User-Agent header is not getting passed to target endpoint

[dolasingh]

I'm adding a user-agent header in assign message policy in pre flow of proxy endpoint. It is being shown in trace but not getting passed to the target endpoint. I checked the curl it made, user agent header is not there.

I'm setting header like this :

<Header name="user-agent">{request.header.user-agent}</Header>

in the curl it is not getting added

[dknezic]

It looks like you're trying to set the user-agent header with the user-agent header value on the inbound request. ie setting the value to whatever the value is? If that's what you are doing, the Header element will be a no-op: if the original request includes a user-agent header, then it will retain that value. If the original request does not include a user-agent header, then the user-agent header will remain unset.

What exactly are you trying to do?

[dolasingh]

@dane knezic the original request includes the user-agent header but it is not retaining in target endpoint call. Here i'm trying to explicitly set the header but it is not working. I can see the user-agent header in trace but not in curl it is making to target server. Attaching the screenshot herescreen-shot-2020-01-10-at-111404-am.png

[dolasingh]

even if I try to set it to any value, it is not setting

<Headername="user-agent">whatsoeverValue</Header>

[sidd-harth]

Did you try retaining the User-Agent header using the TargetEndpoint properties?

<Property name="request.retain.headers">User-Agent,Referer,Accept-Language</Property>

or enable all header

<Property name="request.retain.headers.enabled">true</Property>

https://docs.apigee.com/api-platform/reference/endpoint-properties-reference

BTW yes even I am not able to see the User-agent header in the cURL cmd shown in trace but I was can see that the User-agent header is being passed to my target endpoint.

{request.header.user-agent} ---> this will work.
{request.header.User-Agent} ---> this is recommended.

[dolasingh]

@Siddharth Barahalikar yes I tried setting these properties. Still, it does not retain the headers.

request.header.user-agent is working but only problem is that it is not passing the header to target endpoint. Any other header is being set properly except user-agent/User-Agent. APIGEE is not passing it further.

[sidd-harth]

Could you try testing with POST Method - https://httpbin.org/post target endpoint and check/post the response.

{
  "args": {}, 
  "data": "", 
  "files": {}, 
  "form": {}, 
  "headers": {
    "Accept": "*/*", 
    "Content-Length": "0", 
    "Content-Type": "application/x-www-form-urlencoded", 
    "Host": "httpbin.org", 
    "Name": "sid", 
    "User-Agent": "custom-value"
  }, 
  "json": null, 
  "origin": "50.16.249.180, 35.223.222.179, 50.16.249.180", 
  "url": "https://httpbin.org/post"
}

[dolasingh]

Works fine for this endpoint. It means there is some problem with my target endpoint?

[dchiesa1]

It's hard to say. how are you determining that the header is not reaching the target? You'll need to troubleshoot it and diagnose it yourself.