pkg/helm,pkg/scaffold/helm: add leader election

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - By default the controller-runtime metrics are exposed on port 8383. This is done as part of the scaffold in the main.go file, the port can be adjusted by modifying the `metricsPort` variable. [#786](https://github.com/operator-framework/operator-sdk/pull/786)
 - A new command [`operator-sdk olm-catalog`](https://github.com/operator-framework/operator-sdk/blob/master/doc/sdk-cli-reference.md#olm-catalog) to be used as a parent for SDK subcommands generating code related to Operator Lifecycle Manager (OLM) Catalog integration, and subcommand [`operator-sdk olm-catalog gen-csv`](https://github.com/operator-framework/operator-sdk/blob/master/doc/sdk-cli-reference.md#gen-csv) which generates a Cluster Service Version for an operator so the OLM can deploy the operator in a cluster. ([#673](https://github.com/operator-framework/operator-sdk/pull/673))
+- Helm-based operators have leader election turned on by default. When upgrading, add environment variable `POD_NAME` to your operator's Deployment using the Kubernetes downward API. To see an example, run `operator-sdk new --type=helm ...` and see file `deploy/operator.yaml`. [#1000](https://github.com/operator-framework/operator-sdk/pull/1000)
 
 ### Changed
 

pkg/helm/run.go

@@ -15,6 +15,7 @@
 package helm
 
 import (
+	"context"
 	"fmt"
 	"os"
 	"runtime"
@@ -24,6 +25,7 @@ import (
 	hoflags "github.com/operator-framework/operator-sdk/pkg/helm/flags"
 	"github.com/operator-framework/operator-sdk/pkg/helm/release"
 	"github.com/operator-framework/operator-sdk/pkg/k8sutil"
+	"github.com/operator-framework/operator-sdk/pkg/leader"
 	sdkVersion "github.com/operator-framework/operator-sdk/version"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -99,6 +101,18 @@ func Run(flags *hoflags.HelmOperatorFlags) error {
 		}
 	}
 
+	operatorName, err := k8sutil.GetOperatorName()
+	if err != nil {
+		log.Error(err, "Failed to get operator name")
+		return err
+	}
+	// Become the leader before proceeding
+	err = leader.Become(context.TODO(), operatorName+"-lock")
+	if err != nil {
+		log.Error(err, "Failed to become leader.")
+		return err
+	}
+
 	// Start the Cmd
 	if err = mgr.Start(signals.SetupSignalHandler()); err != nil {
 		log.Error(err, "Manager exited non-zero.")

pkg/scaffold/helm/operator.go

@@ -69,6 +69,10 @@ spec:
                 fieldRef:
                   fieldPath: metadata.namespace
               {{- end}}
+            - name: POD_NAME
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.name
             - name: OPERATOR_NAME
               value: "{{.ProjectName}}"
 `