5.6. Reflection Checkpoint

Shell Scripting:

• What does set -euo pipefail do, and why should it be in every bash script?
• What is the difference between $@ and $* when quoted?
• Error messages should go to which file descriptor? Write the correct redirection.
• How do you make a bash script pause until a service is available?

Ansible:

• What does "agentless" mean for Ansible? What does a managed node need?
• Why are command and shell modules not idempotent, and how do you mitigate this?
• What is an Ansible handler, and when does it execute?

Git:

• What is the difference between git fetch and git pull?
• What does git reset --hard HEAD~1 do, and why is it dangerous on a shared branch?
• Write the git push command that pushes only the main branch to the origin remote.

Orchestration and SSH:

• What three things distinguish Kubernetes from Docker Compose?
• What file permissions must a private SSH key have or SSH will refuse to use it?
• Cloud-init user data scripts run at what point, and how often?