Code review for infrastructure changes in Terraform - Step-by-Step Execution

Process Flow - Code review for infrastructure changes

Developer writes Terraform code

↓

Developer runs 'terraform plan'

↓

Reviewers examine plan output

↓

Reviewers provide feedback

↓

Approve changes

↓

Developer applies

Shows the flow from writing code, planning changes, reviewing, and either approving or requesting updates before applying.

Execution Sample

Terraform

terraform plan
# Shows proposed infrastructure changes
# Reviewers check for errors or risks
terraform apply
# Applies approved changes

This simulates the process of planning and applying infrastructure changes with review steps.

Process Table

Step	Action	Input/Condition	Output/Result	Next Step
1	Developer writes Terraform code	New feature or fix needed	Terraform code ready	Run 'terraform plan'
2	Run 'terraform plan'	Terraform code	Plan output showing changes	Review plan output
3	Review plan output	Plan output	Feedback: Approve or Request changes	If approve -> apply; else -> update code
4	If changes requested	Feedback to developer	Developer updates code	Back to step 2
5	If approved	Approval given	Run 'terraform apply'	Apply changes
6	Run 'terraform apply'	Approved plan	Infrastructure updated	End
7	End	Infrastructure updated	Process complete	None

💡 Process ends after infrastructure is updated successfully.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	After Step 5	Final
Terraform Code	None	Written	Unchanged	May be updated	Updated if requested	Final version	Applied
Plan Output	None	None	Generated	Reviewed	Regenerated if updated	Final approved	None
Review Feedback	None	None	None	Approve or Request	May change	Approved	None
Infrastructure State	Current	Current	Current	Current	Current	Updated	Updated

Key Moments - 3 Insights

Why do we run 'terraform plan' before applying changes?

Because 'terraform plan' shows what changes will happen without making them, so reviewers can check for mistakes or risks before anything is applied. See execution_table step 2 and 3.

What happens if reviewers request changes after seeing the plan?

The developer updates the Terraform code and runs 'terraform plan' again to generate a new plan for review. This loop continues until approval. See execution_table steps 3 and 4.

Can we apply changes without review?

Best practice is to always review the plan output before applying to avoid unintended changes. Skipping review risks errors. See execution_table step 3.

Visual Quiz - 3 Questions

Look at the execution_table, what is the output after running 'terraform plan'?

A Plan output showing changes

B Terraform code ready

C Infrastructure updated

D Feedback: Approve or Request changes

💡 Hint

Check execution_table row with Action 'Run terraform plan' (Step 2) for output.

At which step does the developer update the Terraform code after feedback?

A Step 2

B Step 4

C Step 3

D Step 5

💡 Hint

Look for the step where 'Developer updates code' happens in execution_table.

If the developer skips review and applies changes immediately, which step is missed?

A Step 5

B Step 2

C Step 3

D Step 6

💡 Hint

Review happens at 'Review plan output' step in execution_table.

Concept Snapshot

Code review for infrastructure changes:
1. Write Terraform code.
2. Run 'terraform plan' to see proposed changes.
3. Review plan output carefully.
4. Provide feedback: approve or request changes.
5. Apply changes only after approval.
This prevents errors and ensures safe updates.

Full Transcript

This visual execution shows how infrastructure changes are managed with Terraform code review. First, the developer writes code and runs 'terraform plan' to generate a preview of changes. Reviewers then examine this plan to catch errors or risks. They either approve or request changes. If changes are requested, the developer updates the code and repeats the plan and review steps. Once approved, the developer runs 'terraform apply' to update the infrastructure. This process ensures safe, controlled infrastructure updates.