second attempt at getting interception working in CI in browser

.github/workflows/test-browser.yml

@@ -25,11 +25,53 @@ jobs:
         with:
           node-version: 20.x
       - run: npm ci
+
+      # Set up Python (for pipx)
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.12' 
+
+      # Install pipx (for mitmproxy)
+      # See https://pipx.pypa.io/stable/installation/
+      - name: Install pipx
+        run: |
+          python3 -m pip install --user pipx
+          sudo pipx --global ensurepath
+
+      # https://docs.mitmproxy.org/stable/overview-installation/#installation-from-the-python-package-index-pypi
+      - name: Install mitmproxy
+        run: |
+          pipx install mitmproxy
+          # We use this library in our addon
+          pipx inject mitmproxy websockets
+
+      # This user comes from when originally following the mitmproxy documentation (i.e. intercepting _all_ traffic except that from this user). We no longer do this, but I guess there’s no harm in having a separate user instead of running as root.
+      - name: Create a user to run mitmproxy
+        run: sudo useradd --create-home mitmproxyuser
+
+      # This runs the proxy as the mitmproxyuser user created above (see start-interception-proxy script).
+      - name: Start interception proxy server
+        run: ./start-interception-proxy
+
       - name: Install Playwright browsers and dependencies
         run: npx playwright install --with-deps
-      - env:
+
+      - name: Run the tests
+        env:
           PLAYWRIGHT_BROWSER: ${{ matrix.browser }}
         run: npm run test:playwright
+
+      - name: Save interception proxy server logs
+        if: always()
+        run: sudo journalctl -u ably-sdk-test-proxy.service > interception-proxy-logs.txt
+
+      - name: Upload interception proxy server logs
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: interception-proxy-logs-${{ matrix.browser }}
+          path: interception-proxy-logs.txt
+
       - name: Upload test results
         if: always()
         uses: ably/test-observability-action@v1