chore(nix): refactor, fix library packages

ci/Jenkinsfile.nix-flake

@@ -47,13 +47,13 @@ pipeline {
           steps { script {
             sh("""#!/usr/bin/env bash
               ${nix._sourceProfileInline()}
-              nix build --print-out-paths .#library
+              nix build --print-out-paths .#dynamic-library
             """)
           } }
         }
         stage('Check') {
           steps {
-            sh 'ldd ./result/bin/c'
+            sh 'ldd ./result/bin/libgowaku.a'
           }
         }
       }

default.nix

@@ -0,0 +1,36 @@
+{
+  pkgs ? import <nixpkgs> { },
+  self ? ./.,
+  subPkgs ? "cmd/waku",
+  ldflags ? [],
+  cgoLdflags ? "",
+  output ? null,
+  commit ? builtins.substring 0 7 (self.rev or "dirty"),
+  version ? builtins.readFile ./VERSION,
+}:
+
+pkgs.buildGo120Module {
+  name = "go-waku";
+  src = self;
+
+  subPackages = subPkgs;
+  tags = ["gowaku_no_rln"];
+  ldflags = [
+    "-X github.com/waku-org/go-waku/waku/v2/node.GitCommit=${commit}"
+    "-X github.com/waku-org/go-waku/waku/v2/node.Version=${version}"
+  ] ++ ldflags;
+  CGO_LDFLAGS = cgoLdflags;
+  GOGCCFLAGS = "-fPIC";
+  doCheck = false;
+
+  # Otherwise library would be just called bin/c.
+  postInstall = if builtins.isString output then ''
+    mv $out/bin/* $out/bin/${output}
+  '' else "";
+
+  # FIXME: This needs to be manually changed when updating modules.
+  vendorHash = "sha256-pNkh5ZJEhC/X/SoqfWcm3w7W1EGOT3m2dzePM/XuA9w=";
+
+  # Fix for 'nix run' trying to execute 'go-waku'.
+  meta = { mainProgram = "waku"; };
+}

flake.nix

@@ -34,17 +34,32 @@
           meta = { mainProgram = "waku"; };
         };
     in rec {
-      packages = forAllSystems (system: {
-        node    = buildPackage system ["cmd/waku"];
-        library = buildPackage system ["library/c"];
+      packages = forAllSystems (system: let
+        pkgs = pkgsFor.${system};
+        buildPackage = pkgs.callPackage ./default.nix;
+      in rec {
+        default = node;
+        node = buildPackage {
+          inherit self;
+          subPkgs = ["cmd/waku"];
+        };
+        static-library = buildPackage {
+          inherit self;
+          subPkgs = ["library/c"];
+          ldflags = ["-buildmode=c-archive"];
+          output = "libgowaku.a";
+        };
+        dynamic-library = buildPackage {
+          inherit self;
+          subPkgs = ["library/c"];
+          ldflags = ["-buildmode=c-shared"];
+          cgoLdflags = "-Wl,-Bsymbolic,-soname,libgowaku.so.0";
+          output = "libgowaku.so";
+        };
       });
 
-      defaultPackage = forAllSystems (system:
-        buildPackage system ["cmd/waku"]
-      );
-
       devShells = forAllSystems (system: let
-        pkgs = nixpkgsFor.${system};
+        pkgs = pkgsFor.${system};
         inherit (pkgs) lib stdenv mkShell;
       in {
         default = mkShell {