[build] Test example configs during build (#543)

.github/workflows/go.yml

@@ -88,6 +88,10 @@ jobs:
           go test github.com/cloudprober/cloudprober/probes/ping -c
           sudo PING_HOSTS_V4=${{ env.PING_HOSTS_V4 }} PING_HOSTS_V6=${{ env.PING_HOSTS_V6 }} ./ping.test -test.v -test.run ^TestRunProbeRealICMP$
 
+      - name: Example config tests
+        if: matrix.os == 'ubuntu-latest'
+        run: tools/test_example_configs.sh
+
       - name: Upload test and coverage reports
         if: matrix.os == 'ubuntu-latest'
         uses: actions/upload-artifact@v3

examples/additional_label/cloudprober.cfg

@@ -15,7 +15,7 @@ probe {
   type: HTTP
 
   targets {
-    k8s_targets {
+    k8s {
       namespace: "prod"
       ingresses: ".*"
       labelSelector: "role=ingress-proxy"

tools/test_example_configs.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# This script is used to test the example configurations found
+# in the examples/ directory. If any examples fail to parse
+# or are invalid, this script will fail by returning a non-zero
+# exit code.
+# It is used by the CI system to ensure that the examples are
+# valid and up-to-date.
+
+for example in examples/**/*.cfg; do
+    echo "Testing ${example}"
+    go run cmd/cloudprober.go -configtest -config_file "${example}"
+done