Allow installing packages with apt-get

[dmbaturin]

What's the reason not to allow users to install packages from the standard APT repos?

#411 adds homebrew, but it means everything will be rebuilt from source every time, even tools that are available as binary packages from the repos.

[sztomi]

I'm running into a lot of trouble because of this as well. There is no reason to disallow package installation in a container.

This seems to be the official answer to this:

However, with the newer build image being so out of date (16.04 was released 5 years ago!), it's getting really difficult to just grab a binary from somewhere on the internet and run it (the glibc version will be too old). I want to do a really simple thing: iterate all my images and create a webp version. But webp is missing in the container. I could apt-get install it, but that is not allowed.

[dmbaturin]

@sztomi Do you have a link to that thread?

Also, even if the image wasn't so old, there are still many reasons to install packages with APT.

• Many tools available from Ubuntu repos do not have readily available single binary or AppImage versions.
• Some packages require data (e.g. spell checker dictionaries). Installing with APT will usually give you a complete setup at once, without it you need to repeat the packager's work.
• If you are using a tool for your local builds but cannot install it in the build image, you need to adjust your build procedures just for Netlify.

Last but not least, I believe Netlify is the only CI service that for some reason disallows installing packages. I like the hosting part, but when I started using it, it never came to my mind to check whether installing packages is possible.

[sztomi]

@dmbaturin It's in this thread: https://answers.netlify.com/t/apt-get-install-build-dependency/3095

And I completely agree with your points. This is a baffling limitation.

[jpreynat]

Agreed. This is a huge limitation.
We have a specific Node module that requires preinstalled binaries (krb5-config) to compile through node-gyp, and there's nothing we can do about it because of this limitation.

Using a custom Docker image would also work, but apt-get seems the most decent solution for 99% of use-cases.

[hwittenborn]

Agreed. This is a huge limitation.

I'm feeling that too - a project I work on needs libapt-pkg-dev installed so that it can properly build some development documentation, and that's currently impossible. The package can't even be manually downloaded with apt download libapt-pkg-dev as the cache appears to be being cleared before the image is built or something.