support restore tidb cluster from a specified scheduled backup dir (#804)

Author: onlymellb

charts/tidb-backup/templates/restore-job.yaml

@@ -39,7 +39,7 @@ spec:
       {{- end }}
         env:
         - name: BACKUP_NAME
-          value: {{ .Values.name | quote }}
+          value: {{ .Values.scheduledBackupName | default .Values.name | quote }}
       {{- if .Values.gcp }}
         - name: GOOGLE_APPLICATION_CREDENTIALS
           value: /gcp/credentials.json
@@ -69,10 +69,14 @@ spec:
       volumes:
       - name: data
         persistentVolumeClaim:
+    {{- if .Values.scheduledBackupName }}
+          claimName: {{ .Values.clusterName }}-scheduled-backup
+    {{- else }}
           claimName: {{ .Values.name }}
+    {{- end }}
     {{- if .Values.gcp }}
       - name: gcp-credentials
         secret:
           secretName: {{ .Values.gcp.secretName }}
     {{- end }}
-{{- end }}
+{{- end -}}

charts/tidb-backup/values.yaml

@@ -6,8 +6,14 @@
 clusterName: demo
 
 mode: backup # backup | restore | scheduled-restore
-# name is the backup name
+
+# name is the backup dir name and pvc name for ad-hoc backup and restore
 name: fullbackup-{{ date "200601021504" .Release.Time }}
+
+# scheduledBackupName is the name of a scheduled backup directory,
+# used to restore the tidb cluster from scheduled backup.
+# scheduledBackupName: scheduled-backup-20190822-041004
+
 image:
   pullPolicy: IfNotPresent
   # https://github.com/pingcap/tidb-cloud-backup
@@ -81,4 +87,4 @@ s3: {}
   # secretName is the name of the secret which stores s3 object store access key and secret key
   # You can create the secret by:
   # kubectl create secret generic s3-backup-secret --namespace=<namespace> --from-literal=access_key=<access-key> --from-literal=secret_key=<secret-key>
-  # secretName: s3-backup-secret
+  # secretName: s3-backup-secret