From c18a6a58174642ca88ef23e10f7ba0ae64eb2a5d Mon Sep 17 00:00:00 2001
From: Jonathan Davies <jpds@protonmail.com>
Date: Mon, 25 Aug 2025 12:39:59 +0000
Subject: [PATCH 1/2] grpc-health-probe: init at 0.4.40

---
 pkgs/by-name/gr/grpc-health-probe/package.nix | 27 +++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 pkgs/by-name/gr/grpc-health-probe/package.nix

diff --git a/pkgs/by-name/gr/grpc-health-probe/package.nix b/pkgs/by-name/gr/grpc-health-probe/package.nix
new file mode 100644
index 000000000000..cb140c3e492e
--- /dev/null
+++ b/pkgs/by-name/gr/grpc-health-probe/package.nix
@@ -0,0 +1,27 @@
+{
+  buildGoModule,
+  lib,
+  fetchFromGitHub,
+}:
+
+buildGoModule rec {
+  pname = "grpc-health-probe";
+  version = "0.4.40";
+
+  src = fetchFromGitHub {
+    owner = "grpc-ecosystem";
+    repo = "grpc-health-probe";
+    rev = "v${version}";
+    hash = "sha256-Na0y8fL109flHGJOniEpLgs60xf1V0YlSBrX9iHtymM=";
+  };
+
+  vendorHash = "sha256-eIjDs14PEzoVaRYoxN03pDfYzg4VF1tgskLY9oIkMLE=";
+
+  meta = with lib; {
+    description = "command-line tool to perform health-checks for gRPC applications";
+    homepage = "https://github.com/grpc-ecosystem/grpc-health-probe";
+    license = licenses.asl20;
+    maintainers = with maintainers; [ jpds ];
+    mainProgram = "grpc-health-probe";
+  };
+}

From f704eef1c3d7167c95ea935c7dca71e8d02f2da5 Mon Sep 17 00:00:00 2001
From: Jonathan Davies <jpds@protonmail.com>
Date: Mon, 25 Aug 2025 12:54:57 +0000
Subject: [PATCH 2/2] nixos/thanos: Add check for serving gRPC port

---
 nixos/tests/thanos.nix | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/nixos/tests/thanos.nix b/nixos/tests/thanos.nix
index caadfaa37c2c..d1ba83868bbc 100644
--- a/nixos/tests/thanos.nix
+++ b/nixos/tests/thanos.nix
@@ -42,7 +42,10 @@ in
       {
         virtualisation.diskSize = 2 * 1024;
         virtualisation.memorySize = 2048;
-        environment.systemPackages = [ pkgs.jq ];
+        environment.systemPackages = [
+          pkgs.grpc-health-probe
+          pkgs.jq
+        ];
         networking.firewall.allowedTCPPorts = [ grpcPort ];
         services.prometheus = {
           enable = true;
@@ -178,6 +181,7 @@ in
         virtualisation.diskSize = 2 * 1024;
         virtualisation.memorySize = 2048;
         environment.systemPackages = with pkgs; [
+          grpc-health-probe
           jq
           thanos
         ];
@@ -251,6 +255,13 @@ in
       prometheus.wait_for_open_port(${toString queryPort})
       prometheus.succeed("curl -sf http://127.0.0.1:${toString queryPort}/metrics")
 
+      prometheus.wait_until_succeeds("journalctl -o cat -u thanos-sidecar.service | grep 'listening for serving gRPC'")
+
+      store.wait_until_succeeds("journalctl -o cat -u thanos-store.service | grep 'listening for serving gRPC'")
+
+      for machine in prometheus, store:
+        machine.wait_until_succeeds("grpc-health-probe -addr 127.0.0.1:${toString grpcPort}")
+
       # Let's test if pushing a metric to the pushgateway succeeds:
       prometheus.wait_for_unit("pushgateway.service")
       prometheus.succeed(