Early prototype of backup script

bin/backup

@@ -4,22 +4,33 @@ Run a backup.
 
 Command-Line Arguments
 ======================
+* -c, --use-checksums   use rsync's checksum feature to detect file changes
+* -d, --dry-run         make this backup a dry run
+* -s, --run-post-sync   run sync syscall after backup
+* -v, --verbose         increase script verbosity
+
+On each run of this script, a new snapshot is made and any unchanged
+files are hardlinked into this new snapshot.
 """
 import argparse
 import logging
-import os.path
-import rbackup.rsync as rsync
+import os
+import sys
 
-from rbackup.hierarchy import Repository, Snapshot
+from rbackup.hierarchy.repository import Repository
+from rbackup.rsync import rsync
 
 # ========== Constants ==========
+LOGFORMAT = "==> %(levelname)s %(message)s"
 RSYNC_DEFAULT_OPTS = [
+    "--acls",
     "--archive",
-    "--hard-links",
-    "--prune-dirs",
     "--backup",
-    "--xattrs",
+    "--hard-links",
     "--ignore-missing-args",
+    "--prune-dirs",
+    "--suffix=.old",
+    "--xattrs",
 ]
 EXTRA_RSYNC_OPTS = {
     "dry_run": "--dry-run",
@@ -28,9 +39,11 @@ EXTRA_RSYNC_OPTS = {
     "update": "--update",
 }
 
+ETC_INCLUDE_FILE = "/etc/rbackup/etc-include.conf"
+
 # ========== Logging Setup ==========
 console_formatter = logging.Formatter(LOGFORMAT)
-syslog = logging.getLogger("packaging_scripts")
+syslog = logging.getLogger("rbackup")
 syslog.setLevel(logging.DEBUG)
 
 stdout_handler = logging.StreamHandler(sys.stdout)
@@ -45,6 +58,48 @@ stderr_handler.setFormatter(console_formatter)
 syslog.addHandler(stdout_handler)
 syslog.addHandler(stderr_handler)
 
+
+# ========== Functions ==========
+def backup_all(s, rsync_opts):
+    raise NotImplementedError
+
+
+def backup_etc(s, rsync_opts):
+    """Create a backup of /etc
+
+    :param s: snapshot to back up to
+    :type s: Snapshot object
+    :param opts: options to pass to rsync
+    :type opts: list
+    """
+    local_opts = rsync_opts
+    local_opts.append(f"--files-from={ETC_INCLUDE_FILE}")
+
+    syslog.debug("Creating directory {s.etc_path}")
+    s.etc_dir.mkdir(parents=True, exist_ok=False)
+    rsync(*local_opts, "/etc/", str(s.etc_path))
+
+
+def backup_home():
+    raise NotImplementedError
+
+
+def backup_pkgmanager():
+    raise NotImplementedError
+
+
+def backup_system():
+    raise NotImplementedError
+
+
+DISPATCHER = {
+    "all": backup_all,
+    "etc": backup_etc,
+    "home": backup_home,
+    "system": backup_system,
+}
+
+
 # ========== Main Script ==========
 if __name__ == "__main__":
     parser = argparse.ArgumentParser()
@@ -54,7 +109,7 @@ if __name__ == "__main__":
         action="store_const",
         dest="extra_rsync_opts",
         const=EXTRA_RSYNC_OPTS["checksum"],
-        help="use rsync's checksumming feature to look for changed files"
+        help="use rsync's checksumming feature to look for changed files",
     )
     parser.add_argument(
         "-d",
@@ -65,25 +120,60 @@ if __name__ == "__main__":
         help="pass --dry-run to rsync",
     )
     parser.add_argument(
-        "-v", "--verbose", action="store_true", help="increase script verbosity"
+        "-s",
+        "--run-post-sync",
+        action="store_true",
+        help="run sync operation after backup is complete",
+    )
+    parser.add_argument(
+        "-v",
+        "--verbose",
+        action="store_true",
+        help="increase script verbosity",
+    )
+    parser.add_argument(
+        "operation",
+        choices=["all", "etc", "home", "pkg", "system"],
+        help="the operation to perform",
+        metavar="op",
+    )
+    parser.add_argument(
+        "repository", help="repository to back up to", metavar="repo"
     )
-    parser.add_argument("operation", help="the operation to perform", metavar="op")
-    parser.add_argument("repository", help="repository to back up to", metavar="repo")
 
-    args = parser.parser_args()
+    args = parser.parse_args()
+
+    rsync_opts = []
+    if args.extra_rsync_opts is not None:
+        rsync_opts.extend(args.extra_rsync_opts)
+
+    args = parser.parse_args()
     repo = Repository(args.repository)
 
-    link_dest = hier.prev_snapshot
-
     if args.verbose:
         stdout_handler.setLevel(logging.DEBUG)
 
-    # Handle empty repository
+    if repo.empty:
+        prev_snapshot = None
+    else:
+        prev_snapshot = repo.curr_snapshot
 
-    # else handle regular repository
+    repo.create_snapshot()
+    curr_snapshot = repo.curr_snapshot
 
-    # Backup to hier.curr_snapshot
+    rsync_opts.append(f"--link-dest={prev_snapshot}")
+    rsync_opts.append("--backup-dir=backup")
 
-    # Relink 'prev' to point to latest snapshot
-    os.remove(hier.prev_snapshot_link)
-    os.symlink(curr_snapshot, hier.prev_snapshot_link, target_is_directory=True)
+    DISPATCHER[args.operation](curr_snapshot, rsync_opts)
+
+    snapshot_symlink = repo.path / "current"
+
+    try:
+        snapshot_symlink.unlink()
+    except FileNotFoundError:
+        pass
+
+    snapshot_symlink.symlink_to(curr_snapshot, target_is_directory=True)
+
+    if args.run_post_sync:
+        os.sync()