Make HealthCheckWaitStrategy event based (#789)

Author: cristianrgreco

packages/testcontainers/fixtures/docker-compose/docker-compose-with-healthcheck-unhealthy.yml

@@ -0,0 +1,12 @@
+version: "3.5"
+
+services:
+  container:
+    image: cristianrgreco/testcontainer:1.1.14
+    ports:
+      - 8080
+    healthcheck:
+      test: "curl -f http://localhost:8081/hello-world || exit 1"
+      timeout: 3s
+      interval: 1s
+      retries: 0

packages/testcontainers/src/container-runtime/clients/container/container-client.ts

@@ -24,6 +24,7 @@ export interface ContainerClient {
   logs(container: Container, opts?: ContainerLogsOptions): Promise<Readable>;
   exec(container: Container, command: string[], opts?: Partial<ExecOptions>): Promise<ExecResult>;
   restart(container: Container, opts?: { timeout: number }): Promise<void>;
+  events(container: Container, eventNames: string[]): Promise<Readable>;
   remove(container: Container, opts?: { removeVolumes: boolean }): Promise<void>;
   connectToNetwork(container: Container, network: Network, networkAliases: string[]): Promise<void>;
 }

packages/testcontainers/src/container-runtime/clients/container/docker-container-client.ts

@@ -12,7 +12,7 @@ import { IncomingMessage } from "http";
 import { ExecOptions, ExecResult } from "./types";
 import byline from "byline";
 import { ContainerClient } from "./container-client";
-import { log, execLog, streamToString } from "../../../common";
+import { execLog, log, streamToString } from "../../../common";
 
 export class DockerContainerClient implements ContainerClient {
   constructor(public readonly dockerode: Dockerode) {}
@@ -248,6 +248,19 @@ export class DockerContainerClient implements ContainerClient {
     }
   }
 
+  async events(container: Container, eventNames: string[]): Promise<Readable> {
+    log.debug(`Fetching event stream...`, { containerId: container.id });
+    const stream = (await this.dockerode.getEvents({
+      filters: {
+        type: ["container"],
+        container: [container.id],
+        event: eventNames,
+      },
+    })) as Readable;
+    log.debug(`Fetched event stream...`, { containerId: container.id });
+    return stream;
+  }
+
   protected async demuxStream(containerId: string, stream: Readable): Promise<Readable> {
     try {
       log.debug(`Demuxing stream...`, { containerId });

packages/testcontainers/src/docker-compose-environment/docker-compose-environment.test.ts

@@ -124,6 +124,14 @@ describe("DockerComposeEnvironment", () => {
     await startedEnvironment.down();
   });
 
+  it("should support failing health check wait strategy", async () => {
+    await expect(
+      new DockerComposeEnvironment(fixtures, "docker-compose-with-healthcheck-unhealthy.yml")
+        .withWaitStrategy(await composeContainerName("container"), Wait.forHealthCheck())
+        .up()
+    ).rejects.toThrow(`Health check failed: unhealthy`);
+  });
+
   if (!process.env.CI_PODMAN) {
     it("should stop the container when the health check wait strategy times out", async () => {
       await expect(

packages/testcontainers/src/wait-strategies/health-check-wait-strategy.ts

@@ -1,31 +1,47 @@
 import Dockerode from "dockerode";
 import { AbstractWaitStrategy } from "./wait-strategy";
-import { IntervalRetry, log } from "../common";
+import { log } from "../common";
 import { getContainerRuntimeClient } from "../container-runtime";
 
 export class HealthCheckWaitStrategy extends AbstractWaitStrategy {
   public async waitUntilReady(container: Dockerode.Container): Promise<void> {
     log.debug(`Waiting for health check...`, { containerId: container.id });
+
     const client = await getContainerRuntimeClient();
+    const containerEvents = await client.container.events(container, ["health_status"]);
 
-    const status = await new IntervalRetry<string | undefined, Error>(100).retryUntil(
-      async () => (await client.container.inspect(container)).State.Health?.Status,
-      (healthCheckStatus) => healthCheckStatus === "healthy" || healthCheckStatus === "unhealthy",
-      () => {
-        const timeout = this.startupTimeout;
-        const message = `Health check not healthy after ${timeout}ms`;
+    return new Promise((resolve, reject) => {
+      const timeout = setTimeout(() => {
+        const message = `Health check not healthy after ${this.startupTimeout}ms`;
         log.error(message, { containerId: container.id });
-        throw new Error(message);
-      },
-      this.startupTimeout
-    );
+        containerEvents.destroy();
+        reject(new Error(message));
+      }, this.startupTimeout);
+
+      const onTerminalState = () => {
+        clearTimeout(timeout);
+        containerEvents.destroy();
+        log.debug(`Health check wait strategy complete`, { containerId: container.id });
+      };
+
+      containerEvents.on("data", (data) => {
+        const parsedData = JSON.parse(data);
 
-    if (status !== "healthy") {
-      const message = `Health check failed: ${status}`;
-      log.error(message, { containerId: container.id });
-      throw new Error(message);
-    }
+        const status =
+          parsedData.status.split(":").length === 2
+            ? parsedData.status.split(":")[1].trim() // Docker
+            : parsedData.HealthStatus; // Podman
 
-    log.debug(`Health check wait strategy complete`, { containerId: container.id });
+        if (status === "healthy") {
+          resolve();
+          onTerminalState();
+        } else if (status === "unhealthy") {
+          const message = `Health check failed: ${status}`;
+          log.error(message, { containerId: container.id });
+          reject(new Error(message));
+          onTerminalState();
+        }
+      });
+    });
   }
 }