implemented, tested, and documented the new ngx.redirect(uri, status) method for Lua.

README.markdown

@@ -424,7 +424,43 @@ Named locations are also supported, but query strings are ignored. For example
         ...
     }
 
-This function never returns.
+Note that this is very different from ngx.redirect() in that
+it's just an internal redirect and no new HTTP traffic is involved.
+
+This method never returns.
+
+This method MUST be called before `ngx.send_headers()` or explicit response body
+outputs by either `ngx.print` or `ngx.say`.
+
+This method is very much like the `echo_exec`
+directive in the ngx_echo module.
+
+ngx.redirect(uri, status?)
+--------------------------
+
+Issue an HTTP 301 or 302 redirection to `uri`.
+
+The optional `status` parameter specify whether
+301 or 302 to be used. It's 302 (ngx.HTTP_MOVED_TEMPORARILY) by default.
+
+This method MUST be called before `ngx.send_headers()` or explicit response body
+outputs by either `ngx.print` or `ngx.say`.
+
+Here's a small example:
+
+    return ngx.redirect("/foo")
+
+which is equivalent to
+
+    return ngx.redirect("http://<host>:<port>/foo", ngx.HTTP_MOVED_TEMPORARILY)
+
+where <host> is the current virtual server name and
+<port> is the listerning port.
+
+This method never returns.
+
+This method is very much like the `rewrite` directive with the `redirect` modifier in the standard
+`ngx_rewrite` module.
 
 ngx.send_headers()
 ------------------

src/ngx_http_lua_hook.c

@@ -2060,3 +2060,79 @@ ngx_http_lua_ngx_cookie_time(lua_State *L)
     return 1;
 }
 
+
+int
+ngx_http_lua_ngx_redirect(lua_State *L)
+{
+    ngx_http_lua_ctx_t          *ctx;
+    ngx_int_t                    rc;
+    int                          n;
+    u_char                      *p;
+    u_char                      *uri;
+    size_t                       len;
+    ngx_http_request_t          *r;
+
+    n = lua_gettop(L);
+
+    if (n != 1 && n != 2) {
+        return luaL_error(L, "expecting one or two arguments");
+    }
+
+    p = (u_char *) luaL_checklstring(L, 1, &len);
+
+    if (n == 2) {
+        rc = (ngx_int_t) luaL_checknumber(L, 2);
+
+        if (rc != NGX_HTTP_MOVED_TEMPORARILY &&
+                rc != NGX_HTTP_MOVED_PERMANENTLY)
+        {
+            return luaL_error(L, "only ngx.HTTP_MOVED_TEMPORARILY and "
+                    "ngx.HTTP_MOVED_PERMANENTLY are allowed");
+        }
+    } else {
+        rc = NGX_HTTP_MOVED_TEMPORARILY;
+    }
+
+    lua_getglobal(L, GLOBALS_SYMBOL_REQUEST);
+    r = lua_touserdata(L, -1);
+    lua_pop(L, 1);
+
+    if (r == NULL) {
+        return luaL_error(L, "no request object found");
+    }
+
+    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
+    if (ctx == NULL) {
+        return luaL_error(L, "no request ctx found");
+    }
+
+    if (ctx->headers_sent) {
+        return luaL_error(L, "attempt to call ngx.redirect after sending out the headers");
+    }
+
+    uri = ngx_palloc(r->pool, len);
+    if (uri == NULL) {
+        return luaL_error(L, "out of memory");
+    }
+
+    ngx_memcpy(uri, p, len);
+
+    r->headers_out.location = ngx_list_push(&r->headers_out.headers);
+    if (r->headers_out.location == NULL) {
+        return luaL_error(L, "out of memory");
+    }
+
+    r->headers_out.location->hash = 1;
+    r->headers_out.location->value.len = len;
+    r->headers_out.location->value.data = uri;
+    ngx_str_set(&r->headers_out.location->key, "Location");
+
+    r->headers_out.status = rc;
+
+    ctx->exit_code = rc;
+    ctx->exited = 1;
+
+    lua_pushnil(L);
+    return lua_error(L);
+}
+

src/ngx_http_lua_hook.h

@@ -41,6 +41,7 @@ int ngx_http_lua_ngx_strtime(lua_State *L);
 int ngx_http_lua_ngx_utc_time(lua_State *L);
 int ngx_http_lua_ngx_utc_strtime(lua_State *L);
 int ngx_http_lua_ngx_cookie_time(lua_State *L);
+int ngx_http_lua_ngx_redirect(lua_State *L);
 
 int ngx_http_lua_ngx_location_capture(lua_State *L);
 

src/ngx_http_lua_util.c

@@ -530,6 +530,9 @@ init_ngx_lua_globals(lua_State *L)
     lua_pushcfunction(L, ngx_http_lua_ngx_cookie_time);
     lua_setfield(L, -2, "cookie_time");
 
+    lua_pushcfunction(L, ngx_http_lua_ngx_redirect);
+    lua_setfield(L, -2, "redirect");
+
     lua_createtable(L, 0, 2); /* .location */
     lua_pushcfunction(L, ngx_http_lua_ngx_location_capture);
     lua_setfield(L, -2, "capture");

t/005-exit.t

@@ -201,8 +201,8 @@ Logged in 56
 
         set $key "conv-uid-$arg_uid";
 
-        srcache_fetch GET /memc key=$key;
-        srcache_store PUT /memc key=$key;
+        #srcache_fetch GET /memc key=$key;
+        #srcache_store PUT /memc key=$key;
 
         default_type 'application/json';
 
@@ -281,8 +281,8 @@ Logged in 56
 
         set $key "conv-uid-$arg_uid";
 
-        srcache_fetch GET /memc key=$key;
-        srcache_store PUT /memc key=$key;
+        #srcache_fetch GET /memc key=$key;
+        #srcache_store PUT /memc key=$key;
 
         default_type 'application/json';
 
@@ -358,8 +358,8 @@ Logged in 56
 
         set $key "conv-uri-$query_string";
 
-        srcache_fetch GET /memc key=$key;
-        srcache_store PUT /memc key=$key;
+        #srcache_fetch GET /memc key=$key;
+        #srcache_store PUT /memc key=$key;
 
         default_type 'application/json';
 

t/016-headers.t

@@ -7,8 +7,8 @@ use Test::Nginx::Socket;
 #master_process_enabled(1);
 #log_level('warn');
 
-#repeat_each(120);
-repeat_each(1);
+repeat_each(2);
+#repeat_each(1);
 
 plan tests => blocks() * repeat_each() * 3;
 

t/020-subrequest.t

@@ -355,7 +355,8 @@ PUT: 201
 cached: hello
 
 
-=== TEST 12: POST (with body, memc method)
+
+=== TEST 13: POST (with body, memc method)
 --- config
     location /flush {
         set $memc_cmd flush_all;

t/022-redirect.t

@@ -0,0 +1,122 @@
+# vim:set ft= ts=4 sw=4 et fdm=marker:
+
+use lib 'lib';
+use Test::Nginx::Socket;
+
+#worker_connections(1014);
+#master_process_enabled(1);
+#log_level('warn');
+
+repeat_each(2);
+#repeat_each(1);
+
+plan tests => blocks() * repeat_each() * 3;
+
+#no_diff();
+#no_long_string();
+
+$ENV{TEST_NGINX_PORT} ||= 1984;
+
+run_tests();
+
+__DATA__
+
+=== TEST 1: default 302
+--- config
+    location /read {
+        content_by_lua '
+            ngx.redirect("http://www.taobao.com/foo");
+            ngx.say("hi")
+        ';
+    }
+--- request
+GET /read
+--- response_headers
+Location: http://www.taobao.com/foo
+--- response_body_like: 302 Found
+--- error_code: 302
+
+
+
+=== TEST 2: explicit 302
+--- config
+    location /read {
+        content_by_lua '
+            ngx.redirect("http://www.taobao.com/foo", ngx.HTTP_MOVED_TEMPORARILY);
+            ngx.say("hi")
+        ';
+    }
+--- request
+GET /read
+--- response_headers
+Location: http://www.taobao.com/foo
+--- response_body_like: 302 Found
+--- error_code: 302
+
+
+
+=== TEST 3: explicit 301
+--- config
+    location /read {
+        content_by_lua '
+            ngx.redirect("http://www.taobao.com/foo", ngx.HTTP_MOVED_PERMANENTLY);
+            ngx.say("hi")
+        ';
+    }
+--- request
+GET /read
+--- response_headers
+Location: http://www.taobao.com/foo
+--- response_body_like: 301 Moved Permanently
+--- error_code: 301
+
+
+
+=== TEST 4: bad rc
+--- config
+    location /read {
+        content_by_lua '
+            ngx.redirect("http://www.taobao.com/foo", 404);
+            ngx.say("hi")
+        ';
+    }
+--- request
+GET /read
+--- response_headers
+!Location
+--- response_body_like: 500 Internal Server Error
+--- error_code: 500
+
+
+
+=== TEST 5: no args
+--- config
+    location /read {
+        content_by_lua '
+            ngx.redirect()
+            ngx.say("hi")
+        ';
+    }
+--- request
+GET /read
+--- response_headers
+!Location
+--- response_body_like: 500 Internal Server Error
+--- error_code: 500
+
+
+
+=== TEST 6: relative uri
+--- config
+    location /read {
+        content_by_lua '
+            ngx.redirect("/foo")
+            ngx.say("hi")
+        ';
+    }
+--- request
+GET /read
+--- raw_response_headers_like: Location: http://localhost(?::\d+)?/foo\r\n
+--- response_body_like: 302 Found
+--- error_code: 302
+