fix(kafka): port race on start

Fix the port race on start up by explicitly waiting for the port to be
exposed. Once this is successful run the wait, this prevents the wait
always being run due to way hooks are processed.

modules/kafka/kafka.go

@@ -71,31 +71,16 @@ func Run(ctx context.Context, img string, opts ...testcontainers.ContainerCustom
 		LifecycleHooks: []testcontainers.ContainerLifecycleHooks{
 			{
 				PostStarts: []testcontainers.ContainerHook{
-					// 1. copy the starter script into the container
+					// Use a single hook to copy the starter script and wait for
+					// the Kafka server to be ready. This prevents the wait running
+					// if the starter script fails to copy.
 					func(ctx context.Context, c testcontainers.Container) error {
-						host, err := c.Host(ctx)
-						if err != nil {
-							return err
+						// 1. copy the starter script into the container
+						if err := copyStarterScript(ctx, c); err != nil {
+							return fmt.Errorf("copy starter script: %w", err)
 						}
 
-						inspect, err := c.Inspect(ctx)
-						if err != nil {
-							return err
-						}
-
-						hostname := inspect.Config.Hostname
-
-						port, err := c.MappedPort(ctx, publicPort)
-						if err != nil {
-							return err
-						}
-
-						scriptContent := fmt.Sprintf(starterScriptContent, host, port.Int(), hostname)
-
-						return c.CopyToContainer(ctx, []byte(scriptContent), starterScript, 0o755)
-					},
-					// 2. wait for the Kafka server to be ready
-					func(ctx context.Context, c testcontainers.Container) error {
+						// 2. wait for the Kafka server to be ready
 						return wait.ForLog(".*Transitioning from RECOVERY to RUNNING.*").AsRegexp().WaitUntilReady(ctx, c)
 					},
 				},
@@ -131,6 +116,38 @@ func Run(ctx context.Context, img string, opts ...testcontainers.ContainerCustom
 	return &KafkaContainer{Container: container, ClusterID: clusterID}, nil
 }
 
+// copyStarterScript copies the starter script into the container.
+func copyStarterScript(ctx context.Context, c testcontainers.Container) error {
+	if err := wait.ForExposedPortOnly(publicPort).WaitUntilReady(ctx, c); err != nil {
+		return fmt.Errorf("wait for exposed port: %w", err)
+	}
+
+	host, err := c.Host(ctx)
+	if err != nil {
+		return fmt.Errorf("host: %w", err)
+	}
+
+	inspect, err := c.Inspect(ctx)
+	if err != nil {
+		return fmt.Errorf("inspect: %w", err)
+	}
+
+	hostname := inspect.Config.Hostname
+
+	port, err := c.MappedPort(ctx, publicPort)
+	if err != nil {
+		return fmt.Errorf("mapped port: %w", err)
+	}
+
+	scriptContent := fmt.Sprintf(starterScriptContent, host, port.Int(), hostname)
+
+	if err := c.CopyToContainer(ctx, []byte(scriptContent), starterScript, 0o755); err != nil {
+		return fmt.Errorf("copy to container: %w", err)
+	}
+
+	return nil
+}
+
 func WithClusterID(clusterID string) testcontainers.CustomizeRequestOption {
 	return func(req *testcontainers.GenericContainerRequest) error {
 		req.Env["CLUSTER_ID"] = clusterID