krakend / krakend-martian

Integrate the martian lib in the KrakenD framework

KrakenD martian

The krakend-martian package integrates the martian project into the KrakenD framework.

How to use it

Add your martian DSL definition under the "github.com/devopsfaith/krakend-martian" namespace of the backend section of the config file

"extra_config": {
  "github.com/devopsfaith/krakend-martian": {}
}

More details here: https://github.com/google/martian#modifiers-all-the-way-down

Check the example folder for a complete demo.

Example

• Build and run krakend edition with martian

$ cd example
$ go install ./...
$ GOPATH/bin/example -c example/krakend.json -d -p 8000

• Send a request to the configured endpoint

$ curl -i 127.0.0.1:8000/supu
  HTTP/1.1 200 OK
  Cache-Control: public, max-age=0
  Content-Type: application/json; charset=utf-8
  X-Krakend: Version undefined
  X-Krakend-Completed: true
  Date: Tue, 17 Jul 2018 11:56:33 GMT
  Content-Length: 19

  {"msg":"you rock!"}

And check the logs of the KrakenD: the request modifiers have done their job! See how {"msg":"you rock!"} was added to the payload.

[KRAKEND] ▶ DEBUG config: {[0xc4201839a0] 3s 3.6µs [] 8000 2  map[github_com/devopsfaith/krakend-gologging:map[prefix:[KRAKEND] stdout:true level:DEBUG syslog:false]] 0s 0s 0s 0s false false 0 250 0s 0s 0s 0s 0s 0s false <nil> true 1}
[KRAKEND] ▶ DEBUG Debug enabled
[KRAKEND] ▶ DEBUG Method: GET
[KRAKEND] ▶ DEBUG URL: /__debug/supu
[KRAKEND] ▶ DEBUG Query: map[]
[KRAKEND] ▶ DEBUG Params: [{param /supu}]
[KRAKEND] ▶ DEBUG Headers: map[User-Agent:[KrakenD Version undefined] Content-Length:[19] Content-Type:[] X-Forwarded-For:[127.0.0.1] Accept-Encoding:[gzip]]
[KRAKEND] ▶ DEBUG Body: {"msg":"you rock!"}
[GIN] | 200 |     313.798µs |       127.0.0.1 | GET      /__debug/supu
[GIN] | 200 |    1.556445ms |       127.0.0.1 | GET      /supu

krakend-martian's Issues

martian plugin

Hi. I tried to write martian plugin for correlation id.
There is the link to the repo https://github.com/JaSei/krakend-martian-correlation-header/tree/implementation.
My implementation is based on https://github.com/kpacha/martian-components.

But if I start krakend, there are warnings around the loading of plugins and the martian plugin doesn't work. My feeling is martian plugins didn't load. Because the code of martian-components is 3 years old at least, it's possible the plugin system is changed and doesn't support now martian plugins?

log output maybe looks strange, because it runs in docker-compose
image: devopsfaith/krakend:1.4.1

krakend_ce_1   | [KRAKEND] 2021/10/07 - 16:26:12.874 ▶ WARNIN loading plugins: plugin loader found 1 error(s):
krakend_ce_1   | opening plugin 0 (/opt/krakend/plugins/krakend-martian_correlation_header.so): plugin: symbol ClientRegisterer not found in plugin github.com/JaSei/krakend-martian-correlation-header
krakend_ce_1   | [KRAKEND] 2021/10/07 - 16:26:12.874 ▶ INFO total http executor plugins loaded: 0
krakend_ce_1   | [KRAKEND] 2021/10/07 - 16:26:12.874 ▶ WARNIN loading plugins: plugin loader found 1 error(s):
krakend_ce_1   | opening plugin 0 (/opt/krakend/plugins/krakend-martian_correlation_header.so): plugin: symbol HandlerRegisterer not found in plugin github.com/JaSei/krakend-martian-correlation-header

...

krakend_ce_1   | [KRAKEND] 2021/10/07 - 16:26:12.880 ▶ ERROR {<nil> parse: unknown modifier: header.Correlation} map[github.com/devopsfaith/krakend-martian:map[header.Correlation:map[header_name:X-Correlation-ID]]]

thanks for advice

How to use CEL with krakend-martian?

The docs say that CEL definitions can be used with krakend-martian, but there are no examples using the same.
Any pointers please?

Impossible to modify request body with Lura v2.1.0

Hello! This is a follow up of this comment.
I upgraded to Lura v2.1.0 our krakend-ce installation and Martian configurations seem to break.

I have the feeling that this bug is caused by:

• this change
• Which does not work with pieces of code like this

Could this be the cause?

Thanks 😄

panic: runtime error: invalid memory address or nil pointer dereference

When running example krakend.json we get following error

[GIN-debug] Listening and serving HTTP on XXXX
[GIN-debug] [ERROR] listen tcp: address XXXX: missing port in address
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x45d3279]

goroutine 1 [running]:
github.com/luraproject/lura/v2/router/gin.ginRouter.Run({{0xc00037d040, {0x0, 0x0, 0x0}, 0xc0003f39c0, {0x47e9440, 0xc000460840}, {0x47fea60, 0xc000427bf0}, 0x0}, ...}, ...)
	/Users/rajan/.gvm/pkgsets/go1.17/global/pkg/mod/github.com/luraproject/lura/[email protected]/router/gin/router.go:111 +0x219
main.main()
	/Users/rajan/Desktop/projects/krakend-martian/example/main.go:51 +0x6f8
exit status 2

I updated the krakend.json version to following

"version": 3,

Go version: go1.17
OS: MacOS 12.1
When I run the go file using go run example/main.go -c example/krakend.json -d -p 8080 I get above error.

EDIT:

I also tried to checkout v1.4.0 and tried running the old version but it did not work either and failed with the same error.

header.Filter not working without defined value

The Martian docs state:

In the case that the value is undefined, the contained modifier executes if a request or response contains a header with the defined name.

I am not able to produce the expected result. Here is my KrakenD config:

{
    "$schema": "https://www.krakend.io/schema/v3.json",
    "version": 3,
    "debug_endpoint": true,
    "endpoints": [
        {
            "endpoint": "/",
            "method": "GET",
            "input_headers": [
                "old",
                "new"
            ],
            "backend": [
                {
                    "host": [ "http://127.0.0.1:8080" ],
                    "url_pattern": "/__debug/",
                    "method": "GET",
                    "extra_config": {
                        "modifier/martian": {
                            "header.Filter": {
                                "scope": [ "request" ],
                                "name": "old",
                                "modifier": {
                                    "header.Copy": {
                                        "scope": [ "request" ],
                                        "from": "old",
                                        "to": "new"
                                    }
                                }
                            }
                        }
                    }
                }
            ]
        }
    ]
}

With that configuration I run curl http://127.0.0.1:8080/ -H 'old: testval' and get this result:

If I add "value": "testval" to the header.Filter object then it works:

I've tried setting "value": null as well. That yields the same result as not including the property.

Modify the url from the request's query params to backend path params

Hello, I would like to modify the url from the request's query params to backend path params.

For example:

from

/settings?id=test

to

/settings/{id}

May I know how I should write the config?

"extra_config": {
    "github.com/devopsfaith/krakend-martian":
       {
          "url.Modifier": {
             "scope": ["request"],
             "path": [WHAT SHOUlD I WRITE HERE?]
          }
       }
 }

access to application logger

hi, all
when i using krakend
i add in config file some extraconfig construction
github.com/devopsfaith/krakend-martian
how in krakend-martian component
get access to application logger?
now my code looks like this

func init() {
    parse.Register("collection.modifier", collectionModifierFromJSON)
}
....
func collectionModifierFromJSON(b []byte) (*parse.Result, error) {
...
logger.GetLogger().Debug("...")

id_modifier error

I'm trying to use id_modifier to add transaction ID to header, and configured KrakenD like this.

"extra_config": {
  "github.com/devopsfaith/krakend-martian": {
    "header.Id": {
      "scope": ["request"]
    }
  }
}

But KrakenD is giving me error like,

2021/09/01 09:09:37 [Recovery] 2021/09/01 - 09:09:37 panic recovered:
runtime error: invalid memory address or nil pointer dereference
/usr/local/go/src/runtime/panic.go:212 (0xd4e35a)
/usr/local/go/src/runtime/signal_unix.go:734 (0xd67512)
/go/pkg/mod/github.com/google/[email protected]+incompatible/context.go:185 (0x1790d38)
/go/pkg/mod/github.com/google/[email protected]+incompatible/header/id_modifier.go:53 (0x1790d2a)
/go/pkg/mod/github.com/devopsfaith/[email protected]/martian.go:102 (0x179b2f8)
/go/pkg/mod/github.com/devopsfaith/[email protected]/martian.go:63 (0x179c1a4)
/go/pkg/mod/github.com/luraproject/[email protected]/proxy/http.go:68 (0x10ed22f)
/go/pkg/mod/github.com/luraproject/[email protected]/proxy/balancing.go:76 (0x10ebfb6)
/go/pkg/mod/github.com/luraproject/[email protected]/proxy/http.go:109 (0x10ed950)
/go/pkg/mod/github.com/luraproject/[email protected]/router/gin/endpoint.go:40 (0x191d611)
/go/pkg/mod/github.com/gin-gonic/[email protected]/context.go:165 (0x1917a79)
/go/pkg/mod/github.com/gin-gonic/[email protected]/recovery.go:99 (0x1917a60)
/go/pkg/mod/github.com/gin-gonic/[email protected]/context.go:165 (0x1916b53)
/go/pkg/mod/github.com/gin-gonic/[email protected]/logger.go:241 (0x1916b12)
/go/pkg/mod/github.com/gin-gonic/[email protected]/context.go:165 (0x190cd09)
/go/pkg/mod/github.com/gin-gonic/[email protected]/gin.go:489 (0x190ccef)
/go/pkg/mod/github.com/gin-gonic/[email protected]/gin.go:445 (0x190c7db)
/go/pkg/mod/github.com/rs/[email protected]/cors.go:207 (0x1e2d910)
/usr/local/go/src/net/http/server.go:2069 (0x10acc43)
/go/pkg/mod/github.com/rs/[email protected]/cors.go:207 (0x1e2d910)
/usr/local/go/src/net/http/server.go:2069 (0x10acc43)
/usr/local/go/src/net/http/server.go:2887 (0x10b0302)
/usr/local/go/src/net/http/server.go:1952 (0x10ab72c)
/usr/local/go/src/runtime/asm_amd64.s:1371 (0xd88e40)

Is my configuration wrong? or is it a bug?

Martian status modifier is not supported.

"github.com/devopsfaith/krakend-martian": {
                            "fifo.Group": {
                                "scope": ["response"],
                                "modifiers": [
                                    {
                                        "header.Filter": {
                                            "scope": ["response"],
                                            "name" : "X-Redirect-Status",
                                            "value" : "302",
                                            "modifier": {
                                                "status.Modifier": {
                                                "scope": ["response"],
                                                "statusCode": "302"
                                                }
                                            }
                                        }
                                    }
                                ]
                            }
                        }

resulting in the following error :

{<nil> parse: unknown modifier: status.Modifier} map[github.com/devopsfaith/krakend-martian:map[fifo.Group:map[modifiers:[map[header.Filter:map[scope:[response] name:X-Redirect-Status value:302 modifier:map[status.Modifier:map[scope:[response] statusCode:302]]]]] scope:[response]]]] 

now i did some digging and it seems we are missing :

https://github.com/google/martian/status from the configuration krakend-martian/martian.go