README
¶
STDOUT Metric Exporter
Documentation
¶
Overview ¶
Package stdoutmetric provides an exporter for OpenTelemetry metric telemetry.
The exporter is intended to be used for testing and debugging, it is not meant for production use. Additionally, it does not provide an interchange format for OpenTelemetry that is supported with any stability or compatibility guarantees. If these are needed features, please use the OTLP exporter instead.
Example ¶
package main
import (
"context"
"encoding/json"
"os"
"time"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/exporters/stdout/stdoutmetric"
"go.opentelemetry.io/otel/sdk/instrumentation"
"go.opentelemetry.io/otel/sdk/metric"
"go.opentelemetry.io/otel/sdk/metric/metricdata"
"go.opentelemetry.io/otel/sdk/resource"
semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
)
var (
// Sat Jan 01 2000 00:00:00 GMT+0000.
now = time.Date(2000, time.January, 0o1, 0, 0, 0, 0, time.FixedZone("GMT", 0))
res = resource.NewSchemaless(
semconv.ServiceName("stdoutmetric-example"),
)
mockData = metricdata.ResourceMetrics{
Resource: res,
ScopeMetrics: []metricdata.ScopeMetrics{
{
Scope: instrumentation.Scope{Name: "example", Version: "0.0.1"},
Metrics: []metricdata.Metrics{
{
Name: "requests",
Description: "Number of requests received",
Unit: "1",
Data: metricdata.Sum[int64]{
IsMonotonic: true,
Temporality: metricdata.DeltaTemporality,
DataPoints: []metricdata.DataPoint[int64]{
{
Attributes: attribute.NewSet(attribute.String("server", "central")),
StartTime: now,
Time: now.Add(1 * time.Second),
Value: 5,
},
},
},
},
{
Name: "system.cpu.time",
Description: "Accumulated CPU time spent",
Unit: "s",
Data: metricdata.Sum[float64]{
IsMonotonic: true,
Temporality: metricdata.CumulativeTemporality,
DataPoints: []metricdata.DataPoint[float64]{
{
Attributes: attribute.NewSet(attribute.String("state", "user")),
StartTime: now,
Time: now.Add(1 * time.Second),
Value: 0.5,
},
},
},
},
{
Name: "requests.size",
Description: "Size of received requests",
Unit: "kb",
Data: metricdata.Histogram[int64]{
Temporality: metricdata.DeltaTemporality,
DataPoints: []metricdata.HistogramDataPoint[int64]{
{
Attributes: attribute.NewSet(attribute.String("server", "central")),
StartTime: now,
Time: now.Add(1 * time.Second),
Count: 10,
Bounds: []float64{1, 5, 10},
BucketCounts: []uint64{1, 3, 6, 0},
Sum: 128,
Min: metricdata.NewExtrema[int64](3),
Max: metricdata.NewExtrema[int64](30),
},
},
},
},
{
Name: "latency",
Description: "Time spend processing received requests",
Unit: "ms",
Data: metricdata.Histogram[float64]{
Temporality: metricdata.DeltaTemporality,
DataPoints: []metricdata.HistogramDataPoint[float64]{
{
Attributes: attribute.NewSet(attribute.String("server", "central")),
StartTime: now,
Time: now.Add(1 * time.Second),
Count: 10,
Bounds: []float64{1, 5, 10},
BucketCounts: []uint64{1, 3, 6, 0},
Sum: 57,
},
},
},
},
{
Name: "system.memory.usage",
Description: "Memory usage",
Unit: "By",
Data: metricdata.Gauge[int64]{
DataPoints: []metricdata.DataPoint[int64]{
{
Attributes: attribute.NewSet(attribute.String("state", "used")),
Time: now.Add(1 * time.Second),
Value: 100,
},
},
},
},
{
Name: "temperature",
Description: "CPU global temperature",
Unit: "cel(1 K)",
Data: metricdata.Gauge[float64]{
DataPoints: []metricdata.DataPoint[float64]{
{
Attributes: attribute.NewSet(attribute.String("server", "central")),
Time: now.Add(1 * time.Second),
Value: 32.4,
},
},
},
},
},
},
},
}
)
func main() {
// Print with a JSON encoder that indents with two spaces.
enc := json.NewEncoder(os.Stdout)
enc.SetIndent("", " ")
exp, err := stdoutmetric.New(
stdoutmetric.WithEncoder(enc),
stdoutmetric.WithoutTimestamps(),
)
if err != nil {
panic(err)
}
// Register the exporter with an SDK via a periodic reader.
sdk := metric.NewMeterProvider(
metric.WithResource(res),
metric.WithReader(metric.NewPeriodicReader(exp)),
)
ctx := context.Background()
// This is where the sdk would be used to create a Meter and from that
// instruments that would make measurements of your code. To simulate that
// behavior, call export directly with mocked data.
_ = exp.Export(ctx, &mockData)
// Ensure the periodic reader is cleaned up by shutting down the sdk.
_ = sdk.Shutdown(ctx)
}
Output: { "Resource": [ { "Key": "service.name", "Value": { "Type": "STRING", "Value": "stdoutmetric-example" } } ], "ScopeMetrics": [ { "Scope": { "Name": "example", "Version": "0.0.1", "SchemaURL": "", "Attributes": null }, "Metrics": [ { "Name": "requests", "Description": "Number of requests received", "Unit": "1", "Data": { "DataPoints": [ { "Attributes": [ { "Key": "server", "Value": { "Type": "STRING", "Value": "central" } } ], "StartTime": "0001-01-01T00:00:00Z", "Time": "0001-01-01T00:00:00Z", "Value": 5 } ], "Temporality": "DeltaTemporality", "IsMonotonic": true } }, { "Name": "system.cpu.time", "Description": "Accumulated CPU time spent", "Unit": "s", "Data": { "DataPoints": [ { "Attributes": [ { "Key": "state", "Value": { "Type": "STRING", "Value": "user" } } ], "StartTime": "0001-01-01T00:00:00Z", "Time": "0001-01-01T00:00:00Z", "Value": 0.5 } ], "Temporality": "CumulativeTemporality", "IsMonotonic": true } }, { "Name": "requests.size", "Description": "Size of received requests", "Unit": "kb", "Data": { "DataPoints": [ { "Attributes": [ { "Key": "server", "Value": { "Type": "STRING", "Value": "central" } } ], "StartTime": "0001-01-01T00:00:00Z", "Time": "0001-01-01T00:00:00Z", "Count": 10, "Bounds": [ 1, 5, 10 ], "BucketCounts": [ 1, 3, 6, 0 ], "Min": 3, "Max": 30, "Sum": 128 } ], "Temporality": "DeltaTemporality" } }, { "Name": "latency", "Description": "Time spend processing received requests", "Unit": "ms", "Data": { "DataPoints": [ { "Attributes": [ { "Key": "server", "Value": { "Type": "STRING", "Value": "central" } } ], "StartTime": "0001-01-01T00:00:00Z", "Time": "0001-01-01T00:00:00Z", "Count": 10, "Bounds": [ 1, 5, 10 ], "BucketCounts": [ 1, 3, 6, 0 ], "Min": null, "Max": null, "Sum": 57 } ], "Temporality": "DeltaTemporality" } }, { "Name": "system.memory.usage", "Description": "Memory usage", "Unit": "By", "Data": { "DataPoints": [ { "Attributes": [ { "Key": "state", "Value": { "Type": "STRING", "Value": "used" } } ], "StartTime": "0001-01-01T00:00:00Z", "Time": "0001-01-01T00:00:00Z", "Value": 100 } ] } }, { "Name": "temperature", "Description": "CPU global temperature", "Unit": "cel(1 K)", "Data": { "DataPoints": [ { "Attributes": [ { "Key": "server", "Value": { "Type": "STRING", "Value": "central" } } ], "StartTime": "0001-01-01T00:00:00Z", "Time": "0001-01-01T00:00:00Z", "Value": 32.4 } ] } } ] } ] } { "Resource": [ { "Key": "service.name", "Value": { "Type": "STRING", "Value": "stdoutmetric-example" } } ], "ScopeMetrics": null }
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
Types ¶
type Encoder ¶ added in v0.32.0
type Encoder interface {
// Encode handles the encoding and writing of OpenTelemetry metric data.
Encode(v any) error
}
Encoder encodes and outputs OpenTelemetry metric data-types as human readable text.
type Option ¶
type Option interface {
// contains filtered or unexported methods
}
Option sets exporter option values.
func WithAggregationSelector ¶ added in v0.34.0
func WithAggregationSelector(selector metric.AggregationSelector) Option
WithAggregationSelector sets the AggregationSelector the exporter will use to determine the aggregation to use for an instrument based on its kind. If this option is not used, the exporter will use the DefaultAggregationSelector from the go.opentelemetry.io/otel/sdk/metric package or the aggregation explicitly passed for a view matching an instrument.
func WithEncoder ¶ added in v0.32.0
WithEncoder sets the exporter to use encoder to encode all the metric data-types to an output.
func WithPrettyPrint ¶
func WithPrettyPrint() Option
WithPrettyPrint prettifies the emitted output. This option only works if the encoder is a *json.Encoder, as is the case when using `WithWriter`.
func WithTemporalitySelector ¶ added in v0.34.0
func WithTemporalitySelector(selector metric.TemporalitySelector) Option
WithTemporalitySelector sets the TemporalitySelector the exporter will use to determine the Temporality of an instrument based on its kind. If this option is not used, the exporter will use the DefaultTemporalitySelector from the go.opentelemetry.io/otel/sdk/metric package.
func WithWriter ¶
WithWriter sets the export stream destination. Using this option overrides any previously set encoder.
func WithoutTimestamps ¶
func WithoutTimestamps() Option
WithoutTimestamps sets all timestamps to zero in the output stream.
Source Files
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