adding basic gocron-gorm-lock functionality.

[manuelarte]

What does this do?

Which issue(s) does this PR fix/relate to?

Adding basic gocron-gorm lock functionality. It should be described in the Readme file.

Important topic to discuss:

• It needs the cron_job_locks table to exists in the database because that's where the cron jobs are stored.
• it is using a combination of job name + job execution timestamp (precision to miliseconds) to uniquely identify the running job, so it avoids running several times the same jobs.
• In order to test the implementation, I needed to add a gorm driver, in this case I used postgres, so the driver is included in the go.mod, but I also tested it with another driver and it works, that's actually the magic of Gorm.

List any changes that modify/break current functionality

Have you included tests for your changes?

I added a test following the convention in gocron-redis-lock, I also added an extra test that checks the uniqueness of the job name + timestamp in the database.

Did you document any new/modified functionality?

• [x] Updated example_test.go
• [x] Updated README.md

Notes

Any feedback is appreciated.

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[JohnRoesler]

@manuelarte thanks for your desire to contribute to the open source! See my comments on the design below. Great work!

[rfyiamcool]

👍

[manuelarte]

I updated the PR

[JohnRoesler]

Looks like the test is failing

[manuelarte]

Looks like the test is failing

yes. This is a problem I discovered some time ago. The miliseconds precision (the one I put by default), gives problems since the operation to lock and unlock sometimes takes quite some time. I decided to change the precision to seconds, and change the tests accordingly.

[manuelarte]

I forgot to update one part of one test

[manuelarte]

@JohnRoesler could you run the workflows again?

[manuelarte]

is something else missing?