Skip Terraform apply if plan has 0 changes

[staticaland]

Description

Skip Terraform apply if plan has 0 changes.

-detailed-exitcode - Returns a detailed exit code when the command exits. When provided, this argument changes the exit codes and their meanings to provide more granular information about what the resulting plan contains:

0 = Succeeded with empty diff (no changes)
1 = Error
2 = Succeeded with non-empty diff (changes present)

Therefore, we can use steps.plan.outputs.exitcode and only run the apply job if the exit code is 2.

Motivation

Saves time and money.

[staticaland]

Will be solved in #41

[staticaland]

I wanted to add labels to this issue. We should add labels to repositories with Terraform through this code.

[staticaland]

#83