What is purpose of Terraform Workspaces

Terraform workspace can be used to create multiple environments. Earlier Terraform used to have concept of environments which was later renamed to worspace.

Terraform has introduced the whole sub-command for managing terraform workspaces. The command looks like

terraform workspace --help
Usage: terraform workspace

  New, list, select and delete Terraform workspaces.

Subcommands:
    delete    Delete a workspace
    list      List Workspaces
    new       Create a new workspace
    select    Select a workspace
    show      Show the name of the current workspace

Even if you are not using workspaces now terraform creates a workspace called default automatically

Example of Terraform Workspace

• Lets start with sample as mentioned here
• Copy the script to some new folder
• Start by executing the following command

terraform init

• Execute the following command to find the current workspaces

terraform workspace list

and you will observe the following output

 terraform workspace list
* default

• With terraform workspace you get variable terraform.workspace which has active workspace name that can be used in interpolation
• I will be changing the resource like

resource "aws_vpc" "mainnet" {
    cidr_block = "192.168.0.0/16"

    tags = {
        Name = "mainnet-${terraform.workspace}"
    }
  
}

• Lets create a new workspace called Dev using command

terraform workspace new Dev

which creates new workspace called as Dev and switches you to Dev Workspace

• Lets check the available workspaces by using command

terraform workspace list
  default
* Dev

• Lets see the contents of the folder before apply command

Mode                LastWriteTime         Length Name
----                -------------         ------ ----
d-----        1/27/2019   2:27 PM                .terraform
d-----        1/27/2019   2:27 PM                terraform.tfstate.d
-a----        1/27/2019   2:23 PM            981 main.tf
-a----        1/27/2019  12:33 PM             88 terraform.tfvars
-a----        1/27/2019  12:24 PM            180 variables.tf

• Now executing terraform apply will create a new folder under terraform.tfstate.d as Dev
• Lets now create new workspace called as QA using command

terraform workspace new QA

• Change the values in the terraform.tfvars file and execute terraform apply

terraform apply .

• Now examine your aws account and you will be observing two networks created from same terraform folder with workspaces.

• State files will be stored in terraform.tfstate.d folder.

• You can also extend your state files by using backends as we have discussed in the earlier blog item by adding backends here.

• For further reading refer here