client

Documentation

Overview

Package client provides the instrumentation for an http client.

The detail that metrics and traces provides can be configured with the TransportOptions struct.

Metrics:

Tags for all metrics:
- Host
- URLPattern
- Name (the name might be the combination of the endpoint + url pattern)

Requests:

- num cancelled requests:
    - per context timeout
    - per caller cancellation (for example when sending to multiple hosts)
- content-lenght: the size of the payload to be sent

Responses:
    Tags for all responses:
        - Status Code

- content length: the server side provided content length
- latency: the time since we send the request, until we have the
    response available (might or might not included the time for
    buffereing part or all the payload).

- response bytes read: using the body tracker, account for the actual
    number of bytes read by the client.
- response reading time: measures the time spent

Traces:

Index

• func InstrumentedHTTPClient(c *http.Client, t *TransportOptions, clientName string) *http.Client
• func NewRoundTripper(base http.RoundTripper, metricsOpts TransportMetricsOptions, ...) http.RoundTripper
• type Transport
  • func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error)
• type TransportMetricsOptions
  • func (o *TransportMetricsOptions) Enabled() bool
• type TransportOptions
• type TransportTracesOptions
  • func (o *TransportTracesOptions) Enabled() bool

Functions

func InstrumentedHTTPClient

func InstrumentedHTTPClient(c *http.Client, t *TransportOptions, clientName string) *http.Client

InstrumentedHTTPClient creates a new instrumented http client with the options provided. If the provided options are nil, the default options (with everything enabled, except the detailed connection data: DNS, TLS, time to get a connection...) will be used. Check the TransportOptions struct for details..

func NewRoundTripper

func NewRoundTripper(base http.RoundTripper, metricsOpts TransportMetricsOptions,
	tracesOpts TransportTracesOptions, clientName string, otelState state.OTEL,
) http.RoundTripper

NewRoundTripper creates an instrumented round tripper.

Types

type Transport

type Transport struct {
	// contains filtered or unexported fields
}

Transport is an http.RoundTripper that instruments all outgoing requests with OpenTelemetry metrics and tracing.

The zero value is intended to be a useful default, but for now it's recommended that you explicitly set Propagation, since the default for this may change.

func (*Transport) RoundTrip

func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error)

RoundTrip implements http.RoundTripper, delegating to Base and recording metrics and traces for the request.

type TransportMetricsOptions

type TransportMetricsOptions struct {
	RoundTrip          bool                 // provide the round trip metrics
	ReadPayload        bool                 // provide metrics for the reading the full body
	DetailedConnection bool                 // provide detailed metrics about the connection: dns lookup, tls ...
	FixedAttributes    []attribute.KeyValue // "static" attributes set at config time.
}

TransportMetricsOptions contains the options to enable / disable for reporting metrics, and a set of fixed attributes to add to all metrics.

func (*TransportMetricsOptions) Enabled

func (o *TransportMetricsOptions) Enabled() bool

Enabled tells if metrics should be reported for the transport.

type TransportOptions

type TransportOptions struct {
	MetricsOpts TransportMetricsOptions
	TracesOpts  TransportTracesOptions

	OTELInstance state.OTEL
}

TransportOptions defines the detail we want for the metrics and traces. See [TrasnportMetricsOptions] and TransportTracesOptions for more details. The OTELInstance member defines a function to obtain a State to use with this transport. The state getter is used at configuration time, not at runtime.

type TransportTracesOptions

type TransportTracesOptions struct {
	RoundTrip          bool                 // use a span for the round trip
	ReadPayload        bool                 // use a span for the process of reading the full body
	DetailedConnection bool                 // add extra detail about the connection to the server: dns lookup, tls...
	FixedAttributes    []attribute.KeyValue // "static" attributes set at config time.
	ReportHeaders      bool
}

TransportTracesOptions defines what information is enabled, and extra fixed attributes to add to the trace.

func (*TransportTracesOptions) Enabled

func (o *TransportTracesOptions) Enabled() bool

Enabled returns if the transport should create a trace.