How to enable APK caching

Enabling Package Caching

Note: This document applies to Alpine 1.9 and later versions only

Package caching is useful when the need arises to upgrade packages on read-only media. Package caching allows you to store newer packages in a location on writable media, which Alpine checks for when loading packages on start-up.

This can be enabled either from the console or through the ACF.

Tip: For package upgrades, it is useful to point Alpine Package Manager to repositories on the internet, to easily obtain package upgrades when they become available.

Edit the /etc/apk/repositories file using an editor (nano for instance) and if necessary, add references to the Alpine package repositories. In the example below, the reference to the Alpine CD is maintained, so that if the requested package is available on the local media, it will be obtained from there instead of being downloaded from the remote repository:

Contents of /etc/apk/repositories

/media/cdrom/apks http://dl-3.alpinelinux.org/alpine/v3.3/main

Another example: upgrading from version 3.3 to 3.4 simply change:

http://dl-3.alpinelinux.org/alpine/v3.3/main

to

 http://dl-3.alpinelinux.org/alpine/v3.4/main

Thus, the file will now look like this:

Contents of /etc/apk/repositories

/media/cdrom/apks http://dl-3.alpinelinux.org/alpine/v3.4/main

Note: Starting with version 3.3, there is a new repository called community. Many packages have been moved from the main repository to community to indicate that they are not guaranteed to be supported beyond six months. If you are using any of these packages, be sure to add the community repository. For example: http://dl-3.alpinelinux.org/alpine/v3.3/community

Only one repository is shown above; however, you may also replace http://dl-3.alpinelinux.org/alpine/ with any of the mirrors from: http://rsync.alpinelinux.org/alpine/MIRRORS.txt

After updating the repositories file, obtain the latest index of available packages:

apk update

Tip: Adding the -U/--update-cache to another apk command, as in apk add -U ... or apk upgrade -U, has the same effect as running apk update before the other apk command.

Enable caching from the console

Substitute 'sda1' in the example below for the actual device you will use to store the caching directory.

First upgrade apk-tools:

apk add –u apk-tools

Now enable package caching:

mkdir –p /media/sda1/cache
ln –s /media/sda1/cache /etc/apk/cache

From the ACF

Browse to System > Packages > Cache

Edit Cache Settings:

Tick Enable Cache

Specify the Cache Directory, for example:

/media/sda1/cache

Click Save