vps-ns, vps-www: Set public ns hostnames to ns1 and ns2

.github/workflows/ci.yml

@@ -60,15 +60,46 @@ jobs:
         server: ${{ fromJson(needs.parse-flake.outputs.servers) }}
     steps:
       - uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
       - uses: cachix/install-nix-action@v31
         with:
           extra_nix_config: experimental-features = nix-command flakes pipe-operators
+      - name: Check if build can be skipped
+        id: skip-check
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          last_sha=$(gh api \
+            "repos/${{ github.repository }}/actions/workflows/ci.yml/runs?branch=main&status=success&per_page=1" \
+            --jq '.workflow_runs[0].head_sha // empty')
+
+          if [[ -z "$last_sha" ]]; then
+            echo "No previous successful run found, build required"
+            echo "skip=false" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+
+          echo "Comparing current (${{ github.sha }}) with last successful ($last_sha)"
+
+          current_drv=$(nix eval .#nixosConfigurations.${{ matrix.server }}.config.system.build.toplevel.drvPath --raw)
+          previous_drv=$(nix eval "git+file://$(pwd)?rev=$last_sha#nixosConfigurations.${{ matrix.server }}.config.system.build.toplevel.drvPath" --raw)
+
+          if [[ "$current_drv" == "$previous_drv" ]]; then
+            echo "Derivations match, skipping build"
+            echo "skip=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "Derivations differ, build required"
+            echo "skip=false" >> "$GITHUB_OUTPUT"
+          fi
       - uses: cachix/cachix-action@v15
+        if: steps.skip-check.outputs.skip != 'true'
         with:
           name: sebastian-stork
           authToken: "${{ secrets.CACHIX_AUTH_TOKEN }}"
           useDaemon: false
       - name: Build server
+        if: steps.skip-check.outputs.skip != 'true'
         run: nix build .#nixosConfigurations.${{ matrix.server }}.config.system.build.toplevel --print-build-logs
   deploy:
     needs: [build-check, build-server]

hosts/vps-ns/default.nix

@@ -25,6 +25,7 @@
       private-nameserver.enable = true;
       public-nameserver = {
         enable = true;
+        publicHostName = "ns1";
         zones = [
           "sprouted.cloud"
           "sstork.dev"

hosts/vps-www/default.nix

@@ -23,6 +23,7 @@
 
       services.public-nameserver = {
         enable = true;
+        publicHostName = "ns2";
         zones = [
           "sprouted.cloud"
           "sstork.dev"

modules/nixos/services/nameservers/public.nix

@@ -40,7 +40,7 @@ let
         |> lib.attrValues
         |> lib.filter (host: host.config.custom.services.public-nameserver.enable)
         |> lib.map (host: {
-          name = host.config.custom.networking.hostName;
+          name = host.config.custom.services.public-nameserver.publicHostName;
           inherit (host.config.custom.networking.underlay) address;
         });
     in
@@ -66,6 +66,10 @@ in
 {
   options.custom.services.public-nameserver = {
     enable = lib.mkEnableOption "";
+    publicHostName = lib.mkOption {
+      type = lib.types.nonEmptyStr;
+      default = netCfg.hostName;
+    };
     port = lib.mkOption {
       type = lib.types.port;
       default = 53;

modules/nixos/services/prometheus.nix

@@ -104,12 +104,12 @@ in
                 };
               }
               {
-                alert = "CominDeploymentDifferentCommits";
+                alert = "CominDeploymentCommitMismatch";
                 expr = "count(count by (commit_id) (comin_deployment_info)) > 1";
                 for = "10m";
                 annotations = {
-                  summary = "Comin commit mismatch";
+                  summary = "Hosts are running different commits";
-                  description = "Two or more comin deployments are on different commits.";
+                  description = "Not all hosts are running the same git commit, which may indicate a failed deployment and could lead to incompatible configurations.";
                 };
               }
             ];