# README
Gin 自带的中间件有很多种，可以在 https://github.com/gin-gonic/contrib 找到。
下面是一些常用的中间件
- RestGate：REST API 端点的安全身份验证
- gin-jwt：用于 Gin 框架的 JWT 中间件
- gin-sessions：基于 MongoDB 和 MySQL 的会话中间件
- gin-location：用于公开服务器主机名和方案的中间件
- gin-nice-recovery：异常错误恢复中间件，让您构建更好的用户体验
- gin-limit：限制同时请求，可以帮助解决高流量负载
- gin-oauth2：用于处理 OAuth2
- gin-template：简单易用的 Gin 框架 HTML/模板
- gin-redis-ip-limiter：基于 IP 地址的请求限制器
- gin-access-limit：通过指定允许的源 CIDR 表示法来访问控制中间件
- gin-session：Gin 的会话中间件
- gin-stats：轻量级且有用的请求指标中间件
- gin-session-middleware：一个高效，安全且易于使用的 Go 会话库
- ginception：漂亮的异常页面
- gin-inspector：用于调查 HTTP 请求的 Gin 中间件
Reference
# Functions
AccessLog record access log.
Auth authorize user.
Breaker a circuit breaker middleware.
Cors add cors headers.
GetRequestIDFromContext returns 'RequestID' from the given context if present.
GetRequestIDFromHeaders returns 'RequestID' from the headers if present.
Logging is a middleware function that logs the each request.
Metrics returns a gin.HandlerFunc for exporting some Web metrics.
NoCache is a middleware function that appends headers to prevent the client from caching the HTTP response.
Options is a middleware function that appends headers for options requests and aborts then exits the middleware chain and ends the request.
Ratelimit a circuit breaker middleware.
RequestID is a middleware that injects a 'X-Request-ID' into the context and request/response header of each request.
Secure is a middleware function that appends security and resource access headers.
SignMd5Middleware md5 签名校验中间件.
Timeout 超时中间件.
Tracing returns middleware that will trace incoming requests.
WithGroup with circuit breaker group.
WithLimiter set Limiter implementation, default is bbr limiter.
WithPropagators specifies propagators to use for extracting information from the HTTP requests.
WithTracerProvider specifies a tracer provider to use for creating a tracer.
# Constants
ContextRequestIDKey context request id for context.
HeaderXRequestIDKey http header request ID key.
# Variables
ErrLimitExceed is service unavailable due to rate limit exceeded.
ErrNotAllowed is request failed due to circuit breaker triggered.
Middlewares global middleware.
# Type aliases
BreakerOption is circuit breaker option.
LimiterOption is ratelimit option.
Option specifies instrumentation configuration options.