Installation

From Alpine Linux




This page explains the basics to get started. But before actually installing, it can also help to skim through the Frequenty Asked Questions (FAQ).


Minimal Hardware Requirements

  • At least 100 MB of RAM. [A graphical desktop system may require up to 1 GB minimum.]
  • 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, only needed to save newer data and configurations states of a running system.]

Installation Overview

The general course of actions

[Note: For single-board-computer (SBC) architectures which can not boot .iso images, see e.g. Alpine on ARM for peculiarities.]


As usual, the regular installation procedure starts with three basic steps (additional details for all the steps follow below):


1.) Downloading and verifying the proper stable-release ISO installation image-file for the computer's architecture, and the corresponding sha256 (checksum) and GPG (signature) files.

2.) Either burning the ISO image-file onto a blank CD/DVD/Blu-ray disk with a disk burning software, or flashing the installation image onto a bootable storage device (USB-device, CF-/MMC-/SD-card, floppy, ...).

3.) Booting the computer from the prepared disk or storage device.


The boot process then copies the entire operating system into the RAM, and then runs it completely from RAM. This means that the running command line environment does not depend on reading from the (possibly slow) initial boot media anymore.

Log-in is possible as the user root with its initially empty password.

Then an interactive script called setup-alpine is available at the command line, to configure and install the initial Alpine Linux system.

If the installation should go onto a harddisk, but not overwrite and use the entire disk, or a custom partition layout of the harddisk is desired, this can be configured beforehand. For how to do this, or how to set up RAID, encryption, LVM, etc., see Setting_up_disks_manually.

There are also some more specific setup-scripts available. For example, setup-apkrepos to allow using the apk package manager to install any tool that may be missing. The command line therefore allows to optionally prepare the system before running the interactive setup-alpine script, or, to fine-tune a newly installed system before finally booting it for the first time.

Note that setup-alpine can configure the system to boot into one of three Alpinelinux disk modes, "diskless", "data", and "sys":

Diskless Mode

This is the default boot mode of the .iso images, and setup-alpine configures this if selecting to install to "disk=none". It means that the whole operating system and all applications are loaded into, and then run from, RAM memory. This is extremely fast and can save on unnecessary disk spin-ups, power, and wear.

Customized configurations and package selections may be preserved across reboots, by committing a local backup of the system state to writable storage with lbu commit. And booting with additionally installed packages may also be accellerated by enabling a local package cache.

[ FIXME-1: Storing local configs and the package cache still requires some manual steps to prepare a partition before running setup-alpine and to commit this configuration afterwards.]

To allow for local backups, setup-alpine can configure to store the configs and the package cache on a writable partition. (That same partition may later also be used by individually configuring some important applications to keep their run-time data on it.)

The boot device of the newly configured local 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 is still accelerated by running the system from RAM, however swap storage and the whole /var directory tree gets 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. The mode is useful for having RAM accelerated servers with amounts of variable user-data that exceed the available RAM size, and to let the entire current system state (not just the boot state) survive a system crash according to the particular filesystem's guarantees.

[ FIXME-2: Setup-alpine can not yet configure to store lbu configs to the "data disk" after configuring the data partition. One must still first select to save configs to "none" in setup-alpine (the new data partition is not listed), and has to manually edit /etc/lbu/lbu.conf to set e.g. LBU_MEDIA=sda2, execute a corresponding echo "/dev/sda2 /media/sda2 vfat rw 0 0" >> /etc/fstab afterwards, and save the config with lbu commit to have the partition (here sda2) mounted when booting.]

In data disk mode, the boot device may also remain the initial (and possibly read-only) installation media, or be copied over 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 defaults to create 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.

And to install along another operating systems, see Installing_Alpine_on_HDD_dualbooting.

Additional Details

This material needs expanding ...

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 - ? -
BSD - ? - /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

Under Unix (and thus Linux), "everything is a file" and the data in the image-file can be written onto a device or media with the dd command. Afterwards, eject can remove the target device from the system, to ensure the completion of all writes and clearing of the cache. 

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

Be careful to correctly identify the target device to overwrite, because all previous 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 to write the image to here, then first make sure to un-mount all mounted partitions of the target device individually. For example sdX1 and sdX2. 

umount  /dev/sdX1  /dev/sdX2


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

Warning: This will completely erase the target device /dev/sdX, so before executing, make sure to really have a backup of the data if still need. 

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

Verifying the written installation media

After detaching and re-attaching the device, a bit-wise comparison can verify what has been 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 has been written (and read again) 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 selection for choosing the media to boot from. Depending on the computer the menu may be accessed by quickly (repeatedly) pressing a key when booting starts, or sometimes it is needed to press the button before starting the computer and keep holding it when it 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.`

Custom partitioning of the harddisk

Custom partitioning may be needed for "diskless" or "data disk" mode installs, to create a partition on the harddisk for committing a local backup of the system state to with lbu commit, or to use as the /var mount.

For a "sys" install, a custom partitioning is only needed if the wanted scheme differs from using a whole disk and creating the default /boot, swap and root partitions.

See Setting_up_disks_manually about alpine options for RAID, encryption, LVM, etc.

Manual partitioning is possible using fdisk <target device> which provides a basic text menu interface. A slightly more sophisticated tool can be installed with apk add cfdisk.

Questions asked by setup-alpine

Example setup-alpine session

The setup-alpine script offers to configure:

  • 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. For privacy reasons it is NOT recommended to route every local request to servers like google's 8.8.8.8 .)
  • 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 to trust giving your usage patterns.)
  • SSH (Remote login server. The "openssh" is part of the default install images. Use "none" to disable remote logins, e.g. on laptops.)
  • NTP (Client package to use for keeping the system clock in sync. Package "chrony" is part of the default install images.)
  • Disk Mode (Select between diskless (disk="none"), "data" or "sys", as described above.)
 The data on a chosen device will be overwritten!


Preparing for the first boot

If the configured disk mode was "sys", then simply removing the installation media should be enough to load the newly installed system on next boot.

If the new local system was configured to run in "diskless" or "data" mode, and you don't want to keep it booting from the initial (and possibly read-only) installation media, then the boot system needs to be copied to a 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.

Suppose the target device is /dev/sdXY, then this partition can be prepared for booting with setup-bootable /dev/sdXY.

If code>setup-bootable table was successful, the initial installation media needs to be detatched for the next boot.

Rebooting and testing the new system

When everthing is ready, the system may be power-cycled or rebooted to confirm that everything is working.

The relevant commands for this are reboot or poweroff.


Customizing the installation

The installation script only installs the base operating system. No applications such as a web server, mail server, desktop environment, or web browser are installed, and root is the only user.

Please see the "Post-Install" below, for some common things to do after installation.

Further Documentation

Installing


Post-Install

  • Manual pages are shipped in separate *-doc packages, apk add docs will keep the docs of all installed packages available (e.g. man apk).
  • Setting up a new user

Further Help and Information



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, like e.g. in the Arch Wiki, are to a large degree also well applicable to configure the software on alpine linux, thus can be very useful.

Other Guides

There may still be something useful to find and sort out of the "newbie" install notes in this wiki, but beware that they can contain highly opinionated content and lack explanations.

  1. Newbie_Alpine_Ecosystem
  2. Alpine newbie install manual
  3. Alpine_newbie Install section
  4. https://mckayemu.github.io/alpineinstalls/ All informatin for Spanish users
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