Proposal: Add host resources automatically

build.zig

@@ -47,13 +47,6 @@ pub fn build(b: *std.Build) !void {
         },
     });
 
-    { // Build info
-        const build_info = b.addOptions();
-        build_info.addOption([]const u8, "version", zon.version);
-        build_info.addOption([]const u8, "name", @tagName(zon.name));
-        sdk_mod.addOptions("build_info", build_info);
-    }
-
     // Static library for the OpenTelemetry SDK C users
     const sdk_c_lib_mod = b.createModule(.{
         .root_source_file = b.path("src/c.zig"),
@@ -66,6 +59,14 @@ pub fn build(b: *std.Build) !void {
             .{ .name = "clock", .module = clock_mod },
         },
     });
+    { // Build info
+        const build_info = b.addOptions();
+        build_info.addOption([]const u8, "version", zon.version);
+        build_info.addOption([]const u8, "name", @tagName(zon.name));
+        sdk_mod.addOptions("build_info", build_info);
+        sdk_c_lib_mod.addOptions("build_info", build_info);
+    }
+
     const sdk_lib = b.addLibrary(.{
         .name = "opentelemetry-sdk",
         .linkage = .static,

src/sdk/config.zig

@@ -268,13 +268,21 @@ pub const LogsConfig = struct {
     }
 };
 
+/// Resource detectors enabled via OTEL_EXPERIMENTAL_RESOURCE_DETECTORS.
+pub const ResourceDetectors = struct {
+    host: bool = false,
+    os: bool = false,
+    process: bool = false,
+};
+
 /// Global SDK Configuration
 pub const Configuration = @This();
 
 allocator: std.mem.Allocator,
 
 // Global settings
 sdk_disabled: bool,
+resource_detectors: ResourceDetectors,
 service_name: ?[]const u8,
 resource_attributes: ?[]const u8,
 log_level: LogLevel,
@@ -308,6 +316,7 @@ pub fn init(allocator: std.mem.Allocator, env_map: *const EnvMap) !*Configuratio
     cfg.* = Configuration{
         .allocator = allocator,
         .sdk_disabled = parseBool(env_map, "OTEL_SDK_DISABLED") orelse false,
+        .resource_detectors = parseResourceDetectors(env_map),
         .service_name = if (env_map.get("OTEL_SERVICE_NAME")) |s|
             try allocator.dupe(u8, s)
         else
@@ -378,6 +387,21 @@ fn parseInt(comptime T: type, env_map: *const EnvMap, key: []const u8) ?T {
     return std.fmt.parseInt(T, value, 10) catch null;
 }
 
+/// Parse OTEL_EXPERIMENTAL_RESOURCE_DETECTORS (comma-separated detector names).
+/// Recognized names: "host", "os", "process". Unknown names are silently ignored.
+fn parseResourceDetectors(env_map: *const EnvMap) ResourceDetectors {
+    const value = env_map.get("OTEL_EXPERIMENTAL_RESOURCE_DETECTORS") orelse return .{};
+    var detectors: ResourceDetectors = .{};
+    var iter = std.mem.splitScalar(u8, value, ',');
+    while (iter.next()) |item| {
+        const name = std.mem.trim(u8, item, &std.ascii.whitespace);
+        if (std.ascii.eqlIgnoreCase(name, "host")) detectors.host = true;
+        if (std.ascii.eqlIgnoreCase(name, "os")) detectors.os = true;
+        if (std.ascii.eqlIgnoreCase(name, "process")) detectors.process = true;
+    }
+    return detectors;
+}
+
 /// Parse comma-separated list of propagators
 /// Default: "tracecontext,baggage"
 fn parsePropagators(env_map: *const EnvMap, allocator: std.mem.Allocator) ![]const TracePropagator {

src/sdk/propagation.zig

@@ -177,6 +177,7 @@ test "PropagatorRegistry initialization with baggage" {
     var config = Configuration{
         .allocator = allocator,
         .sdk_disabled = false,
+        .resource_detectors = .{},
         .service_name = null,
         .resource_attributes = null,
         .log_level = .info,
@@ -198,6 +199,7 @@ test "PropagatorRegistry initialization with multiple propagators" {
     var config = Configuration{
         .allocator = allocator,
         .sdk_disabled = false,
+        .resource_detectors = .{},
         .service_name = null,
         .resource_attributes = null,
         .log_level = .info,
@@ -220,6 +222,7 @@ test "PropagatorRegistry with none" {
     var config = Configuration{
         .allocator = allocator,
         .sdk_disabled = false,
+        .resource_detectors = .{},
         .service_name = null,
         .resource_attributes = null,
         .log_level = .info,
@@ -241,6 +244,7 @@ test "CompositePropagator inject and extract baggage" {
     var config = Configuration{
         .allocator = allocator,
         .sdk_disabled = false,
+        .resource_detectors = .{},
         .service_name = null,
         .resource_attributes = null,
         .log_level = .info,
@@ -287,6 +291,7 @@ test "CompositePropagator with baggage disabled" {
     var config = Configuration{
         .allocator = allocator,
         .sdk_disabled = false,
+        .resource_detectors = .{},
         .service_name = null,
         .resource_attributes = null,
         .log_level = .info,
@@ -324,6 +329,7 @@ test "CompositePropagator fields list" {
     var config = Configuration{
         .allocator = allocator,
         .sdk_disabled = false,
+        .resource_detectors = .{},
         .service_name = null,
         .resource_attributes = null,
         .log_level = .info,