Merge ~paulgear/influxdb-charm/+git/influxdb-charm:master into influxdb-charm:master

[Paul Gear]

Provides an MVP backup facility for influxdb per RT#106301; fixes lp:1719891

[Barry Price (barryprice)]

+1

review: Approve

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..5dd0577
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,38 @@
+#!/usr/bin/make
+
+CHARM_DIR := $(PWD)
+REACTIVE_DIR := $(CHARM_DIR)/reactive
+CHARM_NAME := influxdb
+PERSONAL_REPO := $(LOGNAME)
+CSDEST := cs:~$(LOGNAME)/$(CHARM_NAME)
+
+all: clean lint
+
+clean:
+	rm -f $(REACTIVE_DIR)/*.pyc
+
+lint:
+	@flake8 $(REACTIVE_DIR)
+
+git:
+	git push $(PERSONAL_REPO)
+
+check-status:
+	@if [ -n "`git status --porcelain`" ]; then \
+	    echo '!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!'; \
+	    echo '!!! There are uncommitted changes !!!'; \
+	    echo '!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!'; \
+	    false; \
+	fi
+	git clean -fdx
+
+build: check-status
+	@charm build
+
+cspush: lint build
+	cd $(JUJU_REPOSITORY)/builds/$(CHARM_NAME) && \
+	    version=`charm push . $(CSDEST) | awk '/^url:/ {print $$2}'` && \
+	    charm release $$version
+
+upgrade: cspush
+	juju upgrade-charm $(CHARM_NAME)
diff --git a/config.yaml b/config.yaml
index eecbd22..88e99ce 100644
--- a/config.yaml
+++ b/config.yaml
@@ -1,6 +1,6 @@
 options:
   extra_packages:
-    default: influxdb
+    default: influxdb jq
   install_sources:
     default: |
       - deb https://repos.influxdata.com/ubuntu xenial stable
@@ -67,3 +67,11 @@ options:
     description: "Which port to bind to"
     type: int
     default: 8086
+  backup_dir:
+    type: string
+    default: ""
+    description: |
+        If set, enable daily backups of the InfluxDB metastore and all
+        databases to the nominated directory.  See
+        https://docs.influxdata.com/influxdb/v1.3/administration/backup_and_restore/
+        for more information on InfluxDB backups.
diff --git a/reactive/influxdb.py b/reactive/influxdb.py
index 56e7a22..8895dd0 100644
--- a/reactive/influxdb.py
+++ b/reactive/influxdb.py
@@ -1,8 +1,11 @@
 from charmhelpers.core import hookenv
 from charmhelpers.core.host import service_start, service_stop
 from charmhelpers.core.templating import render
-from charms.reactive import when, when_not
-from charms.reactive import set_state
+from charms.reactive import hook, set_state, when, when_any, when_not
+
+import os
+
+CRONFILE = '/etc/cron.daily/influxdb-charm-backup'
 
 
 @when('admin.available')
@@ -25,7 +28,7 @@ def install_influx():
     set_state('influxdb.configured')
 
 
-@when('config.changed')
+@when_any('config.changed.bind_port', 'config.changed.ip_address')
 def config_changed():
     config = hookenv.config()
     port = config.get('bind_port')
@@ -43,6 +46,36 @@ def config_changed():
     service_start('influxdb')
 
 
+@when('config.changed.backup_dir')
+def create_backup_job():
+    config = hookenv.config()
+    backup_dir = config.get('backup_dir')
+    if backup_dir:
+        render(source='influxdb-backup',
+               target=CRONFILE,
+               perms=0o755,
+               context={
+                   'backup_dir': backup_dir,
+                   'backup_retention': 3,
+               })
+    else:
+        old_backup_dir = config.previous('backup_dir')
+        hookenv.log('NOT removing previous backup directory {}'.format(old_backup_dir))
+        try:
+            os.remove(CRONFILE)
+            hookenv.log('Removed {}'.format(CRONFILE))
+        except OSError as e:
+            hookenv.log('Cannot remove {} - ignoring'.format(CRONFILE), hookenv.ERROR)
+
+
+@hook('upgrade-charm')
+def upgrade_charm():
+    # Force config changed on upgrade-charm in case one of the templates changed.
+    set_state('config.changed.backup_dir')
+    set_state('config.changed.bind_port')
+    set_state('config.changed.ip_address')
+
+
 @when('query.api.available')
 def query_available(query):
     config = hookenv.config()
diff --git a/templates/influxdb-backup b/templates/influxdb-backup
new file mode 100644
index 0000000..9c3fdf9
--- /dev/null
+++ b/templates/influxdb-backup
@@ -0,0 +1,31 @@
+#!/bin/bash
+
+# This file managed by juju - do not edit here!
+
+# Back up influxdb databases & metadata to the specified local directory
+
+set -eu
+
+BACKUP_DIR="{{backup_dir}}"
+NUM="{{backup_retention}}"
+TODAY_DIR="$BACKUP_DIR/$(date -I)"
+mkdir -p $TODAY_DIR
+
+DATABASES=$(influx --execute 'show databases' --format=json | jq --raw-output '.results[0].series[0].values[][0]' | grep -ve '^_internal$')
+
+# back up metadata
+influxd backup $TODAY_DIR/metdata
+
+# back up individual databases
+for d in ${DATABASES}; do
+    influxd backup -database $d $TODAY_DIR/$d
+done
+
+# remove old backups - to keep NUM backups we need to delete from directory NUM+1
+(( NUM++ ))
+cd $BACKUP_DIR
+for dir in $(ls -t | tail -n +$NUM); do
+    if [ -d ./$dir ]; then
+	rm -rf ./$dir && echo "Removed $dir"
+    fi
+done
diff --git a/templates/influxdb.conf b/templates/influxdb.conf
index e666bcd..675ce90 100644
--- a/templates/influxdb.conf
+++ b/templates/influxdb.conf
@@ -237,7 +237,7 @@
   # https-private-key = ""
 
   # The JWT auth shared secret to validate requests using JSON web tokens.
-  # shared-sercret = ""
+  # shared-secret = ""
 
   # The default chunk size for result sets that should be chunked.
   # max-row-limit = 0