`client.Ds.QueryMetricsWithExpressions()` returns empty frames

[troibe]

I'm trying to use client.Ds.QueryMetricsWithExpressions() to see if my metrics data source can be queried with a custom query from Grafana.

    type Datasource struct {
        Uid string `json:"uid"`
    }

    type Query struct {
        Datasource Datasource `json:"datasource"`
        Expr       string     `json:"expr"`
        RefId      string     `json:"refId"`
    }

    var queries []models.JSON
    queries = append(queries, Query{
        Datasource: Datasource{Uid: dataSource.Payload.UID},
        Expr:       "up",
        RefId:      "A",
    })

    nowTimestamp := "now"
    priorTimestamp := "now-5m"

    metricRequest := &models.MetricRequest{
        From:    &priorTimestamp,
        Queries: queries,
        To:      &nowTimestamp,
    }
    queryResultOK, queryResultMultiStatus, err := client.Ds.QueryMetricsWithExpressions(metricRequest)

Now using queryResultOK.Payload.Results["A"].Frames[0] to access the frames results in *models.Frame(&models.Frame{Fields:[]*models.Field(nil), Meta:(*models.FrameMeta)(nil), Name:"", RefID:""}). Running the same query in the browser or with postman yields valid results for me.

As described in https://github.com/grafana/grafana-openapi-client-go/pull/90#issuecomment-2014803007 this seems to be an issue with the go data model and JSON not corresponding.

For now I'm just relying on the health check for that metrics data source.

[troibe]

@dhftah Do you think we could take the Frame related changes from https://github.com/grafana/grafana/compare/main...dhftah:frk.grafana:fix-openapi-specification and already make PR out of them?

[dhftah]

@troibe go for it; I couldn't PR grafana itself though as I am not a contributor. I will ask some people

[dhftah]

(you'll also need to regenerate this client when it gets merged in)

[dhftah]

hey it worked now :laughing: https://github.com/grafana/grafana/pull/86456 will submit it

[tskdsb]

+1

[pointerpower]

I'm running into the same problem. Any updates here? I noticed https://github.com/grafana/grafana/pull/86456 was closed. How can we get around this issue?

[muroj]

I'm running into the same problem. Any updates here? I noticed grafana/grafana#86456 was closed. How can we get around this issue?

What worked for me:

1. Download the spec file from the referenced (closed) PR.
2. Generate the client against the custom spec: update the Makefile to point at the custom spec.
3. Point your code at the locally built API client. I added a replace directive to my go.mod:

   replace github.com/grafana/grafana-openapi-client-go => ../grafana-openapi-client-go

Note: I found that the Frame struct field names were different from the standard spec file.