Grafana MCP Server Fails to Discover Datasources

[zisefeizhu]

Description: When attempting to connect to the Grafana instance through the MCP Grafana server, an error has occurred. Despite the Grafana service running normally and being able to successfully access data sources via the API, the MCP server returns an EOF error when attempting to execute this action.

Grafana Version:

12.1.0
Steps to Reproduce:

Check Grafana health status using curl:

curl -v http://10.104.100.33:3000/api/health

Returned Result:

{
"database": "ok",
"version": "12.1.0",
"commit": "1fdeca10151ec766ff2e9e5eaf4c7d05b666dea4",
"enterpriseCommit": "b5c636eacf65c853df4b0639e2ac6761f8c7e241"
}

Check the data sources using curl:

curl -H "Authorization: Bearer glsa_0xZrq7pJEGpKtZfNaGN0hxiNuzKaVVU7_5e8f288b" http://10.104.100.33:3000/api/datasources

Returned Result:

[
{
"id": 3,
"uid": "ceywnxyiyrv28c",
"orgId": 1,
"name": "alertmanager",
"type": "alertmanager",
"typeName": "Alertmanager",
"typeLogoUrl": "public/plugins/alertmanager/img/logo.svg",
"access": "proxy",
"url": "",
"user": "",
"database": "",
"basicAuth": false,
"isDefault": false,
"jsonData": {},
"readOnly": false
},
{
"id": 1,
"uid": "ceu97dbbugz5sd",
"orgId": 1,
"name": "xxx",
"type": "mysql",
"typeName": "MySQL",
"typeLogoUrl": "public/plugins/mysql/img/mysql_logo.svg",
"access": "proxy",
"url": "1xxx6",
"user": "xxx",
"database": "",
"basicAuth": false,
"isDefault": true,
"jsonData": {
"connMaxLifetime": 14400,
"database": "huhang",
"maxIdleConns": 100,
"maxIdleConnsAuto": true,
"maxOpenConns": 100,
"pdcInjected": false
},
"readOnly": false
},
{
"id": 2,
"uid": "dex4wm3yymuwwe",
"orgId": 1,
"name": "yesoreyeram-infinity-datasource",
"type": "yesoreyeram-infinity-datasource",
"typeName": "Infinity",
"typeLogoUrl": "public/plugins/yesoreyeram-infinity-datasource/img/icon.svg",
"access": "proxy",
"url": "",
"user": "",
"database": "",
"basicAuth": false,
"isDefault": false,
"jsonData": {},
"readOnly": false
}
]

Start the MCP Grafana server and observe the error:

podman run --rm -p 8000:8000 -e GRAFANA_URL=http://10.104.100.33:3000
-e GRAFANA_SERVICE_ACCOUNT_TOKEN=glsa_0xZrq7pJEGpKtZfNaGN0hxiNuzKaVVU7_5e8f288b
mcp/grafana -t streamable-http

Error Log:

time=2025-11-17T03:29:54.148Z level=ERROR msg="failed to discover MCP datasources" error="failed to list datasources: Get "http://10.104.100.33:3000/api/datasources\": EOF"

Expected Behavior: I expect to successfully connect and list Grafana data sources through the MCP Grafana server rather than encountering an EOF error.

Additional Information:

Ensure that the MCP Grafana server's access permissions, network configuration, and environment variables are correct.
The Grafana instance is operational and returns valid responses.
Thank you for your attention to this issue. I hope to see a resolution soon!

[zisefeizhu]

curl http://127.0.0.1:8000/healthz
ok%

[sd2k]

@zisefeizhu This is strange, it looks like a networking issue, all I can think of is that maybe your podman network is set up to route 10.104.100.33 connections differently? can you try curling the Grafana API from inside podman?

podman run --rm curlimages/curl curl -v http://10.104.100.33:3000/api/health

(if you could post the full output that would be great)

[zisefeizhu]

@sd2k Thank you for the investigation!
I executed the curl command from inside the Podman container, and here are the results:
podman run --rm docker.io/library/node:22.16.0 curl -v http://10.104.100.33:3000/api/health

Output:
`* Uses proxy env variable NO_PROXY == 'local,169.254/16'
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0* Trying 10.104.100.33:3000...

• Connected to 10.104.100.33 (10.104.100.33) port 3000 (#0)

GET /api/health HTTP/1.1
Host: 10.104.100.33:3000
User-Agent: curl/7.88.1
Accept: /

< HTTP/1.1 200 OK
< Cache-Control: no-store
< Content-Type: application/json; charset=UTF-8
< X-Content-Type-Options: nosniff
< X-Frame-Options: deny
< X-Xss-Protection: 1; mode=block
< Date: Mon, 17 Nov 2025 12:06:19 GMT
< Content-Length: 167
<
{ [167 bytes data]
100 167 100 167 0 0 1596 0 --:--:-- --:--:-- --:--:-- 1670

• Connection #0 to host 10.104.100.33 left intact
  {
  "database": "ok",
  "version": "12.1.0",
  "commit": "1fdeca10151ec766ff2e9e5eaf4c7d05b666dea4",
  "enterpriseCommit": "b5c636eacf65c853df4b0639e2ac6761f8c7e241"
  }`

As you can see, the connection to Grafana is successful, and the API response indicates that everything is functioning correctly.

Could you please let me know how to proceed from here? Thank you!

Feel free to adjust any part of the response if needed!

[sd2k]

@zisefeizhu cool thanks, hmm that is very unusual!

Could you try starting the MCP server with --debug --log-level debug to get more debug logging from the various clients?