500 Error during add a new source with regex

[leafchild0]

Wanted to add a new source with the regex for parsing. It may be related to bad regex, but still, 500 error is not informative. Here is my configuration:

1) Version: td-agent 1.2.6, fluent-ui 1.2.0.
2) OS: MacOs, Linux Debian
3) A new source in the configuration file

<source>
  @type tail
  tag webapp-parsed
  read_from_head true
  path /path-to-file.log
  pos_file /var/lib/fluentd/pos/tomcat-parsed.pos
  <parse>
    @type regexp
    expression /(?<time>[^ ]* [^ ]*) *(?<level>[^ ]*) *(?<thread>\[.*\]) *(?<class>[^ ]*) *(?<message>(.*[\s\S]))/
    time_format %Y-%d-%m %H:%M:%S
  </parse>
</source>

4) Example of the log message to parse
2018-11-06 15:07:31,940 INFO [Delayed executor] DelayedEngine:123 DelayedExecutor started...

5) How to reproduce
Try to use UI to add a new source, select a log file (create a dummy file with a message from point 4).
Select regex and add regex mentioned in point 3. Observe that data has been colored (it's a cool feature). Click next and observe error.

6) Error from fluent-ui logs

F, [2018-11-06T19:14:33.724464 #91986] FATAL -- : [7cdd8704-9acf-49e8-97de-0d06742dcf31]
F, [2018-11-06T19:14:33.724555 #91986] FATAL -- : [7cdd8704-9acf-49e8-97de-0d06742dcf31] ActionView::Template::Error (undefined method `assert_valid_value' for nil:NilClass):
F, [2018-11-06T19:14:33.724765 #91986] FATAL -- : [7cdd8704-9acf-49e8-97de-0d06742dcf31]     12:
[7cdd8704-9acf-49e8-97de-0d06742dcf31]     13: .form-group
[7cdd8704-9acf-49e8-97de-0d06742dcf31]     14:   %label= setting.parse_type
[7cdd8704-9acf-49e8-97de-0d06742dcf31]     15:   - parse_config = setting.create_parser
[7cdd8704-9acf-49e8-97de-0d06742dcf31]     16:   = hidden_field_tag("setting[parse[0]][type]", form.object.parse_type)
[7cdd8704-9acf-49e8-97de-0d06742dcf31]     17:   = form.fields("parse[0]", model: parse_config, builder: FluentdFormBuilder) do |f|
[7cdd8704-9acf-49e8-97de-0d06742dcf31]     18:     - f.object.common_options.each do |key|
F, [2018-11-06T19:14:33.724833 #91986] FATAL -- : [7cdd8704-9acf-49e8-97de-0d06742dcf31]
F, [2018-11-06T19:14:33.724866 #91986] FATAL -- : [7cdd8704-9acf-49e8-97de-0d06742dcf31] app/models/concerns/fluentd/setting/configurable.rb:31:in `initialize'

Please help to resolve the problem with either regex or setup of fluentd.

[okkez]

@leafchild0 Could you try #278 ?

[leafchild0]

@okkez Thanks for the fix, built fluentd-ui with your PR, same error.

[okkez]

@leafchild0 Did you restart you fluentd-ui ?
On my environment, it works well with both development mode and production mode.

[leafchild0]

@okkez Yes, I was using the built gem, then downloaded your PR and re-built everything. Then run the new version.
I guess your fix does the trick, but there may be something else there (i.e. error during regex parsing). I will double check it and let you know in a few days of testing.

[leafchild0]

@okkez Was able to make it work with your fix. Thank you!
This issue can be closed and PR merged.