README
¶
Datadog Tracing Test Server
Sometimes you want to test the trace output you send to Datadog. This library facilitates that by acting as a test Datadog server that captures and stores any traces sent to it through its httptest server.
This library is fairly special-purpose as it hijacks the DD_TRACE_AGENT_URL environment variable in the running binary and ensures only one instance of the test server is ever running in a process. This is important due to the fact that the underlying Datadog tracer is global and multiple calls to reconfigure the tracer will ultimately affect any other running test - therefore, if this mock tracer is used, it should only ever be initialized at the beginning of a test suite run, and tests that use it should ensure that they don't conflict with each other (i.e. emitting the same traces). Alternatively, the tests should be run serially and the state of the server can be reset between runs via a call to server.Reset().
Example Usage
var server *doghouse.MockDatadogServer
func TestMain(m *testing.M) {
server = doghouse.New()
ret := m.Run()
server.Close()
os.Exit(ret)
}
func TestSpan(t *testing.T) {
span := tracer.StartSpan("test.span")
span.Finish()
tracer.Flush()
server.WaitForSpan(t, "test.span")
}
Dependencies
This library uses github.com/tinylib/msgp for generating messagepack marshalers, you can install it with
go install github.com/tinylib/msgp
in order to run go generate.
Documentation
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Index ¶
- type Batch
- type MockDatadogServer
- func (s *MockDatadogServer) Close()
- func (s *MockDatadogServer) ExpectDurationNoSpan(t *testing.T, duration time.Duration, name string)
- func (s *MockDatadogServer) ExpectNoSpan(t *testing.T, name string)
- func (s *MockDatadogServer) ExpectSpan(t *testing.T, name string, parents ...string)
- func (s *MockDatadogServer) ExpectSpanFn(t *testing.T, name string, fn func(span Span) bool, msg string, ...)
- func (s *MockDatadogServer) Reset()
- func (s *MockDatadogServer) ServeHTTP(w http.ResponseWriter, r *http.Request)
- func (s *MockDatadogServer) SetTracePath(path string)
- func (s *MockDatadogServer) WaitDurationForSpan(t *testing.T, duration time.Duration, name string, parents ...string)
- func (s *MockDatadogServer) WaitForSpan(t *testing.T, name string, parents ...string)
- type Span
- type Trace
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Batch ¶
type Batch []Trace
Batch contains a collection of traces sent in bulk to the server.
func (Batch) MarshalMsg ¶
MarshalMsg implements msgp.Marshaler
type MockDatadogServer ¶
type MockDatadogServer struct {
// contains filtered or unexported fields
}
MockDatadogServer is a test server that collects traces sent via Datadog's tracing library.
func New ¶
func New(opts ...tracer.StartOption) *MockDatadogServer
New creates a new MockDatadogServer. This should only be ever used as a singleton due to the fact that the Datadog tracer library uses global state for publishing.
func (*MockDatadogServer) Close ¶
func (s *MockDatadogServer) Close()
Close the underlying test server.
func (*MockDatadogServer) ExpectDurationNoSpan ¶
ExpectDurationNoSpan ensures that the named span has not been received in the given duration.
func (*MockDatadogServer) ExpectNoSpan ¶
func (s *MockDatadogServer) ExpectNoSpan(t *testing.T, name string)
ExpectNoSpan ensures that the named span has not been received within 100 milliseconds.
func (*MockDatadogServer) ExpectSpan ¶
func (s *MockDatadogServer) ExpectSpan(t *testing.T, name string, parents ...string)
Expect a named span with the given optional parents to have been received.
func (*MockDatadogServer) ExpectSpanFn ¶
func (s *MockDatadogServer) ExpectSpanFn(t *testing.T, name string, fn func(span Span) bool, msg string, args ...interface{})
Expect a named span with the given verification function to exist.
func (*MockDatadogServer) Reset ¶
func (s *MockDatadogServer) Reset()
Reset the internal state of the server between test runs.
func (*MockDatadogServer) ServeHTTP ¶
func (s *MockDatadogServer) ServeHTTP(w http.ResponseWriter, r *http.Request)
ServeHTTP is the main handler for requests from the tracing library.
func (*MockDatadogServer) SetTracePath ¶
func (s *MockDatadogServer) SetTracePath(path string)
SetTracePath changes the url path for which the mock server accepts Datadog traces.
func (*MockDatadogServer) WaitDurationForSpan ¶
func (s *MockDatadogServer) WaitDurationForSpan(t *testing.T, duration time.Duration, name string, parents ...string)
WaitDurationForSpan waits a sepecified duration for the server to receive the named span with optional parent matching.
func (*MockDatadogServer) WaitForSpan ¶
func (s *MockDatadogServer) WaitForSpan(t *testing.T, name string, parents ...string)
WaitForSpan waits 10 milliseconds for the server to receive the named span with optional parent matching.
type Span ¶
type Span struct {
Name string `msg:"name"`
Service string `msg:"service"`
Resource string `msg:"resource"`
Type string `msg:"type"`
Start int64 `msg:"start"`
Duration int64 `msg:"duration"`
Meta map[string]string `msg:"meta,omitempty"`
Metrics map[string]float64 `msg:"metrics,omitempty"`
SpanID uint64 `msg:"span_id"`
TraceID uint64 `msg:"trace_id"`
ParentID uint64 `msg:"parent_id"`
Error int32 `msg:"error"`
}
Span represents a single span.
func (*Span) MarshalMsg ¶
MarshalMsg implements msgp.Marshaler
type Trace ¶
type Trace []Span
Trace contains a collection of associated spans.
func (Trace) MarshalMsg ¶
MarshalMsg implements msgp.Marshaler
Source Files