Without `--all`, `journalctl --output=json` encodes a field over 4096
bytes as `null`, so a long host error matched nothing and the check
passed. A repeated `MESSAGE` field arrives as a JSON array of its
values, and `bytes()` on that array raised `TypeError`, which aborted
the whole check.
Pass `--all`, and tell a byte array (all integers) from an array of
field values, decoding each value on its own.
Reproduced against the host journal: a 5000-byte error line read back
as `"MESSAGE":null` and produced no match; an entry with two `MESSAGE`
fields, sent over the native journal socket, read back as
`["error first","error second"]` and crashed `host_errors` with
`TypeError`. With the fix both are reported.
Also clear the two test-lint findings of this PR:
`test_comments_valid` rejects the narrative comment above the
`journalctl` Popen, so it goes; the stderr-to-file choice stays, because
an unread stderr pipe that fills up would block `journalctl` while
stdout is still being read. `test_no_uncached_file_reads` flags the
read of the stub's argument file, which lives in the test's tempdir and
is written per run, so the path-keyed `utils.cache.files.read_text`
could serve a stale body; the read opts out with
`# nocheck: cache-read tempdir fixture`, as the other stub-driven
script tests do.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Problem:
Every compose service logs to journald through
sys-svc-container/templates/base.yml.j2. The daily journal health
check grepped the whole journal for "error", so routine application
errors from containers triggered the host alert (email/Telegram) and
buried real host problems.
Change:
- Read the last day of the journal as JSON (MESSAGE, CONTAINER_ID,
SYSLOG_IDENTIFIER, _SYSTEMD_UNIT) and skip every entry that carries
a CONTAINER_ID field. Docker daemon and system errors are still
reported.
- Report each match as one readable "source: message" line instead
of raw journal output.
- Stream the journalctl output line by line instead of buffering a
whole day of logs in memory.
- Exit 2 with journalctl's stderr if journalctl itself fails, instead
of silently reporting "no errors".
- Rewrite the check in Python (files/python/script.py, deployed by
sys-service like the other sys-ctl-hlth roles) and decode non-UTF-8
messages.
- Fix the success message, which claimed "All docker containers are
healthy".
Impact:
Container log errors no longer raise this host alert on any
installation. Container health stays covered by sys-ctl-hlth-container;
application log analysis belongs in a log platform such as Wazuh.
system_service_suppress_flush is unchanged until a deploy confirms
that no host errors remain.
Tests:
Unit tests run the script against a fake journalctl (8 cases):
container error ignored, daemon error reported, identifier fallback,
non-UTF-8 message, journalctl failure, many container lines streamed
past, clean journal passes. The core cases fail against the previous
script.
kevinveenbirkenbachandClaude Opus 5.5
Prageeth Panicker