- :sunrise: feat(response-rewrite): allow using variable in the header [#4194](https://github.com/apache/apisix/pull/4194)
- :sunrise: feat(ext-plugin): APISIX can support Java, Go and other languages to implement custom plugin [#4183](https://github.com/apache/apisix/pull/4183)
### Bugfix
- fix(DNS): support IPv6 resolver [#4242](https://github.com/apache/apisix/pull/4242)
- fix(healthcheck): only one_loop is needed in the passive health check report [#4116](https://github.com/apache/apisix/pull/4116)
- fix(traffic-split): configure multiple "rules", the request will be confused between upstream [#4092](https://github.com/apache/apisix/pull/4092)
- fix: ensure upstream with domain is cached [#4061](https://github.com/apache/apisix/pull/4061)
- fix: be compatible with the router created before 2.5 [#4056](https://github.com/apache/apisix/pull/4056)
- fix(standalone): the conf should be available during start [#4027](https://github.com/apache/apisix/pull/4027)
- fix: ensure atomic operation in limit-count plugin [#3991](https://github.com/apache/apisix/pull/3991)
- basic-auth plugin should run in rewrite phases. [#2905](https://github.com/apache/apisix/pull/2905)
- fixed the non effective config update in http/udp-logger [#2901](https://github.com/apache/apisix/pull/2901)
- always necessary to save the data of the limit concurrency, and release the statistical status in the log phase [#2465](https://github.com/apache/apisix/pull/2465)
- avoid duplicate auto-generated id [#3003](https://github.com/apache/apisix/pull/3003)
- fix: ctx being contaminated due to a new feature of openresty 1.19. **For openresty 1.19 users, it is recommended to upgrade the APISIX version as soon as possible.** [#3105](https://github.com/apache/apisix/pull/3105)
- fix: correct the validation of route.vars [#3124](https://github.com/apache/apisix/pull/3124)
For more changes, please refer to [Milestone](https://github.com/apache/apisix/milestone/10)
- add a deprecate log for enable_websocket in upstream.[#2691](https://github.com/apache/apisix/pull/2691)
- add a deprecate log for consumer id.[#2829](https://github.com/apache/apisix/pull/2829)
- Added `X-APISIX-Upstream-Status` header to distinguish 5xx errors from upstream or APISIX itself. [#2817](https://github.com/apache/apisix/pull/2817)
- support Nginx configuration snippet. [#2803](https://github.com/apache/apisix/pull/2803)
- :sunrise: **Upgrade protocol to support Apache Skywalking 8.0**[#2389](https://github.com/apache/apisix/pull/2389). So this version only supports skywalking 8.0 protocol. This plugin is disabled by default, you need to modify config.yaml to enable, which is not backward compatible.
-In the 2.3 release, the consumer will only support user names and discard the id. The consumer needs to manually clean up the id field in etcd, otherwise the schema verification will report an error during use
-In the 2.3 release, opening websocket on upstream will no longer be supported
-In version 3.0, the data plane and control plane will be separated into two independent ports, that is, the current port 9080 will only process data plane requests, and no longer process admin API requests
For more changes, please refer to [Milestone](https://github.com/apache/apisix/milestone/8)
- :sunrise: **Migrate from etcd v2 to v3 protocol, which is not backward compatible. Apache APISIX only supports etcd 3.4 and above versions.** [#2036](https://github.com/apache/apisix/pull/2036)
- add labels for upstream object.[#2279](https://github.com/apache/apisix/pull/2279)
- add managed fields in json schema for resources, such as create_time and update_time.[#2444](https://github.com/apache/apisix/pull/2444)
- use interceptors to protect plugin's route[#2416](https://github.com/apache/apisix/pull/2416)
- support multiple ports for http and https listen.[#2409](https://github.com/apache/apisix/pull/2409)
- :bug: **`high priority`** When the data plane receives an instruction to delete a resource(router or upstream etc.), it does not properly clean up the cache, resulting in the existing resources cannot be found. This problem only occurs in the case of long and frequent deletion operations.[#2168](https://github.com/apache/apisix/pull/2168)
- fix routing priority does not take effect.[#2447](https://github.com/apache/apisix/pull/2447)
- set random seed for each worker process at `init_worker` phase, only `init` phase is not enough.[#2357](https://github.com/apache/apisix/pull/2357)
- remove unsupported algorithm in jwt plugin.[#2356](https://github.com/apache/apisix/pull/2356)
- return correct response code when `http_to_https` enabled in redirect plugin.[#2311](https://github.com/apache/apisix/pull/2311)
For more changes, please refer to [Milestone](https://github.com/apache/apisix/milestone/7)
- doc: fixed link syntax in README.md. [1894](https://github.com/apache/apisix/pull/1894)
- doc: fixed image links in zh-cn benchmark. [1896](https://github.com/apache/apisix/pull/1896)
- doc: fixed typos in `FAQ`、`admin-api`、`architecture-design`、`discovery`、`prometheus`、`proxy-rewrite`、`redirect`、`http-logger` documents. [1916](https://github.com/apache/apisix/pull/1916)
- doc: added improvements for OSx unit tests and request validation plugin. [1926](https://github.com/apache/apisix/pull/1926)
- doc: fixed typos in `architecture-design` document. [1938](https://github.com/apache/apisix/pull/1938)
- doc: added the default import path of `Nginx` for unit testing in `Linux` and `macOS` systems in the `how-to-build` document. [1936](https://github.com/apache/apisix/pull/1936)
- doc: add `request-validation` plugin chinese document. [1932](https://github.com/apache/apisix/pull/1932)
- doc: fixed file path of `gRPC transcoding` in `README`. [1945](https://github.com/apache/apisix/pull/1945)
- doc: fixed `uri-blocker` plugin path error in `README`. [1950](https://github.com/apache/apisix/pull/1950)
- doc: fixed `grpc-transcode` plugin path error in `README`. [1946](https://github.com/apache/apisix/pull/1946)
- doc: removed unnecessary configurations for `k8s` document. [1891](https://github.com/apache/apisix/pull/1891)
- reject invalid header[#1462](https://github.com/apache/incubator-apisix/pull/1462) and uri safe encode[#1461](https://github.com/apache/incubator-apisix/pull/1461)
- only allow 127.0.0.1 access admin API and dashboard by default. [#1458](https://github.com/apache/incubator-apisix/pull/1458)
- :sunrise: Support routing priority. You can match different upstream services based on conditions such as header, args, priority, etc. under the same URI. [#998](https://github.com/apache/incubator-apisix/pull/998)
- When no route is matched, an error message is returned. To distinguish it from other 404 requests. [#1013](https://github.com/apache/incubator-apisix/pull/1013)
- The address of the dashboard `/apisix/admin` supports CORS. [#982](https://github.com/apache/incubator-apisix/pull/982)
- The jsonschema validator returns a clearer error message. [#1011](https://github.com/apache/incubator-apisix/pull/1011)
- Upgrade the `ngx_var` module to version 0.5. [#1005](https://github.com/apache/incubator-apisix/pull/1005)
- Upgrade the `lua-resty-etcd` module to version 0.8. [#980](https://github.com/apache/incubator-apisix/pull/980)
- In development mode, the number of workers is automatically adjusted to 1. [#926](https://github.com/apache/incubator-apisix/pull/926)
- Remove the nginx.conf file from the code repository. It is automatically generated every time and cannot be modified manually. [#974](https://github.com/apache/incubator-apisix/pull/974)
- :sunrise: Supported to run APISIX with tengine. [#683](https://github.com/apache/incubator-apisix/pull/683)
- :sunrise: Enabled HTTP2 and supported to set ssl_protocols. [#663](https://github.com/apache/incubator-apisix/pull/663)
- :sunrise: Advanced Debug Mode, Target module function's input arguments or returned value would be printed once this option is enabled. [#614](https://github.com/apache/incubator-apisix/pull/641)
- Support to install APISIX without dashboard. [#686](https://github.com/apache/incubator-apisix/pull/686)
- [Limit Count](https://github.com/apache/incubator-apisix/blob/master/docs/en/latest/plugins/limit-count.md): Supported global limit count with `Redis Server`.[#624](https://github.com/apache/incubator-apisix/pull/624)
- :sunrise: **[support stand-alone mode](https://github.com/apache/incubator-apisix/blob/master/docs/en/latest/stand-alone-cn.md)**: using yaml to update configurations of APISIX, more friendly to kubernetes. [#464](https://github.com/apache/incubator-apisix/pull/464)
- :sunrise: **[MQTT Proxy](https://github.com/apache/incubator-apisix/blob/master/docs/en/latest/plugins/mqtt-proxy.md)**: support to load balance MQTT by `client_id`, both support MQTT 3.1 and 5.0. [#513](https://github.com/apache/incubator-apisix/pull/513)
This release brings many new features, such as IP black and white list, gPRC protocol transcoding, IPv6, IdP (identity provider) services, serverless, Change the default route to radix tree (**not downward compatible**), and more.
- :sunrise: **[gRPC transcoding](https://github.com/apache/incubator-apisix/blob/master/docs/en/latest/plugins/grpc-transcoding.md)**: supports protocol transcoding so that clients can access your gRPC API by using HTTP/JSON. [#395](https://github.com/apache/incubator-apisix/issues/395)
- :sunrise: **[radix tree router](https://github.com/apache/incubator-apisix/blob/master/docs/en/latest/router-radixtree.md)**: The radix tree is used as the default router implementation. It supports the uri, host, cookie, request header, request parameters, Nginx built-in variables, etc. as the routing conditions, and supports common operators such as equal, greater than, less than, etc., more powerful and flexible.**IMPORTANT: This change is not downward compatible. All users who use historical versions need to manually modify their routing to work properly.** [#414](https://github.com/apache/incubator-apisix/issues/414)
- Dynamic upstream supports more parameters, you can specify the upstream uri and host, and whether to enable websocket. [#451](https://github.com/apache/incubator-apisix/pull/451)
- Support for get values from cookies directly from `ctx.var`. [#449](https://github.com/apache/incubator-apisix/pull/449)
- Routing support IPv6. [#331](https://github.com/apache/incubator-apisix/issues/331)
- :sunrise: **[serverless](https://github.com/apache/incubator-apisix/blob/master/docs/en/latest/plugins/serverless.md)**: With serverless support, users can dynamically run any Lua function on a gateway node. Users can also use this feature as a lightweight plugin.[#86](https://github.com/apache/incubator-apisix/pull/86)
- :sunrise: **support IdP**: Support external authentication services, such as Auth0, okta, etc., users can use this to connect to Oauth2.0 and other authentication methods. [#447](https://github.com/apache/incubator-apisix/pull/447)
- [rate limit](https://github.com/apache/incubator-apisix/blob/master/docs/en/latest/plugins/limit-conn.md): Support for more restricted keys, such as `X-Forwarded-For` and `X-Real-IP`, and allows users to use Nginx variables, request headers, and request parameters as keys. [#228](https://github.com/apache/incubator-apisix/issues/228)
- [IP black and white list](https://github.com/apache/incubator-apisix/blob/master/docs/en/latest/plugins/ip-restriction.md) Support IP black and white list for security. [#398](https://github.com/apache/incubator-apisix/pull/398)
- The `PATCH` API is supported and can be modified individually for a configuration without submitting the entire configuration. [#365](https://github.com/apache/incubator-apisix/pull/365)
- :sunrise: **Add the online version of the dashboard**，users can [experience APISIX](http://apisix.iresty.com/) without install. [#374](https://github.com/apache/incubator-apisix/issues/374)
- :sunrise: **[Health Check and Circuit Breaker](https://github.com/apache/incubator-apisix/blob/master/docs/en/latest/health-check.md)**: Enable health check on the upstream node, and will automatically filter unhealthy nodes during load balancing to ensure system stability. [#249](https://github.com/apache/incubator-apisix/pull/249)
- :sunrise: **[OpenTracing](https://github.com/apache/incubator-apisix/blob/master/docs/en/latest/plugins/zipkin.md)**: support Zipkin and Apache SkyWalking. [#304](https://github.com/apache/incubator-apisix/pull/304)
