[#624] Add OutgoingMessage#mail_server_logs

[garethrees]

Part of #624

Basic framework for collecting exim MTA logs for a specific OutgoingMessage.

Based on my current understanding, the last bits to add to get an OutgoingMessage#delivered? value are:

  def delivered?
    delivery_message ? true : false
  end

  def delivery_message
    m = delivery_line.match(/C="(.*)"/i)
    m ? m[0] : nil
  end

  def delivery_line
    mail_server_logs.
      where("line ILIKE :mta AND line ILIKE :msgtype",
             mta: "%#{ mta_id.last }%", msgtype: "%=>%").
        last.
          line
  end

[garethrees]

Marking as 5 - awaiting review for a first pass look. The specs are (sometimes) failing because of some sort of ordering issue (5a30cd3) but I don't t think its worth diving in to unless we're happy with the general progress of this.

I'm interested in edge cases that make mail_server_logs not produce the output you'd expect.

[crowbot]

Looks good - I wonder if there's going to be some value in storing the association between the outgoing message and the log lines at this point - I think it might be easier to use this code to write some associations to the database and then iterate through them examining them than to try and do all that on the fly.

[garethrees]

I wonder if there's going to be some value in storing the association between the outgoing message and the log lines

Made a note on the original ticket #624 (comment) to do this at a later stage once we've used the on-the-fly way to check a random sample of messages and logs.

[crowbot]

👍 Looks good!