feat: add Containerfile to repo

adds a Containerfile so folks can develop with a container

also adds instructions to README and CI job to ensure Containerfile
doesn't get broken

Signed-off-by: Nathan Weinberg <nathansweinberg@gmail.com>

Author: nathan-weinberg

.dockerignore

@@ -0,0 +1,21 @@
+# production
+build
+data
+output
+
+# python
+__pycache__
+.pytest_cache
+.venv
+.poetry
+
+# misc
+.DS_Store
+
+# config
+config/local.json
+.envrc
+
+# logs
+gobble.log
+s3_upload.log

.github/workflows/container.yml

@@ -0,0 +1,74 @@
+name: container
+
+on:
+    pull_request:
+        paths:
+            - Containerfile
+    push:
+        branches:
+            - main
+
+jobs:
+    build:
+        runs-on: ubuntu-latest
+        env:
+            MBTA_V3_API_KEY: ${{ secrets.MBTA_V3_API_KEY }}
+        steps:
+            - name: Checkout repo
+              uses: actions/checkout@v3
+
+            - name: Set up Docker Buildx
+              uses: docker/setup-buildx-action@v3
+
+            - name: Build container image
+              uses: docker/build-push-action@v6
+              with:
+                  context: .
+                  file: ./Containerfile
+                  push: false
+                  tags: gobble:test
+                  load: true
+                  cache-from: type=gha
+                  cache-to: type=gha,mode=max
+                  build-args: |
+                      GIT_ABR_VERSION=${{ github.sha }}
+
+            - name: Create config file
+              run: |
+                  cat >> ./local.json << EOF
+                  {
+                      "mbta": {
+                          "v3_api_key": "${{ secrets.MBTA_V3_API_KEY }}"
+                      },
+                      "modes": ["cr", "bus"],
+                          "gtfs": {
+                          "refresh_interval_days": 7
+                      },
+                      "DATADOG_TRACE_ENABLED": true
+                  }
+
+            - name: Test container starts successfully
+              run: |
+                  # Start the container in the background
+                  docker run -d \
+                    -v ./config/local.json:/app/config/local.json:z \
+                    -v ./data:/app/data:z \
+                    --name gobble \
+                    gobble:test
+
+                  # Wait for the container to start
+                  sleep 10
+
+                  # Check if container is still running
+                  if ! docker ps | grep -q gobble; then
+                    echo "Container failed to start"
+                    docker logs gobble
+                    exit 1
+                  fi
+
+                  # Check if there are any files in data directory
+                  find data -type f -print -quit || exit 1
+
+                  # Cleanup
+                  docker stop gobble
+                  docker rm gobble

Containerfile

@@ -0,0 +1,18 @@
+FROM python:3.12-slim
+
+WORKDIR /app
+
+# Install uv for Python dependency management
+COPY --from=ghcr.io/astral-sh/uv:latest /uv /usr/local/bin/uv
+
+# Copy source code
+COPY . .
+
+# Install dependencies
+RUN uv sync
+
+# Set environment variables
+ENV PYTHONUNBUFFERED=1
+ENV PYTHONPATH=/app/src
+
+ENTRYPOINT ["uv", "run", "python3", "src/gobble.py"]

README.md

@@ -1,6 +1,7 @@
 # gobble
 ![lint](https://github.com/transitmatters/gobble/actions/workflows/lint.yml/badge.svg?branch=main)
 ![test](https://github.com/transitmatters/gobble/actions/workflows/test.yml/badge.svg?branch=main)
+![deploy](https://github.com/transitmatters/gobble/actions/workflows/deploy.yml/badge.svg?branch=main)
 
 ![Screenshot in action](docs/screenshot.png)
 
@@ -18,6 +19,20 @@ Gobble is a service that reads the [MBTA V3 Streaming API](https://www.mbta.com/
 3. Run `uv run src/gobble.py` to start.
 4. Output will be in `data/` in your current working directory. Good luck!
 
+### Container
+
+You can also run Gobble inside a container using the following `docker build` and `docker run` commands
+
+```bash
+docker build -t gobble -f Containerfile .
+docker run \
+    -v ./config/local.json:/app/config/local.json:z \
+    -v ./data:/app/data:z \
+    gobble:latest
+```
+
+Output will be in `data/` in your current working directory. Good luck!
+
 ### Linting
 
 You can run the linter against any code changes with the following commands