fix: replace third-party base image with AWS public ECR image (CVE-2026-31789) (#1250)

* fix: replace third-party base image with AWS public ECR image

Switch Python container Dockerfile from ghcr.io/astral-sh/uv:python3.12-bookworm-slim
to public.ecr.aws/docker/library/python:3.12-slim to remediate CVE-2026-31789 (OpenSSL).
The uv binary is copied from the official image via multi-stage COPY --from.

Constraint: Must preserve uv-based dependency management workflow
Rejected: pip install uv | adds network call and slower builds
Confidence: high
Scope-risk: narrow

* fix: address review — use pip install uv, fix import command, update docs

- Replace COPY --from with pip install uv==0.11.14 to fully eliminate
  third-party image pull at build time
- Update agentcore import Dockerfile generation to use AWS ECR base image
- Update docs/container-builds.md to reflect new base image setup

Constraint: No AWS-hosted uv binary available; pip install is the cleanest path
Confidence: high
Scope-risk: narrow

* fix: pin python base image to bookworm for reproducible builds

Pin to python:3.12-slim-bookworm to prevent silent OS upgrade
when Debian Trixie becomes the default slim tag.

Confidence: high
Scope-risk: narrow

* fix: unpin uv version — install latest via pip

uv is a single static binary with no OS dependencies, so pinning
provides little security value while requiring periodic bumps.

Confidence: high
Scope-risk: narrow

Author: jesseturner21

docs/container-builds.md

@@ -39,7 +39,8 @@ app/MyAgent/
 
 ## Generated Dockerfile
 
-The template uses `ghcr.io/astral-sh/uv:python3.12-bookworm-slim` as the base image with these design choices:
+The template uses `public.ecr.aws/docker/library/python:3.12-slim` as the base image (with `uv` installed via
+`pip install uv`) with these design choices:
 
 - **Layer caching**: Dependencies (`pyproject.toml`) are installed before copying application code
 - **Non-root**: Runs as `bedrock_agentcore` (UID 1000)

src/assets/__tests__/__snapshots__/dockerfile-render.test.ts.snap

@@ -1,7 +1,9 @@
 // Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
 exports[`Dockerfile enableOtel rendering > renders opentelemetry-instrument CMD when enableOtel is true > Dockerfile-enableOtel-true 1`] = `
-"FROM ghcr.io/astral-sh/uv:python3.12-bookworm-slim
+"FROM public.ecr.aws/docker/library/python:3.12-slim-bookworm
+
+RUN pip install --no-cache-dir uv
 
 ARG UV_DEFAULT_INDEX
 ARG UV_INDEX
@@ -39,7 +41,9 @@ CMD ["opentelemetry-instrument", "python", "-m", "main"]
 `;
 
 exports[`Dockerfile enableOtel rendering > renders plain python CMD when enableOtel is false > Dockerfile-enableOtel-false 1`] = `
-"FROM ghcr.io/astral-sh/uv:python3.12-bookworm-slim
+"FROM public.ecr.aws/docker/library/python:3.12-slim-bookworm
+
+RUN pip install --no-cache-dir uv
 
 ARG UV_DEFAULT_INDEX
 ARG UV_INDEX

src/assets/container/python/Dockerfile

@@ -1,4 +1,6 @@
-FROM ghcr.io/astral-sh/uv:python3.12-bookworm-slim
+FROM public.ecr.aws/docker/library/python:3.12-slim-bookworm
+
+RUN pip install --no-cache-dir uv
 
 ARG UV_DEFAULT_INDEX
 ARG UV_INDEX

src/cli/commands/import/actions.ts

@@ -383,7 +383,8 @@ export async function handleImport(options: ImportOptions): Promise<ImportResult
               fs.writeFileSync(
                 destDockerfile,
                 [
-                  'FROM ghcr.io/astral-sh/uv:python3.12-bookworm-slim',
+                  'FROM public.ecr.aws/docker/library/python:3.12-slim-bookworm',
+                  'RUN pip install --no-cache-dir uv',
                   'WORKDIR /app',
                   '',
                   'ENV UV_SYSTEM_PYTHON=1 \\',