Improvements around docker in Playwright

playwright/e2e/register/email.spec.ts

@@ -33,7 +33,7 @@ test.describe("Email Registration", async () => {
             use({
                 template: "email",
                 variables: {
-                    SMTP_HOST: "{{HOST_DOCKER_INTERNAL}}", // This will get replaced in synapseStart
+                    SMTP_HOST: "host.containers.internal",
                     SMTP_PORT: mailhog.instance.smtpPort,
                 },
             }),

playwright/plugins/docker/index.ts

@@ -55,9 +55,10 @@ export class Docker {
         const userInfo = os.userInfo();
         const params = opts.params ?? [];
 
-        if (params?.includes("-v") && userInfo.uid >= 0) {
+        const isPodman = await Docker.isPodman();
+        if (params.includes("-v") && userInfo.uid >= 0) {
             // Run the docker container as our uid:gid to prevent problems with permissions.
-            if (await Docker.isPodman()) {
+            if (isPodman) {
                 // Note: this setup is for podman rootless containers.
 
                 // In podman, run as root in the container, which maps to the current
@@ -74,6 +75,16 @@ export class Docker {
             }
         }
 
+        if (isPodman) {
+            // Make host.containers.internal work to allow the container to talk to other services via host ports.
+            params.push("--network");
+            params.push("slirp4netns:allow_host_loopback=true");
+        } else {
+            // Make host.docker.internal work to allow the container to talk to other services via host ports.
+            params.push("--add-host");
+            params.push("host.containers.internal:host-gateway");
+        }
+
         // Provided we are not running in CI, add a `--rm` parameter.
         // There is no need to remove containers in CI (since they are automatically removed anyway), and
         // `--rm` means that if a container crashes this means its logs are wiped out.
@@ -139,12 +150,4 @@ export class Docker {
         const { stdout } = await exec("docker", ["--help"], false);
         return stdout.toLowerCase().includes("podman");
     }
-
-    /**
-     * Supply the right hostname to use to talk to the host machine. On Docker this
-     * is "host.docker.internal" and on Podman this is "host.containers.internal".
-     */
-    static async hostnameOfHost(): Promise<"host.containers.internal" | "host.docker.internal"> {
-        return (await Docker.isPodman()) ? "host.containers.internal" : "host.docker.internal";
-    }
 }

playwright/plugins/homeserver/synapse/index.ts

@@ -57,20 +57,9 @@ async function cfgDirFromTemplate(opts: StartHomeserverOpts): Promise<Omit<Homes
     if (opts.oAuthServerPort) {
         hsYaml = hsYaml.replace(/{{OAUTH_SERVER_PORT}}/g, opts.oAuthServerPort.toString());
     }
-    hsYaml = hsYaml.replace(/{{HOST_DOCKER_INTERNAL}}/g, await Docker.hostnameOfHost());
     if (opts.variables) {
-        let fetchedHostContainer: Awaited<ReturnType<typeof Docker.hostnameOfHost>> | null = null;
         for (const key in opts.variables) {
-            let value = String(opts.variables[key]);
-
-            if (value === "{{HOST_DOCKER_INTERNAL}}") {
-                if (!fetchedHostContainer) {
-                    fetchedHostContainer = await Docker.hostnameOfHost();
-                }
-                value = fetchedHostContainer;
-            }
-
-            hsYaml = hsYaml.replace(new RegExp("%" + key + "%", "g"), value);
+            hsYaml = hsYaml.replace(new RegExp("%" + key + "%", "g"), String(opts.variables[key]));
         }
     }
 
@@ -106,26 +95,13 @@ export class Synapse implements Homeserver, HomeserverInstance {
      * Start a synapse instance: the template must be the name of
      * one of the templates in the playwright/plugins/synapsedocker/templates
      * directory.
-     *
-     * Any value in `opts.variables` that is set to `{{HOST_DOCKER_INTERNAL}}'
-     * will be replaced with 'host.docker.internal' (if we are on Docker) or
-     * 'host.containers.internal' if we are on Podman.
      */
     public async start(opts: StartHomeserverOpts): Promise<HomeserverInstance> {
         if (this.config) await this.stop();
 
         const synCfg = await cfgDirFromTemplate(opts);
         console.log(`Starting synapse with config dir ${synCfg.configDir}...`);
         const dockerSynapseParams = ["-v", `${synCfg.configDir}:/data`, "-p", `${synCfg.port}:8008/tcp`];
-        if (await Docker.isPodman()) {
-            // Make host.containers.internal work to allow Synapse to talk to the test OIDC server.
-            dockerSynapseParams.push("--network");
-            dockerSynapseParams.push("slirp4netns:allow_host_loopback=true");
-        } else {
-            // Make host.docker.internal work to allow Synapse to talk to the test OIDC server.
-            dockerSynapseParams.push("--add-host");
-            dockerSynapseParams.push("host.docker.internal:host-gateway");
-        }
         const synapseId = await this.docker.run({
             image: "matrixdotorg/synapse:develop",
             containerName: `react-sdk-playwright-synapse`,

playwright/plugins/homeserver/synapse/templates/default/homeserver.yaml

@@ -81,10 +81,8 @@ oidc_providers:
       issuer: "http://localhost:{{OAUTH_SERVER_PORT}}/oauth"
       authorization_endpoint: "http://localhost:{{OAUTH_SERVER_PORT}}/oauth/auth.html"
       # the token endpoint receives requests from synapse, rather than the webapp, so needs to escape the docker container.
-      # Hence, HOST_DOCKER_INTERNAL rather than localhost. This is set to
-      # host.docker.internal on Docker and host.containers.internal on Podman.
-      token_endpoint: "http://{{HOST_DOCKER_INTERNAL}}:{{OAUTH_SERVER_PORT}}/oauth/token"
-      userinfo_endpoint: "http://{{HOST_DOCKER_INTERNAL}}:{{OAUTH_SERVER_PORT}}/oauth/userinfo"
+      token_endpoint: "http://host.containers.internal:{{OAUTH_SERVER_PORT}}/oauth/token"
+      userinfo_endpoint: "http://host.containers.internal:{{OAUTH_SERVER_PORT}}/oauth/userinfo"
       client_id: "synapse"
       discover: false
       scopes: ["profile"]