Add priority on journald log format

[baelter]

WHAT is this pull request doing?

Adds priority to journald formatter

HOW can this pull request be tested?

LOG_LEVEL=DEBUG ./bin/lavinmq -D /tmp/amqp 2>&1 | systemd-cat -t lavinmq

journalctl -t lavinmq --output-fields=PRIORITY,MESSAGE

[kickster97]

I can't test this on my mac, but mapping looks good to me

[jage]

Tried it out, not 100%:

...
Feb 13 12:31:14 dev-frozen-toucan-01 lavinmq[51876]:   INFO<6> lmq.server Listening for MQTT on 127.0.0.1:1883
Feb 13 12:33:28 dev-frozen-toucan-01 lavinmq[51876]:   WARN<6> lmq.launcher Stopping
Feb 13 12:33:28 dev-frozen-toucan-01 lavinmq[51876]:   INFO<6> lmq.vhost[vhost: "/"] Closing connections
...

That warning should be <4>, logged here

lavinmq/src/lavinmq/launcher.cr

Line 83 in 7f85d32

Log.warn { "Stopping" }

too quick to approve

[spuun]

Nice with the JournalErrorWriter!

[jage]

Took the last build for a spin, much better!
Though the re-raised exception not handled byLog is still info.

3  lmq.vhost_store Failed to load vhosts
3  Failed to load vhosts (JSON::ParseException)
3    from usr/share/crystal/src/json/lexer.cr:116 in 'raise'
3    from usr/share/crystal/src/json/lexer.cr:330 in 'unexpected_char'
3    from usr/share/crystal/src/json/lexer.cr:326 in 'unexpected_char'
3    from usr/share/crystal/src/json/lexer/io_based.cr:11:21 in 'consume_number'
3    from usr/share/crystal/src/json/lexer.cr:63:7 in 'next_token'
3    from usr/share/crystal/src/json/lexer.cr:75:5 in 'parse_object'
3    from usr/share/crystal/src/json/parser.cr:37:7 in 'parse_value'
3    from usr/share/crystal/src/json/parser.cr:49:18 in 'parse_array'
3    from usr/share/crystal/src/json/parser.cr:37:7 in 'parse_value'
3    from usr/share/crystal/src/json/parser.cr:117:29 in 'parse'
3    from usr/share/crystal/src/json/any.cr:259:3 in 'initialize'
3    from usr/share/crystal/src/gc/boehm.cr:184:7 in 'start'
3    from usr/src/lavinmq_2.1.0-46-g23e21b5d/src/lavinmq/launcher.cr:76:9 in '__crystal_main'
3    from usr/share/crystal/src/crystal/main.cr:118:5 in 'main'
3    from usr/share/crystal/src/crystal/system/unix/main.cr:10:3 in 'main'
3    from /lib/aarch64-linux-gnu/libc.so.6 in '??'
3    from /lib/aarch64-linux-gnu/libc.so.6 in '__libc_start_main'
3    from /usr/bin/lavinmq in '_start'
3    from ???
6 Unhandled exception: Unexpected char 'b' at line 8, column 5 (JSON::ParseException)
6   from usr/share/crystal/src/json/lexer.cr:116 in 'raise'
6   from usr/share/crystal/src/json/lexer.cr:330 in 'unexpected_char'
6   from usr/share/crystal/src/json/lexer.cr:326 in 'unexpected_char'
6   from usr/share/crystal/src/json/lexer/io_based.cr:11:21 in 'consume_number'
6   from usr/share/crystal/src/json/lexer.cr:63:7 in 'next_token'
6   from usr/share/crystal/src/json/lexer.cr:75:5 in 'parse_object'
6   from usr/share/crystal/src/json/parser.cr:37:7 in 'parse_value'
6   from usr/share/crystal/src/json/parser.cr:49:18 in 'parse_array'
6   from usr/share/crystal/src/json/parser.cr:37:7 in 'parse_value'
6   from usr/share/crystal/src/json/parser.cr:117:29 in 'parse'
6   from usr/share/crystal/src/json/any.cr:259:3 in 'initialize'
6   from usr/share/crystal/src/gc/boehm.cr:184:7 in 'start'
6   from usr/src/lavinmq_2.1.0-46-g23e21b5d/src/lavinmq/launcher.cr:76:9 in '__crystal_main'
6   from usr/share/crystal/src/crystal/main.cr:118:5 in 'main'
6   from usr/share/crystal/src/crystal/system/unix/main.cr:10:3 in 'main'
6   from /lib/aarch64-linux-gnu/libc.so.6 in '??'
6   from /lib/aarch64-linux-gnu/libc.so.6 in '__libc_start_main'
6   from /usr/bin/lavinmq in '_start'
6   from ???
5 lavinmq.service: Main process exited, code=exited, status=1/FAILURE
4 lavinmq.service: Failed with result 'exit-code'.
3 Failed to start lavinmq.service - LavinMQ.

[baelter]

humm, worked before jon suggestion :) I'll have a look....

[carlhoerberg]

Another way is to use sd_journal_print(int priority, const char *format, ...); and write directly to systemd: https://www.man7.org/linux/man-pages/man3/sd_journal_print.3.html

[carlhoerberg]

We can also set the default prioity level for stdout/stderr with the SyslogLevel directive in the [Service] section: https://www.freedesktop.org/software/systemd/man/latest/systemd.exec.html#SyslogLevel=