How to identify wso2 request to backend - wso2

Question

I tried to find a relevant source on the internet but i'm unable to find some info on this.
I want to understand how i can identify wso2 calls to a backend server.
I can set any custom http headers, but anyone can override that in cURL requests. So that can't be a solution. Any other ideas?
EDIT
If its not clear enough - When i will receive a call in my backend server (the API endpoint) then how would i identify if its coming from wso2 or from somewhere else. May be you will say 'HTTP_USER_AGENT' but that can be overridden automatically.

Answer 1

You can create a custom mediation sequence (per API) or a custom handler (global) to inject an http header automatically.

Answer 2

You have to enable wire logs for WSO2 API manager. To do this go to
/repository/conf/log4j.properties file and uncomment
#log4j.logger.org.apache.synapse.transport.http.wire=DEBUG
And restart the API Manager.
Outgoing messages from API Manager will be logged with <<symbol.
example:
[2017-08-17 10:10:49,007] DEBUG - wire HTTPS-Sender I/O dispatcher-1 << "GET /am/sample/pizzashack/v1/api/menu HTTP/1.1[\r][\n]"
[2017-08-17 10:10:49,007] DEBUG - wire HTTPS-Sender I/O dispatcher-1 << "Origin: https://10.100.5.154:9443[\r][\n]"
[2017-08-17 10:10:49,007] DEBUG - wire HTTPS-Sender I/O dispatcher-1 << "Accept: application/json[\r][\n]"
[2017-08-17 10:10:49,008] DEBUG - wire HTTPS-Sender I/O dispatcher-1 << "Referer: https://10.100.5.154:9443/store/apis/info?name=PizzaShackAPI&version=1.0.0&provider=admin[\r][\n]"
[2017-08-17 10:10:49,008] DEBUG - wire HTTPS-Sender I/O dispatcher-1 << "Accept-Encoding: gzip, deflate, br[\r][\n]"
[2017-08-17 10:10:49,008] DEBUG - wire HTTPS-Sender I/O dispatcher-1 << "Accept-Language: en-US,en;q=0.8[\r][\n]"
[2017-08-17 10:10:49,008] DEBUG - wire HTTPS-Sender I/O dispatcher-1 << "Host: localhost:9443[\r][\n]"
[2017-08-17 10:10:49,008] DEBUG - wire HTTPS-Sender I/O dispatcher-1 << "Connection: Keep-Alive[\r][\n]"
[2017-08-17 10:10:49,008] DEBUG - wire HTTPS-Sender I/O dispatcher-1 << "User-Agent: Synapse-PT-HttpComponents-NIO[\r][\n]"
[2017-08-17 10:10:49,008] DEBUG - wire HTTPS-Sender I/O dispatcher-1 << "[\r][\n]"

Answer 3

When a request served through WSO2 API Manager or ESB or EI, there are ways that you can log the request and response.
Please enable the wire logs in conf/log4j.properties file as follows.
#log4j.logger.org.apache.synapse.transport.http.wire=DEBUG
There are four logs types that will be printed when you enable that and will be marked by relevant mark.
Request comes to server ">>"
Request goes out to backend "<<"
Response comes to server ">>"
Response goes to client "<<"