Rollback deployments in Firebase - Step-by-Step Execution

Process Flow - Rollback deployments

Start Deployment

↓

Deploy New Version

↓

Check Deployment Status

↓

Keep

↓

Deploy Previous Version

↓

Deployment Stable

↓

End

This flow shows deploying a new version, checking if it works, and rolling back to the previous version if it fails.

Execution Sample

Firebase

firebase deploy --only hosting
# Check deployment
# If failure, run:
firebase hosting:channel:rollback

Deploys a new hosting version, then rolls back if deployment fails.

Process Table

Step	Action	Deployment Version	Status Check	Result
1	Deploy new version v2	v2	Pending	Deployment started
2	Check deployment status	v2	Failed	Trigger rollback
3	Rollback to previous version v1	v1	Success	Deployment stable
4	End process	v1	N/A	Rollback complete, stable version running

💡 Rollback completed because new deployment v2 failed status check

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
Deployment Version	v1	v2	v2	v1	v1
Deployment Status	Stable	Pending	Failed	Stable	Stable

Key Moments - 3 Insights

Why do we deploy version v2 before checking if it works?

Because deployment must happen first to test if the new version is stable, as shown in step 1 and 2 of the execution_table.

What happens if the deployment status is successful?

If successful, rollback is not triggered and the new version stays live, but in this example, failure caused rollback at step 2.

Does rollback deploy the exact previous version?

Yes, rollback redeploys the last stable version, here v1, as shown in step 3.

Visual Quiz - 3 Questions

Look at the execution table, what is the deployment version after step 3?

A v2

B v3

C v1

D None

💡 Hint

Check the 'Deployment Version' column at step 3 in the execution_table.

At which step does the deployment status become 'Failed'?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look at the 'Deployment Status' column in the variable_tracker after step 2.

If the deployment status was 'Success' at step 2, what would happen next?

A Keep new version live

B Rollback to previous version

C Deploy a new version v3

D End with failure

💡 Hint

Refer to the concept_flow where success leads to keeping the new version.

Concept Snapshot

Rollback deployments:
- Deploy new version
- Check if deployment works
- If fails, rollback to previous stable version
- Use 'firebase hosting:channel:rollback' to revert
- Ensures stable live environment

Full Transcript

This visual execution shows how deploying a new Firebase hosting version works. First, a new version is deployed. Then the deployment status is checked. If the deployment fails, a rollback is triggered to redeploy the previous stable version. This process ensures the live site stays stable. The execution table traces each step, showing deployment versions and status changes. Key moments clarify why deployment happens before checking and how rollback restores stability. The quiz tests understanding of deployment versions and status at each step.

Practice

1.

What is the main purpose of firebase hosting:rollback?

easy

A. To deploy a new version of the website

B. To create a backup of the current deployment

C. To delete all hosting versions permanently

D. To undo a recent deployment and restore the previous version

Solution

1. Step 1: Understand rollback purpose

   Rollback is used to undo a deployment that caused issues by restoring the previous stable version.

2. Step 2: Identify command function

   The command firebase hosting:rollback specifically reverts to the last working deployment.

3. Final Answer:

   To undo a recent deployment and restore the previous version -> Option D

4. Quick Check:

   Rollback = undo deployment [OK]

Hint: Rollback means undo last deployment fast [OK]

Common Mistakes:

• Confusing rollback with deploying new versions
• Thinking rollback deletes all versions
• Assuming rollback creates backups

2.

Which of the following is the correct syntax to rollback the last Firebase Hosting deployment?

easy

A. firebase hosting:rollback

B. firebase rollback hosting

C. firebase deploy:rollback hosting

D. firebase hosting rollback --last

Solution

1. Step 1: Recall correct command structure

   The official Firebase CLI command for rollback is firebase hosting:rollback.

2. Step 2: Check option syntax

   Options B, C, and D do not match the correct Firebase CLI syntax for rollback.

3. Final Answer:

   firebase hosting:rollback -> Option A

4. Quick Check:

   Correct syntax = firebase hosting:rollback [OK]

Hint: Remember exact command: firebase hosting:rollback [OK]

Common Mistakes:

• Swapping command parts order
• Adding extra flags not needed
• Using deploy instead of hosting

3.

Given the deployment history shows versions v5, v6, and v7, with v7 currently live, what will firebase hosting:rollback do?

medium

A. Rollback to version v6

B. Rollback to version v7 again

C. Rollback to version v5

D. Delete all versions except v7

Solution

1. Step 1: Identify current live version

   The current live version is v7, the latest deployment.

2. Step 2: Understand rollback behavior

   Rollback reverts to the previous version before the current one, which is v6.

3. Final Answer:

   Rollback to version v6 -> Option A

4. Quick Check:

   Rollback = previous version v6 [OK]

Hint: Rollback always reverts to the immediate previous version [OK]

Common Mistakes:

• Choosing the oldest version instead of previous
• Thinking rollback redeploys current version
• Assuming rollback deletes versions

4.

You ran firebase hosting:rollback but got an error saying "No previous version found." What is the most likely cause?

medium

A. Firebase CLI is outdated

B. You have no prior deployments to rollback to

C. Your internet connection is down

D. You typed the command incorrectly

Solution

1. Step 1: Analyze error message meaning

   The error "No previous version found" means there is no earlier deployment saved to revert to.

2. Step 2: Consider possible causes

   This usually happens if this is the first deployment or all previous versions were deleted.

3. Final Answer:

   You have no prior deployments to rollback to -> Option B

4. Quick Check:

   No previous version = no rollback possible [OK]

Hint: No previous version means no rollback available [OK]

Common Mistakes:

• Assuming command syntax error
• Blaming network issues
• Ignoring deployment history

5.

You deployed version v10 but found a critical bug. You want to rollback to v9. However, v9 was deleted from the history. What is the best approach to recover your site quickly?

hard

A. Delete v10 and wait for Firebase to restore v9 automatically

B. Run firebase hosting:rollback to get v9 back

C. Redeploy a saved local copy of v9 manually

D. Contact Firebase support to restore v9

Solution

1. Step 1: Understand rollback limitations

   Rollback only works if the previous version exists in deployment history. Since v9 is deleted, rollback cannot restore it.

2. Step 2: Identify recovery method

   The best way is to redeploy a saved local copy of v9 manually to restore the stable version quickly.

3. Step 3: Evaluate other options

   Options B and C won't work because rollback needs the version present, and Firebase does not auto-restore deleted versions. Contact Firebase support to restore v9 may take too long for urgent fixes.

4. Final Answer:

   Redeploy a saved local copy of v9 manually -> Option C

5. Quick Check:

   Deleted version = manual redeploy needed [OK]

Hint: Rollback needs version history; redeploy local copy if missing [OK]

Common Mistakes:

• Expecting rollback to restore deleted versions
• Waiting for automatic Firebase restore
• Ignoring local backups