Add support for several cloud storage remotes using rclone

rclone is an open-source command-line too to get and put files to several
cloud storage services that aren't supported by rsync.

git-remote-gcrypt can now push encrypted repositories to any configured rclone
remote using gcrypt::rclone://<rclone-repo>:<folder> URLs.

Signed-off-by: Beren Minor <beren.minor+git@gmail.com>

2 files changed, 33 insertions, 10 deletions

diff --git a/README.rst b/README.rst
index 8bcc429..21cefc4 100644
--- a/README.rst
+++ b/README.rst
@@ -15,10 +15,10 @@ git-remote-gcrypt is a git remote helper to push and pull from
 repositories encrypted with GnuPG, using a custom format.  This remote
 helper handles URIs prefixed with `gcrypt::`.
 
-Supported backends are `local`, `rsync://` and `sftp://`, where the
-repository is stored as a set of files, or instead any `<giturl>`
-where gcrypt will store the same representation in a git repository,
-bridged over arbitrary git transport.  See "Performance" below for
+Supported backends are `local`, `rsync://` and `sftp://` (and an experimental
+`rclone://` backend), where the repository is stored as a set of files, or
+instead any `<giturl>` where gcrypt will store the same representation in a git
+repository, bridged over arbitrary git transport.  See "Performance" below for
 backends comparison.
 
 The aim is to provide confidential, authenticated git storage and
@@ -119,9 +119,9 @@ Collaboration
     keys of all collaborators and correct participant config.
 
 Dependencies
-    ``rsync`` and ``curl`` for remotes ``rsync:`` and ``sftp:``
-    respectively. The main executable requires a POSIX-compliant shell
-    that supports ``local``.
+    ``rsync``, ``curl`` and ``rclone`` for remotes ``rsync:``, ``sftp:`` and
+    ``rclone:`` respectively. The main executable requires a POSIX-compliant
+    shell that supports ``local``.
 
 GNU Privacy Guard
     Both GPG 1.4 and 2 are supported. You need a personal GPG key. GPG
@@ -149,6 +149,12 @@ rsync URIs
     whereas plain rsync uses either ``user@host:path`` or
     ``rsync://user@host/path``.
 
+rclone URIs
+    The URI format for the rclone backend is the same as rclone URI,
+    ``rclone://<rclone-uri>``, and require to add the corresponding remote
+    in the rclone configuration.
+    Please refer to the rclone documentation for more information.
+
 Repository format
 .................
 
diff --git a/git-remote-gcrypt b/git-remote-gcrypt
index 8b66f2f..d089c57 100755
--- a/git-remote-gcrypt
+++ b/git-remote-gcrypt
@@ -230,6 +230,9 @@ GET()
 	elif isurl rsync "$1"
 	then
 		(exec 0>&-; rsync -I -W "${1#rsync://}"/"$2" "$3" >&2)
+	elif isurl rclone "$1"
+	then
+		(exec 0>&-; rclone copyto "${1#rclone://}"/"$2" "$3" >&2)
 	elif islocalrepo "$1"
 	then
 		cat "$1/$2" > "$3"
@@ -247,6 +250,9 @@ PUT()
 	elif isurl rsync "$1"
 	then
 		rsync -I -W "$3" "${1#rsync://}"/"$2" >&2
+	elif isurl rclone "$1"
+	then
+		rclone copyto "$3" "${1#rclone://}"/"$2" >&2
 	elif islocalrepo "$1"
 	then
 		cat >| "$1/$2" < "$3"
@@ -258,7 +264,7 @@ PUT()
 # Put all PUT changes for repo $1 at once
 PUT_FINAL()
 {
-	if isurl sftp "$1" || islocalrepo "$1" || isurl rsync "$1"
+	if isurl sftp "$1" || islocalrepo "$1" || isurl rsync "$1" || isurl rclone "$1"
 	then
 		:
 	else
@@ -275,6 +281,9 @@ PUTREPO()
 	elif isurl rsync "$1"
 	then
 		rsync -q -r --exclude='*' "$Localdir/" "${1#rsync://}" >&2
+	elif isurl rclone "$1"
+	then
+		rclone mkdir "${1#rclone://}" >&2
 	elif islocalrepo "$1"
 	then
 		mkdir -p "$1"
@@ -295,6 +304,9 @@ REMOVE()
 	then
 		xfeed "$2" rsync -I -W -v -r --delete --include-from=- \
 			--exclude='*' "$Localdir"/ "${1#rsync://}/" >&2
+	elif isurl rclone "$1"
+	then
+		xfeed "$2" rclone delete -v --include-from=/dev/stdin "${1#rclone://}/" >&2
 	elif islocalrepo "$1"
 	then
 		for fn_ in $2; do
@@ -309,7 +321,7 @@ REMOVE()
 
 CLEAN_FINAL()
 {
-	if isurl sftp "$1" || islocalrepo "$1" || isurl rsync "$1"
+	if isurl sftp "$1" || islocalrepo "$1" || isurl rsync "$1" || isurl rclone "$1"
 	then
 		:
 	else
@@ -496,13 +508,18 @@ ensure_connected()
 		echo_info "Updated URL for $r_name, gitception:// -> ()"
 	fi
 
+	if isurl rclone "$URL"; then
+		echo_info "WARNING: git-remote-gcrypt's rclone support is experimental." \
+			"  Keep backups."
+	fi
+
 	# Find the URL fragment
 	url_frag=${URL##*"#"}
 	isnoteq "$url_frag" "$URL" || url_frag=
 	URL=${URL%"#$url_frag"}
 
 	# manifestfile -- sha224 hash if we can, else the default location
-	if isurl sftp "$URL" || islocalrepo "$URL" || isurl rsync "$URL"
+	if isurl sftp "$URL" || islocalrepo "$URL" || isurl rsync "$URL" || isurl rclone "$URL"
 	then
 		# not for gitception
 		isnull "$url_frag" ||