Config Editor, Make & Dockerfile Intelligence

Arbiter provides targeted tools for inspecting and safely modifying local repository configuration files without exposing generic, unbounded filesystem read/write access.

Scoped Configuration File Editor

The Arbiter file editor is strictly restricted to recognized configuration files located inside explicitly registered project boundaries.

Supported Configuration Files

• Environment definitions: .env, .env.local, .env.development, .env.example, .env.template, .env.dist
• Docker Compose definitions: compose.yaml, compose.yml, docker-compose.yaml, docker-compose.yml, compose.override.yaml
• Build files: Makefile, Dockerfile, Dockerfile.*

Safety & Concurrency Guarantees

1. Path Traversal Protection: Paths containing .. or pointing outside registered project directories are rejected immediately.
2. Optimistic Concurrency Control (SHA-256 Pre-Check): To avoid overwriting concurrent edits, save requests require an expected_sha256 hash of the file. If the file on disk has changed since it was loaded in the editor, the save is aborted with a conflict error.
3. Automatic Timestamped Backups: Before applying any edit, Arbiter writes an exact copy to <filename>.bak.<timestamp>.
4. One-Click Undo API: Operators can roll back the latest managed edit at any time via POST /api/v1/projects/{id}/files/undo.

# Preview file edit diff with secret masking
curl -X POST http://127.0.0.1:8765/api/v1/projects/my-project/files/preview \
  -H 'Content-Type: application/json' \
  -d '{
    "path": "compose.yaml",
    "content": "services:\n  web:\n    ports:\n      - \"3001:80\"\n",
    "expected_sha256": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
  }'

Makefile Intelligence & Target Runner

Arbiter parses project Makefiles using static AST extraction rather than executing arbitrary shell targets:

• Target Discovery: Lists all declared targets, comments, and prerequisite dependencies.
• Risk Inference: Evaluates target commands to assign safety risk tiers (e.g. make test vs make clean vs make deploy).
• Target Execution: Running Make targets generates typed ActionSpec proposals with execution timeouts and captured output logs.

# List Make targets for a project via REST
curl http://127.0.0.1:8765/api/v1/projects/my-project/make/targets

# Inspect a specific target
curl http://127.0.0.1:8765/api/v1/projects/my-project/make/targets/build

Dockerfile Heuristic Inspection

Arbiter inspects Dockerfiles in registered projects to provide instant static diagnostics:

• Base Images (FROM): Detects base image repositories, tags, and multi-stage build stages.
• Exposed Ports (EXPOSE): Identifies declared container listening ports to cross-reference with Compose port mappings.
• Entrypoints & Commands (ENTRYPOINT, CMD): Parses executable commands and default arguments.
• Potential Issues: Flags missing expose declarations or outdated base image tags.

# Inspect project Dockerfiles
curl http://127.0.0.1:8765/api/v1/projects/my-project/dockerfiles