Terraform Docker Example | Clone PostgreSQL Database | Create New PostgreSQL Database

This example clones an RDS PostgreSQL database and creates a brand new RDS database.

Step 1 | git clone into docker volume

First we create a docker volume (called vol.postgres.tfstate) and add the terraform module code to it by way of an alpine git container.

docker volume create vol.postgres.tfstate
docker run --interactive \
           --tty         \
	   --rm          \
	   --volume vol.postgres.tfstate:/terraform-work \
	   alpine/git \
	   clone https://github.com/devops4me/terraform-aws-postgres-rds /terraform-work
sudo ls -lah /var/lib/docker/volumes/vol.postgres.tfstate/_data

verify - when you list the files in the container you will see the terraform module's contents there.

Step 2 | terraform init via docker

As our volume contains the terraform module code from git we are now ready to perform a terraform init. We use the devops4me/terraform container container which adds a VOLUME mapping to the hashicorp/terraform container at the /terraform-work location.

docker run --interactive \
           --tty \
	   --rm \
	   --name vm.terraform \
	   --volume vol.postgres.tfstate:/terraform-work \
	   devops4me/terraform init example
sudo ls -lah /var/lib/docker/volumes/vol.postgres.tfstate/_data

verify - the directory listing now contains a .terraform directory.

Step 3 | terraform apply via docker

At last we can run the terraform apply. Provide a role arn only if your organization works with roles alongside the other 3 AWS authentication keys.

docker run --interactive \
           --tty \
	   --rm \
	   --name vm.terraform \
	   --env AWS_DEFAULT_REGION=<<aws-region-key>> \
	   --env AWS_ACCESS_KEY_ID=<<aws-access-key>> \
	   --env AWS_SECRET_ACCESS_KEY=<<aws-secret-key>> \
	   --env TF_VAR_in_role_arn=<<aws-role-arn>> \
	   --env TF_VAR_in_id_of_db_to_clone=<<database_id>> \
	   --env TF_VAR_in_publicly_accessible=true \
	   --volume vol.postgres.tfstate:/terraform-work \
	   devops4me/terraform apply -auto-approve example
sudo ls -lah /var/lib/docker/volumes/vol.postgres.tfstate/_data

verify - the docker volume now has a tfstate file which documents the state of your infrastructure after terraform apply.

Step 4 | terraform destroy via docker

After running plan and apply either once or multiple times you may feel the need to terraform destroy the infrastructure.

docker run --interactive \
           --tty \
	   --rm \
	   --name vm.terraform \
	   --env AWS_DEFAULT_REGION=<<aws-region-key>> \
	   --env AWS_ACCESS_KEY_ID=<<aws-access-key>> \
	   --env AWS_SECRET_ACCESS_KEY=<<aws-secret-key>> \
	   --env TF_VAR_in_role_arn=<<aws-role-arn>> \
	   --volume vol.postgres.tfstate:/terraform-work \
	   devops4me/terraform destroy -auto-approve example
sudo ls -lah /var/lib/docker/volumes/vol.postgres.tfstate/_data

verify - check your AWS console and also note that the volume now has a tfstate backup file created by terraform.