refactor(ops): Split //ops/nixos into different locations r/2482

Splits //ops/nixos into:

* //ops/nixos.nix - utility functions for building systems
* //ops/machines - shared machine definitions (read by readTree)
* //ops/modules - shared NixOS modules (skipped by readTree)

This simplifies working with the configuration fixpoint in whitby, and
is overall a bit more in line with how NixOS systems in user folders
currently work.

Change-Id: I1322ec5cc76c0207c099c05d44828a3df0b3ffc1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2931
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: glittershark <grfn@gws.fyi>

1 files changed, 51 insertions, 0 deletions

diff --git a/ops/modules/sourcegraph.nix b/ops/modules/sourcegraph.nix
new file mode 100644
index 0000000000..a24328f3e3
--- /dev/null
+++ b/ops/modules/sourcegraph.nix
@@ -0,0 +1,51 @@
+# Run sourcegraph, including its entire machinery, in a container.
+# Running it outside of a container is a futile endeavour for now.
+{ depot, config, pkgs, lib, ... }:
+
+let
+  cfg = config.services.depot.sourcegraph;
+in {
+  options.services.depot.sourcegraph = with lib; {
+    enable = mkEnableOption "SourceGraph code search engine";
+
+    port = mkOption {
+      description = "Port on which SourceGraph should listen";
+      type = types.int;
+      default = 3463;
+    };
+
+    cheddarPort = mkOption {
+      description = "Port on which cheddar should listen";
+      type = types.int;
+      default = 4238;
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    # Run a cheddar syntax highlighting server
+    systemd.services.cheddar-server = {
+      wantedBy = [ "multi-user.target" ];
+      script = "${depot.tools.cheddar}/bin/cheddar --listen 0.0.0.0:${toString cfg.cheddarPort} --sourcegraph-server";
+
+      serviceConfig = {
+        DynamicUser = true;
+        Restart = "always";
+      };
+    };
+
+    virtualisation.oci-containers.containers.sourcegraph = {
+      image = "sourcegraph/server:3.26.0";
+
+      ports = [
+        "127.0.0.1:${toString cfg.port}:7080"
+      ];
+
+      volumes = [
+        "/var/lib/sourcegraph/etc:/etc/sourcegraph"
+        "/var/lib/sourcegraph/data:/var/opt/sourcegraph"
+      ];
+
+      environment.SRC_SYNTECT_SERVER = "http://172.17.0.1:${toString cfg.cheddarPort}";
+    };
+  };
+}