Deploy collab like nightly (#7174)

After this change we'll be able to push a tag to github to deploy to
collab.

The advantages of this are that there's no longer a separate step to
first
build the image, and then deploy it.

In the future I'd like to make this happen more automatically (maybe as
part of
bump nightly).

Release Notes:

- N/A

.github/workflows/deploy_collab.yml

@@ -0,0 +1,107 @@
+name: Publish Collab Server Image
+
+on:
+  push:
+    tags:
+      - collab-production
+      - collab-staging
+
+env:
+  DOCKER_BUILDKIT: 1
+  DIGITALOCEAN_ACCESS_TOKEN: ${{ secrets.DIGITALOCEAN_ACCESS_TOKEN }}
+
+jobs:
+  style:
+    name: Check formatting and Clippy lints
+    runs-on:
+      - self-hosted
+      - test
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+        with:
+          clean: false
+          submodules: "recursive"
+          fetch-depth: 0
+
+      - name: Run style checks
+        uses: ./.github/actions/check_style
+
+  tests:
+    name: Run tests
+    runs-on:
+      - self-hosted
+      - test
+    needs: style
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+        with:
+          clean: false
+          submodules: "recursive"
+          fetch-depth: 0
+
+      - name: Run tests
+        uses: ./.github/actions/run_tests
+
+  publish:
+    name: Publish collab server image
+    needs:
+      - style
+      - tests
+    runs-on:
+      - self-hosted
+      - deploy
+    steps:
+      - name: Add Rust to the PATH
+        run: echo "$HOME/.cargo/bin" >> $GITHUB_PATH
+
+      - name: Sign into DigitalOcean docker registry
+        run: doctl registry login
+
+      - name: Prune Docker system
+        run: docker system prune  --filter 'until=720h' -f
+
+      - name: Checkout repo
+        uses: actions/checkout@v4
+        with:
+          clean: false
+          submodules: "recursive"
+
+      - name: Build docker image
+        run: docker build . --build-arg GITHUB_SHA=$GITHUB_SHA --tag registry.digitalocean.com/zed/collab:$GITHUB_SHA
+
+      - name: Publish docker image
+        run: docker push registry.digitalocean.com/zed/collab:${GITHUB_SHA}
+
+  deploy:
+    name: Deploy new server image
+    needs:
+      - publish
+    runs-on:
+      - self-hosted
+      - deploy
+
+    steps:
+      - name: Sign into Kubernetes
+        run: doctl kubernetes cluster kubeconfig save --expiry-seconds 600 ${{ secrets.CLUSTER_NAME }}
+
+      - name: Determine namespace
+        run: |
+          set -eu
+          if [[ $GITHUB_REF_NAME = "collab-production" ]]; then
+            echo "Deploying collab:$GITHUB_SHA to production"
+            echo "KUBE_NAMESPACE=production" >> $GITHUB_ENV
+          elif [[ $GITHUB_REF_NAME = "collab-staging" ]]; then
+            echo "Deploying collab:$GITHUB_SHA to staging"
+            echo "KUBE_NAMESPACE=staging" >> $GITHUB_ENV
+          else
+            echo "cowardly refusing to deploy from an unknown branch"
+            exit 1
+          fi
+
+      - name: Start rollout
+        run: kubectl -n "$KUBE_NAMESPACE" set image deployment/collab collab=registry.digitalocean.com/zed/collab:${GITHUB_SHA}
+
+      - name: Wait for rollout to finish
+        run: kubectl -n "$KUBE_NAMESPACE" rollout status deployment/collab