feature: supported to fetch cookie value from ctx.var which is a easy way.

lua/apisix/core/ctx.lua

@@ -1,15 +1,26 @@
-local tablepool = require("tablepool")
-local get_var = require("resty.ngxvar").fetch
-local get_request = require("resty.ngxvar").request
+local log          = require("apisix.core.log")
+local tablepool    = require("tablepool")
+local get_var      = require("resty.ngxvar").fetch
+local get_request  = require("resty.ngxvar").request
+local ck           = require "resty.cookie"
 local setmetatable = setmetatable
+local ffi          = require("ffi")
+local C            = ffi.C
+local sub_str      = string.sub
 
 
-local _M = {version = 0.1}
+ffi.cdef[[
+int memcmp(const void *s1, const void *s2, size_t n);
+]]
+
+
+local _M = {version = 0.2}
 
 
 do
     local var_methods = {
-        ["method"] = ngx.req.get_method
+        ["method"] = ngx.req.get_method,
+        ["cookie"] = function () return ck:new() end
     }
 
     local mt = {
@@ -19,6 +30,17 @@ do
             if method then
                 val = method()
 
+            elseif C.memcmp(name, "cookie_", 7) == 0 then
+                local cookie = t["cookie"]
+                if cookie then
+                    local err
+                    val, err = cookie:get(sub_str(name, 8))
+                    if not val then
+                        log.warn("failed to fetch cookie value by name: ",
+                                 name, " error: ", err)
+                    end
+                end
+
             else
                 val = get_var(name, t._request)
             end

t/core/ctx.t

@@ -0,0 +1,99 @@
+use t::APISix 'no_plan';
+
+repeat_each(2);
+no_long_string();
+no_root_location();
+
+run_tests;
+
+__DATA__
+
+=== TEST 1: sanity
+--- config
+    location /t {
+        content_by_lua_block {
+            local core = require("apisix.core")
+            local ctx = {}
+            core.ctx.set_vars_meta(ctx)
+
+            ngx.say("remote_addr: ", ctx.var["remote_addr"])
+            ngx.say("server_port: ", ctx.var["server_port"])
+        }
+    }
+--- request
+GET /t
+--- response_body
+remote_addr: 127.0.0.1
+server_port: 1984
+--- no_error_log
+[error]
+
+
+
+=== TEST 2: http header + arg
+--- config
+    location /t {
+        content_by_lua_block {
+            local core = require("apisix.core")
+            local ctx = {}
+            core.ctx.set_vars_meta(ctx)
+
+            ngx.say("http_host: ", ctx.var["http_host"])
+            ngx.say("arg_a: ", ctx.var["arg_a"])
+        }
+    }
+--- request
+GET /t?a=aaa
+--- response_body
+http_host: localhost
+arg_a: aaa
+--- no_error_log
+[error]
+
+
+
+=== TEST 3: cookie + no cookie
+--- config
+    location /t {
+        content_by_lua_block {
+            local core = require("apisix.core")
+            local ctx = {}
+            core.ctx.set_vars_meta(ctx)
+
+            ngx.say("cookie_host: ", ctx.var["cookie_host"])
+        }
+    }
+--- request
+GET /t?a=aaa
+--- response_body
+cookie_host: nil
+--- error_log
+failed to fetch cookie value by name: cookie_host error: no cookie found in the current request
+
+
+
+=== TEST 4: cookie
+--- config
+    location /t {
+        content_by_lua_block {
+            local core = require("apisix.core")
+            local ctx = {}
+            core.ctx.set_vars_meta(ctx)
+
+            ngx.say("cookie_a: ", ctx.var["cookie_a"])
+            ngx.say("cookie_b: ", ctx.var["cookie_b"])
+            ngx.say("cookie_c: ", ctx.var["cookie_c"])
+            ngx.say("cookie_d: ", ctx.var["cookie_d"])
+        }
+    }
+--- more_headers
+Cookie: a=a; b=bb; c=ccc
+--- request
+GET /t?a=aaa
+--- response_body
+cookie_a: a
+cookie_b: bb
+cookie_c: ccc
+cookie_d: nil
+--- no_error_log
+[error]