enhancement: config file probe type validation

Signed-off-by: François Gouteroux <[email protected]>

config/testdata/invalid-probe-type-config.yml

@@ -0,0 +1,6 @@
+modules:
+  http_test:
+    prober: http2
+    timeout: 5s
+    http:
+      body: "Test body"

main.go

@@ -28,6 +28,7 @@ import (
 	"syscall"
 
 	"github.com/alecthomas/kingpin/v2"
+	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
@@ -92,6 +93,11 @@ func run() int {
 	}
 
 	if *configCheck {
+		err := checkModuleProbeType(sc, logger)
+		if err != nil {
+			level.Error(logger).Log("err", err)
+			return 1
+		}
 		level.Info(logger).Log("msg", "Config file is ok exiting...")
 		return 0
 	}
@@ -324,3 +330,19 @@ func computeExternalURL(u, listenAddr string) (*url.URL, error) {
 
 	return eu, nil
 }
+
+func checkModuleProbeType(sc *config.SafeConfig, logger log.Logger) error {
+	var hasErrors bool
+	for name, module := range sc.C.Modules {
+		if _, ok := prober.Probers[module.Prober]; !ok {
+			if logger != nil {
+				level.Error(logger).Log("err", fmt.Sprintf("Unknown probe type '%s' for module name '%s'", module.Prober, name))
+			}
+			hasErrors = true
+		}
+	}
+	if hasErrors {
+		return fmt.Errorf("Config file validation error, one or many invalid probe types found")
+	}
+	return nil
+}

main_test.go

@@ -13,7 +13,11 @@
 
 package main
 
-import "testing"
+import (
+	"github.com/prometheus/blackbox_exporter/config"
+	"github.com/prometheus/client_golang/prometheus"
+	"testing"
+)
 
 func TestComputeExternalURL(t *testing.T) {
 	tests := []struct {
@@ -67,3 +71,17 @@ func TestComputeExternalURL(t *testing.T) {
 		}
 	}
 }
+
+func TestInvalidConfigCheck(t *testing.T) {
+	sc := config.NewSafeConfig(prometheus.NewRegistry())
+
+	err := sc.ReloadConfig("config/testdata/invalid-probe-type-config.yml", nil)
+	if err != nil {
+		t.Fatal("Invalid config file 'config/testdata/invalid-probe-type-config.yml'")
+	}
+
+	err = checkProbeTypeModule(sc, nil)
+	if err == nil {
+		t.Errorf("Error: test should fail")
+	}
+}