file)
 		if err != nil {
+			// XXX: Remove the block below in v4.0.0
+			if data, err2 := ioutil.ReadFile(file); err2 == nil {
+				isFromOldVersion := strings.Contains(string(data), "*core.ServiceStatus")
+				if isFromOldVersion {
+					log.Println("WARNING: Couldn't read file due to recent change in v3.3.0, see https://github.com/TwiN/gatus/issues/191")
+					log.Println("WARNING: Will automatically rename old file to " + file + ".old and overwrite the current file")
+					if err = ioutil.WriteFile(file+".old", data, fs.ModePerm); err != nil {
+						log.Println("WARNING: Tried my best to keep the old file, but it wasn't enough. Sorry, your file will be overwritten :(")
+					}
+					// Return the store regardless of whether there was an error or not
+					return store, nil
+				}
+			}
 			return nil, err
 		}
 	}

storage/store/sql/sql.go

@@ -34,8 +34,8 @@ const (
 )
 
 var (
-	// ErrFilePathNotSpecified is the error returned when path parameter passed in NewStore is blank
-	ErrFilePathNotSpecified = errors.New("file path cannot be empty")
+	// ErrPathNotSpecified is the error returned when the path parameter passed in NewStore is blank
+	ErrPathNotSpecified = errors.New("path cannot be empty")
 
 	// ErrDatabaseDriverNotSpecified is the error returned when the driver parameter passed in NewStore is blank
 	ErrDatabaseDriverNotSpecified = errors.New("database driver cannot be empty")
@@ -45,20 +45,20 @@ var (
 
 // Store that leverages a database
 type Store struct {
-	driver, file string
+	driver, path string
 
 	db *sql.DB
 }
 
-// NewStore initializes the database and creates the schema if it doesn't already exist in the file specified
+// NewStore initializes the database and creates the schema if it doesn't already exist in the path specified
 func NewStore(driver, path string) (*Store, error) {
 	if len(driver) == 0 {
 		return nil, ErrDatabaseDriverNotSpecified
 	}
 	if len(path) == 0 {
-		return nil, ErrFilePathNotSpecified
+		return nil, ErrPathNotSpecified
 	}
-	store := &Store{driver: driver, file: path}
+	store := &Store{driver: driver, path: path}
 	var err error
 	if store.db, err = sql.Open(driver, path); err != nil {
 		return nil, err
@@ -342,7 +342,7 @@ func (s *Store) DeleteAllEndpointStatusesNotInKeys(keys []string) int {
 			query += fmt.Sprintf("$%d,", i+1)
 			args = append(args, keys[i])
 		}
-		query = query[:len(query)-1] + ")" // Remove the last comma and close the parenthesis
+		query = query[:len(query)-1] + ")" // Remove the last comma and add the closing parenthesis
 		result, err = s.db.Exec(query, args...)
 	}
 	if err != nil {

storage/store/sql/sql_test.go

@@ -84,7 +84,7 @@ func TestNewStore(t *testing.T) {
 	if _, err := NewStore("", "TestNewStore.db"); err != ErrDatabaseDriverNotSpecified {
 		t.Error("expected error due to blank driver parameter")
 	}
-	if _, err := NewStore("sqlite", ""); err != ErrFilePathNotSpecified {
+	if _, err := NewStore("sqlite", ""); err != ErrPathNotSpecified {
 		t.Error("expected error due to blank path parameter")
 	}
 	if store, err := NewStore("sqlite", t.TempDir()+"/TestNewStore.db"); err != nil {
@@ -169,8 +169,8 @@ func TestStore_InsertCleansUpEventsAndResultsProperly(t *testing.T) {
 }
 
 func TestStore_Persistence(t *testing.T) {
-	file := t.TempDir() + "/TestStore_Persistence.db"
-	store, _ := NewStore("sqlite", file)
+	path := t.TempDir() + "/TestStore_Persistence.db"
+	store, _ := NewStore("sqlite", path)
 	store.Insert(&testEndpoint, &testSuccessfulResult)
 	store.Insert(&testEndpoint, &testUnsuccessfulResult)
 	if uptime, _ := store.GetUptimeByKey(testEndpoint.Key(), time.Now().Add(-time.Hour), time.Now()); uptime != 0.5 {
@@ -188,7 +188,7 @@ func TestStore_Persistence(t *testing.T) {
 		t.Fatal("sanity check failed")
 	}
 	store.Close()
-	store, _ = NewStore("sqlite", file)
+	store, _ = NewStore("sqlite", path)
 	defer store.Close()
 	ssFromNewStore, _ := store.GetEndpointStatus(testEndpoint.Group, testEndpoint.Name, paging.NewEndpointStatusParams().WithResults(1, common.MaximumNumberOfResults).WithEvents(1, common.MaximumNumberOfEvents))
 	if ssFromNewStore == nil || ssFromNewStore.Group != "group" || ssFromNewStore.Name != "name" || len(ssFromNewStore.Events) != 3 || len(ssFromNewStore.Results) != 2 {

storage/store/store.go

@@ -1,9 +1,12 @@
 package store
 
 import (
+	"context"
+	"log"
 	"time"
 
 	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v3/storage"
 	"github.com/TwiN/gatus/v3/storage/store/common/paging"
 	"github.com/TwiN/gatus/v3/storage/store/memory"
 	"github.com/TwiN/gatus/v3/storage/store/sql"
@@ -56,3 +59,82 @@ var (
 	_ Store = (*memory.Store)(nil)
 	_ Store = (*sql.Store)(nil)
 )
+
+var (
+	store Store
+
+	// initialized keeps track of whether the storage provider was initialized
+	// Because store.Store is an interface, a nil check wouldn't be sufficient, so instead of doing reflection
+	// every single time Get is called, we'll just lazily keep track of its existence through this variable
+	initialized bool
+
+	ctx        context.Context
+	cancelFunc context.CancelFunc
+)
+
+func Get() Store {
+	if !initialized {
+		log.Println("[store][Get] Provider requested before it was initialized, automatically initializing")
+		err := Initialize(nil)
+		if err != nil {
+			panic("failed to automatically initialize store: " + err.Error())
+		}
+	}
+	return store
+}
+
+// Initialize instantiates the storage provider based on the Config provider
+func Initialize(cfg *storage.Config) error {
+	initialized = true
+	var err error
+	if cancelFunc != nil {
+		// Stop the active autoSave task, if there's already one
+		cancelFunc()
+	}
+	if cfg == nil {
+		cfg = &storage.Config{}
+	}
+	if len(cfg.Path) == 0 && cfg.Type != storage.TypePostgres {
+		log.Printf("[store][Initialize] Creating storage provider with type=%s and file=%s", cfg.Type, cfg.Path)
+	} else {
+		log.Printf("[store][Initialize] Creating storage provider with type=%s", cfg.Type)
+	}
+	ctx, cancelFunc = context.WithCancel(context.Background())
+	switch cfg.Type {
+	case storage.TypeSQLite, storage.TypePostgres:
+		store, err = sql.NewStore(string(cfg.Type), cfg.Path)
+		if err != nil {
+			return err
+		}
+	case storage.TypeMemory:
+		fallthrough
+	default:
+		if len(cfg.Path) > 0 {
+			store, err = memory.NewStore(cfg.Path)
+			if err != nil {
+				return err
+			}
+			go autoSave(ctx, store, 7*time.Minute)
+		} else {
+			store, _ = memory.NewStore("")
+		}
+	}
+	return nil
+}
+
+// autoSave automatically calls the Save function of the provider at every interval
+func autoSave(ctx context.Context, store Store, interval time.Duration) {
+	for {
+		select {
+		case <-ctx.Done():
+			log.Printf("[store][autoSave] Stopping active job")
+			return
+		case <-time.After(interval):
+			log.Printf("[store][autoSave] Saving")
+			err := store.Save()
+			if err != nil {
+				log.Println("[store][autoSave] Save failed:", err.Error())
+			}
+		}
+	}
+}

storage/store/store_test.go

@@ -5,6 +5,7 @@ import (
 	"time"
 
 	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v3/storage"
 	"github.com/TwiN/gatus/v3/storage/store/common"
 	"github.com/TwiN/gatus/v3/storage/store/common/paging"
 	"github.com/TwiN/gatus/v3/storage/store/memory"
@@ -520,3 +521,89 @@ func TestStore_DeleteAllEndpointStatusesNotInKeys(t *testing.T) {
 		})
 	}
 }
+
+func TestGet(t *testing.T) {
+	store := Get()
+	if store == nil {
+		t.Error("store should've been automatically initialized")
+	}
+}
+
+func TestInitialize(t *testing.T) {
+	type Scenario struct {
+		Name        string
+		Cfg         *storage.Config
+		ExpectedErr error
+	}
+	scenarios := []Scenario{
+		{
+			Name:        "nil",
+			Cfg:         nil,
+			ExpectedErr: nil,
+		},
+		{
+			Name:        "blank",
+			Cfg:         &storage.Config{},
+			ExpectedErr: nil,
+		},
+		{
+			Name:        "memory-no-path",
+			Cfg:         &storage.Config{Type: storage.TypeMemory},
+			ExpectedErr: nil,
+		},
+		{ // XXX: Remove for v4.0.0. See https://github.com/TwiN/gatus/issues/198
+			Name:        "memory-with-path",
+			Cfg:         &storage.Config{Type: storage.TypeMemory, Path: t.TempDir() + "/TestInitialize_memory-with-path.db"},
+			ExpectedErr: nil,
+		},
+		{
+			Name:        "sqlite-no-path",
+			Cfg:         &storage.Config{Type: storage.TypeSQLite},
+			ExpectedErr: sql.ErrPathNotSpecified,
+		},
+		{
+			Name:        "sqlite-with-path",
+			Cfg:         &storage.Config{Type: storage.TypeSQLite, Path: t.TempDir() + "/TestInitialize_sqlite-with-path.db"},
+			ExpectedErr: nil,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			err := Initialize(scenario.Cfg)
+			if err != scenario.ExpectedErr {
+				t.Errorf("expected %v, got %v", scenario.ExpectedErr, err)
+			}
+			if err != nil {
+				return
+			}
+			if cancelFunc == nil {
+				t.Error("cancelFunc shouldn't have been nil")
+			}
+			if ctx == nil {
+				t.Error("ctx shouldn't have been nil")
+			}
+			if store == nil {
+				t.Fatal("provider shouldn't have been nit")
+			}
+			store.Close()
+			// Try to initialize it again
+			err = Initialize(scenario.Cfg)
+			if err != scenario.ExpectedErr {
+				t.Errorf("expected %v, got %v", scenario.ExpectedErr, err)
+				return
+			}
+			store.Close()
+		})
+	}
+}
+
+func TestAutoSave(t *testing.T) {
+	file := t.TempDir() + "/TestAutoSave.db"
+	if err := Initialize(&storage.Config{Path: file}); err != nil {
+		t.Fatal("shouldn't have returned an error")
+	}
+	go autoSave(ctx, store, 3*time.Millisecond)
+	time.Sleep(15 * time.Millisecond)
+	cancelFunc()
+	time.Sleep(50 * time.Millisecond)
+}

watchdog/watchdog.go

@@ -11,7 +11,7 @@ import (
 	"github.com/TwiN/gatus/v3/config/maintenance"
 	"github.com/TwiN/gatus/v3/core"
 	"github.com/TwiN/gatus/v3/metric"
-	"github.com/TwiN/gatus/v3/storage"
+	"github.com/TwiN/gatus/v3/storage/store"
 )
 
 var (
@@ -29,13 +29,13 @@ func Monitor(cfg *config.Config) {
 	for _, endpoint := range cfg.Endpoints {
 		if endpoint.IsEnabled() {
 			// To prevent multiple requests from running at the same time, we'll wait for a little before each iteration
-			time.Sleep(1111 * time.Millisecond)
+			time.Sleep(777 * time.Millisecond)
 			go monitor(endpoint, cfg.Alerting, cfg.Maintenance, cfg.DisableMonitoringLock, cfg.Metrics, cfg.Debug, ctx)
 		}
 	}
 }
 
-// monitor monitors a single endpoint in a loop
+// monitor a single endpoint in a loop
 func monitor(endpoint *core.Endpoint, alertingConfig *alerting.Config, maintenanceConfig *maintenance.Config, disableMonitoringLock, enabledMetrics, debug bool, ctx context.Context) {
 	// Run it immediately on start
 	execute(endpoint, alertingConfig, maintenanceConfig, disableMonitoringLock, enabledMetrics, debug)
@@ -88,7 +88,7 @@ func execute(endpoint *core.Endpoint, alertingConfig *alerting.Config, maintenan
 
 // UpdateEndpointStatuses updates the slice of endpoint statuses
 func UpdateEndpointStatuses(endpoint *core.Endpoint, result *core.Result) {
-	if err := storage.Get().Insert(endpoint, result); err != nil {
+	if err := store.Get().Insert(endpoint, result); err != nil {
 		log.Println("[watchdog][UpdateEndpointStatuses] Failed to insert data in storage:", err.Error())
 	}
 }