CI observability enhancements. (#1193)

- Adds a a `--log-root` option to `swift system start`, propagating the
value as `CONTAINER_LOG_ROOT` to services for logging to files instead
of the OS log facility. This is not a "production" capability as it
neither merges nor rotates logs.
- Currently we don't collect logs on CI builds, and we don't have
permission to run the `log` command there. The PR adds `--log-root` to
the CI test phase, archives the results, and uploads the archive as an
artifact.
- Use FilePath from swift-system for the log root. Foundation URL is a
bit of a footgun for filesystem paths, so unless we identify a
showstopper, we should incrementally transition to this type everywhere
except where we really need network URLs.
- Output the hostname of the CI runner at the start of the test phase so
we can identify runner-specific issues where they exist.
- Fix formatting for log messages with multiple metadata items, and fix
unstructured messages on instances that weren't found using `grep -r
'log\.' Sources`.
- Adds command reference documentation for `--log-root`.

.github/workflows/common.yml

@@ -71,16 +71,38 @@ jobs:
       - name: Test the container project
         run: |
           APP_ROOT=$(mktemp -d -p "${RUNNER_TEMP}")
+          LOG_ROOT="${APP_ROOT}/logs"
           trap 'rm -rf "${APP_ROOT}"; echo Removing data directory ${APP_ROOT}' EXIT
-          echo "Created data directory ${APP_ROOT}"
+          echo "created data directory: ${APP_ROOT}"
+          echo "hostname: $(hostname)"
           export NO_PROXY="${NO_PROXY},192.168.0.0/16,fe80::/10"
           echo NO_PROXY=${NO_PROXY}
           export no_proxy="${no_proxy},192.168.0.0/16,fe80::/10"
           echo no_proxy=${no_proxy}
-          make APP_ROOT="${APP_ROOT}" test install-kernel integration
+          echo "APP_ROOT=${APP_ROOT}" >> $GITHUB_ENV
+          echo "LOG_ROOT=${LOG_ROOT}" >> $GITHUB_ENV
+          make APP_ROOT="${APP_ROOT}" LOG_ROOT="${LOG_ROOT}" test install-kernel integration || status=$?
+          if [ -d "${LOG_ROOT}" ] ; then
+            echo "Collecting logs from ${LOG_ROOT}..."
+            tar czf container-logs.tar.gz -C "$(dirname "${LOG_ROOT}")" "$(basename "${LOG_ROOT}")"
+            echo "Log archive created: container-logs.tar.gz"
+          fi
+          if [ "${status:-0}" -ne "0" ] ; then
+            echo "Tests failed with status: ${status}"
+            exit ${status}
+          fi
         env:
           DEVELOPER_DIR: "/Applications/Xcode-latest.app/Contents/Developer"
 
+      - name: Upload logs if present
+        if: always()
+        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6
+        with:
+          name: container-test-logs
+          path: container-logs.tar.gz
+          retention-days: 14
+          if-no-files-found: ignore
+
       - name: Save documentation artifact
         uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6
         with: