Add nix flake support

With this commit, we add nix flake support. Flakes are evaluated in pure
evaluation mode. The script generate.sh does not work in pure evaluation
mode since it node2nix fetches itself resources from the network. In
order to enable pure evaluation, we add the generated nix files to this
repository.

.gitignore

@@ -1,4 +1 @@
-node-env.nix
+/result
-node-packages.nix
-node2nix.nix
-supplement.nix

README.markdown

@@ -4,7 +4,7 @@ This repository contains files for building
 [financier](https://gitlab.com/mpuppe/financier/) with the
 [Nix](https://nixos.org/manual/nix/stable/) package manager.
 
-You first need to generate the necessary Nix files:
+First, you should update the necessary Nix files:
 
 ``` bash
 nix-shell --run 'bash generate.sh'

flake.lock

@@ -0,0 +1,41 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1631561581,
+        "narHash": "sha256-3VQMV5zvxaVLvqqUrNz3iJelLw30mIVSfZmAaauM3dA=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "7e5bf3925f6fbdfaf50a2a7ca0be2879c4261d19",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1631995179,
+        "narHash": "sha256-LvF8CexAKQl+8BInOGxBa072Pys5sqaXxulB5NdX5QM=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "ef9c06512bdec723fb3007a259c375006f422084",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,18 @@
+{
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+  outputs = { self, nixpkgs, flake-utils }:
+    let overlay = import ./overlay.nix;
+    in flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+          overlays = [ overlay ];
+        };
+      in {
+        packages = { inherit (pkgs) financier-dist; };
+        defaultPackage = self.packages.${system}.financier-dist;
+      }) // {
+        inherit overlay;
+        nixosModule = import ./module.nix;
+      };
+}

module.nix

@@ -1,8 +1,8 @@
 { config, lib, pkgs, system, ... }:
 with lib;
 let
+  inherit (pkgs) financier-dist;
   cfg = config.services.financier;
-  financier-dist = import ./dist.nix { inherit pkgs system; };
 in {
   imports = [ ];
 
@@ -29,6 +29,8 @@ in {
   };
 
   config = mkIf cfg.enable {
+    nixpkgs.overlays = [ (import ./overlay.nix) ];
+
     networking.firewall.allowedTCPPorts = [ 80 443 ];
 
     services.nginx = mkIf (cfg.server == "nginx") {

node-env.nix

@@ -0,0 +1,567 @@
+# This file originates from node2nix
+
+{lib, stdenv, nodejs, python2, pkgs, libtool, runCommand, writeTextFile}:
+
+let
+  # Workaround to cope with utillinux in Nixpkgs 20.09 and util-linux in Nixpkgs master
+  utillinux = if pkgs ? utillinux then pkgs.utillinux else pkgs.util-linux;
+
+  python = if nodejs ? python then nodejs.python else python2;
+
+  # Create a tar wrapper that filters all the 'Ignoring unknown extended header keyword' noise
+  tarWrapper = runCommand "tarWrapper" {} ''
+    mkdir -p $out/bin
+
+    cat > $out/bin/tar <<EOF
+    #! ${stdenv.shell} -e
+    $(type -p tar) "\$@" --warning=no-unknown-keyword --delay-directory-restore
+    EOF
+
+    chmod +x $out/bin/tar
+  '';
+
+  # Function that generates a TGZ file from a NPM project
+  buildNodeSourceDist =
+    { name, version, src, ... }:
+
+    stdenv.mkDerivation {
+      name = "node-tarball-${name}-${version}";
+      inherit src;
+      buildInputs = [ nodejs ];
+      buildPhase = ''
+        export HOME=$TMPDIR
+        tgzFile=$(npm pack | tail -n 1) # Hooks to the pack command will add output (https://docs.npmjs.com/misc/scripts)
+      '';
+      installPhase = ''
+        mkdir -p $out/tarballs
+        mv $tgzFile $out/tarballs
+        mkdir -p $out/nix-support
+        echo "file source-dist $out/tarballs/$tgzFile" >> $out/nix-support/hydra-build-products
+      '';
+    };
+
+  includeDependencies = {dependencies}:
+    lib.optionalString (dependencies != [])
+      (lib.concatMapStrings (dependency:
+        ''
+          # Bundle the dependencies of the package
+          mkdir -p node_modules
+          cd node_modules
+
+          # Only include dependencies if they don't exist. They may also be bundled in the package.
+          if [ ! -e "${dependency.name}" ]
+          then
+              ${composePackage dependency}
+          fi
+
+          cd ..
+        ''
+      ) dependencies);
+
+  # Recursively composes the dependencies of a package
+  composePackage = { name, packageName, src, dependencies ? [], ... }@args:
+    builtins.addErrorContext "while evaluating node package '${packageName}'" ''
+      DIR=$(pwd)
+      cd $TMPDIR
+
+      unpackFile ${src}
+
+      # Make the base dir in which the target dependency resides first
+      mkdir -p "$(dirname "$DIR/${packageName}")"
+
+      if [ -f "${src}" ]
+      then
+          # Figure out what directory has been unpacked
+          packageDir="$(find . -maxdepth 1 -type d | tail -1)"
+
+          # Restore write permissions to make building work
+          find "$packageDir" -type d -exec chmod u+x {} \;
+          chmod -R u+w "$packageDir"
+
+          # Move the extracted tarball into the output folder
+          mv "$packageDir" "$DIR/${packageName}"
+      elif [ -d "${src}" ]
+      then
+          # Get a stripped name (without hash) of the source directory.
+          # On old nixpkgs it's already set internally.
+          if [ -z "$strippedName" ]
+          then
+              strippedName="$(stripHash ${src})"
+          fi
+
+          # Restore write permissions to make building work
+          chmod -R u+w "$strippedName"
+
+          # Move the extracted directory into the output folder
+          mv "$strippedName" "$DIR/${packageName}"
+      fi
+
+      # Unset the stripped name to not confuse the next unpack step
+      unset strippedName
+
+      # Include the dependencies of the package
+      cd "$DIR/${packageName}"
+      ${includeDependencies { inherit dependencies; }}
+      cd ..
+      ${lib.optionalString (builtins.substring 0 1 packageName == "@") "cd .."}
+    '';
+
+  pinpointDependencies = {dependencies, production}:
+    let
+      pinpointDependenciesFromPackageJSON = writeTextFile {
+        name = "pinpointDependencies.js";
+        text = ''
+          var fs = require('fs');
+          var path = require('path');
+
+          function resolveDependencyVersion(location, name) {
+              if(location == process.env['NIX_STORE']) {
+                  return null;
+              } else {
+                  var dependencyPackageJSON = path.join(location, "node_modules", name, "package.json");
+
+                  if(fs.existsSync(dependencyPackageJSON)) {
+                      var dependencyPackageObj = JSON.parse(fs.readFileSync(dependencyPackageJSON));
+
+                      if(dependencyPackageObj.name == name) {
+                          return dependencyPackageObj.version;
+                      }
+                  } else {
+                      return resolveDependencyVersion(path.resolve(location, ".."), name);
+                  }
+              }
+          }
+
+          function replaceDependencies(dependencies) {
+              if(typeof dependencies == "object" && dependencies !== null) {
+                  for(var dependency in dependencies) {
+                      var resolvedVersion = resolveDependencyVersion(process.cwd(), dependency);
+
+                      if(resolvedVersion === null) {
+                          process.stderr.write("WARNING: cannot pinpoint dependency: "+dependency+", context: "+process.cwd()+"\n");
+                      } else {
+                          dependencies[dependency] = resolvedVersion;
+                      }
+                  }
+              }
+          }
+
+          /* Read the package.json configuration */
+          var packageObj = JSON.parse(fs.readFileSync('./package.json'));
+
+          /* Pinpoint all dependencies */
+          replaceDependencies(packageObj.dependencies);
+          if(process.argv[2] == "development") {
+              replaceDependencies(packageObj.devDependencies);
+          }
+          replaceDependencies(packageObj.optionalDependencies);
+
+          /* Write the fixed package.json file */
+          fs.writeFileSync("package.json", JSON.stringify(packageObj, null, 2));
+        '';
+      };
+    in
+    ''
+      node ${pinpointDependenciesFromPackageJSON} ${if production then "production" else "development"}
+
+      ${lib.optionalString (dependencies != [])
+        ''
+          if [ -d node_modules ]
+          then
+              cd node_modules
+              ${lib.concatMapStrings (dependency: pinpointDependenciesOfPackage dependency) dependencies}
+              cd ..
+          fi
+        ''}
+    '';
+
+  # Recursively traverses all dependencies of a package and pinpoints all
+  # dependencies in the package.json file to the versions that are actually
+  # being used.
+
+  pinpointDependenciesOfPackage = { packageName, dependencies ? [], production ? true, ... }@args:
+    ''
+      if [ -d "${packageName}" ]
+      then
+          cd "${packageName}"
+          ${pinpointDependencies { inherit dependencies production; }}
+          cd ..
+          ${lib.optionalString (builtins.substring 0 1 packageName == "@") "cd .."}
+      fi
+    '';
+
+  # Extract the Node.js source code which is used to compile packages with
+  # native bindings
+  nodeSources = runCommand "node-sources" {} ''
+    tar --no-same-owner --no-same-permissions -xf ${nodejs.src}
+    mv node-* $out
+  '';
+
+  # Script that adds _integrity fields to all package.json files to prevent NPM from consulting the cache (that is empty)
+  addIntegrityFieldsScript = writeTextFile {
+    name = "addintegrityfields.js";
+    text = ''
+      var fs = require('fs');
+      var path = require('path');
+
+      function augmentDependencies(baseDir, dependencies) {
+          for(var dependencyName in dependencies) {
+              var dependency = dependencies[dependencyName];
+
+              // Open package.json and augment metadata fields
+              var packageJSONDir = path.join(baseDir, "node_modules", dependencyName);
+              var packageJSONPath = path.join(packageJSONDir, "package.json");
+
+              if(fs.existsSync(packageJSONPath)) { // Only augment packages that exist. Sometimes we may have production installs in which development dependencies can be ignored
+                  console.log("Adding metadata fields to: "+packageJSONPath);
+                  var packageObj = JSON.parse(fs.readFileSync(packageJSONPath));
+
+                  if(dependency.integrity) {
+                      packageObj["_integrity"] = dependency.integrity;
+                  } else {
+                      packageObj["_integrity"] = "sha1-000000000000000000000000000="; // When no _integrity string has been provided (e.g. by Git dependencies), add a dummy one. It does not seem to harm and it bypasses downloads.
+                  }
+
+                  if(dependency.resolved) {
+                      packageObj["_resolved"] = dependency.resolved; // Adopt the resolved property if one has been provided
+                  } else {
+                      packageObj["_resolved"] = dependency.version; // Set the resolved version to the version identifier. This prevents NPM from cloning Git repositories.
+                  }
+
+                  if(dependency.from !== undefined) { // Adopt from property if one has been provided
+                      packageObj["_from"] = dependency.from;
+                  }
+
+                  fs.writeFileSync(packageJSONPath, JSON.stringify(packageObj, null, 2));
+              }
+
+              // Augment transitive dependencies
+              if(dependency.dependencies !== undefined) {
+                  augmentDependencies(packageJSONDir, dependency.dependencies);
+              }
+          }
+      }
+
+      if(fs.existsSync("./package-lock.json")) {
+          var packageLock = JSON.parse(fs.readFileSync("./package-lock.json"));
+
+          if(![1, 2].includes(packageLock.lockfileVersion)) {
+             process.stderr.write("Sorry, I only understand lock file versions 1 and 2!\n");
+             process.exit(1);
+          }
+
+          if(packageLock.dependencies !== undefined) {
+              augmentDependencies(".", packageLock.dependencies);
+          }
+      }
+    '';
+  };
+
+  # Reconstructs a package-lock file from the node_modules/ folder structure and package.json files with dummy sha1 hashes
+  reconstructPackageLock = writeTextFile {
+    name = "addintegrityfields.js";
+    text = ''
+      var fs = require('fs');
+      var path = require('path');
+
+      var packageObj = JSON.parse(fs.readFileSync("package.json"));
+
+      var lockObj = {
+          name: packageObj.name,
+          version: packageObj.version,
+          lockfileVersion: 1,
+          requires: true,
+          dependencies: {}
+      };
+
+      function augmentPackageJSON(filePath, dependencies) {
+          var packageJSON = path.join(filePath, "package.json");
+          if(fs.existsSync(packageJSON)) {
+              var packageObj = JSON.parse(fs.readFileSync(packageJSON));
+              dependencies[packageObj.name] = {
+                  version: packageObj.version,
+                  integrity: "sha1-000000000000000000000000000=",
+                  dependencies: {}
+              };
+              processDependencies(path.join(filePath, "node_modules"), dependencies[packageObj.name].dependencies);
+          }
+      }
+
+      function processDependencies(dir, dependencies) {
+          if(fs.existsSync(dir)) {
+              var files = fs.readdirSync(dir);
+
+              files.forEach(function(entry) {
+                  var filePath = path.join(dir, entry);
+                  var stats = fs.statSync(filePath);
+
+                  if(stats.isDirectory()) {
+                      if(entry.substr(0, 1) == "@") {
+                          // When we encounter a namespace folder, augment all packages belonging to the scope
+                          var pkgFiles = fs.readdirSync(filePath);
+
+                          pkgFiles.forEach(function(entry) {
+                              if(stats.isDirectory()) {
+                                  var pkgFilePath = path.join(filePath, entry);
+                                  augmentPackageJSON(pkgFilePath, dependencies);
+                              }
+                          });
+                      } else {
+                          augmentPackageJSON(filePath, dependencies);
+                      }
+                  }
+              });
+          }
+      }
+
+      processDependencies("node_modules", lockObj.dependencies);
+
+      fs.writeFileSync("package-lock.json", JSON.stringify(lockObj, null, 2));
+    '';
+  };
+
+  prepareAndInvokeNPM = {packageName, bypassCache, reconstructLock, npmFlags, production}:
+    let
+      forceOfflineFlag = if bypassCache then "--offline" else "--registry http://www.example.com";
+    in
+    ''
+        # Pinpoint the versions of all dependencies to the ones that are actually being used
+        echo "pinpointing versions of dependencies..."
+        source $pinpointDependenciesScriptPath
+
+        # Patch the shebangs of the bundled modules to prevent them from
+        # calling executables outside the Nix store as much as possible
+        patchShebangs .
+
+        # Deploy the Node.js package by running npm install. Since the
+        # dependencies have been provided already by ourselves, it should not
+        # attempt to install them again, which is good, because we want to make
+        # it Nix's responsibility. If it needs to install any dependencies
+        # anyway (e.g. because the dependency parameters are
+        # incomplete/incorrect), it fails.
+        #
+        # The other responsibilities of NPM are kept -- version checks, build
+        # steps, postprocessing etc.
+
+        export HOME=$TMPDIR
+        cd "${packageName}"
+        runHook preRebuild
+
+        ${lib.optionalString bypassCache ''
+          ${lib.optionalString reconstructLock ''
+            if [ -f package-lock.json ]
+            then
+                echo "WARNING: Reconstruct lock option enabled, but a lock file already exists!"
+                echo "This will most likely result in version mismatches! We will remove the lock file and regenerate it!"
+                rm package-lock.json
+            else
+                echo "No package-lock.json file found, reconstructing..."
+            fi
+
+            node ${reconstructPackageLock}
+          ''}
+
+          node ${addIntegrityFieldsScript}
+        ''}
+
+        npm ${forceOfflineFlag} --nodedir=${nodeSources} ${npmFlags} ${lib.optionalString production "--production"} rebuild
+
+        if [ "''${dontNpmInstall-}" != "1" ]
+        then
+            # NPM tries to download packages even when they already exist if npm-shrinkwrap is used.
+            rm -f npm-shrinkwrap.json
+
+            npm ${forceOfflineFlag} --nodedir=${nodeSources} ${npmFlags} ${lib.optionalString production "--production"} install
+        fi
+    '';
+
+  # Builds and composes an NPM package including all its dependencies
+  buildNodePackage =
+    { name
+    , packageName
+    , version
+    , dependencies ? []
+    , buildInputs ? []
+    , production ? true
+    , npmFlags ? ""
+    , dontNpmInstall ? false
+    , bypassCache ? false
+    , reconstructLock ? false
+    , preRebuild ? ""
+    , dontStrip ? true
+    , unpackPhase ? "true"
+    , buildPhase ? "true"
+    , ... }@args:
+
+    let
+      extraArgs = removeAttrs args [ "name" "dependencies" "buildInputs" "dontStrip" "dontNpmInstall" "preRebuild" "unpackPhase" "buildPhase" ];
+    in
+    stdenv.mkDerivation ({
+      name = "node_${name}-${version}";
+      buildInputs = [ tarWrapper python nodejs ]
+        ++ lib.optional (stdenv.isLinux) utillinux
+        ++ lib.optional (stdenv.isDarwin) libtool
+        ++ buildInputs;
+
+      inherit nodejs;
+
+      inherit dontStrip; # Stripping may fail a build for some package deployments
+      inherit dontNpmInstall preRebuild unpackPhase buildPhase;
+
+      compositionScript = composePackage args;
+      pinpointDependenciesScript = pinpointDependenciesOfPackage args;
+
+      passAsFile = [ "compositionScript" "pinpointDependenciesScript" ];
+
+      installPhase = ''
+        # Create and enter a root node_modules/ folder
+        mkdir -p $out/lib/node_modules
+        cd $out/lib/node_modules
+
+        # Compose the package and all its dependencies
+        source $compositionScriptPath
+
+        ${prepareAndInvokeNPM { inherit packageName bypassCache reconstructLock npmFlags production; }}
+
+        # Create symlink to the deployed executable folder, if applicable
+        if [ -d "$out/lib/node_modules/.bin" ]
+        then
+            ln -s $out/lib/node_modules/.bin $out/bin
+        fi
+
+        # Create symlinks to the deployed manual page folders, if applicable
+        if [ -d "$out/lib/node_modules/${packageName}/man" ]
+        then
+            mkdir -p $out/share
+            for dir in "$out/lib/node_modules/${packageName}/man/"*
+            do
+                mkdir -p $out/share/man/$(basename "$dir")
+                for page in "$dir"/*
+                do
+                    ln -s $page $out/share/man/$(basename "$dir")
+                done
+            done
+        fi
+
+        # Run post install hook, if provided
+        runHook postInstall
+      '';
+    } // extraArgs);
+
+  # Builds a node environment (a node_modules folder and a set of binaries)
+  buildNodeDependencies =
+    { name
+    , packageName
+    , version
+    , src
+    , dependencies ? []
+    , buildInputs ? []
+    , production ? true
+    , npmFlags ? ""
+    , dontNpmInstall ? false
+    , bypassCache ? false
+    , reconstructLock ? false
+    , dontStrip ? true
+    , unpackPhase ? "true"
+    , buildPhase ? "true"
+    , ... }@args:
+
+    let
+      extraArgs = removeAttrs args [ "name" "dependencies" "buildInputs" ];
+    in
+      stdenv.mkDerivation ({
+        name = "node-dependencies-${name}-${version}";
+
+        buildInputs = [ tarWrapper python nodejs ]
+          ++ lib.optional (stdenv.isLinux) utillinux
+          ++ lib.optional (stdenv.isDarwin) libtool
+          ++ buildInputs;
+
+        inherit dontStrip; # Stripping may fail a build for some package deployments
+        inherit dontNpmInstall unpackPhase buildPhase;
+
+        includeScript = includeDependencies { inherit dependencies; };
+        pinpointDependenciesScript = pinpointDependenciesOfPackage args;
+
+        passAsFile = [ "includeScript" "pinpointDependenciesScript" ];
+
+        installPhase = ''
+          mkdir -p $out/${packageName}
+          cd $out/${packageName}
+
+          source $includeScriptPath
+
+          # Create fake package.json to make the npm commands work properly
+          cp ${src}/package.json .
+          chmod 644 package.json
+          ${lib.optionalString bypassCache ''
+            if [ -f ${src}/package-lock.json ]
+            then
+                cp ${src}/package-lock.json .
+            fi
+          ''}
+
+          # Go to the parent folder to make sure that all packages are pinpointed
+          cd ..
+          ${lib.optionalString (builtins.substring 0 1 packageName == "@") "cd .."}
+
+          ${prepareAndInvokeNPM { inherit packageName bypassCache reconstructLock npmFlags production; }}
+
+          # Expose the executables that were installed
+          cd ..
+          ${lib.optionalString (builtins.substring 0 1 packageName == "@") "cd .."}
+
+          mv ${packageName} lib
+          ln -s $out/lib/node_modules/.bin $out/bin
+        '';
+      } // extraArgs);
+
+  # Builds a development shell
+  buildNodeShell =
+    { name
+    , packageName
+    , version
+    , src
+    , dependencies ? []
+    , buildInputs ? []
+    , production ? true
+    , npmFlags ? ""
+    , dontNpmInstall ? false
+    , bypassCache ? false
+    , reconstructLock ? false
+    , dontStrip ? true
+    , unpackPhase ? "true"
+    , buildPhase ? "true"
+    , ... }@args:
+
+    let
+      nodeDependencies = buildNodeDependencies args;
+    in
+    stdenv.mkDerivation {
+      name = "node-shell-${name}-${version}";
+
+      buildInputs = [ python nodejs ] ++ lib.optional (stdenv.isLinux) utillinux ++ buildInputs;
+      buildCommand = ''
+        mkdir -p $out/bin
+        cat > $out/bin/shell <<EOF
+        #! ${stdenv.shell} -e
+        $shellHook
+        exec ${stdenv.shell}
+        EOF
+        chmod +x $out/bin/shell
+      '';
+
+      # Provide the dependencies in a development shell through the NODE_PATH environment variable
+      inherit nodeDependencies;
+      shellHook = lib.optionalString (dependencies != []) ''
+        export NODE_PATH=${nodeDependencies}/lib/node_modules
+        export PATH="${nodeDependencies}/bin:$PATH"
+      '';
+    };
+in
+{
+  buildNodeSourceDist = lib.makeOverridable buildNodeSourceDist;
+  buildNodePackage = lib.makeOverridable buildNodePackage;
+  buildNodeDependencies = lib.makeOverridable buildNodeDependencies;
+  buildNodeShell = lib.makeOverridable buildNodeShell;
+}

node2nix.nix

@@ -0,0 +1,21 @@
+# This file has been generated by node2nix 1.9.0. Do not edit!
+
+{pkgs ? import <nixpkgs> {
+    inherit system;
+  }, system ? builtins.currentSystem, nodejs ? pkgs."nodejs-12_x"}:
+
+let
+  globalBuildInputs = pkgs.lib.attrValues (import ./supplement.nix {
+    inherit nodeEnv;
+    inherit (pkgs) stdenv lib nix-gitignore fetchurl fetchgit;
+  });
+  nodeEnv = import ./node-env.nix {
+    inherit (pkgs) stdenv lib python2 runCommand writeTextFile;
+    inherit pkgs nodejs;
+    libtool = if pkgs.stdenv.isDarwin then pkgs.darwin.cctools else null;
+  };
+in
+import ./node-packages.nix {
+  inherit (pkgs) fetchurl nix-gitignore stdenv lib fetchgit;
+  inherit nodeEnv globalBuildInputs;
+}

overlay.nix

@@ -0,0 +1,3 @@
+final: prev: {
+  financier-dist = import ./dist.nix { inherit (prev) pkgs system; };
+}