Anzu

# Automation Setup

Cron is used to schedule timers of when Anzu would remind its users about tasks to be done and times of when Anzu would delete expired tasks. Cronjobs are run by default at the following times (GMT +7 time):

  • 01:00 (to clean up expired tasks)
  • 17:00 (to remind a user / group / room about a task)

You can change the timezone and the number of times you want to be reminded by editing the configuration file at constants/constants.ts.

If you have a paid LINE subscription, you can add more reminders. However, as I am stuck with the free version, I'll keep them at two reminders per day.

A note to keep in mind that if there are no expired tasks (or no tasks are available), Anzu will not notify anything at 01:00 or 17:00. This is done so that the bandwith is not wasted. Another thing to note is that by default, this application uses the long reminder function for the schedulers (refer to functions/scheduleFunctions.ts).

# Automation Considerations

We have to take into consideration that Heroku free dynos sleep every 30 minutes when our application is not running. When our application is sleeping, the cronjobs made with node-cron will not run.

In order to circumvent the above case, we are going to use cronjobs to ping the Heroku server, so that it will wake up before the cronjobs start.

  • You can change the time and the timezone of the cronjob by changing the code according to the cron syntax. Here is an excellent site (opens new window) that describes the cron syntax.
crontab -l
crontab -e
  • The reason the crontab is setup like this is so that it gives Heroku time to prepare before running the cronjobs made with node-cron. We just need to ping the webserver (a small GET request) so that it wakes up.
55 00 * * * cd "$HOME/Anzu/auto" && bash ping-webserver.sh <link_to_webserver>
55 16 * * * cd "$HOME/Anzu/auto" && bash ping-webserver.sh <link_to_webserver>
  • In order to check if our crontab had run successfully, we could use the following command.
sudo grep CRON /var/log/syslog

# Additional Configurations

  • This part is optional. You might want to setup SSH into your Git, as I also have a script named keep-track.sh to always pull from the latest remote repository to keep my local repository updated. Don't forget to set the origin URL.
cd $HOME
ssh-keygen -t rsa -b 4096 -C <your_github_email>
cd .ssh
ls -a             # Check out your RSA '.pub' name.
cat id_rsa.pub    # The default identifier is 'id_rsa'. You probably have a different identifier.

# Then, configure your access keys with your GitHub configuration. After that, test your connection.
ssh -T git@github.com
git remote set-url origin git+ssh://git@github.com/username/reponame.git
  • You can run keep-track.sh by using the following cronjobs. In this example, I run the script everyday at 09:00 AM.
00 09 * * * cd "$HOME/Anzu/auto" && bash keep-track.sh

# Example Of Reminders

Below is the example of Anzu reminding someone.

Hello everyone! How are you?

This is an automated message from Anzu to remind you all of your schedules. Here is it:

... (your tasks)

Good luck and stay in high spirits!

Belos is the example of Anzu cleaning up tasks.

Hello everyone! Did you sleep well?

Anzu just wants to let you know that she has cleaned up several expired tasks. Here is it:

... (your expired tasks)

Thank you and good luck!

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