clean up cookie extraction

docker/nginx/libs/skynet/account.lua

@@ -17,12 +17,16 @@ local anon_limits = {
 -- get all non empty authentication headers from request, we want to return
 -- all of them and let accounts service deal with validation and prioritisation
 function _M.get_auth_headers()
+    local utils = require("utils")
     local request_headers = ngx.req.get_headers()
     local headers = {}
 
-    -- if skynet_jwt is set, include it as a cookie
+    -- try to extract skynet-jwt cookie from cookie header
-    if ngx.var.skynet_jwt ~= "" then
+    local skynet_jwt_cookie = utils.extract_cookie(request_headers["Cookie"], "skynet[-]jwt")
-        headers["Cookie"] = "skynet-jwt=" .. ngx.var.skynet_jwt
+
+    -- if skynet-jwt cookie is present, pass it as is
+    if skynet_jwt_cookie then
+        headers["Cookie"] = skynet_jwt_cookie
     end
 
     -- if authorization header is set, pass it as is

docker/nginx/libs/utils.lua

@@ -9,4 +9,32 @@ function _M.is_table_empty(check)
     return next(check) == nil
 end
 
+-- extract full cookie name and value by its name from cookie string
+-- note: name matcher argument is a pattern so you will need to escape
+-- any special characters, read more https://www.lua.org/pil/20.2.html
+function _M.extract_cookie(cookie_string, name_matcher)
+    if cookie_string == nil then return nil end -- nil safeguard
+
+    local start, stop = string.find(cookie_string, name_matcher .. "=[^;]+")
+
+    if start then
+        return string.sub(cookie_string, start, stop)
+    end
+
+    return nil
+end
+
+-- extract just the cookie value by its name from cookie string
+-- note: name matcher argument is a pattern so you will need to escape
+-- any special characters, read more https://www.lua.org/pil/20.2.html
+function _M.extract_cookie_value(cookie_string, name_matcher)
+    local cookie = _M.extract_cookie(cookie_string, name_matcher)
+
+    if cookie == nil then return nil end
+
+    local value_start = string.find(cookie, "=") + 1
+
+    return string.sub(cookie, value_start)
+end
+
 return _M

docker/nginx/libs/utils.spec.lua

@@ -9,3 +9,71 @@ describe("is_table_empty", function()
         assert.is_false(utils.is_table_empty({ ["foo"] = "bar" }))
     end)
 end)
+
+describe("extract_cookie", function()
+    local cookie_string = "aaa=bbb; skynet-jwt=MTY0NzUyr8jD-ytiWtspm0tGabKfooxeIDuWcXhJ3lnY0eEw==; xxx=yyy"
+
+    it("should return nil if cookie string is nil", function()
+        local cookie = utils.extract_cookie_value(nil, "aaa")
+        
+        assert.is_nil(cookie)
+    end)
+
+    it("should return nil if cookie name is not found", function()
+        local cookie = utils.extract_cookie(cookie_string, "foo")
+        
+        assert.is_nil(cookie)
+    end)
+
+    it("should return cookie if cookie_string starts with that cookie name", function()
+        local cookie = utils.extract_cookie(cookie_string, "aaa")
+        
+        assert.are.equals(cookie, "aaa=bbb")
+    end)
+
+    it("should return cookie if cookie_string ends with that cookie name", function()
+        local cookie = utils.extract_cookie(cookie_string, "xxx")
+        
+        assert.are.equals(cookie, "xxx=yyy")
+    end)
+
+    it("should return cookie with custom matcher", function()
+        local cookie = utils.extract_cookie(cookie_string, "skynet[-]jwt")
+        
+        assert.are.equals(cookie, "skynet-jwt=MTY0NzUyr8jD-ytiWtspm0tGabKfooxeIDuWcXhJ3lnY0eEw==")
+    end)
+end)
+
+describe("extract_cookie_value", function()
+    local cookie_string = "aaa=bbb; skynet-jwt=MTY0NzUyr8jD-ytiWtspm0tGabKfooxeIDuWcXhJ3lnY0eEw==; xxx=yyy"
+
+    it("should return nil if cookie string is nil", function()
+        local value = utils.extract_cookie_value(nil, "aaa")
+        
+        assert.is_nil(value)
+    end)
+
+    it("should return nil if cookie name is not found", function()
+        local value = utils.extract_cookie_value(cookie_string, "foo")
+        
+        assert.is_nil(value)
+    end)
+
+    it("should return value if cookie_string starts with that cookie name", function()
+        local value = utils.extract_cookie_value(cookie_string, "aaa")
+        
+        assert.are.equals(value, "bbb")
+    end)
+
+    it("should return cookie if cookie_string ends with that cookie name", function()
+        local value = utils.extract_cookie_value(cookie_string, "xxx")
+        
+        assert.are.equals(value, "yyy")
+    end)
+
+    it("should return cookie with custom matcher", function()
+        local value = utils.extract_cookie_value(cookie_string, "skynet[-]jwt")
+        
+        assert.are.equals(value, "MTY0NzUyr8jD-ytiWtspm0tGabKfooxeIDuWcXhJ3lnY0eEw==")
+    end)
+end)

docker/nginx/nginx.conf

@@ -117,13 +117,6 @@ http {
     proxy_set_header X-Forwarded-Host  $host;
     proxy_set_header X-Forwarded-Proto $scheme;
 
-    # skynet-jwt contains dash so we cannot use $cookie_skynet-jwt
-    # https://richardhart.me/2012/03/18/logging-nginx-cookies-with-dashes/
-    map $http_cookie $skynet_jwt {
-        default '';
-        ~skynet-jwt=(?<match>[^\;]+) $match;
-    }
-
     include /etc/nginx/conf.d/*.conf;
     include /etc/nginx/conf.extra.d/*.conf;
 }