jochen
138d9afd7b
Two files say one fact, the machine's name, and nothing owned /etc/hostname. The name written is the operator's hostname setting, with no default: three of four machines call themselves something other than their mesh name, and renaming one is the operator's call. It takes effect at the next boot.
35 lines
2.1 KiB
Markdown
35 lines
2.1 KiB
Markdown
# hostname
|
|
|
|
The machine's names (novox/hq ADR 0199, ADR 0223): it holds the node seat `node-hostname` and owns
|
|
the two files that say what a machine is called — `/etc/hostname` and the machine's own lines in
|
|
`/etc/hosts`. It was `hosts`, holding `node-hosts-file`; the seat was renamed, and the old name
|
|
resolves to it as an alias.
|
|
|
|
## What it writes
|
|
|
|
- **`/etc/hostname`, whole**: the module's `hostname` setting, and nothing else. There is no
|
|
default. A machine's name is the operator's: the mesh's name for a machine and the name it calls
|
|
itself need not be the same, and writing the mesh's name silently would rename a machine. Set it
|
|
per machine — `settings set hostname '{"hostname": "<name>"}' --node <node>` — before the module
|
|
is assigned there; without it the module is left out of that machine's declaration, naming the
|
|
key. A mesh-wide `{"hostname": "${machine:name}"}` makes every machine call itself by its mesh
|
|
name, and a machine's own setting still overrides it.
|
|
- **The machine's own lines in `/etc/hosts`**, as the mesh's marked region at the start of the file:
|
|
`localhost` and `127.0.1.1` with the machine's mesh name. Every other line is the operator's, kept
|
|
byte for byte and given back when the module goes.
|
|
|
|
## When a new name takes effect
|
|
|
|
At the machine's **next boot**. The kernel's name is set from `/etc/hostname` when the machine
|
|
starts; writing the file changes what `hostnamectl` reports as the static name and nothing that is
|
|
running. The module declares nothing that would set it live: a graphical session's X authority is
|
|
keyed by the name the session started under, so changing it underneath a running session refuses
|
|
every new window until the person logs in again. Reboot when that is acceptable, or run
|
|
`hostnamectl hostname <name>` by hand.
|
|
|
|
## Its verbs
|
|
|
|
`<node>/node-hostname.entries`, `.add` and `.remove`: the hosts file's lines, each marked whose it
|
|
is; add one address and its names to the operator's lines; remove a name or an address from them.
|
|
They change the machine's file and nothing else. `/etc/hostname` has no verb — it is the setting.
|