server: Add ability to mount server at prefix (#14544)

* Add server_prefix

* Correct server path env

* Rename cli flag to --api-prefix

* Change all to api_prefix

common/arg.cpp

@@ -2734,6 +2734,13 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
             params.public_path = value;
         }
     ).set_examples({LLAMA_EXAMPLE_SERVER}).set_env("LLAMA_ARG_STATIC_PATH"));
+    add_opt(common_arg(
+        {"--api-prefix"}, "PREFIX",
+        string_format("prefix path the server serves from, without the trailing slash (default: %s)", params.api_prefix.c_str()),
+        [](common_params & params, const std::string & value) {
+            params.api_prefix = value;
+        }
+    ).set_examples({LLAMA_EXAMPLE_SERVER}).set_env("LLAMA_ARG_API_PREFIX"));
     add_opt(common_arg(
         {"--no-webui"},
         string_format("Disable the Web UI (default: %s)", params.webui ? "enabled" : "disabled"),

common/common.h

@@ -370,6 +370,7 @@ struct common_params {
 
     std::string hostname      = "127.0.0.1";
     std::string public_path   = "";                                                                         // NOLINT
+    std::string api_prefix    = "";                                                                         // NOLINT
     std::string chat_template = "";                                                                         // NOLINT
     bool use_jinja = false;                                                                                 // NOLINT
     bool enable_chat_template = true;

tools/server/server.cpp

@@ -4806,14 +4806,14 @@ int main(int argc, char ** argv) {
         // register static assets routes
         if (!params.public_path.empty()) {
             // Set the base directory for serving static files
-            bool is_found = svr->set_mount_point("/", params.public_path);
+            bool is_found = svr->set_mount_point(params.api_prefix + "/", params.public_path);
             if (!is_found) {
                 LOG_ERR("%s: static assets path not found: %s\n", __func__, params.public_path.c_str());
                 return 1;
             }
         } else {
             // using embedded static index.html
-            svr->Get("/", [](const httplib::Request & req, httplib::Response & res) {
+            svr->Get(params.api_prefix + "/", [](const httplib::Request & req, httplib::Response & res) {
                 if (req.get_header_value("Accept-Encoding").find("gzip") == std::string::npos) {
                     res.set_content("Error: gzip is not supported by this browser", "text/plain");
                 } else {
@@ -4829,37 +4829,37 @@ int main(int argc, char ** argv) {
     }
 
     // register API routes
-    svr->Get ("/health",              handle_health); // public endpoint (no API key check)
-    svr->Get ("/metrics",             handle_metrics);
-    svr->Get ("/props",               handle_props);
-    svr->Post("/props",               handle_props_change);
-    svr->Post("/api/show",            handle_api_show);
-    svr->Get ("/models",              handle_models); // public endpoint (no API key check)
-    svr->Get ("/v1/models",           handle_models); // public endpoint (no API key check)
-    svr->Get ("/api/tags",            handle_models); // ollama specific endpoint. public endpoint (no API key check)
-    svr->Post("/completion",          handle_completions); // legacy
-    svr->Post("/completions",         handle_completions);
-    svr->Post("/v1/completions",      handle_completions_oai);
-    svr->Post("/chat/completions",    handle_chat_completions);
-    svr->Post("/v1/chat/completions", handle_chat_completions);
-    svr->Post("/api/chat",            handle_chat_completions); // ollama specific endpoint
-    svr->Post("/infill",              handle_infill);
-    svr->Post("/embedding",           handle_embeddings); // legacy
-    svr->Post("/embeddings",          handle_embeddings);
-    svr->Post("/v1/embeddings",       handle_embeddings_oai);
-    svr->Post("/rerank",              handle_rerank);
-    svr->Post("/reranking",           handle_rerank);
-    svr->Post("/v1/rerank",           handle_rerank);
-    svr->Post("/v1/reranking",        handle_rerank);
-    svr->Post("/tokenize",            handle_tokenize);
-    svr->Post("/detokenize",          handle_detokenize);
-    svr->Post("/apply-template",      handle_apply_template);
+    svr->Get (params.api_prefix + "/health",              handle_health); // public endpoint (no API key check)
+    svr->Get (params.api_prefix + "/metrics",             handle_metrics);
+    svr->Get (params.api_prefix + "/props",               handle_props);
+    svr->Post(params.api_prefix + "/props",               handle_props_change);
+    svr->Post(params.api_prefix + "/api/show",            handle_api_show);
+    svr->Get (params.api_prefix + "/models",              handle_models); // public endpoint (no API key check)
+    svr->Get (params.api_prefix + "/v1/models",           handle_models); // public endpoint (no API key check)
+    svr->Get (params.api_prefix + "/api/tags",            handle_models); // ollama specific endpoint. public endpoint (no API key check)
+    svr->Post(params.api_prefix + "/completion",          handle_completions); // legacy
+    svr->Post(params.api_prefix + "/completions",         handle_completions);
+    svr->Post(params.api_prefix + "/v1/completions",      handle_completions_oai);
+    svr->Post(params.api_prefix + "/chat/completions",    handle_chat_completions);
+    svr->Post(params.api_prefix + "/v1/chat/completions", handle_chat_completions);
+    svr->Post(params.api_prefix + "/api/chat",            handle_chat_completions); // ollama specific endpoint
+    svr->Post(params.api_prefix + "/infill",              handle_infill);
+    svr->Post(params.api_prefix + "/embedding",           handle_embeddings); // legacy
+    svr->Post(params.api_prefix + "/embeddings",          handle_embeddings);
+    svr->Post(params.api_prefix + "/v1/embeddings",       handle_embeddings_oai);
+    svr->Post(params.api_prefix + "/rerank",              handle_rerank);
+    svr->Post(params.api_prefix + "/reranking",           handle_rerank);
+    svr->Post(params.api_prefix + "/v1/rerank",           handle_rerank);
+    svr->Post(params.api_prefix + "/v1/reranking",        handle_rerank);
+    svr->Post(params.api_prefix + "/tokenize",            handle_tokenize);
+    svr->Post(params.api_prefix + "/detokenize",          handle_detokenize);
+    svr->Post(params.api_prefix + "/apply-template",      handle_apply_template);
     // LoRA adapters hotswap
-    svr->Get ("/lora-adapters",       handle_lora_adapters_list);
-    svr->Post("/lora-adapters",       handle_lora_adapters_apply);
+    svr->Get (params.api_prefix + "/lora-adapters",       handle_lora_adapters_list);
+    svr->Post(params.api_prefix + "/lora-adapters",       handle_lora_adapters_apply);
     // Save & load slots
-    svr->Get ("/slots",               handle_slots);
-    svr->Post("/slots/:id_slot",      handle_slots_action);
+    svr->Get (params.api_prefix + "/slots",               handle_slots);
+    svr->Post(params.api_prefix + "/slots/:id_slot",      handle_slots_action);
 
     //
     // Start the server