[Raspberry Pi 3] Initial Ubuntu Settings on Raspberry Pi, Including How to Change the Hostname

A memo series for Raspberry Pi-related work. This continues the initial setup: changing the hostname, setting a static IP address, and creating a swap file.

Test Environment

Raspberry Pi 3
Ubuntu 18.04.04 LTS 32-bit

Change the Hostname

$ sudo hostnamectl set-hostname rpi3.nosubject.io

Configure a Static IP Address

I wrote about configuring this from a PC before booting in [Raspberry Pi 3] Installing Ubuntu 18.04 LTS (No Keyboard or Display Required), but if you are already logged in to Ubuntu, do the following.

$ sudo vi /etc/netplan/50-cloud-init.yaml # 内容を編集 
$ sudo netplan apply # 設定を反映

# This file is generated from information provided by the datasource.  Changes
# to it will not persist across an instance reboot.  To disable cloud-init's
# network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
network:
    ethernets:
        eth0:
            addresses:
            - 192.168.11.5/24
            dhcp4: false
            gateway4: 192.168.11.254
            nameservers:
                addresses:
                - 192.168.11.254
    version: 2
    wifis:
        wlan0:
            access-points:
                myssid012345:
                    password: mypassword012345
            addresses:
            - 192.168.11.3/24
            dhcp4: false
            gateway4: 192.168.11.254
            nameservers:
                addresses:
                - 192.168.11.254
            optional: false

Create Swap

Frequent writes apparently affect the life of the SD card, so you only need to configure swap if it is necessary.

$ sudo apt-get install dphys-swapfile # パッケージ入れる
$ sudo dphys-swapfile install # Swapファイルを作って適用
 computing size, want /var/swap=1724MByte, checking existing: keeping it
$ sudo vi /etc/dphys-swapfile # サイズを変更するにはここを直す
--- CONF_SWAPSIZE=
+++ CONF_SWAPSIZE=2048

Change Locale and Time Zone

By default it is UTC, so change it to JST. Also add the Japanese locale.

$ date
 Sat Mar 14 14:51:20 UTC 2020
$ sudo timedatectl set-timezone Asia/Tokyo
$ date
 Sat Mar 14 23:51:33 JST 2020

$ locale -a
 C
 C.UTF-8
 POSIX
 en_US.utf8
$ sudo locale-gen ja_JP.UTF-8
 Generating locales (this might take a while)…
   ja_JP.UTF-8… done
 Generation complete.
$ locale -a
 C
 C.UTF-8
 POSIX
 en_US.utf8
 ja_JP.utf8

Would it be good to write these settings in system-boot's user-data and have them run automatically too?

TODO: Backups, SD Card Life Extension Measures, and Similar Tasks

If you use it as a server without thinking about anything, the SD card will fail in one or two years even without that much access. Brute-force attacks against SSHd come constantly, so log writes from that may be part of the cause.
Take measures like the following.
Extend the Life of a Raspberry Pi SD Card / microSD Card
Complete measures for Raspberry Pi microSD card life

Update

These settings can be run automatically on first boot using the method I wrote about in [Raspberry Pi 4] Headless Install of Ubuntu 20.10: How to Install Without a Keyboard or Display.