fix: use t3.large and add Buildx for visualizer EC2

[gamaware]

Summary

• Upgrade visualizer CloudFormation from t3.medium to t3.large
• Add Docker Buildx plugin install to UserData (required by latest Compose)
• Update LAB wait time estimate to 5-10 minutes

Test plan

• Deployed CloudFormation stack (CREATE_COMPLETE)
• Verified visualizer loads at http://PUBLIC_IP:8081 (HTTP 200)
• Tested replication API (INSERT + SELECT + SHOW REPLICA STATUS)
• Tested ACID transfer API (BEGIN, DELETE, INSERT, COMMIT)
• Tested EXPLAIN API (rows: 9212, full scan)
• Tested SQL console API (SELECT query returns tabular results)
• Stack deleted cleanly

Summary by CodeRabbit

• Documentation

  • Updated expected environment setup time to 5–10 minutes

• Chores

  • Upgraded EC2 instance type for increased capacity
  • Added Docker Buildx CLI support to the provisioned environment

[coderabbitai]

Caution

Review failed

Pull request was closed or merged during review

📝 Walkthrough

Walkthrough

Updated EC2 CloudFormation infrastructure for the database visualizer lab by upgrading the instance type from t3.medium to t3.large and extending the bootstrap script to install Docker Buildx plugin with architecture detection. Documentation updated to reflect extended stack creation time.

Changes

Cohort / File(s)	Summary
Documentation Update 10-databases/visualizer/LAB-VISUALIZER.md	Updated EC2 stack completion time from 3–5 minutes to 5–10 minutes, noting Docker image pulling and visualizer image building as the cause of the delay.
CloudFormation Infrastructure 10-databases/visualizer/cloudformation.yaml	Upgraded EC2 instance type from t3.medium to t3.large. Extended UserData script to install Docker Buildx CLI plugin post-Docker Compose, including CPU architecture detection, GitHub release fetching, binary download, and executable permission configuration.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~5 minutes

Possibly related PRs

• feat: add CloudFormation template for Lab 09 EC2 provisioning #36: Modifies EC2 CloudFormation templates' UserData to install Docker Buildx plugin and adjusts instance sizing
• fix: install Docker Buildx plugin for EC2 setup script #33: Adds Docker Buildx plugin installation to EC2 user-data provisioning with architecture-aware download logic

Poem

🐰 A medium box grew to large, ✨
Buildx now joins Docker's charge,
Architecture aware, downloads with care,
Minutes stretched, but building's fair! 🐳

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'fix: use t3.large and add Buildx for visualizer EC2' directly and clearly summarizes the main changes: upgrading the EC2 instance type and adding Docker Buildx support.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/visualizer-ec2-instance-size

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_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[gamaware]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.

Two-line fix: CloudFormation instance type t3.medium -> t3.large, and added Docker Buildx plugin install to UserData (required by latest Docker Compose for image building). Verified end-to-end on EC2: stack deploys, visualizer loads, all 4 API endpoints work.

[Copilot]

Pull request overview

This PR updates the Lab 10 database visualizer’s EC2 provisioning and lab instructions to support the current Docker Compose build flow and improve runtime reliability by increasing instance capacity.

Changes:

• Upgraded the visualizer EC2 instance type from t3.medium to t3.large.
• Added Docker Buildx plugin installation to EC2 UserData (required for docker compose build on the provisioned AMI/Docker package).
• Updated the lab’s CloudFormation stack creation time estimate to 5–10 minutes.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
10-databases/visualizer/cloudformation.yaml	Increases instance size and installs the Docker Buildx CLI plugin alongside Compose in UserData.
10-databases/visualizer/LAB-VISUALIZER.md	Updates expected stack creation time to reflect initial image pulls/build.