Hi,
I was setting up a front-end that interfaces with an API backend however I couldn't use that API due to the limitation on HTTP keep-alive or HTTP persistence feature were not possible on Node-RED "http request" core node.
The backend system requires an API login first in order perform subsequent API requests. It expects me to first send the credentials to the url http://10.10.10.10:8888/, then it reply with a new URL in the location header (sample response http://10.10.10.10:8888/lskdh234hv02n), this new URL I must use in subsequent requests.
In order to use the newly provided URL by the response, the first HTTP request should keep the initial HTTP request open (TCP connection should be kept) so next requests use the same TCP session. However this is not happening when sending HTTP request from the "http request" node on Node-RED due to the nature of this node was designed. I confirmed this using wireshark and compared the capture with another capture using postman when doing the same API activity.
On Node-RED, I tried to inject and enforce the header "connection: keep-alive" in the before the http request node, however Node-Red is overwriting this header value with "connection: close\r\n" specifically. I confirmed this behavior by sending other headers like User-Agent, Test-Header, I can see them in my request and they arrive to the back-end but the connection header is still coming with "close\r\n"
Here is what I'm injecting before the HTTP request node to manipulate the connection header:
msg.headers = {
"connection" : "keep-alive",
"my-custom-header": "samplevalue",
"User-Agent": "My User Agent"
}
return msg;
I see "User-Agent" and "my-custom-header" correctly set but the "connection" is still close.
How I made it work:
Simply I used the www-request node (alternative to the http-request node), thanks to the builders and maintainers of this node. However, I had to modify the node code, I added the forever options to the opts in the www-request.js file and that fixed the entire issue.
I have also modified the .html .js and locale files and added this option to the node, now it is fully functional and available on my local www-request node. I think this feature is useful in similar cases. The code is ready, shall I pull a request for it?
