GT-345 Optional JSON logger format (#1252)

Author: jwierzbo

CHANGELOG.md

@@ -15,6 +15,7 @@
 - (Feature) Optional ResignLeadership Action
 - (Feature) Improve CRD Management and deprecate CRD Chart
 - (Bugfix) Fix invalid Timeout calculation in case of ActionList
+- (Feature) Optional JSON logger format
 
 ## [1.2.24](https://github.com/arangodb/kube-arangodb/tree/1.2.24) (2023-01-25)
 - (Bugfix) Fix deployment creation on ARM64

cmd/cmd.go

@@ -1,7 +1,7 @@
 //
 // DISCLAIMER
 //
-// Copyright 2016-2022 ArangoDB GmbH, Cologne, Germany
+// Copyright 2016-2023 ArangoDB GmbH, Cologne, Germany
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -45,7 +45,6 @@ import (
 	"k8s.io/client-go/kubernetes"
 	typedCore "k8s.io/client-go/kubernetes/typed/core/v1"
 	"k8s.io/client-go/tools/record"
-	"k8s.io/klog"
 
 	"github.com/arangodb/kube-arangodb/pkg/api"
 	deploymentApi "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
@@ -103,6 +102,7 @@ var (
 		hardLimit uint64
 	}
 
+	logFormat     string
 	logLevels     []string
 	serverOptions struct {
 		host            string
@@ -183,6 +183,7 @@ func init() {
 	f.StringVar(&serverOptions.tlsSecretName, "server.tls-secret-name", "", "Name of secret containing tls.crt & tls.key for HTTPS server (if empty, self-signed certificate is used)")
 	f.StringVar(&serverOptions.adminSecretName, "server.admin-secret-name", defaultAdminSecretName, "Name of secret containing username + password for login to the dashboard")
 	f.BoolVar(&serverOptions.allowAnonymous, "server.allow-anonymous-access", false, "Allow anonymous access to the dashboard")
+	f.StringVar(&logFormat, "log.format", "pretty", "Set log format. Allowed values: 'pretty', 'JSON'. If empty, default format is used")
 	f.StringArrayVar(&logLevels, "log.level", []string{defaultLogLevel}, fmt.Sprintf("Set log levels in format <level> or <logger>=<level>. Possible loggers: %s", strings.Join(logging.Global().Names(), ", ")))
 	f.BoolVar(&apiOptions.enabled, "api.enabled", true, "Enable operator HTTP and gRPC API")
 	f.IntVar(&apiOptions.httpPort, "api.http-port", defaultAPIHTTPPort, "HTTP API port to listen on")
@@ -272,6 +273,12 @@ func executeMain(cmd *cobra.Command, args []string) {
 		logger.Err(err).Fatal("Unable to parse log level")
 	}
 
+	// Set root logger to stdout (JSON formatted) if not prettified
+	if strings.ToUpper(logFormat) == "JSON" {
+		logging.Global().SetRoot(zerolog.New(os.Stdout).With().Timestamp().Logger())
+	} else if strings.ToLower(logFormat) != "pretty" && logFormat != "" {
+		logger.Fatal("Unknown log format: %s", logFormat)
+	}
 	logging.Global().ApplyLogLevels(levels)
 
 	podNameParts := strings.Split(name, "-")
@@ -280,11 +287,7 @@ func executeMain(cmd *cobra.Command, args []string) {
 		return in.Str("operator-id", operatorID)
 	})
 
-	kl := logging.Global().RegisterAndGetLogger("klog", logging.Info)
-
-	klog.SetOutput(kl.InfoIO())
-	klog.Info("nice to meet you")
-	klog.Flush()
+	logger.Info("nice to meet you")
 
 	// Check operating mode
 	if !operatorOptions.enableDeployment && !operatorOptions.enableDeploymentReplication && !operatorOptions.enableStorage &&

docs/design/README.md

@@ -14,3 +14,5 @@
 - [Topology awareness](./topology_awareness.md)
 - [Configuring timezone](./configuring_tz.md)
 - [Operator API](./api.md)
+- [Logging](./logging.md)
+

docs/design/logging.md

@@ -0,0 +1,43 @@
+# Logging configuration
+
+## Operator logging
+
+### Log level
+
+To adjust logging level of the operator, you can use `operator.args` in chart template value 
+as described in [Additional configuration](./additional_configuration.md).
+
+For example, to set log level to `INFO` and `DEBUG` for `requests` package, you can use the following value:
+```yaml
+operator:
+  args: ["--log.level=INFO", "--log.level=requests=DEBUG"]
+```
+
+### Log format
+
+By default, operator logs in `pretty` format.
+
+To switch logging format to the JSON, you can use `operator.args` in chart template value:
+```yaml
+operator:
+  args: ["--log.format=pretty"]
+```
+
+## ArangoDeployment logging
+
+By default, ArangoDeployment logs in `pretty` format.
+
+To switch logging format to the JSON we need to pass `--log.use-json-format` argument to the ArangoDB server in the deployment:
+```yaml
+apiVersion: database.arangodb.com/v1
+kind: ArangoDeployment
+metadata:
+  name: single
+spec:
+  mode: Single
+  single:
+    args:
+      - --log.use-json-format
+      - --log.level=INFO
+      - --log.level=backup=TRACE
+```

go.mod

@@ -48,6 +48,7 @@ require (
 	github.com/stretchr/testify v1.7.1
 	golang.org/x/sync v0.0.0-20220601150217-0de741cfad7f
 	golang.org/x/sys v0.0.0-20210806184541-e5e7981a1069
+	golang.org/x/text v0.3.6
 	golang.org/x/time v0.0.0-20210723032227-1f47c861a9ac
 	google.golang.org/grpc v1.47.0
 	google.golang.org/protobuf v1.28.0
@@ -56,7 +57,6 @@ require (
 	k8s.io/apiextensions-apiserver v0.18.3
 	k8s.io/apimachinery v0.22.15
 	k8s.io/client-go v12.0.0+incompatible
-	k8s.io/klog v1.0.0
 	sigs.k8s.io/yaml v1.2.0
 )
 
@@ -67,7 +67,6 @@ require (
 	github.com/cespare/xxhash/v2 v2.1.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/evanphx/json-patch v4.11.0+incompatible // indirect
-	github.com/gin-contrib/pprof v1.4.0 // indirect
 	github.com/gin-contrib/sse v0.1.0 // indirect
 	github.com/go-logr/logr v0.4.0 // indirect
 	github.com/go-openapi/jsonpointer v0.19.5 // indirect
@@ -105,7 +104,6 @@ require (
 	golang.org/x/net v0.0.0-20211209124913-491a49abca63 // indirect
 	golang.org/x/oauth2 v0.0.0-20210402161424-2e8d93401602 // indirect
 	golang.org/x/term v0.0.0-20210220032956-6a3ed077a48d // indirect
-	golang.org/x/text v0.3.6 // indirect
 	google.golang.org/appengine v1.6.7 // indirect
 	google.golang.org/genproto v0.0.0-20220617124728-180714bec0ad // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect