Tidying up the new Metrics implementations (#1974)

* Unit tests to check tagging and aggregation of Prometheus metrics

* Removing the logger output routing (because it doesn't actually work in the logger implementation)

* Emitting values with the logging reporter

Co-authored-by: chris <chris@Profanity.local>

metrics/logging/reporter_test.go

@@ -1,11 +1,9 @@
 package logging
 
 import (
-	"bytes"
 	"testing"
 	"time"
 
-	log "github.com/micro/go-micro/v3/logger"
 	"github.com/micro/go-micro/v3/metrics"
 
 	"github.com/stretchr/testify/assert"
@@ -20,10 +18,6 @@ func TestLoggingReporter(t *testing.T) {
 	assert.Equal(t, ":9000", reporter.options.Address)
 	assert.Equal(t, "/prometheus", reporter.options.Path)
 
-	// Make a log buffer and create a new logger to use it:
-	logBuffer := new(bytes.Buffer)
-	reporter.logger = log.NewLogger(log.WithLevel(log.TraceLevel), log.WithOutput(logBuffer), log.WithFields(convertTags(reporter.options.DefaultTags)))
-
 	// Check that our implementation is valid:
 	assert.Implements(t, new(metrics.Reporter), reporter)
 
@@ -45,7 +39,4 @@ func TestLoggingReporter(t *testing.T) {
 	assert.NoError(t, reporter.Gauge("test.gauge.1", 98, tags))
 	assert.NoError(t, reporter.Timing("test.timing.1", time.Second, tags))
 	assert.NoError(t, reporter.Timing("test.timing.2", time.Minute, tags))
-
-	// Test reading back the metrics from the logbuffer (doesn't seem to work because the output still goes to StdOut):
-	// assert.Contains(t, logBuffer.String(), "level=debug service=prometheus-test Count metric: map[tag1:false tag2:true]")
 }