Fix linking of libsodium for linux

[Bartel-C8]

Bumped into this issue myself when trying to build it on a Docket Debian 9 machine (circleci/node:gallium-stretch-browsers) with:

circleci@38f5f51a4027:~/git/klstr-ctrl$ cat /etc/os-release 
PRETTY_NAME="Debian GNU/Linux 9 (stretch)"
NAME="Debian GNU/Linux"
VERSION_ID="9"
VERSION="9 (stretch)"
VERSION_CODENAME=stretch
ID=debian

circleci@38f5f51a4027:~/git/klstr-ctrl$ gcc --version
gcc (Debian 8.3.0-6) 8.3.0
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

circleci@38f5f51a4027:~/git/klstr-ctrl$ cmake --version
cmake version 3.16.3

CMake suite maintained and supported by Kitware (kitware.com/cmake)

circleci@38f5f51a4027:~/git/klstr-ctrl$ node -v
v16.13.1

-- Detected ZMQ Version - 4.3.5
-- Found PkgConfig: /usr/bin/pkg-config (found version "0.29") 

-- Checking for module 'libsodium'
--   Found libsodium, version 1.0.17
-- Found sodium: /usr/lib/x86_64-linux-gnu/libsodium.so  

Compiling works fine, but when trying to run/require the .node module, I got the following error:

node: symbol lookup error: node_modules/zeromq/build/Release/zeromq.node: undefined symbol: sodium_init

I also found a bug report on stackoverflow by coincidence:
https://stackoverflow.com/questions/74796706/node-application-doesnt-start-with-zeromq-node-undefined-symbol-sodium-init

Apparently, as found in this post on stackoverflow: https://stackoverflow.com/questions/57740825/use-libsodium-in-napi, bindings.gyp also needs the libsodium libraries dependency in order to link properly.

I did not change anything for Windows. As I suspect everything works okay there.
I guess it's also OS/gcc/cmake/node related. As on my other VM build machine (Ubuntu 20.04 / gcc 9.4.0 / cmake 3.16.3 / node v18.12.1), I didn't have linker problems.
I switched to an older build system as my findings of incompatible GLIBC versions, as described here: #529 (comment)

For setting up the docker build environment (maybe for future reference, as it was quite a pain: python 3.6 dependency, cmake 3.13+ dependency (https://stackoverflow.com/questions/68986713/git-bash-on-windows-cmake-error-the-source-directory-does-not-exists#comment121926826_68987727) / gcc 7+ (c++17) ):

  # Add the repository key
  - wget https://people.debian.org/~paravoid/python-all/unofficial-python-all.asc
  - sudo mv unofficial-python-all.asc /etc/apt/trusted.gpg.d/
  # Add the repository to your sources.list
  - sudo apt-get remove python3.5 gcc
  - sudo apt autoremove
  - echo "deb http://people.debian.org/~paravoid/python-all stretch main" | sudo tee /etc/apt/sources.list.d/python-all.list
  - echo "deb http://ftp.debian.org/debian stretch-backports-sloppy main" | sudo tee /etc/apt/sources.list.d/backports.list
  - echo "deb http://ftp.debian.org/debian buster main" | sudo tee /etc/apt/sources.list.d/buster.list
  - sudo apt-get update
  - sudo apt-get install -y --no-install-recommends --no-install-suggests python3.6 pkg-config libsodium-dev
  - sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.6 1
  - sudo apt-get install -y -t stretch-backports-sloppy libarchive13
  - sudo apt-get install -y -t stretch-backports cmake
  - sudo apt-get install -y -t buster gcc-8 g++ build-essential
  - export NODE_OPTIONS="--max-old-space-size=4096"

[Bartel-C8]

Build fails now:

Actually, it is a correct bug/warning, as currently for linux builds, libsodium is not used, but defined as statically loaded:
https://github.com/zeromq/zeromq.js/actions/runs/3642070979/jobs/6148750421

-- Checking for module 'libsodium'
--   No package 'libsodium' found
-- Checking for module 'sodium'
--   No package 'sodium' found
CMake Warning (dev) at /home/runner/cmake/cmake-3.25.0-linux-x86_64/share/cmake-3.25/Modules/FindPackageHandleStandardArgs.cmake:438 (message):
-- Could NOT find sodium (missing: SODIUM_LIBRARIES SODIUM_INCLUDE_DIRS) 
  The package name passed to `find_package_handle_standard_args` (sodium)
  does not match the name of the calling package (Sodium).  This can lead to
  problems in calling code that expects `find_package` result variables
  (e.g., `_FOUND`) to follow a certain pattern.
Call Stack (most recent call first):
  builds/cmake/Modules/FindSodium.cmake:42 (find_package_handle_standard_args)
  CMakeLists.txt:266 (find_package)
This warning is for project developers.  Use -Wno-dev to suppress it.

CMake Warning at CMakeLists.txt:280 (message):
-- Using tweetnacl for CURVE security
-- Looking for kqueue
  libsodium not installed, instead using builtin tweetnacl, you may want to
  install libsodium and run cmake again

So I will add libsodium to the linux build environment?

We should consider adding libsodium-cmake as a build dependency from source maybe, to make it more easy/clear?

https://github.com/robinlinden/libsodium-cmake

[aminya]

This should not be needed here since it is handled inside CMake.
Do you get an error without this?

[Bartel-C8]

I know. But somehow it is needed for node-gyp in order to resolve symbols properly!
(In older build systems)
I verified this on the setup described above.

No compile error without this, but a runtime error:

bartel@ubuntu:~/Desktop/linux-unpacked$ node test.js 
node: symbol lookup error: node_modules/zeromq/build/Release/zeromq.node: undefined symbol: sodium_init

bartel@ubuntu:~/Desktop/linux-unpacked$ cat test.js 
const zeromq = require("./node_modules/zeromq/build/Release/zeromq.node")
console.log(zeromq)

[mgrewe]

Hi, I can confirm that this solved my issue with compiling native library for usage with electron (requires build against specific node version) on Linux (up-to-date Manjaro/Arch). Is there any chance to have this fix in official package? Cheers, Martin