remark42/backend/vendor/github.com/go-pkgz/rest

REST helpers and middleware

Install and update

go get -u github.com/go-pkgz/rest

Middlewares

AppInfo middleware

Adds info to every response header:

• App-Name - application name
• App-Version - application version
• Org - organization
• M-Host - host name from instance-level $MHOST env

Ping-Pong middleware

Responds with pong on GET /ping. Also responds to anything with /ping suffix, like /v2/ping

example for both:

> http GET https://remark42.radio-t.com/ping

HTTP/1.1 200 OK
Date: Sun, 15 Jul 2018 19:40:31 GMT
Content-Type: text/plain
Content-Length: 4
Connection: keep-alive
App-Name: remark42
App-Version: master-ed92a0b-20180630-15:59:56
Org: Umputun

pong

Logger middleware

Logs request, request handling time and response. Log record fields in order of occurrence:

• Request's HTTP method
• Requested URL (with sanitized query)
• Remote IP
• Response's HTTP status code
• Response body size
• Request handling time
• Userinfo associated with the request (optional)
• Request subject (optional)
• Request ID (if X-Request-ID present)
• Request body (optional)

remote IP can be masked with user defined function

example: 019/03/05 17:26:12.976 [INFO] GET - /api/v1/find?site=remark - 8e228e9cfece - 200 (115) - 4.47784618s

Recoverer middleware

Recoverer is a middleware that recovers from panics, logs the panic (and a backtrace), and returns a HTTP 500 (Internal Server Error) status if possible.

OnlyFrom middleware

OnlyFrom middleware allows access for limited list of source IPs. Such IPs can be defined as complete ip (like 192.168.1.12), prefix (129.168.) or CIDR (192.168.0.0/16)

Metrics middleware

Metrics middleware responds to GET /metrics with list of expvar. Optionally allows to restrict list of source ips.

BlackWords middleware

BlackWords middleware doesn't allow user-defined words in the request body.

SizeLimit middleware

SizeLimit middleware checks if body size is above the limit and returns StatusRequestEntityTooLarge (413)

Trace middleware

It looks for X-Request-ID header and makes it as a random id (if not found), then populates it to the result's header and to the request's context.

Helpers

• rest.JSON - map alias, just for convenience type JSON map[string]interface{}
• rest.RenderJSON - renders json response from interface{}
• rest.RenderJSONFromBytes - renders json response from []byte
• rest.RenderJSONWithHTML - renders json response with html tags and forced charset=utf-8
• rest.SendErrorJSON - makes {error: blah, details: blah} json body and responds with given error code. Also adds context to logged message

Caching

Cache wrapper provides loading cache for rest/http responses. See cache readme for more details and examples.