From da853702d68b4b9a42dbdac7c59f4d7d5cb213a7 Mon Sep 17 00:00:00 2001
From: YuanSheng Wang <membphis@gmail.com>
Date: Thu, 31 Oct 2019 10:19:22 +0800
Subject: [PATCH] feature: supported `redirect` plugin. (#732)

---
 conf/config.yaml                |   1 +
 doc/README.md                   |   1 +
 doc/README_CN.md                |   1 +
 doc/plugins/redirect.md         | 100 ++++++++++
 lua/apisix/plugins/redirect.lua | 119 ++++++++++++
 t/admin/plugins.t               |   2 +-
 t/debug/debug-mode.t            |   1 +
 t/plugin/redirect.t             | 332 ++++++++++++++++++++++++++++++++
 8 files changed, 556 insertions(+), 1 deletion(-)
 create mode 100644 doc/plugins/redirect.md
 create mode 100644 lua/apisix/plugins/redirect.lua
 create mode 100644 t/plugin/redirect.t

diff --git a/conf/config.yaml b/conf/config.yaml
index a7d70849..68cf4e65 100644
--- a/conf/config.yaml
+++ b/conf/config.yaml
@@ -87,6 +87,7 @@ plugins:                          # plugin list
   - serverless-post-function
   - openid-connect
   - proxy-rewrite
+  - redirect
 
 stream_plugins:
   - mqtt-proxy
diff --git a/doc/README.md b/doc/README.md
index 632dc136..56591f06 100644
--- a/doc/README.md
+++ b/doc/README.md
@@ -53,3 +53,4 @@ Plugins
 * [serverless](plugins/serverless-cn.md)：AllowS to dynamically run Lua code at *different* phase in APISIX.
 * [ip-restriction](plugins/ip-restriction.md): IP whitelist/blacklist.
 * openid-connect
+* [redirect](plugins/redirect.md): URI redirect.
diff --git a/doc/README_CN.md b/doc/README_CN.md
index 66360ed4..20e69ef1 100644
--- a/doc/README_CN.md
+++ b/doc/README_CN.md
@@ -54,3 +54,4 @@ Reference document
 * [serverless](plugins/serverless-cn.md)：允许在 APISIX 中的不同阶段动态运行 Lua 代码。
 * [ip-restriction](plugins/ip-restriction-cn.md): IP 黑白名单。
 * openid-connect
+* [redirect](plugins/redirect-cn.md): URI 重定向。
diff --git a/doc/plugins/redirect.md b/doc/plugins/redirect.md
new file mode 100644
index 00000000..7b3f734e
--- /dev/null
+++ b/doc/plugins/redirect.md
@@ -0,0 +1,100 @@
+[中文](redirect-cn.md)
+
+# redirect
+
+URI redirect.
+
+### Parameters
+
+|Name    |Required|Description|
+|------- |-----|------|
+|uri     |required| New uri which can contain Ningx variable, eg: `/test/index.html`, `$uri/index.html`. You can refer to variables in a way similar to `${xxx}` to avoid ambiguity, eg: `${uri}foo/index.html`. If you just need the original `$` character, add `\` in front of it, like this one: `/\$foo/index.html`. If you refer to a variable name that does not exist, this will not produce an error, and it will be used as an empty string.|
+|ret_code|option|Response code, the default value is `302`.|
+
+### Example
+
+#### Enable Plugin
+
+Here's a mini example, enable the `redirect` plugin on the specified route:
+
+```shell
+curl http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -d '
+{
+    "uri": "/test/index.html",
+    "plugins": {
+        "redirect": {
+            "uri": "/test/default.html",
+            "ret_code": 301
+        }
+    },
+    "upstream": {
+        "type": "roundrobin",
+        "nodes": {
+            "127.0.0.1:80": 1
+        }
+    }
+}'
+```
+
+And we can use any Nginx built-in variable in the new URI.
+
+```shell
+curl http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -d '
+{
+    "uri": "/test",
+    "plugins": {
+        "redirect": {
+            "uri": "$uri/index.html",
+            "ret_code": 301
+        }
+    },
+    "upstream": {
+        "type": "roundrobin",
+        "nodes": {
+            "127.0.0.1:80": 1
+        }
+    }
+}'
+```
+
+#### Test Plugin
+
+Testing based on the above examples :
+
+```shell
+$ curl http://127.0.0.1:9080/test/index.html -i
+HTTP/1.1 301 Moved Permanently
+Date: Wed, 23 Oct 2019 13:48:23 GMT
+Content-Type: text/html
+Content-Length: 166
+Connection: keep-alive
+Location: /test/default.html
+
+...
+```
+
+We can check the response code and the response header `Location`.
+
+It shows that the `redirect` plugin is in effect.
+
+#### Disable Plugin
+
+When you want to disable the `redirect` plugin, it is very simple,
+ you can delete the corresponding json configuration in the plugin configuration,
+  no need to restart the service, it will take effect immediately :
+
+```shell
+curl http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -d '
+{
+    "uri": "/test/index.html",
+    "plugins": {},
+    "upstream": {
+        "type": "roundrobin",
+        "nodes": {
+            "127.0.0.1:80": 1
+        }
+    }
+}'
+```
+
+The `redirect` plugin has been disabled now. It works for other plugins.
diff --git a/lua/apisix/plugins/redirect.lua b/lua/apisix/plugins/redirect.lua
new file mode 100644
index 00000000..89eec658
--- /dev/null
+++ b/lua/apisix/plugins/redirect.lua
@@ -0,0 +1,119 @@
+local core = require("apisix.core")
+local tab_insert = table.insert
+local tab_concat = table.concat
+local re_gmatch = ngx.re.gmatch
+local ipairs = ipairs
+
+local lrucache = core.lrucache.new({
+    ttl = 300, count = 100
+})
+
+
+local schema = {
+    type = "object",
+    properties = {
+        ret_code = {type = "integer", minimum = 200, default = 302},
+        uri = {type = "string", minLength = 2},
+    },
+    required = {"uri"},
+}
+
+
+local plugin_name = "rewrite"
+
+local _M = {
+    version = 0.1,
+    priority = 900,
+    name = plugin_name,
+    schema = schema,
+}
+
+
+local function parse_uri(uri)
+
+    local reg = [[ (\\\$[0-9a-zA-Z_]+) | ]]         -- \$host
+                .. [[ \$\{([0-9a-zA-Z_]+)\} | ]]    -- ${host}
+                .. [[ \$([0-9a-zA-Z_]+) | ]]        -- $host
+                .. [[ (\$|[^$\\]+) ]]               -- $ or others
+    local iterator, err = re_gmatch(uri, reg, "jiox")
+    if not iterator then
+        return nil, err
+    end
+
+    local t = {}
+    while true do
+        local m, err = iterator()
+        if err then
+            return nil, err
+        end
+
+        if not m then
+            break
+        end
+
+        tab_insert(t, m)
+    end
+
+    return t
+end
+
+
+function _M.check_schema(conf)
+    local ok, err = core.schema.check(schema, conf)
+    if not ok then
+        return false, err
+    end
+
+    local uri_segs, err = parse_uri(conf.uri)
+    if not uri_segs then
+        return false, err
+    end
+    core.log.info(core.json.delay_encode(uri_segs))
+
+    return true
+end
+
+
+    local tmp = {}
+local function concat_new_uri(uri, ctx)
+    local pased_uri_segs, err = lrucache(uri, nil, parse_uri, uri)
+    if not pased_uri_segs then
+        return nil, err
+    end
+
+    core.table.clear(tmp)
+
+    for _, uri_segs in ipairs(pased_uri_segs) do
+        local pat1 = uri_segs[1]    -- \$host
+        local pat2 = uri_segs[2]    -- ${host}
+        local pat3 = uri_segs[3]    -- $host
+        local pat4 = uri_segs[4]    -- $ or others
+        core.log.info("parsed uri segs: ", core.json.delay_encode(uri_segs))
+
+        if pat2 or pat3 then
+            tab_insert(tmp, ctx.var[pat2 or pat3])
+        else
+            tab_insert(tmp, pat1 or pat4)
+        end
+    end
+
+    return tab_concat(tmp, "")
+end
+
+
+function _M.rewrite(conf, ctx)
+    core.log.info("plugin rewrite phase, conf: ", core.json.delay_encode(conf))
+
+    local new_uri, err = concat_new_uri(conf.uri, ctx)
+    if not new_uri then
+        core.log.error("failed to generate new uri by: ", conf.uri, " error: ",
+                       err)
+        core.response.exit(500)
+    end
+
+    core.response.set_header("Location", new_uri)
+    core.response.exit(conf.ret_code)
+end
+
+
+return _M
diff --git a/t/admin/plugins.t b/t/admin/plugins.t
index 6d458dcc..9044d4ba 100644
--- a/t/admin/plugins.t
+++ b/t/admin/plugins.t
@@ -30,6 +30,6 @@ __DATA__
 --- request
 GET /apisix/admin/plugins/list
 --- response_body_like eval
-qr/\["limit-req","limit-count","limit-conn","key-auth","prometheus","node-status","jwt-auth","zipkin","ip-restriction","grpc-transcode","serverless-pre-function","serverless-post-function","openid-connect","proxy-rewrite"\]/
+qr/\["limit-req","limit-count","limit-conn","key-auth","prometheus","node-status","jwt-auth","zipkin","ip-restriction","grpc-transcode","serverless-pre-function","serverless-post-function","openid-connect","proxy-rewrite","redirect"\]/
 --- no_error_log
 [error]
diff --git a/t/debug/debug-mode.t b/t/debug/debug-mode.t
index 49d6b8e3..42b3b1ab 100644
--- a/t/debug/debug-mode.t
+++ b/t/debug/debug-mode.t
@@ -65,6 +65,7 @@ loaded plugin and sort by priority: 1003 name: limit-conn
 loaded plugin and sort by priority: 1002 name: limit-count
 loaded plugin and sort by priority: 1001 name: limit-req
 loaded plugin and sort by priority: 1000 name: node-status
+loaded plugin and sort by priority: 900 name: redirect
 loaded plugin and sort by priority: 506 name: grpc-transcode
 loaded plugin and sort by priority: 500 name: prometheus
 loaded plugin and sort by priority: 0 name: example-plugin
diff --git a/t/plugin/redirect.t b/t/plugin/redirect.t
new file mode 100644
index 00000000..6edd2158
--- /dev/null
+++ b/t/plugin/redirect.t
@@ -0,0 +1,332 @@
+BEGIN {
+    if ($ENV{TEST_NGINX_CHECK_LEAK}) {
+        $SkipReason = "unavailable for the hup tests";
+
+    } else {
+        $ENV{TEST_NGINX_USE_HUP} = 1;
+        undef $ENV{TEST_NGINX_USE_STAP};
+    }
+}
+
+use t::APISIX 'no_plan';
+
+repeat_each(1);
+no_long_string();
+no_shuffle();
+no_root_location();
+log_level('info');
+run_tests;
+
+__DATA__
+
+=== TEST 1: sanity
+--- config
+    location /t {
+        content_by_lua_block {
+            local plugin = require("apisix.plugins.redirect")
+            local ok, err = plugin.check_schema({
+                ret_code = 302,
+                uri = '/foo',
+            })
+            if not ok then
+                ngx.say(err)
+            end
+
+            ngx.say("done")
+        }
+    }
+--- request
+GET /t
+--- response_body
+done
+--- no_error_log
+[error]
+
+
+
+=== TEST 2: default ret_code
+--- config
+    location /t {
+        content_by_lua_block {
+            local plugin = require("apisix.plugins.redirect")
+            local ok, err = plugin.check_schema({
+                -- ret_code = 302,
+                uri = '/foo',
+            })
+            if not ok then
+                ngx.say(err)
+            end
+
+            ngx.say("done")
+        }
+    }
+--- request
+GET /t
+--- response_body
+done
+--- no_error_log
+[error]
+
+
+
+=== TEST 3: add plugin with new uri: /test/add
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/routes/1',
+                ngx.HTTP_PUT,
+                [[{
+                    "plugins": {
+                        "redirect": {
+                            "uri": "/test/add",
+                            "ret_code": 301
+                        }
+                    },
+                    "uri": "/hello"
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- request
+GET /t
+--- response_body
+passed
+--- no_error_log
+[error]
+
+
+
+=== TEST 4: redirect
+--- request
+GET /hello
+--- response_headers
+Location: /test/add
+--- error_code: 301
+--- no_error_log
+[error]
+
+
+
+=== TEST 5: add plugin with new uri: $uri/test/add
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/routes/1',
+                ngx.HTTP_PUT,
+                [[{
+                    "plugins": {
+                        "redirect": {
+                            "uri": "$uri/test/add",
+                            "ret_code": 301
+                        }
+                    },
+                    "uri": "/hello"
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- request
+GET /t
+--- response_body
+passed
+--- no_error_log
+[error]
+
+
+
+=== TEST 6: redirect
+--- request
+GET /hello
+--- response_headers
+Location: /hello/test/add
+--- error_code: 301
+--- no_error_log
+[error]
+
+
+
+=== TEST 7: add plugin with new uri: $uri/test/a${arg_name}c
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/routes/1',
+                ngx.HTTP_PUT,
+                [[{
+                    "plugins": {
+                        "redirect": {
+                            "uri": "$uri/test/a${arg_name}c",
+                            "ret_code": 302
+                        }
+                    },
+                    "uri": "/hello"
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- request
+GET /t
+--- response_body
+passed
+--- no_error_log
+[error]
+
+
+
+=== TEST 8: redirect
+--- request
+GET /hello?name=json
+--- response_headers
+Location: /hello/test/ajsonc
+--- error_code: 302
+--- no_error_log
+[error]
+
+
+
+=== TEST 9: add plugin with new uri: /foo$$uri
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/routes/1',
+                ngx.HTTP_PUT,
+                [[{
+                    "plugins": {
+                        "redirect": {
+                            "uri": "/foo$$uri",
+                            "ret_code": 302
+                        }
+                    },
+                    "uri": "/hello"
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- request
+GET /t
+--- response_body
+passed
+--- no_error_log
+[error]
+
+
+
+=== TEST 10: redirect
+--- request
+GET /hello?name=json
+--- response_headers
+Location: /foo$/hello
+--- error_code: 302
+--- no_error_log
+[error]
+
+
+
+=== TEST 11: add plugin with new uri: \\$uri/foo$uri\\$uri/bar
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/routes/1',
+                ngx.HTTP_PUT,
+                [[{
+                    "plugins": {
+                        "redirect": {
+                            "uri": "\\$uri/foo$uri\\$uri/bar",
+                            "ret_code": 301
+                        }
+                    },
+                    "uri": "/hello"
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- request
+GET /t
+--- response_body
+passed
+--- no_error_log
+[error]
+
+
+
+=== TEST 12: redirect
+--- request
+GET /hello
+--- response_headers
+Location: \$uri/foo/hello\$uri/bar
+--- error_code: 301
+--- no_error_log
+[error]
+
+
+
+=== TEST 13: add plugin with new uri: $uri/$bad_var/bar
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/routes/1',
+                ngx.HTTP_PUT,
+                [[{
+                    "plugins": {
+                        "redirect": {
+                            "uri": "$uri/$bad_var/bar",
+                            "ret_code": 301
+                        }
+                    },
+                    "uri": "/hello"
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- request
+GET /t
+--- response_body
+passed
+--- no_error_log
+[error]
+
+
+
+=== TEST 14: redirect
+--- request
+GET /hello
+--- response_headers
+Location: /hello//bar
+--- error_code: 301
+--- no_error_log
+[error]