nixos: add gerrit module

Co-authored-by: edef <edef@edef.eu>
Co-authored-by: Florian Klink <flokli@flokli.de>

5 files changed, 294 insertions, 0 deletions

diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
index ccdc39eecd8..b931dc8eb80 100644
--- a/nixos/modules/module-list.nix
+++ b/nixos/modules/module-list.nix
@@ -823,6 +823,7 @@
   ./services/web-apps/documize.nix
   ./services/web-apps/dokuwiki.nix
   ./services/web-apps/frab.nix
+  ./services/web-apps/gerrit.nix
   ./services/web-apps/gotify-server.nix
   ./services/web-apps/grocy.nix
   ./services/web-apps/icingaweb2/icingaweb2.nix
diff --git a/nixos/modules/services/web-apps/gerrit.nix b/nixos/modules/services/web-apps/gerrit.nix
new file mode 100644
index 00000000000..b184c0754d4
--- /dev/null
+++ b/nixos/modules/services/web-apps/gerrit.nix
@@ -0,0 +1,218 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  cfg = config.services.gerrit;
+
+  # NixOS option type for git-like configs
+  gitIniType = with types;
+    let
+      primitiveType = either str (either bool int);
+      multipleType = either primitiveType (listOf primitiveType);
+      sectionType = lazyAttrsOf multipleType;
+      supersectionType = lazyAttrsOf (either multipleType sectionType);
+    in lazyAttrsOf supersectionType;
+
+  gerritConfig = pkgs.writeText "gerrit.conf" (
+    lib.generators.toGitINI cfg.settings
+  );
+
+  # Wrap the gerrit java with all the java options so it can be called
+  # like a normal CLI app
+  gerrit-cli = pkgs.writeShellScriptBin "gerrit" ''
+    set -euo pipefail
+    jvmOpts=(
+      ${lib.escapeShellArgs cfg.jvmOpts}
+      -Xmx${cfg.jvmHeapLimit}
+    )
+    exec ${cfg.jvmPackage}/bin/java \
+      "''${jvmOpts[@]}" \
+      -jar ${cfg.package}/webapps/${cfg.package.name}.war \
+      "$@"
+  '';
+
+  gerrit-plugins = pkgs.runCommand
+    "gerrit-plugins"
+    {
+      buildInputs = [ gerrit-cli ];
+    }
+    ''
+      shopt -s nullglob
+      mkdir $out
+
+      for name in ${toString cfg.builtinPlugins}; do
+        echo "Installing builtin plugin $name.jar"
+        gerrit cat plugins/$name.jar > $out/$name.jar
+      done
+
+      for file in ${toString cfg.plugins}; do
+        name=$(echo "$file" | cut -d - -f 2-)
+        echo "Installing plugin $name"
+        ln -sf "$file" $out/$name
+      done
+    '';
+in
+{
+  options = {
+    services.gerrit = {
+      enable = mkEnableOption "Gerrit service";
+
+      package = mkOption {
+        type = types.package;
+        default = pkgs.gerrit;
+        description = "Gerrit package to use";
+      };
+
+      jvmPackage = mkOption {
+        type = types.package;
+        default = pkgs.jre_headless;
+        defaultText = "pkgs.jre_headless";
+        description = "Java Runtime Environment package to use";
+      };
+
+      jvmOpts = mkOption {
+        type = types.listOf types.str;
+        default = [
+          "-Dflogger.backend_factory=com.google.common.flogger.backend.log4j.Log4jBackendFactory#getInstance"
+          "-Dflogger.logging_context=com.google.gerrit.server.logging.LoggingContext#getInstance"
+        ];
+        description = "A list of JVM options to start gerrit with.";
+      };
+
+      jvmHeapLimit = mkOption {
+        type = types.str;
+        default = "1024m";
+        description = ''
+          How much memory to allocate to the JVM heap
+        '';
+      };
+
+      listenAddress = mkOption {
+        type = types.str;
+        default = "[::]:8080";
+        description = ''
+          <literal>hostname:port</literal> to listen for HTTP traffic.
+
+          This is bound using the systemd socket activation.
+        '';
+      };
+
+      settings = mkOption {
+        type = gitIniType;
+        default = {};
+        description = ''
+          Gerrit configuration. This will be generated to the
+          <literal>etc/gerrit.config</literal> file.
+        '';
+      };
+
+      plugins = mkOption {
+        type = types.listOf types.package;
+        default = [];
+        description = ''
+          List of plugins to add to Gerrit. Each derivation is a jar file
+          itself where the name of the derivation is the name of plugin.
+        '';
+      };
+
+      builtinPlugins = mkOption {
+        type = types.listOf (types.enum cfg.package.passthru.plugins);
+        default = [];
+        description = ''
+          List of builtins plugins to install. Those are shipped in the
+          <literal>gerrit.war</literal> file.
+        '';
+      };
+
+      serverId = mkOption {
+        type = types.str;
+        description = ''
+          Set a UUID that uniquely identifies the server.
+
+          This can be generated with
+          <literal>nix-shell -p utillinux --run uuidgen</literal>.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+
+    services.gerrit.settings = {
+      cache.directory = "/var/cache/gerrit";
+      container.heapLimit = cfg.jvmHeapLimit;
+      gerrit.basePath = lib.mkDefault "git";
+      gerrit.serverId = cfg.serverId;
+      httpd.inheritChannel = "true";
+      httpd.listenUrl = lib.mkDefault "http://${cfg.listenAddress}";
+      index.type = lib.mkDefault "lucene";
+    };
+
+    # Add the gerrit CLI to the system to run `gerrit init` and friends.
+    environment.systemPackages = [ gerrit-cli ];
+
+    systemd.sockets.gerrit = {
+      unitConfig.Description = "Gerrit HTTP socket";
+      wantedBy = [ "sockets.target" ];
+      listenStreams = [ cfg.listenAddress ];
+    };
+
+    systemd.services.gerrit = {
+      description = "Gerrit";
+
+      wantedBy = [ "multi-user.target" ];
+      requires = [ "gerrit.socket" ];
+      after = [ "gerrit.socket" "network.target" ];
+
+      path = [
+        gerrit-cli
+        pkgs.bash
+        pkgs.coreutils
+        pkgs.git
+        pkgs.openssh
+      ];
+
+      environment = {
+        GERRIT_HOME = "%S/gerrit";
+        GERRIT_TMP = "%T";
+        HOME = "%S/gerrit";
+        XDG_CONFIG_HOME = "%S/gerrit/.config";
+      };
+
+      preStart = ''
+        set -euo pipefail
+
+        # bootstrap if nothing exists
+        if [[ ! -d git ]]; then
+          gerrit init --batch --no-auto-start
+        fi
+
+        # install gerrit.war for the plugin manager
+        rm -rf bin
+        mkdir bin
+        ln -sfv ${cfg.package}/webapps/${cfg.package.name}.war bin/gerrit.war
+
+        # copy the config, keep it mutable because Gerrit
+        ln -sfv ${gerritConfig} etc/gerrit.config
+
+        # install the plugins
+        rm -rf plugins
+        ln -sv ${gerrit-plugins} plugins
+      ''
+      ;
+
+      serviceConfig = {
+        CacheDirectory = "gerrit";
+        DynamicUser = true;
+        ExecStart = "${gerrit-cli}/bin/gerrit daemon --console-log";
+        LimitNOFILE = 4096;
+        StandardInput = "socket";
+        StandardOutput = "journal";
+        StateDirectory = "gerrit";
+        WorkingDirectory = "%S/gerrit";
+      };
+    };
+  };
+
+  meta.maintainers = with lib.maintainers; [ edef zimbatm ];
+}
diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index 51b463747b0..3501c551625 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -97,6 +97,7 @@ in
   fontconfig-default-fonts = handleTest ./fontconfig-default-fonts.nix {};
   freeswitch = handleTest ./freeswitch.nix {};
   fsck = handleTest ./fsck.nix {};
+  gerrit = handleTest ./gerrit.nix {};
   gotify-server = handleTest ./gotify-server.nix {};
   grocy = handleTest ./grocy.nix {};
   gitdaemon = handleTest ./gitdaemon.nix {};
diff --git a/nixos/tests/gerrit.nix b/nixos/tests/gerrit.nix
new file mode 100644
index 00000000000..e8b5cb4c4fe
--- /dev/null
+++ b/nixos/tests/gerrit.nix
@@ -0,0 +1,56 @@
+import ./make-test-python.nix ({ pkgs, ... }:
+
+let
+  lfs = pkgs.fetchurl {
+    url = "https://gerrit-ci.gerritforge.com/job/plugin-lfs-bazel-master/90/artifact/bazel-bin/plugins/lfs/lfs.jar";
+    sha256 = "023b0kd8djm3cn1lf1xl67yv3j12yl8bxccn42lkfmwxjwjfqw6h";
+  };
+
+in {
+  name = "gerrit";
+
+  meta = with pkgs.stdenv.lib.maintainers; {
+    maintainers = [ flokli zimbatm ];
+  };
+
+  nodes = {
+    server =
+      { config, pkgs, ... }: {
+        networking.firewall.allowedTCPPorts = [ 80 2222 ];
+
+        virtualisation.memorySize = 1024;
+
+        services.gerrit = {
+          enable = true;
+          serverId = "aa76c84b-50b0-4711-a0a0-1ee30e45bbd0";
+          listenAddress = "[::]:80";
+          jvmPackage = pkgs.jdk12_headless;
+          jvmHeapLimit = "1g";
+
+          plugins = [ lfs ];
+          builtinPlugins = [ "hooks" "webhooks" ];
+          settings = {
+            gerrit.canonicalWebUrl = "http://server";
+            lfs.plugin = "lfs";
+            plugins.allowRemoteAdmin = true;
+            sshd.listenAddress = "[::]:2222";
+            sshd.advertisedAddress = "[::]:2222";
+          };
+        };
+      };
+
+    client =
+      { ... }: {
+      };
+  };
+
+  testScript = ''
+    start_all()
+    server.wait_for_unit("gerrit.service")
+    server.wait_for_open_port(80)
+    client.succeed("curl http://server")
+
+    server.wait_for_open_port(2222)
+    client.succeed("nc -z server 2222")
+  '';
+})
diff --git a/pkgs/applications/version-management/gerrit/default.nix b/pkgs/applications/version-management/gerrit/default.nix
index be84b7abc82..1aa7afcd98b 100644
--- a/pkgs/applications/version-management/gerrit/default.nix
+++ b/pkgs/applications/version-management/gerrit/default.nix
@@ -14,6 +14,24 @@ stdenv.mkDerivation rec {
     ln -s ${src} "$out"/webapps/gerrit-${version}.war
   '';
 
+  passthru = {
+    # A list of plugins that are part of the gerrit.war file.
+    # Use `java -jar gerrit.war ls | grep plugins/` to generate that list.
+    plugins = [
+      "codemirror-editor"
+      "commit-message-length-validator"
+      "delete-project"
+      "download-commands"
+      "gitiles"
+      "hooks"
+      "plugin-manager"
+      "replication"
+      "reviewnotes"
+      "singleusergroup"
+      "webhooks"
+    ];
+  };
+
   meta = with stdenv.lib; {
     homepage = "https://www.gerritcodereview.com/index.md";
     license = licenses.asl20;