Installation

From Alpine Linux
Revision as of 17:17, 22 December 2023 by Zcrayfish (talk | contribs) (→‎Unix/Linux: Remove gnu'isms from dd command.)


This page exists to provide a basic overview to get started. Before actually installing, it can help to skim through the Frequently Asked Questions (FAQ), as well as to refer to the official installation guide at docs.alpinelinux.org.

Tip: This is a wiki!

If something isn't correct, or is incomplete, you will have to figure it out, or ask for the correct solution in the community.

And then carefully edit the wiki page.

Just as those before who did it for you.

Minimal Hardware Requirements

  • At least 128 MB of RAM. [A graphical desktop system may require up to 512 minimum.]. Note that an installation itself (from ISO) generally requires at least 320 MB during installation.
  • At least 0-700 MB space on a writable storage device. [Only required in "sys" or "data" mode installations (explained below). It is optional in "diskless" mode, where it may be used to save newer data and configurations states of a running system.]

For more information please check Requirements

Installation Overview

The general course of action

Note:
  • For single-board-computer (SBC) architectures which can not boot .iso images, see Alpine on ARM for peculiarities.
  • For headless system, initial network setup may be fed by pre-built apkovl overlay file, custom-made or via 3rd party

As usual, starting an installation procedure requires some basic steps (additional details for all the steps follow below):

  1. Downloading and verifying the proper stable-release ISO installation image-file for the target computer's architecture with their corresponding sha256 (checksum) and GPG (signature) files.
  2. Preparing the installation media (e.g.: CD, DVD, USB drive, SD Card, etc).
  3. Optionally, custom-made headless apkovl can be done by first booting the install media on some computer with a display and keyboard attached, or in a virtual machine, and doing an intermediate "diskless" setup of just the boot media (more details below), i.e. using the offical setup-alpine to configure the system's network, possibly for dhcp if needed, a ssh server, and a login user. Choosing "disks=none" for now, yet, configure to store configs on the boot media (if it is writable, otherwise on a separate storage media). And afterwards calling lbu commit to store the configs as local backup. Then your completed setup, including its securely created own private keys, will readily get (re)loaded on every subsequent (headless) boot from your custom-build <hostname>.apkovl.tar.gz stored on the boot media (or on an auxilary media or server location, in case the boot media is read-only).
  4. Booting the target computer from the prepared disk or storage device.

The boot process of the alpine installation image first copies the entire operating system into the RAM memory, and then already starts a complete Alpine Linux system from there. It will initially only provide a basic command line environment that does not depend on reading from any (possibly slow) initial boot media, anymore.

Local log-in is possible as the user root. Initially, the root user has no password.

At the command prompt, an interactive script named setup-alpine is available to configure and install the initial Alpine Linux system.

The question-and-answer dialog of setup-alpine takes care of the base configuration and allows to configure the system to boot into one of three different Alpine Linux "disk" modes: "diskless"(none), "data", or "sys".

These modes are explained in more detail in the following subsections.

Note: It is really helpful for many cases that it is possible to first only complete a basic setup of the initial "diskless" installation media in order to prepare for the installation of the target system. For example, also to download and install some specific driver or software tool. And to possibly use more specific setup-scripts afterwards in order to proceed with the final installation in a custom way. A most basic pre-setup of just the "diskless" system may be completed by running setup-alpine and answering "none" when asked for the disk to use, for where to store configs, and for the location of the package cache.

Examples of preparation options:

  • Preparing a custom partitioning or filesystem scheme that avoids to use and/or overwrite an entire disk (details below).
  • Installing something that may be missing in the live system to configure the hardware, e.g. by using the alpine package manager apk.

Examples of proceeding options:

  • setup-lbu to configure a "local backup" location for the diskless system, and lbu commit to then save the local configuration state.
  • setup-apkcache to configure a local package cache storage location.
  • setup-disk to add a "data" mode partition, or do a classic full install of the "diskless" system onto a "sys" disk or partition.

There are many more setup-scripts available. All these tools may also be run later to adjust specific configurations. For example, to set up a graphical environment as covered under Post-Installation below.

Diskless Mode

This means the entire operating system with all applications are first loaded into RAM and then only run from there. This is the method already used to boot the .iso installation images, however setup-alpine can also configure the installed system to continue to boot like this if "disk=none" is specified. The mode is extremely fast and can save on unnecessary disk spin-ups, power, and wear. It is similar to what other linux distributions may call a "frugal" install or boot into with a "toram" option.

Custom configurations and package installations may optionally still be preserved or "persist" across reboots by using the Alpine local backup tool lbu. It enables committing and reverting system states by using .apkovl files that are saved to writable storage and loaded when booting. If additional or updated packages have been added to the system, these may also be made available for automatic (re)installation during the boot phase without any (re)downloading, by enabling a local package cache on the writable storage.

[FIXME-1: Storing local configs and the package cache on internal disks still require some manual steps to have the partition listed, i.e. making a /etc/fstab entry, mountpoint, and mount, *before* running setup-alpine. The linked workaround also still requires to commit these configurations to disk manually before rebooting.]

If a writable partition is available, setup-alpine can be told to store the configs and the package cache on that writable partition. (Later, another directory on that same partition or another available partition may also be mounted as /home, or for example, for selected important applications to keep their run-time and user data on it.)

The boot device of the newly configured local "diskless" system may remain the initial (and possibly read-only) installation media. But it is also possible to copy the boot system to a partition (e.g. /dev/sdXY) with setup-bootable.

Data Disk Mode

This mode also runs from system RAM, thus it enjoys the same accelerated operation speed as "diskless" mode. However, swap storage and the entire /var directory tree get mounted from a persistent storage device (two newly created partitions). The directory /var holds e.g. all log files, mailspools, databases, etc., as well as lbu backup commits and the package cache. This mode is useful for having RAM accelerated servers with variable amounts of user-data that exceed the available RAM size. It enables the entire current system state (not just the boot state) to survive a system crash in accordance with the particular filesystem guarantees.

[FIXME-2]: Setup-alpine will create the data partition and mount it as /var, but setup-alpine's "data" disk mode can not yet configure lbu config storage settings automatically. The current workaround, is to select "none" at the 'where to store configs' prompt (as the new data partition is not listed anyway) and configure lbu manually after setup-alpine exits, and before rebooting:

  1. Identify the created data partition, e.g. /dev/sdXY, and its filesystemtype, e.g. using lsblk
  2. Manually edit the lbu backups location in /etc/lbu/lbu.conf and configure LBU_MEDIA=sdXY (according to the previous findings).
  3. Save the configuration on that partition for the next boot with lbu commit.
  4. If (a new) partition fails to get mounted, execute: mkdir /media/sdXY ; echo "/dev/sdXY /media/sdXY fstype noauto,rw 0 0" >> /etc/fstab, and try lbu commit again.

In data disk mode, the boot device may also remain the initial (and possibly read-only) installation media, or be copied to a partition (e.g. /dev/sdXY) with setup-bootable.

System Disk Mode

This is a traditional hard-disk install.

If this mode is selected, the setup-alpine script creates three partitions on the selected storage device, /boot, swap and / (the filesystem root). This mode may, for example, be used for generic desktop and development machines.

For custom partitioning, see Setting up disks manually.

To install along side another operating systems, see Dualbooting.

Preparing for the installation

Note: This "Additional Details" section needs to be consolidated with the work at https://docs.alpinelinux.org (not finished) (Restructuring things there, moving and linking from here or there?).

Verifying the downloaded image-file

Commands to verify the checksum and GPG signature of a downloaded image-file on different systems.
OS type SHA256 check SHA256 calculation (to be compared manually) GPG signature verification
Linux sha256sum -c alpine-*.iso.sha256 curl https://alpinelinux.org/keys/ncopa.asc | gpg --import ;

gpg --verify alpine-<version>.iso.asc alpine-<version>.iso

MACOS - ? - shasum -a 256 alpine-*.iso - ? -
OpenBSD sha256 -C alpine-*.sha256 alpine-*.iso doas pkg_add gnupg;

ftp -o - https://alpinelinux.org/keys/ncopa.asc | gpg --import ; gpg --verify alpine-<version>.iso.asc alpine-<version>.iso

FreeBSD - ? - /usr/local/bin/shasum -a 256 alpine-*.iso - ? -
NetBSD - ? - /usr/local/bin/shasum -a 256 alpine-*.iso - ? -
Windows (PowerShell installed) - ? - Get-FileHash .\alpine-<image-version>.iso -Algorithm SHA256 - ? -

Flashing (direct data writing) the installation image-file onto a device or media

Note: These instructions are exclusively for x86_64 and x86. For ARM boards, see Alpine on ARM#Preparing installation media.

Unix/Linux

Under Unix (and thus Linux), "everything is a file" and the data in the image-file can be written to a device or media with the dd command. Afterward, executing the eject command removes the target device from the system and ensures the write cache is completely flushed.

dd if=<iso-file-to-read-in> of=<target-device-node-to-write-out-to> bs=4M; eject <target-device-node-to-write-to>

Be careful to correctly identify the target device as any data on it will be lost! All connected "bulk storage devices" can be listed with lsblk and blkid. 

# lsblk
NAME            MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sdX               0:0    0  64,0G  0 disk  
├─sdX1            0:1    0     2G  0 part  
└─sdX2            0:2    0    30G  0 part  /mnt/sdX2

# blkid
/dev/sdX1: LABEL="some" UUID="..." TYPE="vfat"
/dev/sdX2: LABEL="other" UUID="..." TYPE="ext4"

For example, if /dev/sdX is the desired target device, first make sure you un-mount all mounted partitions of the target device. For example sdX1 and sdX2:

umount /dev/sdX1 /dev/sdX2


For dd's output-file (of=), however, do not specify a partition number. For example, write to sdX, not sdX1:

Warning: This will overwrite the target device /dev/sdX, so before executing, make sure you have a backup of the data if you can't afford to lose it.

dd if=~/Downloads/alpine-standard-3.00.0-x86_64.iso of=/dev/sdX bs=4M; eject /dev/sdX

Windows

For example, there is the Rufus program. Rufus will enable you to create bootable USB flash drives under Windows.

Rufus has been tested and works for Alpine Linux 3.12.x with the following settings:

  • Partition scheme: MBR
  • Target system: BIOS or UEFI
  • File system: FAT32
  • Cluster size: 4096 bytes (default)

Verifying the written installation media

After detaching and re-attaching the device, a bit-wise comparison can verify the data written to the device (instead of just data buffered in RAM). If the comparison terminates with an end-of-file error on the .iso file side, all the contents from the image have been written (and re-read) successfully: 

# cmp ~/Downloads/alpine-standard-3.00.0-x86_64.iso /dev/sdX
cmp: EOF on alpine-standard-3.00.0-x86_64.iso

Booting from external devices

Insert the boot media to a proper drive or port of the computer and turn the machine on, or restart it, if already running.

If the computer does not automatically boot from the desired device, one needs to bring up the boot menu and choose the media to boot from. Depending on the computer, the menu may be accessed by repeatedly pressing a key quickly when booting starts. Some computers require that you press the button before starting the computer and hold it down while the computer boots. Typical keys are: `F9`-`F12`, sometimes `F7` or `F8`. If these don't bring up the boot menu, it may be necessary to enter the BIOS configuration and adjust the boot settings, for which typical keys are: `Del.` `F1` `F2` `F6` or `Esc.`

Installation Step Details

Custom partitioning of the harddisk

It is possible to specify configurations for RAID, encryption, LVM, etc. as well as manual partitioning.

For "diskless" or "data disk" mode installs, manual partitioning may be needed to prepare the harddisk for committing local backups of the system state with lbu commit, to have a place for a package cache, or to use it for a /var mount.

For a "sys" install, custom partitioning is needed only if the desired scheme differs from overwriting an entire disk, or using the default set of a /boot, swap and root partition on the disk.

See Setting up disks manually for the alpine options for RAID, encryption, LVM, etc. and manual partitioning.

Questions asked by setup-alpine

Example setup-alpine session

The setup-alpine script offers the following configuration options:

  • Keyboard Layout (Local keyboard language and usage mode, e.g. us and variant of us-nodeadkeys.)
  • Hostname (The name for the computer.)
  • Network (For example, automatic IP address discovery with the "DHCP" protocol.)
  • DNS Servers (Domain Name Servers to query. If unsure, leaving DNS domain name blank and using 9.9.9.9 2620:fe::fe for DNS is typically adequate.)
  • Timezone
  • Proxy (Proxy server to use for accessing the web. Use "none" for direct connections to the internet.)
  • Mirror (From where to download packages. Choose the organization you trust giving your usage patterns to.)
  • SSH (Secure SHell remote access server. "Openssh" is part of the default install image. Use "none" to disable remote login, e.g. on laptops.)
  • NTP (Network Time Protocol client used for keeping the system clock in sync with a time server. Package "chrony" is part of the default install image.)
  • Disk Mode (Select between diskless (disk="none"), "data" or "sys", as described above.)
Warning: The data on a chosen device will be overwritten!


Preparing for the first boot

If setup-alpine has finished configuring the "sys" disk mode, the system should be ready to reboot right away (see next subsection).

If the new local system was configured to run in "diskless" or "data" mode, and you do not want keep booting from the initial (and possibly read-only) installation media, the boot system needs to be copied to another device or partition.

The target partition may be identified using lsblk (after installing it with apk add lsblk) and/or blkid, similar to previously identifying the initial installation media device.

The procedure to copy the boot system is explained at setup-bootable

Once everything is in place, save your customized configuration with lbu commit before rebooting.

Rebooting and testing the new system

First, remove the initial installation media from the boot drive, or detach it from the port it's connected to.

The system may now be power-cycled or rebooted to confirm everything is working correctly.

The relevant commands for this are poweroff or reboot.

Completing the installation

The installation script installs only the base operating system. No applications e.g. web server, mail server, desktop environment, or web browsers are installed.

Please look under Post-Installation below, for some common things to do after installation.

Further Installation Instructions

Note: Specific topics should be kept on separate, individually manageable topic-pages and only get listed with a direct reference (link) on this general page.

Installation

Also see other Installation Category pages.

Post-Installation






Broader Usage Guides

General Documentation

Tip: Alpine Linux packages stay close to the upstream design. Therefore, all upstream documentation about configuring a software package, as well as good configuration guides from other distributions that stay close to upstream, e.g. those in the ArchWiki, are to a large degree, also applicable to configuring the software on Alpine Linux, thus can be very useful.
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