Refactor Docker backups into modular pipeline

.env.example

@@ -1,7 +1,26 @@
-# /etc/dockerbackup/.env
-RCLONE_REMOTE="gdrive:backuplocation/sublocation"
-SOURCE_DIR="/mybackups"
-PRUNE_ROOT="/mybackups"
-OUT_DIR="/tmp"
+# Copy to .env and customise on each Docker server. Keep .env out of Git.
+SOURCE_BASE_DIR="/dockervolumes"
+BACKUP_ROOT="/dockerbackups"
+CONTAINERS_FILE="containers.local.txt"
+BACKUP_HOSTNAME="beaver"
+
+# Main pipeline method order. Add future method names here.
+BACKUP_METHODS="rclone smb"
 KEEP_COUNT=5
-ZSTD_EXTRA_OPTS="-T0 -12"
+PULL_IMAGES=1
+START_TIMEOUT=90
+WAIT_INTERVAL=3
+START_RETRIES=1
+LOCK_FILE="/run/lock/zorruno-docker-backup.lock"
+
+# Rclone destination becomes <remote>/beaver/.
+RCLONE_ENABLED=0
+RCLONE_REMOTE="gdrive:dockerbackups"
+RCLONE_EXTRA_ARGS=""
+
+# The SMB share must already be mounted by the operating system.
+# Destination becomes <mount>/beaver/ when SMB_HOST_SUBDIR=1.
+SMB_ENABLED=0
+SMB_MOUNT="/mnt/dockerbackups"
+SMB_HOST_SUBDIR=1
+SMB_RSYNC_ARGS="-a"