#191: Handle memory issue caused by migration from Service to Endpoint

.dockerignore

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

.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

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)
@@ -246,7 +246,7 @@ storage:
   type: sqlite
   file: 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:
 ```yaml
@@ -254,7 +254,7 @@ storage:
   type: postgres
   file: "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 +798,29 @@ 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 +845,7 @@ Gatus can be deployed on Terraform by using the following module: [terraform-kub
 
 
 ## Running the tests
-```
+```console
 go test ./... -mod vendor
 ```
 

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

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

storage/store/memory/memory.go

@@ -2,7 +2,11 @@ package memory
 
 import (
 	"encoding/gob"
+	"io/fs"
+	"io/ioutil"
+	"log"
 	"sort"
+	"strings"
 	"sync"
 	"time"
 
@@ -40,6 +44,20 @@ func NewStore(file string) (*Store, error) {
 	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
+				}
+			}
+			// XXX: Remove the block above in v4.0.0
 			return nil, err
 		}
 	}