Doesn't work in alpine docker container

[jfrolich]

sh: /opt/app/cms/node_modules/gentype/gentype.exe: not found

Graphq_ppx_re had the same problem:

teamwalnut/graphql-ppx#44
teamwalnut/graphql-ppx#60

[cristianoc]

@jfrolich are executables built on alpine compatible with other distributions and not the other way around?
These are the current Azure CI settings:

  - template: .ci/build-platform.yml
    parameters:
      platform: Linux
      vmImage: ubuntu-16.04

[cristianoc]

Feel free to send a PR and we can test it.

[jfrolich]

Yes I believe you can just use an alpine container, and then it also works on other distributions.

[baransu]

It requires building on alpine and using static linking. I figured it out thanks to @anmonteiro help

[cristianoc]

Is there an example of doing that on Azure?

[baransu]

I'm not sure.

I'm using dune-workspace and custom release profile for that:
https://github.com/baransu/graphql_ppx_re/blob/master/dune-workspace#L3
https://github.com/baransu/graphql_ppx_re/blob/master/.github/workflows/pipeline.yml#L51

I'm also using custom docker container with esy preinstalled on alpine:
https://github.com/baransu/graphql_ppx_re/blob/master/.github/workflows/pipeline.yml#L16

I'm not familiar with how genType release pipeline works. I hope it will help.

[jfrolich]

Feel free to send a PR and we can test it.

Sorry I indeed found out that genType was not already using docker. So this is probably not an easy PR. Not sure if this is already tackled in https://github.com/jchavarri/hello-ppx-esy, but that repo is a great PPX starter with CI etc. set up. It might make sense to adopt this standard tooling so every improvement to that is easy to pull in to individual ppx-es. (Just an idea).

[cristianoc]

@jfrolich probably a good idea to continue the discussion on discord in the native-development channel, as this is going to affect other projects too. Doing it now.

[cristianoc]

Btw genType produces a single binary and has zero dependencies, so a quick workaround is to just build from source, while a CI solution is investigated.

[baransu]

It seems there is a fix which doesn't require genType to be compiled with alpine: facebook/flow#3649 (comment)
You have to add:

RUN wget -q -O /etc/apk/keys/sgerrand.rsa.pub https://alpine-pkgs.sgerrand.com/sgerrand.rsa.pub && \
    wget https://github.com/sgerrand/alpine-pkg-glibc/releases/download/2.25-r0/glibc-2.25-r0.apk && \
    apk add glibc-2.25-r0.apk

It slightly increases image size but works with the current version of genType and flow in that case which also by default doesn't work on alpine.

[cristianoc]

@baransu thanks for the reference.
The next question is how to do that on azure.

[cristianoc]

@baransu thanks for the reference.
The next question is how to do that on azure.

Actually, I might have misunderstood the point. Are you saying that it's not necessary to make an alpine build at all?

[baransu]

Probably yes. I've added the above snippet and created a custom docker image based on alpine with that line. Now genType and flow (I'm also using) works. The downside is the size of the container but I really don't care.

[jfrolich]

Yeah, that fixes it because the dynamic dependency on glibc (which is quite big). To make a static binary you can compile it with musl-libc. Then it will work everywhere, even on systems that do not have glibc (like small docker images). To do that you can install musl on the CI and add a compiler flag:
https://wiki.musl-libc.org/getting-started.html#Building-a-cross-compiler-targeting-musl-libc.

[anmonteiro]

I'm still in the camp of shipping a fully static binary, given that there are Linux distributions that are explicitly no FHS compliant. NixOS is the example I use.

[cristianoc]

@anmonteiro if we find a general way to do this for esy projects, we can reuse it.
Looks like Azure only has a couple of linux distros, and we're currently using ubuntu. Not sure if one would have to use a docker container on top, or how else to generate the binary.

[anmonteiro]

it should be straightforward to install musl-tools in Ubuntu and use that.

[cristianoc]

Closing for now.

[phenax]

+1 for statically linked binary. Facing the same issue on NixOS.

[quinn-dougherty]

Is this related to gentype not installed correctly warning leading to .gen files not being produced? On nixos in a flake. I'm trying it with and without patchelfing.

[quinn-dougherty]

Yeah, that fixes it because the dynamic dependency on glibc (which is quite big). To make a static binary you can compile it with musl-libc. Then it will work everywhere, even on systems that do not have glibc (like small docker images). To do that you can install musl on the CI and add a compiler flag:
https://wiki.musl-libc.org/getting-started.html#Building-a-cross-compiler-targeting-musl-libc.

What would this look like in a yarn install workflow?

[cristianoc]

The project has moved inside the upcoming v10.1 compiler. No need to install genType separately in future.

[cristianoc]

The project page will change once v10.1 is out and used regularly.