What port?

[Daxcor69]

I am sorry if this is a dumb question, it feels like it. The documentation doesn't say if the metrics are exposed on a different port than the one the app.listen specifies. I have tried to curl that http://127.0.0.1:8080/metrics refuses to connect. I am assuming that once included in my application I can't use the metrics route for my own stuff as it is reserved (unless I change it via the options). So my assumptions are same ip/port as specified in the app.listen directive, just takes over the /metrics route. Just want to make sure this is correct..so I can trouble shoot further.

thanks

[Daxcor69]

I get this error when I hit the /metrics route.

TypeError [ERR_INVALID_ARG_TYPE]: The "chunk" argument must be of type string or an instance of Buffer. Received an instance of Promise
    at ServerResponse.end (_http_outgoing.js:785:13)
    at ServerResponse.end (/mnt/application_code/www/node_modules/express-session/index.js:355:19)
    at ExpressMiddleware.middleware (/mnt/application_code/www/node_modules/prometheus-api-metrics/src/express-middleware.js:99:24)
    at Layer.handle [as handle_request] (/mnt/application_code/www/node_modules/express/lib/router/layer.js:95:5)
    at trim_prefix (/mnt/application_code/www/node_modules/express/lib/router/index.js:317:13)
    at /mnt/application_code/www/node_modules/express/lib/router/index.js:284:7
    at Function.process_params (/mnt/application_code/www/node_modules/express/lib/router/index.js:335:12)
    at next (/mnt/application_code/www/node_modules/express/lib/router/index.js:275:10)
    at methodOverride (/mnt/application_code/www/node_modules/method-override/index.js:65:14)
    at Layer.handle [as handle_request] (/mnt/application_code/www/node_modules/express/lib/router/layer.js:95:5)
    at trim_prefix (/mnt/application_code/www/node_modules/express/lib/router/index.js:317:13)
    at /mnt/application_code/www/node_modules/express/lib/router/index.js:284:7
    at Function.process_params (/mnt/application_code/www/node_modules/express/lib/router/index.js:335:12)
    at next (/mnt/application_code/www/node_modules/express/lib/router/index.js:275:10)
    at module.exports (/mnt/application_code/www/node_modules/express-ejs-layouts/lib/express-layouts.js:116:3)
    at Layer.handle [as handle_request] (/mnt/application_code/www/node_modules/express/lib/router/layer.js:95:5)

[yorch]

This is due to prom-client v13 having breaking changes that this library hasn't incorporated yet. Created a PR to upgrade it

[Daxcor69]

What is the status of the breaking changes? Does prom-client now work with your package?

[yorch]

My PR was merged and the package owner released version 3.2.0, so you should be able to use it with prom-client@13.x.