Prometheus Endpoint is not available

[chengyak]

I set the Prometheus by adding the plugin like
usePrometheus({
// all optional, and by default, all set to false, please opt-in to the metrics you wish to get
requestCount: true, // requries execute to be true as well
requestSummary: true, // requries execute to be true as well
parse: true,
validate: true,
contextBuilding: true,
execute: true,
errors: true,
resolvers: true, // requires "execute" to be true as well
resolversWhitelist: ['Mutation.', 'Query.'], // reports metrics als for these resolvers, leave undefined to report all fields
deprecatedFields: true,

})

with graph-mesh, but i cannot see the metrics in /metrics path. What is the right way to expose the metrics info to an endpoint?

[dotansimha]

Hi @chengyak !

With the pure Envelop plugin usePrometheus, we do not provide the service or the runtime for the Prom server.
Since this plugin only hooks to your prom-client instance, you should use the same instance, and just return it over JSON response, something like:

server.on("GET", "/metrics", async (req, res) => {
  res.header('Content-Type', promClient.register.contentType);
  const result = await promClient.register.metrics();
  res.send(result)
}

In GraphQL-Mesh, we have a configuration to set this up automatically for you, so you don't need to use the raw Envelop plugin, and you should use the Mesh plugin for Prom (see https://www.the-guild.dev/graphql/mesh/docs/plugins/prometheus).

[chengyak]

Thanks for the reply @dotansimha , yeah I understand there is a plugin I can use with GraphQL-Mesh but how i can expose this endpoint with default GraphQL-Yoga? or if we need to do so, we have to use the custom server? Thanks again.

[dotansimha]

To use with Yoga v2, you'll need to expose it from your HTTP server, and implement a similar endpoint to what I shared before.

With v3 (currently in alpha, we plan to rework some parts of Envelop/Yoga and introduce those plugins with a built-in HTTP setup, see dotansimha/graphql-yoga#1732)

[chengyak]

Thanks, so if i understand it correctly, to use this in GraphQL-mesh now, i need to use custom server to expose this, in the future, there will be Envelop plug i can use to add a http endpoint to the GraphQL Yoga

[dotansimha]

Yes, but with Mesh, you can use the built-in plugin, it also exposes /metrics since the latest release (see ardatan/graphql-mesh#4645 )