Terraform

Installing Terraform

On a Ubuntu machine run the following command

Setting up provider

1. Create a directory with any name and cd  to the directory

2. Create a file named providers.tf with the following content. This will enable the OpenStack provider

   providers.tf

   # Define required providers terraform { required_version = ">= 0.14.0" required_providers { openstack = { source = "terraform-provider-openstack/openstack" version = "~> 1.35.0" } } } provider "openstack" {}

   
   
   

3. Declare the cloud information. It is recommended that you refer to Using the OpenStack Command Line Interface . You can also declare it in the providers.tf  however, you will have to declare your login details in plain text which is not secure.

4. Run terraform init

   $ terraform init Initializing the backend... Initializing provider plugins... - Reusing previous version of terraform-provider-openstack/openstack from the dependency lock file - Using previously-installed terraform-provider-openstack/openstack v1.35.0 Terraform has been successfully initialized! You may now begin working with Terraform. Try running "terraform plan" to see any changes that are required for your infrastructure. All Terraform commands should now work. If you ever set or change modules or backend configuration for Terraform, rerun this command to reinitialize your working directory. If you forget, other commands will detect it and remind you to do so if necessary.

   
   
   

Applying config via terraform

To create a configuration you need the deploy.tf for your configuration and variable.tf  for the variables in the provider folder 

I have create an example that will create a set of instances with a volume attached to it.

deploy.tf

variables.tf

To change the variable you can either change the default in variable.tf  or by passing the -var "<variable-name>=<value>"  flag during terraform plan  or terraform apply . 

On thing to note is that you should create ssh keys via the web interface or OpenStack clients and reference it in terraform since terraform will store configuration in plain text which will expose your ssh key. 

To save the plan to a file you can use the -out=<path> flag. This will make sure when you apply the plan, terraform uses the correct plan

After you have edited the files, you can run

terraform plan to preview the changes

e.g.

terrafor apply plan to apply the changes

e.g.

Reference

You should refer to Terraform Registry for details on how to use the providers

Here are some of the common providers