fix: use public Chainguard base images instead of private ECR

[RoxyFarhad]

Testing:

• Built the Agentex UI image locally
• Built the Agentex Server Image locally

Greptile Summary

This PR removes the dependency on private ECR golden base images by switching both the Python backend (agentex/Dockerfile) and the Node.js frontend (agentex-ui/Dockerfile) to use publicly available Chainguard images pulled directly from cgr.dev. The corresponding AWS OIDC authentication and ECR login steps are removed from the integration-test workflow. As a secondary change, the Python Dockerfile is refactored to use a standard /opt/venv virtual environment instead of installing packages directly into the system Python prefix, which simplifies the multi-stage COPY logic considerably. The UI Dockerfile also fixes a pre-existing bug where NODE_ENV=production was set before npm ci, inadvertently excluding dev dependencies needed for the Next.js build.

Key changes:

• Both Dockerfiles now pull from cgr.dev/chainguard instead of 022465994601.dkr.ecr.us-west-2.amazonaws.com
• Workflow removes AWS OIDC (id-token: write) permissions and the ECR login steps; job-level permissions block is dropped and the job correctly inherits workflow-level contents: read + packages: read
• Python backend now installs into /opt/venv instead of the system Python, simplifying the production-stage COPY to a single directory
• UI Dockerfile correctly installs all deps (including dev) before the build, then prunes dev deps — fixing the broken NODE_ENV=production-before-npm ci ordering
• Both Dockerfiles use unpinned latest-dev tags (previously python:3.12-dev and node:20-dev), which introduces non-determinism and risks silent major-version upgrades on future builds

Confidence Score: 3/5

• Functionally correct and a meaningful simplification, but the switch to unpinned latest-dev tags introduces build non-determinism that could silently break things on future runs.
• The core goal (removing private ECR dependency) is achieved cleanly, and the workflow permission changes are correct. The main risk is that both Dockerfiles now use cgr.dev/chainguard/python:latest-dev and cgr.dev/chainguard/node:latest-dev without version pins. Chainguard's latest tag tracks the newest stable release and can advance major versions (e.g., Python 3.12 → 3.13, Node 20 → 22) automatically. The original ECR images were pinned to python:3.12 and node:20, so this is a regression in reproducibility. Additionally, using latest-dev independently in both the base and production stages of the Python Dockerfile creates a subtle risk: if Chainguard pushes an update between the two pulls within a single build, the build-time and run-time Python versions could differ.
• Both agentex/Dockerfile and agentex-ui/Dockerfile use unpinned latest-dev image tags and should be revisited to restore version pins.

Important Files Changed

Filename	Overview
agentex/Dockerfile	Migrates from private ECR to public Chainguard images. Replaces system-level Python installation with an isolated venv at /opt/venv, significantly simplifying the multi-stage COPY logic. Both the base and production stages use unpinned latest-dev tags, which introduces non-determinism and the risk of silent major-version upgrades.
agentex-ui/Dockerfile	Migrates from private ECR to public Chainguard node image. Fixes a pre-existing bug where NODE_ENV=production was set before npm ci, causing dev dependencies required for the Next.js build to be omitted. The fix installs all deps, builds, then prunes dev deps. Uses unpinned latest-dev tag.
.github/workflows/integration-tests.yml	Removes job-level permissions block and the two AWS/ECR steps from run-integration-tests. The job now correctly inherits workflow-level permissions (contents: read, packages: read), so the GHCR login and checkout steps are unaffected. Clean removal with no side effects.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    subgraph Before
        A1[Private ECR\n022465994601.dkr.ecr.us-west-2.amazonaws.com] -->|AWS OIDC + ECR Login| B1[python:3.12-dev / node:20-dev]
        B1 --> C1[Build image]
    end

    subgraph After
        A2[Public Chainguard Registry\ncgr.dev/chainguard] -->|No auth required| B2[python:latest-dev / node:latest-dev]
        B2 --> C2[Build image]
    end

    subgraph Workflow Change
        W1[run-integration-tests job] -->|Removed| W2[AWS credentials step]
        W1 -->|Removed| W3[ECR login step]
        W1 -->|Removed| W4[Job-level permissions block]
        W1 -->|Inherits from workflow level| W5[contents: read\npackages: read]
    end

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Prompt To Fix All With AI

This is a comment left during a code review.
Path: agentex/Dockerfile
Line: 1

Comment:
**Unpinned `latest-dev` tag risks non-deterministic builds**

The original ECR image used a pinned `python:3.12-dev` tag. Switching to `cgr.dev/chainguard/python:latest-dev` removes that version pin. Chainguard's `latest` tag follows the newest stable release and could silently advance to Python 3.13 or beyond on the next build, potentially introducing breaking changes (e.g., Python 3.13 removed several deprecated APIs).

Consider pinning to a specific minor version for reproducibility:

```suggestion
FROM cgr.dev/chainguard/python:3.12-dev AS base
```

The same applies to the production stage at line 55.

How can I resolve this? If you propose a fix, please make it concise.

---

This is a comment left during a code review.
Path: agentex/Dockerfile
Line: 55

Comment:
**Unpinned `latest-dev` tag in production stage**

Same concern as the `base` stage — the production image also uses `cgr.dev/chainguard/python:latest-dev`. Because both the `base` and `production` stages use `latest-dev` independently, there is also a risk that two separate image pulls resolve to different digests if Chainguard pushes an update between pulls during a single build, resulting in a mismatched Python runtime between build-time and run-time.

```suggestion
FROM cgr.dev/chainguard/python:3.12-dev AS production
```

How can I resolve this? If you propose a fix, please make it concise.

---

This is a comment left during a code review.
Path: agentex-ui/Dockerfile
Line: 2

Comment:
**Unpinned `latest-dev` tag**

The original ECR image was pinned to `node:20-dev`. Using `cgr.dev/chainguard/node:latest-dev` could silently upgrade to Node.js 22, 24, or beyond on any future build. Node.js major-version upgrades can include breaking changes in native addons (relevant here since `sharp` is a native module) and built-in API behaviour.

```suggestion
FROM cgr.dev/chainguard/node:20-dev
```

How can I resolve this? If you propose a fix, please make it concise.

_{Last reviewed commit: "fix: use public Chai..."}