Notes on Clarence | Backend, AI, DevOps, Infrastructure

AWS CDK Tips

Sat, 11 Jul 2026 00:00:00 +0800

Version and safety scope

Last reviewed: July 11, 2026

This is a general command reference, not a version-pinned runbook. Check the installed version, current official documentation, and the target account, host, and path before use. Commands that deploy, destroy, delete, prune, sync, upgrade, or change system settings can cause cost, downtime, or data loss; preview changes and back up where appropriate.

Daily commands

cdk init app --language typescript
cdk synth
cdk diff
cdk deploy
cdk deploy --all
cdk destroy

Run cdk diff before deployment and keep environment-specific values out of construct code.

AWS CLI Quick Reference

Sat, 11 Jul 2026 00:00:00 +0800

Version and safety scope

Last reviewed: July 11, 2026

Install and configure

brew install awscli
aws --version
aws configure
aws configure --profile production
aws configure list --profile production
aws sts get-caller-identity --profile production

Use named profiles for production or customer accounts. Avoid long-lived credentials in shell history or shared notes.

macOS Administration Commands

Sat, 11 Jul 2026 00:00:00 +0800

Version and safety scope

Last reviewed: July 11, 2026

Launchpad and Dock

defaults write com.apple.dock ResetLaunchPad -bool true
killall Dock

defaults write com.apple.dock autohide -bool true
defaults write com.apple.dock tilesize -int 50
killall Dock

Dock changes usually need killall Dock before they appear.

Ollama Setup and Usage

Sat, 11 Jul 2026 00:00:00 +0800

Version and safety scope

Last reviewed: July 11, 2026

Install and run

curl -fsSL https://ollama.com/install.sh | sh
ollama serve
ollama pull gemma2:9b
ollama pull llama3.1:8b
ollama list

Use smaller models first when testing prompts, then move to larger models after the workflow is stable.

Package Management Commands

Sat, 11 Jul 2026 00:00:00 +0800

Version and safety scope

Last reviewed: July 11, 2026

Homebrew

brew update
brew install git node hugo
brew install --cask visual-studio-code
brew list
brew outdated
brew upgrade
brew cleanup

Use brew outdated before broad upgrades on machines used for active development.

System Administration Commands

Sat, 11 Jul 2026 00:00:00 +0800

Version and safety scope

Last reviewed: July 11, 2026

System inspection

uname -a
cat /etc/os-release
lscpu
free -h
df -h
lsblk
ip addr show
ip route show

Capture these basics first when documenting a server incident.

Docker Commands

Sat, 11 Jul 2026 00:00:00 +0800

Version and safety scope

Last reviewed: July 11, 2026

Images and containers

docker pull nginx:latest
docker images
docker ps
docker ps -a
docker run -d --name web -p 8080:80 nginx
docker exec -it web sh
docker logs -f web
docker stop web
docker rm web

Name long-running containers so logs and operational commands are easier to read.