MINOR: httpclient/lua: httpclient:get() API in lua

This commit provides an hlua_httpclient object which is a bridge between
the httpclient and the lua API.

The HTTPClient is callable in lua this way:

    local httpclient = core.httpclient()
    local response = httpclient:get("http://127.0.0.1:9000/?s=9999")
    core.Debug("Status: ".. res.status .. ", Reason : " .. res.reason .. ", Len:" .. string.len(res.body) .. "\n")

The resulting response object will provide a "status" field which
contains the status code, a "reason" string which contains the reason
string, and a "body" field which contains the response body.

The implementation uses the httpclient callback to wake up the lua task
which yield each time it pushes some data. The httpclient works in the
same thread as the lua task.

diff --git a/include/haproxy/hlua-t.h b/include/haproxy/hlua-t.h
index 17f659f86c2bd9377aa496f5c55f2e8412557243..fa694b5323c35c647515ca0c65b0d411b631f5a5 100644 (file)
--- a/include/haproxy/hlua-t.h
+++ b/include/haproxy/hlua-t.h
@@ -43,6 +43,7 @@
 #define CLASS_CHANNEL      "Channel"
 #define CLASS_HTTP         "HTTP"
 #define CLASS_HTTP_MSG     "HTTPMessage"
+#define CLASS_HTTPCLIENT   "HTTPClient"
 #define CLASS_MAP          "Map"
 #define CLASS_APPLET_TCP   "AppletTCP"
 #define CLASS_APPLET_HTTP  "AppletHTTP"
@@ -184,6 +185,12 @@ struct hlua_concat {
        int len;
 };
 
+/* This struct is used to store the httpclient */
+struct hlua_httpclient {
+       struct httpclient *hc; /* ptr to the httpclient instance */
+       luaL_Buffer b; /* buffer used to prepare strings. */
+};
+
 #else /* USE_LUA */
 /************************ For use when Lua is disabled ********************/
 

diff --git a/src/hlua.c b/src/hlua.c
index 4bce23f760d45072ba88089c2f1313d8481b4892..37f1afa38b57cb9abb9bf19c7896ffe5edd50b10 100644 (file)
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -38,6 +38,7 @@
 #include <haproxy/hlua.h>
 #include <haproxy/hlua_fcn.h>
 #include <haproxy/http_ana.h>
+#include <haproxy/http_client.h>
 #include <haproxy/http_fetch.h>
 #include <haproxy/http_htx.h>
 #include <haproxy/http_rules.h>
@@ -273,6 +274,7 @@ static int class_fetches_ref;
 static int class_converters_ref;
 static int class_http_ref;
 static int class_http_msg_ref;
+static int class_httpclient_ref;
 static int class_map_ref;
 static int class_applet_tcp_ref;
 static int class_applet_http_ref;
@@ -6881,6 +6883,164 @@ __LJMP static int hlua_http_msg_unset_eom(lua_State *L)
        return 0;
 }
 
+/*
+ *
+ *
+ * Class HTTPClient
+ *
+ *
+ */
+__LJMP static struct hlua_httpclient *hlua_checkhttpclient(lua_State *L, int ud)
+{
+       return MAY_LJMP(hlua_checkudata(L, ud, class_httpclient_ref));
+}
+
+__LJMP static int hlua_httpclient_new(lua_State *L)
+{
+       struct hlua_httpclient *hlua_hc;
+       struct hlua *hlua;
+
+       /* Get hlua struct, or NULL if we execute from main lua state */
+       hlua = hlua_gethlua(L);
+       if (!hlua)
+               return 0;
+
+       /* Check stack size. */
+       if (!lua_checkstack(L, 3)) {
+               hlua_pusherror(L, "httpclient: full stack");
+               goto err;
+       }
+       /* Create the object: obj[0] = userdata. */
+       lua_newtable(L);
+       hlua_hc = MAY_LJMP(lua_newuserdata(L, sizeof(*hlua_hc)));
+       lua_rawseti(L, -2, 0);
+       memset(hlua_hc, 0, sizeof(*hlua_hc));
+
+       hlua_hc->hc = httpclient_new(hlua, 0, IST_NULL);
+       if (!hlua_hc->hc)
+               goto err;
+
+       /* Pop a class stream metatable and affect it to the userdata. */
+       lua_rawgeti(L, LUA_REGISTRYINDEX, class_httpclient_ref);
+       lua_setmetatable(L, -2);
+
+       return 1;
+
+ err:
+       WILL_LJMP(lua_error(L));
+       return 0;
+}
+
+
+/*
+ * Callback of the httpclient, this callback wakes the lua task up, once the
+ * httpclient receives some data
+ *
+ */
+
+static void hlua_httpclient_res_cb(struct httpclient *hc)
+{
+       struct hlua *hlua = hc->caller;
+
+       if (!hlua || !hlua->task)
+               return;
+
+       task_wakeup(hlua->task, TASK_WOKEN_MSG);
+}
+
+/*
+ * For each yield, checks if there is some data in the httpclient and push them
+ * in the lua buffer, once the httpclient finished its job, push the result on
+ * the stack
+ */
+__LJMP static int hlua_httpclient_get_yield(lua_State *L, int status, lua_KContext ctx)
+{
+       struct buffer *tr;
+       int res;
+       struct hlua *hlua = hlua_gethlua(L);
+       struct hlua_httpclient *hlua_hc = hlua_checkhttpclient(L, 1);
+
+
+       tr = get_trash_chunk();
+
+       res = httpclient_res_xfer(hlua_hc->hc, tr);
+       luaL_addlstring(&hlua_hc->b, b_orig(tr), res);
+
+       if (!httpclient_data(hlua_hc->hc) && httpclient_ended(hlua_hc->hc)) {
+
+               luaL_pushresult(&hlua_hc->b);
+               lua_settable(L, -3);
+
+               lua_pushstring(L, "status");
+               lua_pushinteger(L, hlua_hc->hc->res.status);
+               lua_settable(L, -3);
+
+
+               lua_pushstring(L, "reason");
+               lua_pushlstring(L, hlua_hc->hc->res.reason.ptr, hlua_hc->hc->res.reason.len);
+               lua_settable(L, -3);
+
+               return 1;
+       }
+
+       if (httpclient_data(hlua_hc->hc))
+               task_wakeup(hlua->task, TASK_WOKEN_MSG);
+
+
+       MAY_LJMP(hlua_yieldk(L, 0, 0, hlua_httpclient_get_yield, TICK_ETERNITY, 0));
+       return 0;
+}
+
+/*
+ * Sends and receive an HTTP request
+ *
+ * httpclient.get(url, headers)
+ */
+
+__LJMP static int hlua_httpclient_get(lua_State *L)
+{
+       struct hlua_httpclient *hlua_hc;
+       struct hlua *hlua;
+       const char *url_str;
+
+       hlua = hlua_gethlua(L);
+
+       if (!hlua || !hlua->task)
+               WILL_LJMP(luaL_error(L, "The 'get' function is only allowed in "
+                                    "'frontend', 'backend' or 'task'"));
+
+       if (lua_gettop(L) < 1 || lua_gettop(L) > 2)
+               WILL_LJMP(luaL_error(L, "'get' needs between 1 or 2 arguments"));
+
+       /* arg 1: URL */
+       if (lua_type(L, -1) == LUA_TSTRING)
+               url_str = lua_tostring(L, -1);
+
+       hlua_hc = hlua_checkhttpclient(L, 1);
+
+       hlua_hc->hc->req.url = istdup(ist(url_str));
+       hlua_hc->hc->req.meth = HTTP_METH_GET;
+
+       /* update the httpclient callbacks */
+       hlua_hc->hc->ops.res_stline = hlua_httpclient_res_cb;
+       hlua_hc->hc->ops.res_headers = hlua_httpclient_res_cb;
+       hlua_hc->hc->ops.res_payload = hlua_httpclient_res_cb;
+       hlua_hc->hc->ops.res_end = hlua_httpclient_res_cb;
+
+
+       httpclient_req_gen(hlua_hc->hc, hlua_hc->hc->req.url, HTTP_METH_GET, NULL);
+       httpclient_start(hlua_hc->hc);
+
+       /* we return a "res" object */
+       lua_newtable(L);
+
+       luaL_buffinit(L, &hlua_hc->b);
+       lua_pushstring(L, "body");
+
+       MAY_LJMP(hlua_yieldk(L, 0, 0, hlua_httpclient_get_yield, TICK_ETERNITY, 0));
+       return 0;
+}
+
 /*
  *
  *
@@ -11209,6 +11369,7 @@ lua_State *hlua_init_state(int thread_num)
        hlua_class_function(L, "set_map", hlua_set_map);
        hlua_class_function(L, "del_map", hlua_del_map);
        hlua_class_function(L, "tcp", hlua_socket_new);
+       hlua_class_function(L, "httpclient", hlua_httpclient_new);
        hlua_class_function(L, "log", hlua_log);
        hlua_class_function(L, "Debug", hlua_log_debug);
        hlua_class_function(L, "Info", hlua_log_info);
@@ -11514,6 +11675,22 @@ lua_State *hlua_init_state(int thread_num)
 
        /* Register previous table in the registry with reference and named entry. */
        class_http_msg_ref = hlua_register_metatable(L, CLASS_HTTP_MSG);
+
+       /*
+        *
+        * Register class HTTPClient
+        *
+        */
+
+       /* Create and fill the metatable. */
+       lua_newtable(L);
+       lua_pushstring(L, "__index");
+       lua_newtable(L);
+       hlua_class_function(L, "get",         hlua_httpclient_get);
+       lua_settable(L, -3); /* Sets the __index entry. */
+
+
+       class_httpclient_ref = hlua_register_metatable(L, CLASS_HTTPCLIENT);
        /*
         *
         * Register class AppletTCP