Way to run commands in the block sequentially

[kingdonb]

Was #19 closed without a fix? I can't find any mention of "sequential" in the code, not sure how complicated it will be to code but I'd give it a shot if you're still willing to consider a PR. The documentation shows an example with multiple tasks, it is unclear that these won't run sequentially.

every 3.hours do # 1.minute 1.day 1.week 1.month 1.year is also supported
  runner "MyModel.some_process"
  rake "my:rake:task"
  command "/usr/bin/my_great_command"
end

I read this and actually assumed the rake task was meant to run as a pre-requisite to my_great_command and that these commands would be run in order -- this shows what you get when you assume, you get it wrong! I got it wrong.

In my case, we are including documentation strings that are intended to mark up our cron.log with datestamps and they are printed out of order.

How clear and well-organized this looks:

every :day, :at => ['02:15am','08:15am','02:15pm','08:15pm'] do
        command "date"
        command "echo 'Foo the Bar'"
    full_runner "Bar::fooer.foo"
end

every :day, :at => ['02:17am','08:17am','02:17pm','08:17pm'] do
        command "date"
        command "echo 'Bat the Baz'"
    full_runner "Baz::bat.batter_up"
end

every '0 10-22 * * *' do
        command "date"
        command "echo 'Reticulating Splines'"
    full_runner "SplinesController.reticulate_all_splines"
end

every '15 10-22 * * *' do
        command "date"
        command "echo 'Frobnicate the Frobnicator'"
    full_runner "FrobnicatorController.frobnicate"
end

every '20 10-22 * * *' do
        command "date"
        command "echo 'Clinking Glasses'"
    full_runner "Glass.all.each do {|g| g.clink_neighbor}"
end

every '25 10-22 * * *' do
        command "date"
        command "echo 'Calling Taxis'"
    full_runner "ClosingTime::friday.ubers_for_everyone"
end

but look at what you get in cron.log:

Fri Apr  7 20:00:02 UTC 2017
Reticulating Splines
Foo the Bar
Frobnicate the Frobnicator
Fri Apr  7 20:15:02 UTC 2017
Fri Apr  7 20:15:02 UTC 2017
Bat the Baz
Fri Apr  7 20:17:01 UTC 2017
Fri Apr  7 20:20:02 UTC 2017
Clinking Glasses
Calling Taxis
Fri Apr  7 20:25:02 UTC 2017

Not at all what I was trying to achieve. Not sure now how to get there from here.

[kingdonb]

I think I can achieve what I was trying to do by modifying my job types.

It's as simple as adding a :parameter to the job type, and changing the job to print the date and the label before running the command.

Scheduled job configuration now looks more like this:

job_type :full_runner, ". $HOME/.bash_profile; . $HOME/.bashrc; . $HOME/env.log; cd :path && echo -e $(date -u '+%Z%H:%M:%S %Y-%m-%d')'\\t'\":label\" :output && bundle exec rails runner -e :environment ':task' :output"
job_type :run_command, ". $HOME/.bash_profile; . $HOME/.bashrc; . $HOME/env.log; cd :path && echo -e $(date -u '+%Z%H:%M:%S %Y-%m-%d')'\\t'\":label\" :output && :task :output"


every :day, :at => ['02:15am','08:15am','02:15pm','08:15pm'] do
  full_runner "Bar::fooer.foo",
    label: 'Foo the Bar'
end

Output turns out looking like this:

UTC16:21:00 2017-07-13	Foo the Bar

That's pretty much all I wanted.

The job_type description is a little more complicated now, but it does what I need in the right order, and it's not the worst place to have extra complexity. It might be nice to add an option to timestamp jobs like this. (Leaving the issue open in case you agree, my problem is solved but I'll be happy to take a stab at submitting a Pull Request for this if you think it would be valuable to add it.)

Cron is not set up in any way to handle processing sequential jobs, and I think it would introduce unnecessary complexity to the final crontab entries to try and make it produce sequential results. DelayedJob and Starling look like good suggestions for how to get that type of behavior. I just wanted to put some sensible output in the log file, with timestamps and labels or comments.