Migrations for your Terraform state
NOTE: There are a few hard-coded things and custom logic for our case. Working on it to make it easy for other people to adopt.
Install with:
go get -u carwow/terraform-migrate
It currently only works within CircleCI. Requires a CIRCLE_TOKEN environment
variable and a backend.tf file where your terraform backend is defined.
Migrations go in the ../../migrations directory. They are prefixed with a
number with no leading zeros e.g. 1_import_resource.sh, and are an executable
file.
After running terraform init but before terraform plan, run:
terraform-migrate init && terraform-migrate plan
This sets up a lock on CircleCI's environment variables, disables the terraform
backend, by moving the backend.tf file to backend.tf.disable, and
re-initializes terraform with -force-copy which copies the terraform state
locally. From this point on all terraform commands that change the state apply
on the local state so you can do whatever you what on your migration file.
Then on your master branch, between the terraform init and terraform plan
commands, instead of running terraform-migrate init && terraform-migrate plan, run:
terraform-migrate apply
This will run the migration directly on the remote state.
See an example CircleCI configuration file and an example migration file in the examples directory.