bug: RPC endpoint returns text/html as content type

[jakubgs]

Problem

RPC endpoint sets Content-Type: text/html; charset=utf-8 when returning a JSON response.

Impact

Ansible 2.13 - or more exactly uri module - is more strict about HTTP response content types, and I no longer get the actual JSON response when I query the RPC API using uri task;
https://github.com/status-im/infra-role-nim-waku/blob/eed1a10ccea90c3b33af845ba54334530467a625/tasks/query.yml#L7-L19

To reproduce

Just query the RPC:

< HTTP/1.1 200 OK
< Server: nim-json-rpc
< Content-Length: 653
< Content-Type: text/html; charset=utf-8
< Date: Wed, 07 Jun 2023 13:15:58 GMT
< Connection: keep-alive
< 
{ [653 bytes data]
* Connection #0 to host localhost left intact
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
...

Expected behavior

The go-waku node does this correctly:

< HTTP/1.1 200 OK
< Content-Type: application/json; charset=utf-8
< X-Content-Type-Options: nosniff
< Date: Wed, 07 Jun 2023 13:17:38 GMT
< Content-Length: 1228
< 
{ [1228 bytes data]
* Connection #0 to host localhost left intact
{
  "result": {
...

nwaku version/commit hash

[email protected]:~ % /docker/nim-waku-v2/rpc.sh get_waku_v2_debug_v1_version
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "nightly-2-gba8ec7"
}

[Ivansete-status]

Edited: the next comment is incorrect.

Afternoon @jakubgs,

Checking the nwaku code I don't see any place where the Content-Type is enforced.

However, I've noticed that the Content-Type present in the response is exactly the same as the one given in the request:

e.g.:

---

What if we add the next snippet in https://github.com/status-im/infra-role-nim-waku/blob/eed1a10ccea90c3b33af845ba54334530467a625/tasks/query.yml#L10 ?

headers:
      Content-Type: "application/json; charset=utf-8"

[jakubgs]

I already do that:

[email protected]:~ % tail -n10 /docker/nim-waku-v2/rpc.sh 
# The jq script checks if error exists and adjusts exit code.
curl --request POST \
    --verbose \
    --silent \
    --show-error \
    --fail-with-body \
    --header 'Content-type:application/json' \
    --data "${PAYLOAD}" \
    "${URL}" | \
    jq -e '., if .error != null then null|halt_error(2) else halt end'

[email protected]:~ % /docker/nim-waku-v2/rpc.sh get_waku_v2_debug_v1_version
*   Trying 127.0.0.1:8545...
* Connected to localhost (127.0.0.1) port 8545 (#0)
> POST / HTTP/1.1
> Host: localhost:8545
> User-Agent: curl/7.81.0
> Accept: */*
> Content-type:application/json
> Content-Length: 93
> 
} [93 bytes data]
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Server: nim-json-rpc
< Content-Length: 55
< Content-Type: text/html; charset=utf-8
< Date: Wed, 07 Jun 2023 13:56:13 GMT
< Connection: keep-alive
< 
{ [55 bytes data]
* Connection #0 to host localhost left intact
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "nightly-2-gba8ec7"
}

Doesn't work.

[jakubgs]

Also, doesn't work for Ansible either. Already tried that, since it was an obvious thing to test.

[Ivansete-status]

Ok, please ignore my last comment. It actually returns the type "text/html" too.

[vpavlin]

Looking at the json_rpc implementation (https://github.com/status-im/nim-json-rpc) I don't see a way to explicitly enforce headers (neither in server setup nor in method execution) which is kinda weird cause returning JSON as text/html is definitelly a problem

[Ivansete-status]

I think I saw what needs to be changed. I'll submit the PR to that repo shortly.

[Ivansete-status]

We'll need to get this merged and then, update the submodule accordingly in nwaku.
status-im/nim-json-rpc#165

Sorry for the previous confusion!