Automatic reloading of the helper pod manifest by the provisioner

README.md

@@ -236,7 +236,12 @@ The scripts receive their input as environment variables:
 
 #### Reloading
 
-The provisioner supports automatic configuration reloading. Users can change the configuration using `kubectl apply` or `kubectl edit` with config map `local-path-config`. There is a delay between when the user updates the config map and the provisioner picking it up.
+The provisioner supports automatic configuration reloading. Users can change the configuration using `kubectl apply` or `kubectl edit` with config map `local-path-config`. There is a delay between when the user updates the config map and the provisioner picking it up. In order for this to occur for updates made to the helper pod manifest, the following environment variable must be added to the provisioner container. If not, then the manifest used for the helper pod will be the same as what was in the config map when the provisioner was last restarted/deployed.
+
+```yaml
+- name: CONFIG_MOUNT_PATH
+  value: /etc/config/
+```
 
 When the provisioner detects the configuration changes, it will try to load the new configuration. Users can observe it in the log
 >time="2018-10-03T05:56:13Z" level=debug msg="Applied config: {\"nodePathMap\":[{\"node\":\"DEFAULT_PATH_FOR_NON_LISTED_NODES\",\"paths\":[\"/opt/local-path-provisioner\"]},{\"node\":\"yasker-lp-dev1\",\"paths\":[\"/opt\",\"/data1\"]},{\"node\":\"yasker-lp-dev3\"}]}"

deploy/chart/local-path-provisioner/templates/deployment.yaml

@@ -72,6 +72,8 @@ spec:
           env:
             - name: POD_NAMESPACE
               value: {{ .Release.Namespace }}
+            - name: CONFIG_MOUNT_PATH
+              value: /etc/config/
           resources:
             {{- toYaml .Values.resources | nindent 12 }}
       volumes:

deploy/local-path-storage.yaml

@@ -104,6 +104,8 @@ spec:
               valueFrom:
                 fieldRef:
                   fieldPath: metadata.namespace
+            - name: CONFIG_MOUNT_PATH
+              value: /etc/config/
       volumes:
         - name: config-volume
           configMap:

main.go

@@ -48,6 +48,7 @@ var (
 	DefaultProvisioningRetryCount = pvController.DefaultFailedProvisionThreshold
 	FlagDeletionRetryCount        = "deletion-retry-count"
 	DefaultDeletionRetryCount     = pvController.DefaultFailedDeleteThreshold
+	EnvConfigMountPath            = "CONFIG_MOUNT_PATH"
 )
 
 func cmdNotFound(c *cli.Context, command string) {

provisioner.go

@@ -169,6 +169,29 @@ func (p *LocalPathProvisioner) refreshConfig() error {
 	return err
 }
 
+func (p *LocalPathProvisioner) refreshHelperPod() error {
+	p.configMutex.Lock()
+	defer p.configMutex.Unlock()
+
+	helperPodFile, envExists := os.LookupEnv(EnvConfigMountPath)
+	if !envExists {
+		return nil
+	}
+
+	helperPodFile = filepath.Join(helperPodFile, DefaultHelperPodFile)
+	newHelperPod, err := loadFile(helperPodFile)
+	if err != nil {
+		return err
+	}
+
+	p.helperPod, err = loadHelperPodFile(newHelperPod)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func (p *LocalPathProvisioner) watchAndRefreshConfig() {
 	go func() {
 		ticker := time.NewTicker(ConfigFileCheckInterval)
@@ -179,6 +202,9 @@ func (p *LocalPathProvisioner) watchAndRefreshConfig() {
 				if err := p.refreshConfig(); err != nil {
 					logrus.Errorf("failed to load the new config file: %v", err)
 				}
+				if err := p.refreshHelperPod(); err != nil {
+					logrus.Errorf("failed to load the new helper pod manifest: %v", err)
+				}
 			case <-p.ctx.Done():
 				logrus.Infof("stop watching config file")
 				return

util.go

@@ -3,7 +3,7 @@ package main
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 
 	v1 "k8s.io/api/core/v1"
@@ -16,7 +16,7 @@ func loadFile(filepath string) (string, error) {
 		return "", err
 	}
 	defer f.Close()
-	helperPodYaml, err := ioutil.ReadAll(f)
+	helperPodYaml, err := io.ReadAll(f)
 	if err != nil {
 		return "", err
 	}