feat: support etcd auth in etcd client via environment variables.

xllm/core/common/etcd_client.cpp

@@ -32,6 +32,17 @@ EtcdClient::EtcdClient(const std::string& etcd_addr)
   }
 }
 
+EtcdClient::EtcdClient(const std::string& etcd_addr,
+                       const std::string& username,
+                       const std::string& password)
+    : client_(etcd_addr, username, password), etcd_addr_(etcd_addr) {
+  auto response = client_.put("XLLM_PING", "PING");
+  if (!response.is_ok()) {
+    LOG(FATAL) << "etcd connect to etcd server failed: "
+               << response.error_message();
+  }
+}
+
 EtcdClient::~EtcdClient() {
   stop_watch();
 

xllm/core/common/etcd_client.h

@@ -30,6 +30,9 @@ using Callback = std::function<void(const etcd::Response&)>;
 class EtcdClient {
  public:
   EtcdClient(const std::string& etcd_addr);
+  EtcdClient(const std::string& etcd_addr,
+             const std::string& username,
+             const std::string& password);
   ~EtcdClient();
 
   void add_watch(const std::string& key_prefix,

xllm/core/runtime/xservice_client.cpp

@@ -26,6 +26,7 @@ limitations under the License.
 #include <algorithm>
 #include <unordered_map>
 
+#include "util/env_var.h"
 #include "util/hash_util.h"
 #include "util/net.h"
 #include "util/uuid.h"
@@ -35,6 +36,8 @@ namespace {
 static std::string ETCD_MASTER_SERVICE_KEY = "XLLM:SERVICE:MASTER";
 static std::string ETCD_XSERVICES_KEY_PREFIX =
     "XLLM:SERVICE:";  // all xllm_service registeration prefix
+constexpr const char* kEtcdUsernameEnvVar = "ETCD_USERNAME";
+constexpr const char* kEtcdPasswordEnvVar = "ETCD_PASSWORD";
 static std::unordered_map<xllm_service::proto::InstanceType, std::string>
     ETCD_KEYS_PREFIX_MAP = {
         {xllm_service::proto::InstanceType::DEFAULT, "XLLM:DEFAULT:"},
@@ -90,7 +93,23 @@ bool XServiceClient::init(const std::string& etcd_addr,
   chan_options_.max_retry = 3;
   chan_options_.timeout_ms = FLAGS_rpc_channel_timeout_ms;
 
-  etcd_client_ = std::make_unique<EtcdClient>(etcd_addr);
+  const std::string etcd_username =
+      util::get_optional_string_env(kEtcdUsernameEnvVar).value_or("");
+  const std::string etcd_password =
+      util::get_optional_string_env(kEtcdPasswordEnvVar).value_or("");
+  const bool has_etcd_auth_user = !etcd_username.empty();
+  const bool has_etcd_auth_password = !etcd_password.empty();
+  if (has_etcd_auth_user != has_etcd_auth_password) {
+    LOG(ERROR) << "Both " << kEtcdUsernameEnvVar << " and "
+               << kEtcdPasswordEnvVar << " must be set together.";
+    return false;
+  }
+  if (has_etcd_auth_user) {
+    etcd_client_ =
+        std::make_unique<EtcdClient>(etcd_addr, etcd_username, etcd_password);
+  } else {
+    etcd_client_ = std::make_unique<EtcdClient>(etcd_addr);
+  }
 
   // connect master xllm_service
   while (!etcd_client_->get_master_service(ETCD_MASTER_SERVICE_KEY,

xllm/core/util/env_var.cpp

@@ -62,6 +62,14 @@ std::string get_string_env(const std::string& name) {
   return std::string(val);
 }
 
+std::optional<std::string> get_optional_string_env(const std::string& name) {
+  const char* val = std::getenv(name.c_str());
+  if (val == nullptr) {
+    return std::nullopt;
+  }
+  return std::string(val);
+}
+
 double get_double_env(const std::string& key, double defaultValue = -1) {
   const char* val = std::getenv(key.c_str());
   if (val == nullptr) {

xllm/core/util/env_var.h

@@ -29,6 +29,7 @@ bool get_bool_env(const std::string& key, bool defaultValue);
 int64_t get_int_env(const std::string& key, int64_t defaultValue);
 
 std::string get_string_env(const std::string& name);
+std::optional<std::string> get_optional_string_env(const std::string& name);
 
 // Get the timeout in seconds for process group test operations.
 // This timeout is used when waiting for process group initialization tests