make: add helper to rebase local branches to incorporate upstream changes

Makefile

@@ -31,6 +31,14 @@ test-setup:
 	#git ls-files -z | tar --null -T - -cf - | tar -C /tmp/test-borg -xvf -
 	/tmp/test-borg/initial-setup.sh
 
+# Pull master and rebase "setup-$HOSTNAME" branch onto it
+.PHONY: rebase
+rebase:
+	git checkout master
+	git pull
+	git checkout -
+	git rebase master
+
 .PHONY: clean
 clean:
 	rm -f README.html

backup.py

@@ -241,10 +241,8 @@ def main(argv: list[str]):
     base = pathlib.Path(__file__).parent
     parser.add_argument('-c', '--config',
                         help="Config file", default=str(base / "config.yaml"))
-    parser.add_argument('-b', '--borg',
+    parser.add_argument('-v', '--vars',
-                        help="Borg command", default=str(base / "borg.sh"))
+                        help="Variables file", default=str(base / "vars.sh"))
-    parser.add_argument('-N', '--notify',
-                        help="Notify command", default=str(base / "notify.sh"))
     parser.add_argument('-n', '--dry-run', action="store_true",
                         help="Just print log output, don't run borg")
     parser.add_argument('-d', '--debug', action="store_true",
@@ -253,6 +251,27 @@ def main(argv: list[str]):
     args = parser.parse_args()
     config = Config(args.config)
 
+    # Parse variables from vars.sh
+    hostname = os.uname().nodename
+    borg = str(base / "borg.sh")
+    notify = str(base / "notify.sh")
+    try:
+        with open(args.vars) as f:
+            for line in f:
+                m = re.match(r"\s*export\s*([A-Z_]+)=(.*)", line)
+                if not m:
+                    continue
+                var = m.group(1)
+                value = m.group(2)
+                if var == "HOSTNAME":
+                    hostname = value
+                if var == "BORG":
+                    borg = value
+                if var == "BORG_DIR":
+                    notify = pathlib.Path(value) / "notify.sh"
+    except Exception as e:
+        self.log('W', f"failed to parse variables from {args.vars}: {str(e)}")
+
     # Run backup
     backup = Backup(config, args.dry_run)
     captured_output: list[bytes] = []
@@ -265,7 +284,7 @@ def main(argv: list[str]):
                 backup.run(out)
         sys.stdout.flush()
     else:
-        borg = subprocess.Popen([args.borg,
+        borg = subprocess.Popen([borg,
                                  "create",
                                  "--verbose",
                                  "--list",
@@ -275,7 +294,7 @@ def main(argv: list[str]):
                                  "--compression", "zstd,3",
                                  "--paths-from-stdin",
                                  "--paths-delimiter", "\\0",
-                                 "::{hostname}-{now:%Y%m%d-%H%M%S}"],
+                                 "::" + hostname + "-{now:%Y%m%d-%H%M%S}"],
                                 stdin=subprocess.PIPE,
                                 stdout=subprocess.PIPE,
                                 stderr=subprocess.STDOUT)
@@ -367,7 +386,7 @@ def main(argv: list[str]):
                 summary = warnmsg
 
             # Call notify.sh
-            res = subprocess.run([args.notify, summary, email], input=body_text)
+            res = subprocess.run([notify, summary, email], input=body_text)
             if res.returncode != 0:
                 backup.log('E', f"failed to send notification")
                 errors += 1