pylint: user newer pylint

Older pylint version had issues with distutils imports:

pylint-dev/pylint#73

.pylintrc

@@ -3,6 +3,7 @@ disable=
     bad-option-value,
     duplicate-code,
     fixme,
+    import-outside-toplevel,
     invalid-name,
     len-as-condition,
     locally-disabled,

pghoard/archive_sync.py

@@ -185,19 +185,20 @@ def check_wal_archive_integrity(self, new_backup_on_failure):
                     return 0
                 valid_timeline = True
                 continue
-            elif not valid_timeline:
+
+            if not valid_timeline:
                 msg = "{} file {} missing, integrity check from {} to {} failed".format(
                     archive_type, wal_file, current_wal_file, first_required_wal_file)
                 if not new_backup_on_failure:
                     raise SyncError(msg)
                 self.log.error("Requesting new basebackup: %s", msg)
                 self.request_basebackup()
                 return 0
-            else:
-                # Go back one timeline and flag the current timeline as invalid, this will prevent segment
-                # number from being decreased on the next iteration.
-                valid_timeline = False
-                current_tli -= 1
+
+            # Go back one timeline and flag the current timeline as invalid, this will prevent segment
+            # number from being decreased on the next iteration.
+            valid_timeline = False
+            current_tli -= 1
 
     def request_basebackup(self):
         resp = requests.put("{base}/archive/basebackup".format(base=self.base_url))

pghoard/pghoard.py

@@ -447,9 +447,11 @@ def startup_walk_for_missed_files(self):
                         self.metrics.increase("pghoard.incomplete_partial_wal_segment")
                         os.truncate(full_path, 0)
                     continue
-                elif not wal.WAL_RE.match(filename) and not wal.TIMELINE_RE.match(filename):
+
+                if not wal.WAL_RE.match(filename) and not wal.TIMELINE_RE.match(filename):
                     self.log.warning("Found invalid file %r from incoming xlog directory", full_path)
                     continue
+
                 compression_event = {
                     "delete_file_after_compression": True,
                     "full_path": full_path,

pghoard/restore.py

@@ -522,7 +522,8 @@ def fetch_all(self):
                 self.last_progress_ts = time.monotonic()
                 if self.errors:
                     break
-                elif retry == 2:
+
+                if retry == 2:
                     self.log.error("Download stalled despite retries, aborting")
                     self.errors = 1
                     break

requirements.txt

@@ -1,11 +1,11 @@
-astroid==2.0.0
+astroid
 botocore
 cryptography
 flake8
 httplib2 
 mock
 psycopg2
-pylint==2.2.2
+pylint>=2.4.3
 pytest
 python-dateutil 
 python-snappy

test/test_pghoard.py

@@ -389,6 +389,8 @@ def test_pause_on_disk_full(self, db, pghoard_separate_volume):
             xlogs = pghoard.transfer_agent_state[site]["upload"]["xlog"]["xlogs_since_basebackup"]
             if xlogs >= 15:
                 break
-            elif time.monotonic() - start > 15:
+
+            if time.monotonic() - start > 15:
                 assert False, "Expected at least 15 xlog uploads, got {}".format(xlogs)
+
             time.sleep(0.1)