Terraform in GitHub Actions - Step-by-Step Execution

Process Flow - Terraform in GitHub Actions

Start: Push code to GitHub

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GitHub Actions workflow triggers

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Set up Terraform environment

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Terraform init: Prepare backend and providers

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Terraform plan: Show changes

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Terraform apply: Make changes

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Workflow ends with success or failure

This flow shows how pushing code triggers GitHub Actions to run Terraform commands step-by-step.

Execution Sample

Terraform

name: Terraform
on: [push]
jobs:
  terraform:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: hashicorp/setup-terraform@v2
      - run: terraform init
      - run: terraform plan
      - run: terraform apply -auto-approve

This GitHub Actions workflow runs Terraform init, plan, and apply on every push.

Process Table

Step	Action	Command Run	Result	Next Step
1	Trigger workflow	push event	Workflow starts	Checkout code
2	Checkout code	actions/checkout@v3	Code available	Setup Terraform
3	Setup Terraform	hashicorp/setup-terraform@v2	Terraform ready	terraform init
4	Terraform init	terraform init	Backend and providers initialized	terraform plan
5	Terraform plan	terraform plan	Plan shows changes	terraform apply
6	Terraform apply	terraform apply -auto-approve	Infrastructure updated	Workflow ends
7	End	N/A	Success or failure reported	Stop

💡 Workflow stops after apply completes or if any step fails.

Status Tracker

Variable	Start	After Step 3	After Step 4	After Step 5	After Step 6	Final
Code checked out	No	Yes	Yes	Yes	Yes	Yes
Terraform installed	No	Yes	Yes	Yes	Yes	Yes
Backend initialized	No	No	Yes	Yes	Yes	Yes
Plan created	No	No	No	Yes	Yes	Yes
Infrastructure applied	No	No	No	No	Yes	Yes

Key Moments - 3 Insights

Why does the workflow fail if 'terraform init' is not successful?

'terraform init' sets up backend and providers needed for plan and apply. Without it, later steps cannot run, as shown in execution_table step 4.

What happens if 'terraform plan' shows no changes?

Even if no changes are planned, 'terraform apply' runs but makes no updates. This is shown in execution_table step 5 and 6.

Why do we use '-auto-approve' in 'terraform apply'?

It skips manual confirmation so the workflow can run unattended, as seen in execution_table step 6.

Visual Quiz - 3 Questions

Look at the execution_table, what is the result after step 4?

A Code available

B Backend and providers initialized

C Plan shows changes

D Infrastructure updated

💡 Hint

Check the 'Result' column for step 4 in execution_table.

At which step does the infrastructure get updated?

A Step 6

B Step 4

C Step 3

D Step 5

💡 Hint

Look for 'Infrastructure updated' in the 'Result' column.

If the 'terraform init' step fails, what happens next?

A Workflow continues to plan

B Apply runs anyway

C Workflow stops with failure

D Code checkout repeats

💡 Hint

Refer to the exit_note and step 4 in execution_table.

Concept Snapshot

Terraform in GitHub Actions:
- Triggered by code push
- Steps: checkout, setup, init, plan, apply
- 'terraform init' prepares environment
- 'terraform plan' previews changes
- 'terraform apply -auto-approve' updates infra
- Workflow stops on failure or success

Full Transcript

This visual execution shows how Terraform runs inside GitHub Actions. When code is pushed, the workflow starts and checks out the code. Then it sets up Terraform. Next, 'terraform init' prepares the backend and providers. After that, 'terraform plan' shows what changes will happen. Finally, 'terraform apply -auto-approve' makes the changes automatically. The workflow ends with success or failure depending on these steps. Variables like code checked out and infrastructure applied change step-by-step. Key points include the importance of 'terraform init' and the use of '-auto-approve' to avoid manual input. The quiz questions help check understanding of each step's result and workflow behavior.