Add healthcheck for divviup-api to compose.yaml (#1097)

Adds a simple healthcheck on the `divviup-api` service in `compose.yaml`
that tickles the health endpoint. Also adds a check to the Docker CI job
that runs Docker compose and waits 120 seconds for it to become healthy.

Part of #1096

.github/workflows/docker.yml

@@ -26,10 +26,43 @@ jobs:
         with:
           context: .
           push: false
+          load: true
           cache-from: |
             type=gha,scope=main-${{ matrix.rust-features }}
             type=gha,scope=${{ github.ref_name }}-${{ matrix.rust-features }}
           cache-to: type=gha,scope=${{ github.ref_name }}-${{ matrix.rust-features }},mode=max
           build-args: |
             GIT_REVISION=${{ steps.git.outputs.GIT_REVISION }}
             RUST_FEATURES=${{ matrix.rust-features }}
+      # Test the dev compose, which should use the images built earlier. Technically this is only
+      # interesting when feature integration-testing is on, but we may as well exercise both.
+      - name: Compose (dev)
+        id: compose-dev
+        run: docker compose -f compose.dev.yaml up --wait --wait-timeout 120
+      - name: Inspect dev containers
+        if: ${{ failure() && steps.compose-dev.outcome != 'success' }}
+        run: |
+          docker compose ps
+          for NAME in `docker compose ps --format json | jq -r '.Name'`; do
+            docker inspect $NAME
+          done
+
+  # Test the non-dev compose, which we use for demo purposes. This pulls images from remote repos,
+  # so no need to build anything.
+  # Ideally we'd test on macOS and Windows, too, but those runners don't have Docker:
+  # https://github.com/actions/runner-images/issues/2150
+  # https://github.com/actions/runner/issues/904
+  compose:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Compose
+        id: compose
+        run: docker compose up --wait --wait-timeout 120
+      - name: Inspect containers
+        if: ${{ failure() && steps.compose.outcome != 'success' }}
+        run: |
+          docker compose ps
+          for NAME in `docker compose ps --format json | jq -r '.Name'`; do
+            docker inspect $NAME
+          done

compose.yaml

@@ -54,9 +54,11 @@ services:
         condition: service_started
 
   divviup_api:
-    image: ${DIVVIUP_API_IMAGE:-us-west2-docker.pkg.dev/divviup-artifacts-public/divviup-api/divviup_api:0.3.12}
+    image: ${DIVVIUP_API_IMAGE:-us-west2-docker.pkg.dev/divviup-artifacts-public/divviup-api/divviup_api_integration_test:0.3.12}
     ports:
       - "8080:8080"
+    healthcheck:
+      test: ["CMD", "/bin/sh", "-c", "wget http://0.0.0.0:8080/health -O - >/dev/null"]
     environment:
       RUST_LOG: info
       AUTH_URL: https://auth.example