Ansible for Sysadmins — MyAdminDesk

This is an original planning guide. It is not a vendor manual, an official standard, or legal advice. Example addresses use documentation ranges. Review every command before you paste it.

What this hour is for

Ansible talks to an inventory. The ad-hoc builder drafts one module. The playbook generator drafts a short play. The inventory converter changes INI and YAML. The vault builder drafts a vault command. None of them connect to a host.

Every host in the inventory is one you administer. Do not point a play at a network you do not own. host_key_checking false is not the habit you copy in. The vault password is not in the ticket or in git. prompt-for-this marks it.

One task. Do not run the play during the reading. A secret in a vars file is a secret you remove.

The change you can finish

Apply nothing while you are writing the note. When the lab window opens, it is one change on the host named in the ticket. Read the draft, then the host, then decide.

Rollback is the file, the package version, or the snapshot you saved first. You do not invent a rollback after the only copy is gone.

List hosts you administer.
Draft one task.
Leave host-key checking on.
Put secrets in vault, with the password out of the note.
Do not run the play during the reading.
Stop.

Mistakes that outlive the command

Ansible for Sysadmins goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.

A host you do not administer.
host_key_checking turned off as the default.
The vault password in git.
A play run during the reading.
Several unrelated tasks in the first play.

Decisions to write down

One decision for Ansible for Sysadmins: The inventory is yours. One task. Host-key checking stays on. The vault password is not in the note. And nothing was run yet.

Checks before you call it done

Confirm this before you call the change done: The hosts are written. The task is one module you can explain. No foreign host is listed. No vault password is in the file. And nothing was run. If one of those fails, stop.

# Hosts you administer only.
# Do not disable host-key checking as the habit.
# Vault password stays out of git.
# Do not run the play during the reading.

Before you leave the host

Ansible for Sysadmins ends when the hostname in the prompt matches the hostname in the ticket. If it does not, you are on the wrong host. Stop. A command that succeeded on the wrong host is not progress.

The draft stays a draft until a person has read the names in it. A generator does not log into the host and does not know which disk is empty. You delete a line that names a host, a path, or an account you did not write down.

192.0.2.10/24, gateway 192.0.2.1, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. They belong in the note. They are not values you leave on a host because a draft included them.

prompt-for-this is a reminder that a secret is missing. It is not a password, a key, or a token you save in the ticket or in git. The real secret stays in the password store.

One change is the window. If two things move and the result is wrong, you will not know which one did it. The next change waits for its own page.

If the same step fails twice, stop for the day. The failure is the result. Adding a forum command beside a half-applied change produces a host nobody can rebuild. Restore the copy you took first.

A second person reads the hostname and the change aloud. If they cannot find them in the ticket, the note is not done. Silence is not agreement. Then leave the host alone.

This page is a planning guide. It is not a vendor manual, not an official standard, and not permission to touch a host you do not administer. You do not disable a firewall, AppArmor, or SELinux to make a check pass.

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