From 01d0e6d9a43defaa5a1647048fe631024e110e7f Mon Sep 17 00:00:00 2001
From: Yecheng Fu <fuyecheng@qiniu.com>
Date: Tue, 1 Aug 2017 09:47:20 +0000
Subject: [PATCH] RBD provisioner use provisioner name as identitiy if not
 specified, and support `PROVISIONER_NAME` envionment variable.

In production, provisioner should not use random identity on start.
Because, provisioner Pod may crash or be recreated on different nodes, if
a provisioner generates random identity string each time, then it will
cannot manage old PVs it provisioned before. In this commit, I change
the default behavior to use `provision.ProvisionerName` constant as
default identity instead of random UUID string.
---
 ceph/rbd/cmd/rbd-provisioner/main.go | 26 ++++++++++++++++++++------
 ceph/rbd/deployment.yaml             |  3 +++
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/ceph/rbd/cmd/rbd-provisioner/main.go b/ceph/rbd/cmd/rbd-provisioner/main.go
index c96ae85dc82..082aa13ad75 100644
--- a/ceph/rbd/cmd/rbd-provisioner/main.go
+++ b/ceph/rbd/cmd/rbd-provisioner/main.go
@@ -18,11 +18,11 @@ package main
 
 import (
 	"flag"
+	"os"
 
 	"github.com/golang/glog"
 	"github.com/kubernetes-incubator/external-storage/ceph/rbd/pkg/provision"
 	"github.com/kubernetes-incubator/external-storage/lib/controller"
-	"k8s.io/apimachinery/pkg/util/uuid"
 	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
@@ -35,6 +35,10 @@ var (
 	id         = flag.String("id", "", "Unique provisioner identity")
 )
 
+const (
+	provisionerNameKey = "PROVISIONER_NAME"
+)
+
 func main() {
 	flag.Parse()
 	flag.Set("logtostderr", "true")
@@ -46,10 +50,6 @@ func main() {
 	} else {
 		config, err = rest.InClusterConfig()
 	}
-	prID := string(uuid.NewUUID())
-	if *id != "" {
-		prID = *id
-	}
 	if err != nil {
 		glog.Fatalf("Failed to create config: %v", err)
 	}
@@ -58,6 +58,20 @@ func main() {
 		glog.Fatalf("Failed to create client: %v", err)
 	}
 
+	prName := provision.ProvisionerName
+	prNameFromEnv := os.Getenv(provisionerNameKey)
+	if prNameFromEnv != "" {
+		prName = prNameFromEnv
+	}
+
+	// By default, we use provision name as provisioner identity.
+	// User may specify their own identity with `-id` flag to distinguish each
+	// others, if they deploy more than one RBD provisioners under same provisioner name.
+	prID := prName
+	if *id != "" {
+		prID = *id
+	}
+
 	// The controller needs to know what the server version is because out-of-tree
 	// provisioners aren't officially supported until 1.5
 	serverVersion, err := clientset.Discovery().ServerVersion()
@@ -74,7 +88,7 @@ func main() {
 	// PVs
 	pc := controller.NewProvisionController(
 		clientset,
-		provision.ProvisionerName,
+		prName,
 		rbdProvisioner,
 		serverVersion.GitVersion,
 	)
diff --git a/ceph/rbd/deployment.yaml b/ceph/rbd/deployment.yaml
index 07a5707db37..f323725c8dc 100644
--- a/ceph/rbd/deployment.yaml
+++ b/ceph/rbd/deployment.yaml
@@ -14,3 +14,6 @@ spec:
       containers:
       - name: rbd-provisioner
         image: "quay.io/external_storage/rbd-provisioner:latest"
+        env:
+        - name: PROVISIONER_NAME
+          value: ceph.com/rbd