Merge lp:~thedac/charms/precise/solr-jetty/persistent-storage into lp:~charmers/charms/precise/solr-jetty/trunk

[David Ames]

Use persistent storage when configured

[Matthew Wedgwood (mew)]

Confirmed that boolean values are always "True" or "False", never "true" etc

Approved.

review: Approve

[lp:~thedac/charms/precise/solr-jetty/persistent-storage]

16. By Matthew Wedgwood on 2013-04-24

[thedac] Use persistent storage when configured

=== modified file 'config.yaml'
--- config.yaml	2013-04-22 20:19:35 +0000
+++ config.yaml	2013-04-24 18:07:30 +0000
@@ -33,3 +33,23 @@
     default: ""
     type: string
     description: Health check regex on output from check_url
+  volume-ephemeral:
+    type: boolean
+    default: true
+    description: >
+      If false, the /var/lib/solr will be symlinked to persistent storage. A 
+         configure-error state will be raised if
+         volume-map[$JUJU_UNIT_NAME] is not set (see "volume-map"
+         below).
+      If true, solr-jetty will run from its default directory /var/lib/solr/.
+         All data will be destroyed with the instance.
+      Note volumes require charmsupport to be installed
+  volume-map:
+    type: string
+    default: '{}'
+    description: >
+      YAML map as e.g. "{ solr-jetty/0: /dev/vdb, solr-jetty/1: /dev/vdb}".
+      Service units will raise a configure-error if volume-persistent
+      is 'true' and no volume-map value is set. Use 'juju set' to set a
+      value and 'juju resolved' to complete configuration.
+      Note volumes require charmsupport to be installed

=== modified file 'hooks/config-changed'
--- hooks/config-changed	2012-09-27 13:12:55 +0000
+++ hooks/config-changed	2013-04-24 18:07:30 +0000
@@ -52,3 +52,9 @@
 fi
 
 open-port 8080/tcp
+
+# If persistent storage is configured, mount and use it
+EPHEMERAL=$(config-get volume-ephemeral)
+if [[ "$EPHEMERAL" != 'True'  ]]; then
+	/usr/bin/python scripts/mount-volume.py
+fi

=== modified file 'hooks/install'
--- hooks/install	2013-01-03 22:13:12 +0000
+++ hooks/install	2013-04-24 18:07:30 +0000
@@ -14,5 +14,12 @@
     done
 fi
 
+
+apt-add-repository -y ppa:charmsupport/ppa
+apt-get update
+
+# charmsupport for persistent storage support
+apt-get install python-charmsupport
+
 # default-jdk should be a prerequisite for jetty (Bug#1046732)
 apt-get install -y solr-jetty default-jdk curl

=== modified file 'revision'
--- revision	2012-09-06 16:01:05 +0000
+++ revision	2013-04-24 18:07:30 +0000
@@ -1,1 +1,1 @@
-1
+3

=== added directory 'scripts'
=== added file 'scripts/mount-volume.py'
--- scripts/mount-volume.py	1970-01-01 00:00:00 +0000
+++ scripts/mount-volume.py	2013-04-24 18:07:30 +0000
@@ -0,0 +1,65 @@
+#!/usr/bin/env python
+
+import sys
+import os
+from charmsupport import volumes
+from charmsupport import hookenv
+from charmsupport import host
+from pwd import getpwnam
+
+def storage_is_persistent():
+    if os.path.islink(SOLR_DIR):
+        target = os.readlink(SOLR_DIR)
+        if os.path.ismount(target):
+            return True
+    return False
+
+def volume_change_pre():
+    host.service_stop('jetty')
+
+
+def volume_change_post():
+    pass
+
+
+def set_permissions():
+    if storage_is_persistent():
+        # make sure data on external storage are owned
+        # by the jetty user
+        jetty_uid = getpwnam('jetty').pw_uid
+        os.chown(SOLR_DIR, jetty_uid, -1)
+        for root, dirs, files in os.walk(SOLR_DIR):
+            for file in files:
+                os.chown(os.path.join(root, file), jetty_uid, -1)
+            for subdir in dirs:
+                os.chown(os.path.join(root, subdir), jetty_uid, -1)
+
+
+SOLR_DIR = '/var/lib/solr'
+SAVED_DIR = "{}.{}".format(SOLR_DIR, 'charm_saved')
+
+if __name__ == '__main__':
+    try:
+        mountpoint = volumes.configure_volume(before_change=volume_change_pre, after_change=volume_change_post)
+    except volumes.VolumeConfigurationError:
+        hookenv.log('Storage could not be configured', hookenv.ERROR)
+        sys.exit(1)
+
+    if mountpoint == 'ephemeral':
+        if os.path.islink(SOLR_DIR):
+            os.remove(SOLR_DIR)
+            if os.path.isdir(SAVED_DIR):
+                os.rename(SAVED_DIR, SOLR_DIR)
+            else:
+                os.path.mkdir(SOLR_DIR)
+    else:
+        if not storage_is_persistent():
+            try:
+                os.rename(SOLR_DIR, SAVED_DIR)
+            except OSError as e:
+                hookenv.log('ERROR: could not preserve existing log directory', hookenv.ERROR)
+                hookenv.log(e.strerror, hookenv.ERROR)
+                sys.exit(1)
+            os.symlink(mountpoint, SOLR_DIR)
+            set_permissions()
+            host.service_start('jetty')