feat(ops/modules): initialise module for running livegrep

Change-Id: Ic22118def24089cda25ccc74c9da670d41c6b323
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10936
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>

ops/machines/whitby/default.nix

@@ -17,6 +17,7 @@ in
     (mod "josh.nix")
     (mod "journaldriver.nix")
     (mod "known-hosts.nix")
+    (mod "livegrep.nix")
     (mod "monorepo-gerrit.nix")
     (mod "owothia.nix")
     (mod "panettone.nix")
@@ -370,6 +371,9 @@ in
     # Run a SourceGraph code search instance
     sourcegraph.enable = true;
 
+    # Run a livegrep code search instance
+    livegrep.enable = true;
+
     # Run the Panettone issue tracker
     panettone = {
       enable = true;

ops/modules/livegrep.nix

@@ -0,0 +1,89 @@
+# Configures a code search instance using Livegrep.
+#
+# We do not currently build Livegrep in Nix, because it's a complex,
+# multi-language Bazel build and doesn't play nicely with Nix.
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.services.depot.livegrep;
+
+  livegrepConfig = {
+    name = "livegrep";
+
+    fs_paths = [{
+      name = "depot";
+      path = "/depot";
+      metadata.url_pattern = "https://code.tvl.fyi/tree/{path}?id={version}#n{lno}";
+    }];
+
+    repositories = [{
+      name = "depot";
+      path = "/depot";
+      revisions = [ "HEAD" ];
+
+      metadata = {
+        url_pattern = "https://code.tvl.fyi/tree/{path}?id={version}#n{lno}";
+        remote = "https://cl.tvl.fyi/depot.git";
+      };
+    }];
+  };
+
+  configFile = pkgs.writeText "livegrep-config.json" (builtins.toJSON livegrepConfig);
+
+  # latest as of 2024-02-17
+  image = "ghcr.io/livegrep/livegrep/base:033fa0e93c";
+in
+{
+  options.services.depot.livegrep = with lib; {
+    enable = mkEnableOption "Run livegrep code search for depot";
+
+    port = mkOption {
+      description = "Port on which livegrep web UI should listen";
+      type = types.int;
+      default = 5477; # lgrp
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    virtualisation.oci-containers.containers.livegrep-codesearch = {
+      inherit image;
+      extraOptions = [ "--net=host" ];
+
+      volumes = [
+        "${configFile}:/etc/livegrep-config.json:ro"
+        "/var/lib/gerrit/git/depot.git:/depot:ro"
+      ];
+
+      entrypoint = "/livegrep/bin/codesearch";
+      cmd = [
+        "-grpc"
+        "0.0.0.0:5427" # lgcs
+        "-reload_rpc"
+        "-revparse"
+        "/etc/livegrep-config.json"
+      ];
+    };
+
+    virtualisation.oci-containers.containers.livegrep-frontend = {
+      inherit image;
+      dependsOn = [ "livegrep-codesearch" ];
+      extraOptions = [ "--net=host" ];
+
+      entrypoint = "/livegrep/bin/livegrep";
+      cmd = [
+        "-listen"
+        "0.0.0.0:${toString cfg.port}"
+        "-reload"
+        "-connect"
+        "localhost:5427"
+        "-docroot"
+        "/livegrep/web"
+        # TODO(tazjin): docroot with styles etc.
+      ];
+    };
+  };
+}
+
+
+# sudo docker exec -ti livegrep /livegrep/bin/codesearch -reload_rpc -revparse /var/lib/livegrep/config.jsno
+# sudo docker run -d --ip 172.17.0.3 --name livegrep -v /var/lib/livegrep:/varlib/livegrep -v /var/lib/gerrit/git/depot.git:/depot:ro -v /home/tazjin/livegrep-web:/livegrep/web:ro ghcr.io/livegrep/livegrep/base /livegrep/bin/livegrep -listen 0.0.0.0:8910 -reload -docroot /livegrep/webbsudo docker run -d --ip 172.17.0.3 --name livegrep -v /var/lib/livegrep:/varlib/livegrep -v /var/lib/gerrit/git/depot.git:/depot:ro -v /home/tazjin/livegrep-web:/livegrep/web:ro ghcr.io/livegrep/livegrep/base /livegrep/bin/livegrep -listen 0.0.0.0:8910 -reload -docroot /livegrep/webb

ops/modules/www/grep.tvl.fyi.nix

@@ -7,15 +7,12 @@
   ];
 
   config = {
-    # Short link support (i.e. plain http://at) for users with a
-    # configured tvl.fyi/tvl.su search domain.
     services.nginx.virtualHosts."grep.tvl.fyi" = {
       enableACME = true;
       forceSSL = true;
 
       locations."/" = {
-        # experimental: manually run Docker container
-        proxyPass = "http://172.17.0.3:8910";
+        proxyPass = "http://127.0.0.1:${toString config.services.depot.livegrep.port}";
       };
     };
   };