log timestamps instead of a simple touch

resticbackup/cli.py

@@ -1,11 +1,10 @@
 import os
 import argparse
 import subprocess
-from socket import getfqdn
 
 from resticbackup.types import ClientConfig, load_config, load_base_config, list_configs
 from resticbackup.lib import ExecWrapper, init_ok, die, pdie, checkp, get_retention_args, \
-    get_newest_snapshot, touch_statefile
+    get_newest_snapshot, update_statefile
 
 
 def cmd_backup(args, parser):
@@ -55,10 +54,10 @@ def cmd_backup(args, parser):
         # perform junk deletion
         checkp(config.run(["prune"]))
 
-    # touch if necessary
-    if config.touch_complete:
-        path = config.touch_complete.format(name=args.name)
-        touch_statefile(path)
+    # update statefile if configured
+    if config.statefile:
+        path = config.statefile.format(name=args.name)
+        update_statefile(path)
 
 
 def cmd_restore(args, parser):

resticbackup/lib.py

@@ -1,6 +1,7 @@
 import os
 import sys
 import json
+import time
 import subprocess
 
 
@@ -127,12 +128,22 @@ def get_retention_args(schedule):
         raise Exception("unknown retention function {}".format(mode))
 
 
-def touch_statefile(path):
+def update_statefile(path):
+    """
+    the statefile contains a json list of timestamps of the last 10 times the backup completed
+    """
     d = os.path.dirname(path)
     if not os.path.exists(d):
         os.makedirs(d)
-    if os.path.exists(path):
-        os.utime(path)
-    else:
-        with open(path, "w"):
-            pass
+
+    try:
+        with open(path) as f:
+            state = json.load(f)
+    except (json.decoder.JSONDecodeError, FileNotFoundError):
+        state = []
+
+    state.append(int(time.time()))
+    state = state[0:10]
+
+    with open(path, "w") as f:
+        json.dump(state, f)

resticbackup/types.py

@@ -67,7 +67,7 @@ class ClientConfig:
     server_type: str
     uri: str
     secret: str
-    touch_complete: str
+    statefile: str
     backup: BackupConfig
 
     @property
@@ -90,14 +90,14 @@ class ClientConfig:
         server_type, server = main["server"].split(":", 1)
         if server_type != "s3":
             raise Exception("unsupported server type: {}".format(server_type))
-        touch_path = main.get("touch_complete")
-        if touch_path is not None and not touch_path.startswith("/"):
-            raise Exception("touch path must be absolute: {}".format(touch_path))
+        statefile = main.get("statefile")
+        if statefile is not None and not statefile.startswith("/"):
+            raise Exception("statefile path must be absolute: {}".format(statefile))
         return ClientConfig(
             server_type=server_type,
             uri=urlparse(server),
             secret=main["secret"],
-            touch_complete=touch_path,
+            statefile=statefile,
             backup=backup
         )