Alpine provided by Andronix is open source including all the scripts needed for installing it. You can take a look at it here.
Download size - 2 MB
Open the Andronix App and click on the Alpine card.
Click the Install button.
The first three options will install Ubuntu 19 with the mentioned Desktop Environment. The last Non-DE variant installs Alpine without any Desktop Environment and is recommended for using the distro only with a Command Line Interface.
Use the command below to update your termux packages so that you're running the updated versions of the required packages.
Tap & hold anywhere on the screen and press Paste.
Press Enter and wait till the installation completes.
Type the following command to start the distro and press enter.
Now if you see
[email protected] in Termux then you have successfully started Alpine.