Address PR review feedback for container support

- Add port comments to Dockerfile EXPOSE directive
- Fix container runtime null check (info.runtime !== null)
- Use path.join() in getDockerfilePath for cross-platform support
- Use CONTAINER_RUNTIMES constant instead of hardcoded array
- Change dynamic import to static import in container-dev-server
- Check ports sequentially to avoid bind race conditions

Author: tejaskash

src/assets/container/python/Dockerfile

@@ -16,6 +16,9 @@ USER bedrock_agentcore
 
 COPY . .
 
+# 8080: AgentCore runtime endpoint
+# 8000: Local dev server (uvicorn)
+# 9000: OpenTelemetry collector
 EXPOSE 8080 8000 9000
 
 CMD ["opentelemetry-instrument", "python", "-m", "{{entrypoint}}"]

src/cli/external-requirements/checks.ts

@@ -135,8 +135,8 @@ export async function checkDependencyVersions(projectSpec: AgentCoreProjectSpec)
   let containerRuntimeAvailable = true;
   if (requiresContainerRuntime(projectSpec)) {
     const info = await detectContainerRuntime();
-    containerRuntimeAvailable = info !== null;
-    if (!info) {
+    containerRuntimeAvailable = info.runtime !== null;
+    if (!info.runtime) {
       // This is a warning, not an error - deploy still works via CodeBuild
       // We don't add to errors[] since it's not blocking
     }

src/cli/operations/dev/container-dev-server.ts

@@ -1,4 +1,5 @@
 import { CONTAINER_INTERNAL_PORT, DOCKERFILE_NAME } from '../../../lib';
+import { detectContainerRuntime, getStartHint } from '../../external-requirements/detect';
 import { DevServer, type LogLevel, type SpawnConfig } from './dev-server';
 import { convertEntrypointToModule } from './utils';
 import { spawnSync } from 'child_process';
@@ -32,7 +33,6 @@ export class ContainerDevServer extends DevServer {
     const { onLog } = this.options.callbacks;
 
     // 1. Detect container runtime
-    const { detectContainerRuntime, getStartHint } = await import('../../external-requirements/detect');
     const { runtime, notReadyRuntimes } = await detectContainerRuntime();
     if (!runtime) {
       if (notReadyRuntimes.length > 0) {

src/lib/constants.ts

@@ -1,3 +1,5 @@
+import { join } from 'path';
+
 // Re-export all schema constants from schema
 export * from '../schema';
 
@@ -60,5 +62,5 @@ export const START_HINTS: Record<ContainerRuntime, string> = {
  * Get the Dockerfile path for a given code location.
  */
 export function getDockerfilePath(codeLocation: string): string {
-  return `${codeLocation}/${DOCKERFILE_NAME}`;
+  return join(codeLocation, DOCKERFILE_NAME);
 }

src/lib/packaging/container.ts

@@ -1,5 +1,5 @@
 import type { AgentEnvSpec } from '../../schema';
-import { DOCKERFILE_NAME, ONE_GB } from '../constants';
+import { CONTAINER_RUNTIMES, DOCKERFILE_NAME, ONE_GB } from '../constants';
 import { PackagingError } from './errors';
 import { resolveCodeLocation } from './helpers';
 import type { ArtifactResult, PackageOptions, RuntimePackager } from './types/packaging';
@@ -9,10 +9,10 @@ import { join } from 'path';
 
 /**
  * Detect container runtime synchronously.
- * Checks docker, podman, finch in order; returns the first available binary name.
+ * Checks runtimes in CONTAINER_RUNTIMES order; returns the first available binary name.
  */
 function detectContainerRuntimeSync(): string | null {
-  for (const runtime of ['docker', 'finch', 'podman']) {
+  for (const runtime of CONTAINER_RUNTIMES) {
     const result = spawnSync('which', [runtime], { stdio: 'pipe' });
     if (result.status === 0) {
       const versionResult = spawnSync(runtime, ['--version'], { stdio: 'pipe' });