Terraform Beginner Bootcamp 2023

Semantic Versioning 🧙

This project is going utilize semantic versioning for its tagging. semver.org

The general format:

MAJOR.MINOR.PATCH, eg. 1.0.1

MAJOR version when you make incompatible API changes
MINOR version when you add functionality in a backward compatible manner
PATCH version when you make backward compatible bug fixes

Install the Terraform CLI

Considerations with the Terrafor CLI Changes

The Terraform CLI installation instructions have changed due to gpg keypring changes. So we needed to refer to the latest install CLI instructions via Terraform Documentation and change the scripting for install.

Install Terraform CLI

Example of checking OS Version:

$ cat /etc/os-release
PRETTY_NAME="Ubuntu 22.04.3 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.3 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy

Considerations for Linux Distribution

This project is built against Ubuntu. Please consider checking your Linux distribution and change accordingly to your distribution needs. How To Check OS Version In Linux

Refactoring into Bash Scripts

While fixing the Terraform CLI gpg deprecation issues we noticed that the bash script steps were a considerable amount more code. So we decided to create a bash script to install the Terraform CLI.

This bash script is located here: ./bin/install_terraform_cli

This will keep the Gitpod Task File (.gitpod.yml) tidy.
This allows us an easier to debug and execute manually Terraform CLI install.
This will allow better portability for other projects that need to insall Terraform CLI.

Shebang Considerations

A Shebang (prounced Sha-bang) tells the bash script what program that will interpret the script. eg. #!/bin/bash

ChatGPT recommended this format for bash: #!/usr/bin/env bash

For portability for different OS distributions
Will search the user's PATH for the bash executable

https://en.wikipedia.org/wiki/Shebang_(Unix)

Execution Considerations

When executing the bash script we can use the ./ shorthand notation to execute the bash script.

eg. ./bin/install_terraform_cli

If we are using a script in gitpod.yml, we need to point the script to a program to interpret it.

eg.source ./bin/install_terraform_cli

Linux Permissions Considerations

In order to make our bash scripts executable we need to change the Linux permission for the fix to be executable at the user mode.

chmod u+x ./bin/install_terraform_cli

Alternatively:

chmod 744 ./bin/install_terraform_cli

https://en.wikipedia.org/wiki/Chmod

Gitpod Lifecycle (Before, Init, Command)

We need to be careful when using the Init, because it will not rerun if we restart an existing workspace.

https://www.gitpod.io/docs/configure/workspaces/tasks

Working with Env Vars

env command

We can list out all Environment Variables (Env vars) usign the env command.

We can filter specific env vars using grep eg. env | grep AWS_

Setting and Unsetting Env Vars

In the terminal we can set using export HELLO='world'

In the terminal we unset using unset HELLO

We can set an env var temporarily when we just run a command.

HELLO='world' ./bin/print_message

Within a bash script we can set env without writing export eg.

#!/usr/bin/env bash

HELLO='world'

echo $HELLO

Printing Vars

We can print an env var using echo eg. echo $HELLO

Scoping of Env Vars

When you open up new bash terminals in VSCode, it will not be aware of env vars that you have set in another window.

If you want Env Vars to persist across all future bash terminals that you open, you need to set env vars in your bash profile. eg. .bash_profile

Persisting Env Vars in Gitpod

NOTE: Because I have set my Github email to private, Gitpod cannot determine what my email is for committing and pushing to remote. Which means that I have to set the global git email and Gitpod env var to my private email every time I launch Gitpod. To get around this I have created a bash script, bin/set_global_git_email to automate setting the email for me.

We can persist env vars into gitpod by storing them in Gitpod Secrets Storage.

gp env HELLO='world'

All future workspaces launched will set the env vars for all bash terminals openend in those workspaces.

You can also set env vars in the .gitpod.yml but this can only contain non-sensitive env vars.

AWC CLI Installation

AWS CLI is installed for the project via the bash script ./bin/install_aws_cli

Getting Started Install (AWS CLI) AWS CLI Env Vars

We can check if our AWS credentials are configured correctly, by running the following cli command:

aws sts get-caller-identity

If it is successful you should see a JSON payload return that looks like this:

{
    "UserId": "4IRA2KXJX8T247NSJRUSR",
    "Account": "123456789012",
    "Arn": "arn:aws:iam::123456789012:user/terraform-beginner-bootcamp-2023"
}

We'll need to generate AWS CLI credentials from IAM User in order to use AWS CLI.

Terraform Basics

Terraform Registry

Terraform sources their providers and modules from the Terraform registry which is located at registry registry.terraform.io

Provider is an interface to APIs that will allow you to create resources in Terraform.
Modules are a way to make large amounts of Terraform code modular, portable, and sharable.

Random Terraform Provider

Terraform Console

We can see a list of all the Terraform commands by simply typing terraform

Terraform Init

terraform init

At the start of a new Terraform project we will run terraform init to download the binaries for the Terraform providers that we'll use in this project.

Terraform Plan

terraform plan

This will generate out a changeset about the state of our infrastructure and what will be changed.

We can output this changeset ie. "plan" to be passed to an apply, but often you can just ignore outputting.

Terraform Apply

terraform apply

This will run a plan and pass the changeset to be executed by Terraform. Apply should prompt us yes or no.

If we want to automatically approve an apply we can provide auto approve flag eg. terraform apply --auto-approve.

Terraform Destroy

terraform destroy This will destroy resources

You can also use the auto approve flag to skip the approve prompt e.g. terraform apply --auto-approve

Terraform Lock Files

.terraform.lock.hcl contains the locked versioning for the providers or modules that should be used with this project.

The Terraform Lock File should be commited to your Version Control System (VSC) eg. Github.

Terraform State Files

.terraform.tfstate contains information about the current state of your infrastructure.

This file should not be committed to your VCS.

This file can contain sensitive data.

If you lose this file, you lose knowing the state of your infrastructure.

.terraform.tfstate.backup is the previous state.

Terraform Directory

.terraform directory contains binaries of Terraform providers.

Issues with Terraform Cloud Login and Gitpod Workspace

When attempting to run terraform login it will launch in bash a wiswig view to generate a token. However, it does not work as expected in Gitpod VSCode in the browser.

The work around is to manually generate a token in Terraform Cloud.

https://app.terraform.io/app/settings/tokens?source=terraform-login

Then create the file manually here:

touch /home/gitpod/.terraform.d/credentials.tfrc.json
open /home/gitpod/.terraform.d/credentials.tfrc.json

Provide the following code (replace your token in the file):

{
    "credentials": {
        "app.terraform.io": {
            "token": "YOUR-TERRAFORM-CLOUD-TOKEN"
        }
    }
}

We have automated this work around with the following bash script bin/generate_tfrc_credentials

AWS Basics

S3 Buckets

Creating an S3 Bucket

Bucket names must be unique within the global namespace, and can only accept lowercase characters and numbers.

gpoliko / terraform-beginner-bootcamp-2023