From 83ba9575f9ae4faba38b57c6d9f6d0889259cd55 Mon Sep 17 00:00:00 2001
From: Anthony Yeh <enisoc@google.com>
Date: Wed, 18 Jan 2017 14:25:06 -0800
Subject: [PATCH] Use subPath to keep data dir out of volume root.

The data dir should not be at the root of the volume, because many
volume types create files or directories there automatically.
The database initialization script requires the data dir to be empty,
and we shouldn't try to guess which files may exist.

In particular, by retaining lost+found, it also becomes possible
to recover files that end up there.
---
 docs/tutorials/stateful-application/mysql-statefulset.yaml | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/docs/tutorials/stateful-application/mysql-statefulset.yaml b/docs/tutorials/stateful-application/mysql-statefulset.yaml
index 106f77cd99..d8ee2d9ac9 100644
--- a/docs/tutorials/stateful-application/mysql-statefulset.yaml
+++ b/docs/tutorials/stateful-application/mysql-statefulset.yaml
@@ -16,8 +16,6 @@ spec:
             "image": "mysql:5.7",
             "command": ["bash", "-c", "
               set -ex\n
-              # mysqld --initialize expects an empty data dir.\n
-              rm -rf /mnt/data/lost+found\n
               # Generate mysql server-id from pod ordinal index.\n
               [[ `hostname` =~ -([0-9]+)$ ]] || exit 1\n
               ordinal=${BASH_REMATCH[1]}\n
@@ -32,7 +30,6 @@ spec:
               fi\n
             "],
             "volumeMounts": [
-              {"name": "data", "mountPath": "/mnt/data"},
               {"name": "conf", "mountPath": "/mnt/conf.d"},
               {"name": "config-map", "mountPath": "/mnt/config-map"}
             ]
@@ -54,7 +51,7 @@ spec:
               xtrabackup --prepare --target-dir=/var/lib/mysql\n
             "],
             "volumeMounts": [
-              {"name": "data", "mountPath": "/var/lib/mysql"},
+              {"name": "data", "mountPath": "/var/lib/mysql", "subPath": "mysql"},
               {"name": "conf", "mountPath": "/etc/mysql/conf.d"}
             ]
           }
@@ -72,6 +69,7 @@ spec:
         volumeMounts:
         - name: data
           mountPath: /var/lib/mysql
+          subPath: mysql
         - name: conf
           mountPath: /etc/mysql/conf.d
         resources:
@@ -140,6 +138,7 @@ spec:
         volumeMounts:
         - name: data
           mountPath: /var/lib/mysql
+          subPath: mysql
         - name: conf
           mountPath: /etc/mysql/conf.d
         resources: