server: add initial tool isolation support (via docker) (#26507)

* server: add initial tool isolation support (via docker)

* add docs

* adapt get_info

* py: fix type check

* cont

* separate tools_io_sandbox / tools_io_docker

* rename sandbox --> isolate

* x-tool-docker --> x-tool-runtime

---------

Co-authored-by: Pascal <admin@serveurperso.com>

common/arg.cpp

@@ -3308,6 +3308,16 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
             params.server_tools = parse_csv_row(value);
         }
     ).set_examples({LLAMA_EXAMPLE_SERVER}).set_env("LLAMA_ARG_TOOLS"));
+    add_opt(common_arg(
+        {"--tools-runtime"}, "OPTION",
+        "experimental: run tools in a separate runtime environment (default: none, use host environment)\n"
+        "available options:\n"
+        "  'docker:<image>': spin up a new Docker container and reuse it for all invocations, clean up on server exit\n"
+        "  'docker-container:<id>': use an existing Docker container by ID, won't stop on server exit\n",
+        [](common_params & params, const std::string & value) {
+            params.server_tools_runtime = value;
+        }
+    ).set_examples({LLAMA_EXAMPLE_SERVER}).set_env("LLAMA_ARG_TOOLS_RUNTIME"));
     add_opt(common_arg(
         {"--mcp-servers-config"}, "PATH",
         "experimental: path to JSON file with MCP server definitions (Cursor-compatible format) - do not enable in untrusted environments (default: none)\n"

common/common.h

@@ -655,6 +655,7 @@ struct common_params {
 
     // enable built-in tools
     std::vector<std::string> server_tools;
+    std::string server_tools_runtime;
 
     // MCP server configs (Cursor-compatible JSON)
     std::string mcp_servers_config;   // path to JSON file with MCP server definitions