Readiness Probe: Check for acVersion file only if it is present (#994)

Author: irajdeep

cmd/readiness/main.go

@@ -3,13 +3,14 @@ package main
 import (
 	"encoding/json"
 	"fmt"
-	"go.uber.org/zap/zapcore"
-	"gopkg.in/natefinch/lumberjack.v2"
 	"io"
 	"io/ioutil"
 	"os"
 	"time"
 
+	"go.uber.org/zap/zapcore"
+	"gopkg.in/natefinch/lumberjack.v2"
+
 	"github.com/mongodb/mongodb-kubernetes-operator/pkg/readiness/config"
 	"github.com/mongodb/mongodb-kubernetes-operator/pkg/readiness/headless"
 	"github.com/mongodb/mongodb-kubernetes-operator/pkg/readiness/health"

controllers/mongodb_tls.go

@@ -142,7 +142,7 @@ func getPemOrConcatenatedCrtAndKey(getter secret.Getter, mdb mdbv1.MongoDBCommun
 	certKey := getCertAndKey(getter, mdb, secretName)
 	pem := getPem(getter, mdb, secretName)
 	if certKey == "" && pem == "" {
-		return "", fmt.Errorf(`Neither "%s" nor the pair "%s"/"%s" were present in the TLS secret`, tlsSecretPemName, tlsSecretCertName, tlsSecretKeyName)
+		return "", fmt.Errorf(`neither "%s" nor the pair "%s"/"%s" were present in the TLS secret`, tlsSecretPemName, tlsSecretCertName, tlsSecretKeyName)
 	}
 	if certKey == "" {
 		return pem, nil
@@ -151,7 +151,7 @@ func getPemOrConcatenatedCrtAndKey(getter secret.Getter, mdb mdbv1.MongoDBCommun
 		return certKey, nil
 	}
 	if certKey != pem {
-		return "", fmt.Errorf(`If all of "%s", "%s" and "%s" are present in the secret, the entry for "%s" must be equal to the concatenation of "%s" with "%s"`, tlsSecretCertName, tlsSecretKeyName, tlsSecretPemName, tlsSecretPemName, tlsSecretCertName, tlsSecretKeyName)
+		return "", fmt.Errorf(`if all of "%s", "%s" and "%s" are present in the secret, the entry for "%s" must be equal to the concatenation of "%s" with "%s"`, tlsSecretCertName, tlsSecretKeyName, tlsSecretPemName, tlsSecretPemName, tlsSecretCertName, tlsSecretKeyName)
 	}
 	return certKey, nil
 }

controllers/mongodb_tls_test.go

@@ -276,7 +276,7 @@ func TestPemSupport(t *testing.T) {
 
 		err = r.ensureTLSResources(mdb)
 		assert.Error(t, err)
-		assert.Contains(t, err.Error(), `If all of "tls.crt", "tls.key" and "tls.pem" are present in the secret, the entry for "tls.pem" must be equal to the concatenation of "tls.crt" with "tls.key"`)
+		assert.Contains(t, err.Error(), `if all of "tls.crt", "tls.key" and "tls.pem" are present in the secret, the entry for "tls.pem" must be equal to the concatenation of "tls.crt" with "tls.key"`)
 
 	})
 }

pkg/readiness/headless/headless.go

@@ -1,6 +1,7 @@
 package headless
 
 import (
+	"fmt"
 	"io/ioutil"
 	"os"
 	"strconv"
@@ -12,6 +13,10 @@ import (
 	"go.uber.org/zap"
 )
 
+const (
+	acVersionPath string = "/var/lib/automation/config/acVersion/version"
+)
+
 // performCheckHeadlessMode validates if the Agent has reached the correct goal state
 // The state is fetched from K8s automation config Secret directly to avoid flakiness of mounting process
 // Dev note: there is an alternative way to get current namespace: to read from
@@ -21,23 +26,29 @@ import (
 func PerformCheckHeadlessMode(health health.Status, conf config.Config) (bool, error) {
 	var targetVersion int64
 	var err error
+
 	targetVersion, err = secret.ReadAutomationConfigVersionFromSecret(conf.Namespace, conf.ClientSet, conf.AutomationConfigSecretName)
 	if err != nil {
-		file, err := os.Open("/var/lib/automation/config/acVersion/version")
-		if err != nil {
-			return false, err
-		}
-		defer file.Close()
-		data, err := ioutil.ReadAll(file)
-
-		if err != nil {
-			return false, err
-		}
+		// this file is expected to be present in case of AppDB, there is no point trying to access it in
+		// community, it masks the underlying error
+		if _, pathErr := os.Stat(acVersionPath); !os.IsNotExist(pathErr) {
+			file, err := os.Open(acVersionPath)
+			if err != nil {
+				return false, err
+			}
+			defer file.Close()
 
-		targetVersion, err = strconv.ParseInt(string(data), 10, 64)
+			data, err := ioutil.ReadAll(file)
+			if err != nil {
+				return false, err
+			}
 
-		if err != nil {
-			return false, err
+			targetVersion, err = strconv.ParseInt(string(data), 10, 64)
+			if err != nil {
+				return false, err
+			}
+		} else {
+			return false, fmt.Errorf("failed to fetch automation-config secret name: %s, err: %s", conf.AutomationConfigSecretName, err)
 		}
 	}