dup: support backups to Amazon S3 buckets

Thanks to stefan <s.freudenberg@jpberlin.de> for the patch.
This fixes Redmine bug #658.

AUTHORS

@@ -31,3 +31,4 @@ dan@garthwaite.org -- reportspace bugfix
 Tuomas Jormola <tj@solitudo.net> -- "when = manual" option
 Ian Beckwith <ianb@erislabs.net> -- dup bandwidthlimit fix
 Olivier Berger <oberger@ouvaton.org> -- dup debug output bugfix, reportinfo option
+stefan <s.freudenberg@jpberlin.de> -- dup support for Amazon S3 buckets

ChangeLog

@@ -59,6 +59,7 @@ version 0.9.7 -- UNRELEASED
 	 . Report duplicity output as "info" so that it can be included in
 	   report e-mail when reportinfo is on (Closes: #563734)
 	 . Fix include/exclude paths with spaces
+	 . Support backups to Amazon S3 buckets, thanks to stefan for the patch.
     helper changes
 	dup:
 	 . Do not propose to exclude /home/*/.gnupg twice anymore

README

@@ -182,6 +182,16 @@ blank by hitting return.
 The included helper program "ninjahelper" will walk you through creating
 an rdiff-backup configuration, and will set up the ssh keys for you.
 
+
+Amazon Simple Storage Service (S3)
+==================================
+
+Duplicity can store backups on Amazon S3 buckets, taking care of encryption.
+Since it performs incremental backups it minimizes the number of request per
+operation therefore reducing the costs. The boto Python interface to Amazon
+Web Services is needed to use duplicity with S3 (Debian package: python-boto).
+
+
 INSTALLATION
 ============
    

examples/example.dup

@@ -8,6 +8,8 @@
 
 ## passed directly to duplicity, e.g. to increase verbosity set this to:
 ## options = --verbosity 8
+## when using the Amazon S3 backend to create buckets in Europe:
+## options = --s3-european-buckets --s3-use-new-style
 ##
 ## Default:
 # options = 
@@ -158,11 +160,21 @@ exclude = /home/*/.gnupg
 ## examples include:
 ## desturl = file:///usr/local/backup
 ## desturl = rsync://user@other.host//var/backup/bla
+## desturl = s3+http://
 ## the default value of this configuration option is not set:
 ##
 ## Default:
 # desturl = 
 
+## Amazon Web Services Access Key ID and Secret Access Key, needed for backups
+## to S3 buckets.
+## awsaccesskeyid = YOUR_AWS_ACCESS_KEY_ID
+## awssecretaccesskey = YOUR_AWS_SECRET_KEY
+##
+## Default:
+# awsaccesskeyid = 
+# awssecretaccesskey = 
+
 ## bandwith limit, in kbit/s ; default is 0, i.e. no limit an example
 ## setting would be:
 ## bandwidthlimit = 128

handlers/dup.helper.in

@@ -403,6 +403,12 @@ keep = $dup_keep
 # bandwithlimit. For details, see duplicity manpage, section "URL FORMAT".
 #desturl = file:///usr/local/backup
 #desturl = rsync://user@other.host//var/backup/bla
+#desturl = s3+http://your_bucket
+
+# Amazon Web Services Access Key ID and Secret Access Key, needed for backups
+# to S3 buckets.
+#awsaccesskeyid = YOUR_AWS_ACCESS_KEY_ID
+#awssecretaccesskey = YOUR_AWS_SECRET_KEY
 
 # bandwith limit, in kbit/s ; default is 0, i.e. no limit
 #bandwidthlimit = 128

handlers/dup.in

@@ -26,6 +26,8 @@ setsection dest
 getconf incremental yes
 getconf keep 60
 getconf desturl
+getconf awsaccesskeyid
+getconf awssecretaccesskey
 getconf sshoptions
 getconf bandwidthlimit 0
 getconf desthost
@@ -38,6 +40,9 @@ destdir=${destdir%/}
 [ -n "$desturl" -o -n "$destdir" ]  || fatal "The destination directory (destdir) must be set when desturl is not used."
 [ -n "$include" -o -n "$vsinclude" ]  || fatal "No source includes specified"
 [ -n "$password" ] || fatal "The password option must be set."
+if [ "`echo $desturl | @AWK@ -F ':' '{print $1}'`" == "s3+http" ]; then
+   [ -n "$awsaccesskeyid" -a -n "$awssecretaccesskey" ]  || fatal "AWS access keys must be set for S3 backups."
+fi
 
 ### VServers
 # If vservers are configured, check that the ones listed in $vsnames do exist.
@@ -227,6 +232,12 @@ set +o noglob
 
 execstr_source=${execstr_source//\\*/\\\\\\*}
 
+### If desturl is an S3 URL export the AWS environment variables
+if [ "`echo $desturl | @AWK@ -F ':' '{print $1}'`" == "s3+http" ]; then
+   export AWS_ACCESS_KEY_ID="$awsaccesskeyid"
+   export AWS_SECRET_ACCESS_KEY="$awssecretaccesskey"
+fi
+
 ### Cleanup commands (duplicity >= 0.4.4)
 
 # cleanup