Upgrade to repository main
This material is obsolete ...
This was for older Alpine systems. (Discuss)
How to upgrade to signed repositories
From Alpine 1.9 alpha18 and newer the packages and repositories are signed. Due to this change the index format changed. Index was also renamed from APK_INDEX.gz to APKINDEX.tar.gz.
We used this occation to also merge the core and extra repositories into a single repository: main.
If you boot from CF, USB, or cdrom and run from tmpfs, then it's just a matter of replacing the boot media and reboot. If you boot and run from a harddisk, then it's really recommended to reinstall the system.
This document shows how to upgrade to the signed 'main' repository if you still want to try it. It might work, it might not.
Before you start, you should make a backup of your configuration. This can be done with the lbu utility.
lbu package backup.apkovl.tar.gz
Copy the backup.apkovl.tar.gz to a safe place. Might be handy in case the upgrade fail and you end up reinstalling.
Upgrading basic packages
Then you will need a newer version of apk-tools. Use wget to download a static version of apk.
wget http://dl-3.alpinelinux.org/alpine/v1.9/apk.static chmod +x apk.static
Verify that the apk version is atleast 2.0_rc1.
Now, replace the 'core' and 'extra' repositories with 'main' in '/etc/apk/repositories' with a text editor.
Then upgrade latest alpine-base, which will include the needed keys.
./apk.static add --update-cache --upgrade --allow-untrusted alpine-base
Now we should have the keys and latest apk-tools. Start the upgrade and re-install of the recompiled and signed packages.
Note: It might work, it might break your system, so, again, make sure you have that backup.
apk upgrade --available
If things went well, it should be a matter of rebooting and you are done.