🐛 Send out mail only once every force interval

Author: MarcelWaldvogel

CHANGELOG.md

@@ -14,6 +14,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/).
 
 ## Fixed
 - Handle that `.gnupg` also is in the volume now
+- Send out mail only every force interval. Also, do not trigger immediate
+  addition of a mail reply only, avoiding double commits/timestamps every
+  force interval on idle repositories.
 
 ## Changed
 

Makefile

@@ -109,7 +109,7 @@ gen-docker-dev:python-package
 		(echo "### THIS FILE WAS AUTOGENERATED, CHANGES WILL BE LOST ###" && \
 		sed -e 's/^##DEVONLY## *//' -e '/##PRODONLY##$$/d' \
 		< autoblockchainify/$$i ) > autoblockchainify-dev/$$i; done
-	for i in health.sh; do \
+	for i in run-autoblockchainify.sh health.sh; do \
 		(head -1 autoblockchainify/$$i && \
 		echo "### THIS FILE WAS AUTOGENERATED, CHANGES WILL BE LOST ###" && \
 		sed -e 's/^##DEVONLY## *//' -e '/##PRODONLY##$$/d' \

autoblockchainify/commit.py

@@ -20,8 +20,9 @@
 
 # Committing to git and obtaining timestamps
 
-import datetime
+from datetime import datetime, timezone
 import logging as _logging
+from pathlib import Path
 import subprocess
 import sys
 import threading
@@ -53,12 +54,15 @@ def cross_timestamp(repo, branch, server):
                          % (branch, server))
 
 
-def has_changes(repo):
+def has_user_changes(repo):
     """Check whether there are uncommitted changes, i.e., whether
-    `git status -z` has any output."""
+    `git status -z` has any output. A modification of only `pgp-timestamp.sig`
+    is ignored, as it is neither necessary nor desirable to trigger on it:
+    (a) our own timestamp is not really needed on it and
+    (b) it would cause an unnecessary second timestamp per idle force period."""
     ret = subprocess.run(['git', 'status', '-z'],
                          cwd=repo, capture_output=True, check=True)
-    return len(ret.stdout) > 0
+    return len(ret.stdout) > 0 and ret.stdout != b' M pgp-timestamp.sig\0'
 
 
 def pending_merge(repo):
@@ -69,7 +73,7 @@ def pending_merge(repo):
 def commit_current_state(repo):
     """Force a commit; will be called only if a commit has to be made.
     I.e., if there really are changes or the force duration has expired."""
-    now = datetime.datetime.now(datetime.timezone.utc)
+    now = datetime.now(timezone.utc)
     nowstr = now.strftime('%Y-%m-%d %H:%M:%S UTC')
     subprocess.run(['git', 'add', '.'],
                    cwd=repo, check=True)
@@ -85,9 +89,9 @@ def head_older_than(repo, duration):
     r = git.Repository(repo)
     if r.head_is_unborn:
         return False
-    now = datetime.datetime.utcnow()
-    if datetime.datetime.utcfromtimestamp(r.head.peel().commit_time) + duration < now:
-        return True
+    now = datetime.utcnow()
+    return datetime.utcfromtimestamp(
+        r.head.peel().commit_time) + duration < now
 
 
 def do_commit():
@@ -108,18 +112,18 @@ def do_commit():
     # Allow 5% of an interval tolerance, such that small timing differences
     # will not lead to lengthening the duration by one commit_interval
     force_interval = (autoblockchainify.config.arg.commit_interval
-        * (autoblockchainify.config.arg.force_after_intervals - 0.05))
+                      * (autoblockchainify.config.arg.force_after_intervals - 0.05))
     try:
         repo = autoblockchainify.config.arg.repository
         # If a merge (a manual process on the repository) is detected,
         # try to not interfere with the manual process and wait for the
         # next forced update
-        if ((has_changes(repo) and not pending_merge(repo))
+        if ((has_user_changes(repo) and not pending_merge(repo))
                 or head_older_than(repo, force_interval)):
             # 1. Commit
             commit_current_state(repo)
 
-            # 2. Timestamp using Zeitgitter
+            # 2. Timestamp (synchronously) using Zeitgitter
             repositories = autoblockchainify.config.arg.push_repository
             branches = autoblockchainify.config.arg.push_branch
             for r in autoblockchainify.config.arg.zeitgitter_servers:
@@ -132,15 +136,14 @@ def do_commit():
                 logging.info("Pushing upstream to %s" % r)
                 push_upstream(repo, r, branches)
 
-            # 4. Timestamp by mail (asynchronous)
+            # 4. Timestamp by mail (asynchronously)
             if autoblockchainify.config.arg.stamper_own_address:
-                logging.info("cross-timestamping by mail")
-                autoblockchainify.mail.async_email_timestamp()
+                autoblockchainify.mail.async_email_timestamp(wait=force_interval)
 
-            logging.info("do_commit done")
+        logging.info("do_commit done")
     except Exception as e:
         logging.error("Unhandled exception in do_commit() thread: %s: %s" %
-                (e, ''.join(traceback.format_tb(sys.exc_info()[2]))))
+                      (e, ''.join(traceback.format_tb(sys.exc_info()[2]))))
 
 
 def loop():

autoblockchainify/mail.py

@@ -314,7 +314,19 @@ def wait_for_receive(logfile):
                     logging.error("No response received, giving up")
 
 
-def async_email_timestamp(resume=False):
+def not_modified_in(file, wait):
+    """Has `logfile` not been modified in ~`wait` seconds?
+    Non-existent file is considered to *not* fulfill this."""
+    try:
+        stat = file.stat()
+        mtime = datetime.utcfromtimestamp(stat.st_mtime)
+        now = datetime.utcnow()
+        return mtime + wait < now
+    except FileNotFoundError:
+        return False
+
+
+def async_email_timestamp(resume=False, wait=None):
     """If called with `resume=True`, tries to resume waiting for the mail"""
     path = autoblockchainify.config.arg.repository
     repo = git.Repository(path)
@@ -326,6 +338,7 @@ def async_email_timestamp(resume=False):
         return
     head = repo.head
     logfile = Path(path, 'pgp-timestamp.tmp')
+    sigfile = Path(path, 'pgp-timestamp.sig')
     if resume:
         if not logfile.is_file():
             logging.info("Not resuming mail timestamp: No pending mail reply")
@@ -336,12 +349,15 @@ def async_email_timestamp(resume=False):
             logging.info("Not resuming mail timestamp: No revision info")
             return
     else:  # Fresh request
-        new_rev = ("git commit %s\nTimestamp requested at %s\n" %
-                   (head.target.hex,
-                    strftime("%Y-%m-%d %H:%M:%S UTC", gmtime())))
-        with serialize_create:
-            with logfile.open('w') as f:
-                f.write(new_rev)
-        send(new_rev)
-    threading.Thread(target=wait_for_receive, args=(logfile,),
-                     daemon=True).start()
+        # No recent attempts or results for mail timestamping
+        if (not sigfile.is_file() or not_modified_in(logfile, wait)
+                or not_modified_in(sigfile, wait)):
+            new_rev = ("git commit %s\nTimestamp requested at %s\n" %
+                       (head.target.hex,
+                        strftime("%Y-%m-%d %H:%M:%S UTC", gmtime())))
+            with serialize_create:
+                with logfile.open('w') as f:
+                    f.write(new_rev)
+                send(new_rev)
+        threading.Thread(target=wait_for_receive, args=(logfile,),
+                         daemon=True).start()