refactor: make server packages buildable via packages.*

8 files changed, 254 insertions, 0 deletions

diff --git a/nixos/profiles/server/default.nix b/nixos/profiles/server/default.nix
index 6e744a6..3e917c2 100644
--- a/nixos/profiles/server/default.nix
+++ b/nixos/profiles/server/default.nix
@@ -4,6 +4,8 @@
   imports = [
     ../common
     ./detect-hostname-change.nix
+    ./prometheus-sql-exporter.nix
+    ./prometheus-storagebox-exporter.nix
   ];
 
   services = {
diff --git a/nixos/profiles/server/pkgs/alloy-nix-config/alloy_nix_config.go b/nixos/profiles/server/pkgs/alloy-nix-config/alloy_nix_config.go
new file mode 100644
index 0000000..4b6eb63
--- /dev/null
+++ b/nixos/profiles/server/pkgs/alloy-nix-config/alloy_nix_config.go
@@ -0,0 +1,129 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"maps"
+	"os"
+	"slices"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	if len(os.Args) != 3 {
+		fmt.Fprintf(os.Stderr, "usage: %s <json_path> <out_path>\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	jsonPath := os.Args[1]
+	outPath := os.Args[2]
+
+	jsonData, err := os.ReadFile(jsonPath)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error reading file %s: %v\n", jsonPath, err)
+		os.Exit(1)
+	}
+
+	// It would be nice to preserve the order of blocks ... except that we can't
+	// because Nix already doesn't preserve the order of attribute sets.
+	var config map[string]any
+	if err := json.Unmarshal(jsonData, &config); err != nil {
+		fmt.Fprintf(os.Stderr, "error parsing JSON: %v\n", err)
+		os.Exit(1)
+	}
+
+	result := formatConfig(config)
+
+	if err := os.WriteFile(outPath, []byte(result), 0644); err != nil {
+		fmt.Fprintf(os.Stderr, "error writing file %s: %v\n", outPath, err)
+		os.Exit(1)
+	}
+}
+
+func formatConfig(config map[string]any) string {
+	var s strings.Builder
+
+	for _, blockName := range slices.Sorted(maps.Keys(config)) {
+		labels := config[blockName]
+
+		if labelsMap, ok := labels.(map[string]any); ok {
+			for label, block := range labelsMap {
+				if blockMap, ok := block.(map[string]any); ok {
+					s.WriteString(formatBlock(blockName, label, blockMap, 0))
+				}
+			}
+		}
+	}
+
+	return s.String()
+}
+
+func formatBlock(blockName string, label string, block map[string]any, indent int) string {
+	var s strings.Builder
+
+	s.WriteString(strings.Repeat("  ", indent))
+	s.WriteString(blockName)
+	if label != "" {
+		s.WriteString(fmt.Sprintf(` %s`, strconv.Quote(label)))
+	}
+	s.WriteString(" {\n")
+
+	var blocks []any
+	if blocksValue, exists := block["blocks"]; exists {
+		if blocksList, ok := blocksValue.([]any); ok {
+			blocks = blocksList
+		}
+		delete(block, "blocks")
+	}
+
+	for _, key := range slices.Sorted(maps.Keys(block)) {
+		s.WriteString(strings.Repeat("  ", indent+1))
+		s.WriteString(fmt.Sprintf("%s = %s\n", key, formatValue(block[key])))
+	}
+
+	for _, blockItem := range blocks {
+		if blockMap, ok := blockItem.(map[string]any); ok {
+			var name string
+			if nameValue, exists := blockMap["name"]; exists {
+				if nameStr, ok := nameValue.(string); ok {
+					name = nameStr
+				}
+				delete(blockMap, "name")
+			}
+
+			s.WriteString(formatBlock(name, "", blockMap, indent+1))
+		}
+	}
+
+	s.WriteString(strings.Repeat("  ", indent))
+	s.WriteString("}\n")
+
+	return s.String()
+}
+
+func formatValue(value any) string {
+	switch v := value.(type) {
+	case string:
+		return strconv.Quote(v)
+	case map[string]any:
+		if ref, exists := v["$ref"]; exists {
+			if refStr, ok := ref.(string); ok {
+				return refStr
+			}
+		}
+		var parts []string
+		for _, name := range slices.Sorted(maps.Keys(v)) {
+			parts = append(parts, fmt.Sprintf("%s=%s,", name, formatValue(v[name])))
+		}
+		return "{" + strings.Join(parts, " ") + "}"
+	case []any:
+		var parts []string
+		for _, item := range v {
+			parts = append(parts, formatValue(item))
+		}
+		return "[" + strings.Join(parts, ", ") + "]"
+	default:
+		return fmt.Sprintf("%v", v)
+	}
+}
diff --git a/nixos/profiles/server/pkgs/alloy-nix-config/go.mod b/nixos/profiles/server/pkgs/alloy-nix-config/go.mod
new file mode 100644
index 0000000..2916089
--- /dev/null
+++ b/nixos/profiles/server/pkgs/alloy-nix-config/go.mod
@@ -0,0 +1,3 @@
+module push-f.com/alloy-nix-config
+
+go 1.24.5
diff --git a/nixos/profiles/server/pkgs/alloy-nix-config/package.nix b/nixos/profiles/server/pkgs/alloy-nix-config/package.nix
new file mode 100644
index 0000000..981b612
--- /dev/null
+++ b/nixos/profiles/server/pkgs/alloy-nix-config/package.nix
@@ -0,0 +1,8 @@
+{ buildGoModule }:
+
+buildGoModule {
+  pname = "alloy-nix-config";
+  version = "git";
+  src = ./.;
+  vendorHash = null;
+}
diff --git a/nixos/profiles/server/pkgs/prometheus-sql-exporter.nix b/nixos/profiles/server/pkgs/prometheus-sql-exporter.nix
new file mode 100644
index 0000000..e049396
--- /dev/null
+++ b/nixos/profiles/server/pkgs/prometheus-sql-exporter.nix
@@ -0,0 +1,18 @@
+{
+  lib,
+  buildGoModule,
+  sources,
+}:
+buildGoModule {
+  pname = "sql_exporter";
+  version = sources.prometheus-sql-exporter.version;
+  src = sources.prometheus-sql-exporter;
+  vendorHash = "sha256-eZxxmqoiXPdjZs/lwbzvWco9mDFy0zmpGDcqTIyWbK4=";
+
+  meta = with lib; {
+    description = "Database-agnostic SQL exporter for Prometheus";
+    mainProgram = "sql_exporter";
+    homepage = "https://github.com/burningalchemist/sql_exporter";
+    license = licenses.mit;
+  };
+}
diff --git a/nixos/profiles/server/pkgs/prometheus-storagebox-exporter.nix b/nixos/profiles/server/pkgs/prometheus-storagebox-exporter.nix
new file mode 100644
index 0000000..d4fd13e
--- /dev/null
+++ b/nixos/profiles/server/pkgs/prometheus-storagebox-exporter.nix
@@ -0,0 +1,22 @@
+{
+  lib,
+  buildGoModule,
+  sources,
+}:
+buildGoModule {
+  pname = "storagebox_exporter";
+  version = sources.prometheus-storagebox-exporter.version;
+  src = sources.prometheus-storagebox-exporter;
+  vendorHash = "sha256-3aBklYmPHELcLG+3sOEDd9qkrJyDrC52LfhOOY/6sOc=";
+
+  meta = with lib; {
+    description = "Modern Prometheus exporter for Hetzner Storage Box with comprehensive metrics";
+    mainProgram = "prometheus-storagebox-exporter";
+    homepage = "https://github.com/crstian19/prometheus-storagebox-exporter";
+    license = licenses.mit;
+  };
+
+  postPatch = ''
+    substituteInPlace go.mod --replace 'go 1.25.5' 'go 1.25.4'
+  '';
+}
diff --git a/nixos/profiles/server/prometheus-sql-exporter.nix b/nixos/profiles/server/prometheus-sql-exporter.nix
new file mode 100644
index 0000000..fe2ef7b
--- /dev/null
+++ b/nixos/profiles/server/prometheus-sql-exporter.nix
@@ -0,0 +1,39 @@
+# TODO: submit burningalchemist's sql_exporter to nixpkgs
+{ config, lib, pkgs, sources, ... }:
+
+let
+  sqlExporter = pkgs.callPackage ./pkgs/prometheus-sql-exporter.nix { inherit sources; };
+  cfg = config.services.prometheus-sql-exporter;
+  configFile = builtins.toFile "config.yaml" (builtins.toJSON cfg.config);
+  validateConfig = file:
+    pkgs.runCommand "validate-config"
+      {
+        nativeBuildInputs = [sqlExporter];
+      }
+      ''
+        sql_exporter -config.check -config.file "${file}"
+        ln -s "${file}" "$out"
+      '';
+in
+{
+  options.services.prometheus-sql-exporter = {
+    enable = lib.mkEnableOption "sql-exporter";
+    port = lib.mkOption {
+      type = lib.types.int;
+    };
+    config = lib.mkOption {
+      type = (pkgs.formats.json {}).type;
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.services.prometheus-sql-exporter = {
+      serviceConfig = {
+        ExecStart = "${sqlExporter}/bin/sql_exporter -config.file ${validateConfig configFile} -web.listen-address :${toString cfg.port}";
+        DynamicUser = "true";
+        User = "prometheus-sql-exporter";
+      };
+      wantedBy = ["multi-user.target"];
+    };
+  };
+}
diff --git a/nixos/profiles/server/prometheus-storagebox-exporter.nix b/nixos/profiles/server/prometheus-storagebox-exporter.nix
new file mode 100644
index 0000000..16b03e6
--- /dev/null
+++ b/nixos/profiles/server/prometheus-storagebox-exporter.nix
@@ -0,0 +1,33 @@
+# TODO: submit Christian's storagebox exporter to nixpkgs
+{ config, lib, pkgs, sources, ... }:
+
+let
+  storageboxExporter = pkgs.callPackage ./pkgs/prometheus-storagebox-exporter.nix { inherit sources; };
+  cfg = config.services.prometheus-storagebox-exporter;
+in
+{
+  options.services.prometheus-storagebox-exporter = {
+    enable = lib.mkEnableOption "storagebox-exporter";
+    port = lib.mkOption {
+      type = lib.types.int;
+    };
+    hetznerTokenFile = lib.mkOption {
+      type = lib.types.path;
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.services.storagebox-exporter = {
+      serviceConfig = {
+        ExecStart = "${storageboxExporter}/bin/prometheus-storagebox-exporter";
+        DynamicUser = "true";
+        LoadCredential = "hetznerToken:${cfg.hetznerTokenFile}";
+      };
+      environment = {
+        HETZNER_TOKEN_FILE = "%d/hetznerToken";
+        LISTEN_ADDRESS = ":${toString cfg.port}";
+      };
+      wantedBy = ["multi-user.target"];
+    };
+  };
+}