add docker logs to provider

server/src/service/network/DockerProvider.ts

@@ -2,7 +2,9 @@ import { IStatusProvider } from "@/service/network/IStatusProvider.js";
 import { DockerStatusPayload, MonitorStatusResponse } from "@/types/network.js";
 
 import {
+	DOCKER_LOG_TAIL_LINES,
 	DockerContainerInfo,
+	DockerContainerLogs,
 	DockerContainerMount,
 	DockerContainerPort,
 	DockerContainerState,
@@ -10,6 +12,8 @@ import {
 	DockerContainerSummary,
 	DockerHealthStatus,
 	DockerHealthStatuses,
+	DockerLogLine,
+	DockerLogStream,
 	DockerPortProtocol,
 	DockerPortProtocols,
 } from "@/domain/docker/docker.type.js";
@@ -23,6 +27,9 @@ type DockerodeType = typeof Dockerode;
 
 const SERVICE_NAME = "DockerProvider";
 const STATS_CONCURRENCY = 5;
+const DOCKER_LOG_MAX_LINE_BYTES = 4096;
+const DOCKER_LOG_TRUNCATION_MARKER = " …[truncated]";
+const DOCKER_LOG_TS_REGEX = /^(\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2})(?:\.(\d{1,9}))?Z /;
 
 export interface DockerError extends Error {
 	statusCode?: number;
@@ -119,10 +126,14 @@ export class DockerProvider implements IStatusProvider<DockerStatusPayload> {
 		};
 	}
 
+	private toContainerName = (summary: Dockerode.ContainerInfo): string => {
+		return summary.Names?.[0]?.replace(/^\//, "") ?? summary.Id.slice(0, 12);
+	};
+
 	private async toContainerInfo(docker: Dockerode, summary: Dockerode.ContainerInfo): Promise<DockerContainerInfo> {
 		const info: DockerContainerInfo = {
 			id: summary.Id,
-			name: summary.Names?.[0]?.replace(/^\//, "") ?? summary.Id.slice(0, 12),
+			name: this.toContainerName(summary),
 			image: summary.Image,
 			state: this.toContainerState(summary.State),
 			status: summary.Status,
@@ -198,6 +209,76 @@ export class DockerProvider implements IStatusProvider<DockerStatusPayload> {
 		}));
 	}
 
+	// Log parsing
+	private isMultiplexed(buffer: Buffer): boolean {
+		return buffer.length >= 8 && buffer.readUInt8(0) <= 2 && buffer.readUInt8(1) === 0 && buffer.readUInt8(2) === 0 && buffer.readUInt8(3) === 0;
+	}
+
+	// Docker will will merge stdout and stderr if stared with `-t`.
+	// Most containers will _not_ be run with `-t` though, in which case logs come in frames of [header][payload]
+	private demuxLogBuffer = (buffer: Buffer): { stream: DockerLogStream; chunk: string }[] => {
+		if (!this.isMultiplexed(buffer)) return [{ stream: "stdout", chunk: buffer.toString("utf8") }]; // `-t` case, log is just a string, return it
+		const frames: { stream: DockerLogStream; chunk: string }[] = [];
+		let offset = 0; // Start reading at the first byte of the first header
+		while (offset + 8 <= buffer.length) {
+			// Every 8 bytes is a header, if < 8 bytes at the end, invalid frame, stop
+			const streamType = buffer.readUint8(offset); // First byte of the header is the stream type: 0 = stdin, 1 = stdout, 2 = stderr
+			const payloadSize = buffer.readUint32BE(offset + 4); // Byte 4 to 7 describe how many payload bytes follow the header
+			const payloadStart = offset + 8; // Advance to the payload (header 8 bytes long)
+			const payloadEnd = Math.min(payloadStart + payloadSize, buffer.length); // End is the start of the payload + payload size.
+			frames.push({ stream: streamType === 2 ? "stderr" : "stdout", chunk: buffer.toString("utf-8", payloadStart, payloadEnd) });
+			offset = payloadEnd;
+		}
+		return frames;
+	};
+
+	private truncateLog = (text: string): string => {
+		if (Buffer.byteLength(text, "utf8") <= DOCKER_LOG_MAX_LINE_BYTES) return text;
+		const cut = Buffer.from(text, "utf8").subarray(0, DOCKER_LOG_MAX_LINE_BYTES).toString("utf8").replace(/�$/, "");
+		return cut + DOCKER_LOG_TRUNCATION_MARKER;
+	};
+
+	// Docker drops trailing zeroes form timestamps. Pad out timestamps for correct string comparison
+	private toLogLine(stream: DockerLogStream, raw: string): DockerLogLine | null {
+		const match = raw.match(DOCKER_LOG_TS_REGEX);
+		if (!match) return null; // If there's no time stamp, something is wrong with this line, drop it
+		const ts = `${match[1]}.${(match[2] ?? "").padEnd(9, "0")}Z`;
+		const text = raw.slice(match[0].length).replace(/\r$/, "");
+		return { ts, stream, text: this.truncateLog(text) };
+	}
+
+	private parseLogBuffer = (buffer: Buffer): DockerLogLine[] => {
+		const lines: DockerLogLine[] = [];
+		const demuxedBuffer = this.demuxLogBuffer(buffer);
+		for (const byteStream of demuxedBuffer) {
+			const { stream, chunk } = byteStream;
+			for (const raw of chunk.split("/n")) {
+				if (raw.length === 0) continue;
+				const line = this.toLogLine(stream, raw);
+				if (line) lines.push(line);
+			}
+		}
+		return lines;
+	};
+
+	private toContainerLogs = async (docker: Dockerode, summary: Dockerode.ContainerInfo): Promise<DockerContainerLogs | null> => {
+		const containerName = this.toContainerName(summary);
+		try {
+			const buffer = await docker
+				.getContainer(summary.Id)
+				.logs({ follow: false, stdout: true, stderr: true, timestamps: true, tail: DOCKER_LOG_TAIL_LINES });
+			return { containerId: summary.Id, containerName, lines: this.parseLogBuffer(buffer) };
+		} catch (error: unknown) {
+			this.logger.warn({
+				message: `Failed to read logs for container ${containerName}`,
+				service: SERVICE_NAME,
+				method: "toContainerLogs",
+				details: { containerId: summary.Id, error: error instanceof Error ? error.message : String(error) },
+			});
+			return null;
+		}
+	};
+
 	handle = async (monitor: Monitor): Promise<MonitorStatusResponse<DockerStatusPayload>> => {
 		try {
 			const docker = new this.DockerLib(this.toDockerOptions(monitor));
@@ -226,6 +307,8 @@ export class DockerProvider implements IStatusProvider<DockerStatusPayload> {
 
 			const summaries = await docker.listContainers({ all: true });
 			const containers = await this.mapWithConcurrency(summaries, STATS_CONCURRENCY, (s) => this.toContainerInfo(docker, s));
+			const rawLogs = await this.mapWithConcurrency(summaries, STATS_CONCURRENCY, (s) => this.toContainerLogs(docker, s));
+			const logs = rawLogs.filter((log) => log !== null);
 			const summary: DockerContainerSummary = {
 				total: containers.length,
 				running: containers.filter((c) => c.state === "running").length,
@@ -240,7 +323,7 @@ export class DockerProvider implements IStatusProvider<DockerStatusPayload> {
 				code: 200,
 				message: "Docker host is reachable",
 				responseTime,
-				payload: { containers, summary },
+				payload: { containers, summary, logs },
 			};
 		} catch (error: unknown) {
 			if (error instanceof AppError) throw error;