Installing Go Lang on Alpine Linux#

In my previous post I showed how you can build your own WSL distro from Alpine root image. If you followed along, and then proceded to use the resulting distro, you would have been very frusted....I apoligize.

The first attempt at installing any real language like Go or Rust or NodeJS would have resulted in another explosion of packages.

I chose Alpine thinking that since this is used so heavily to package apps into docker images, it really must have been silm and dependency free. I tried installing Go Language from apk package manager and it started pulling libgcc, gcc and a bunch of other libraries.

Seeing this heavy handed approach, I decided to start over. I downloaded the prebuilt Go binaries straight from the source, but I ran into a few caveats so I decided to document the entire process here:

Download the compressed archive:

$ cd /usr/bin $ wget https://golang.org/GetYourProperLinuxURL
$ tar -xf golang-linux.tar.gz ## This is an example file name.
$ rm golang-linux.tar.gz

Add the Go Lang binaries path to your PATH environment variable:
```
$ PATH="$PATH:/usr/bin/go/bin"
```
You can also directly edit your /etc/profile file and add /usr/bin/go/bin at the end of your PATH variable's list of values.
Try running Go
```
$ go version -ash: go: not found
```
However, gofmt would be working fine!
```
$ gofmt
```
Try not to lose your mind after this incredulity. Let's debug this by inspecting the go binary in /usr/bin/go/bin.
Install file and patchelf packages.
```
$ apk add file patchelf
```
Don't fret about these, we will get rid of them very soon.
Inspect the Package:
```
/usr/bin/go/bin $ file go hugo
.... dynamically linked, **interpreter /lib64/ld-linux-x86-64.so.2 ...
```
So the interpreter is set to ld-linux-x86... we will simply swap it with Alpine's default /lib/libc.musl-x86_64.so.1

To know your default interpreter in Alpine simply go to /lib and look for a name like ld-musl-...-so.1 and alongside will be a file libc.musl... which would be a symlink to the original ld-musl... interpreter. We will use this symlink, since package managers may update the original interpreter and redirect this symlink to the updated file.

To update the interpreter we will use patchelf:

$ patchelf --set-interpreter /lib/libc.musl-x86_64.so.1 go

Test if everything is working.
```
$ go version go version go1.15.3 linux/amd64
```
I also tested this by compiling hugo project with CGO enabled it worked without any hiccups. With the only side-effect that the resulting binary was also linked to the original ld-linux file and needed to patch the resulting hugo binary as well.
You no longer need file and patchelf, if you are building statically linked binaries. Feel free to remove them.
```
$ apk del -r patchelf file
```

Fin.#

Hope you found this helpful. If I have done something incredibly stupid and there's a simple configuration option to change the interpreter from ld-linux to libc.musl please let me know. :)