// Returns a thread-compatible implementation of GCM interactions.
func NewCore() (*GcmCore, error) {
token, err := gce.NewAuthTokenProvider(GCMAuthScope)
if err != nil {
return nil, err
}
// Detect project.
project, err := metadata.ProjectID()
if err != nil {
return nil, err
}
core := &GcmCore{
token: token,
project: project,
exportedMetrics: make(map[string]metricDescriptor),
lastValue: gcstore.New(time.Hour),
}
// Wait for an initial token.
_, err = core.token.WaitForToken()
if err != nil {
return nil, err
}
if err := core.listMetrics(); err != nil {
return nil, err
}
return core, nil
}
// Returns a thread-compatible implementation of GCM interactions.
func NewCore() (*GcmCore, error) {
// TODO: Retry OnGCE call for ~15 seconds before declaring failure.
time.Sleep(3 * time.Second)
// Only support GCE for now.
if !metadata.OnGCE() {
return nil, fmt.Errorf("the GCM sink is currently only supported on GCE")
}
// Detect project.
project, err := metadata.ProjectID()
if err != nil {
return nil, err
}
// Check required service accounts
err = gce.VerifyAuthScope(GCLAuthScope)
if err != nil {
return nil, err
}
core := &GcmCore{
project: project,
exportedMetrics: make(map[string]metricDescriptor),
lastValue: gcstore.New(time.Hour),
}
// Get an initial token.
err = core.refreshToken()
if err != nil {
return nil, err
}
if err := core.listMetrics(); err != nil {
return nil, err
}
return core, nil
}