| // Copyright 2018 Google LLC |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| // Package metadata provides methods for creating and accessing context.Context objects |
| // with Google Cloud Functions metadata. |
| package metadata // import "cloud.google.com/go/functions/metadata" |
| |
| import ( |
| "context" |
| "time" |
| ) |
| |
| type contextKey struct{} |
| |
| // Metadata holds Google Cloud Functions metadata. |
| type Metadata struct { |
| // EventID is a unique ID for the event. For example: "70172329041928". |
| EventID string `json:"eventId"` |
| // Timestamp is the date/time this event was created. |
| Timestamp time.Time `json:"timestamp"` |
| // EventType is the type of the event. For example: "google.pubsub.topic.publish". |
| EventType string `json:"eventType"` |
| // Resource is the resource that triggered the event. |
| Resource Resource `json:"resource"` |
| } |
| |
| // Resource holds Google Cloud Functions resource metadata. |
| // Resource values are dependent on the event type they're from. |
| type Resource struct { |
| // Service is the service that triggered the event. |
| Service string `json:"service"` |
| // Name is the name associated with the event. |
| Name string `json:"name"` |
| // Type is the type of event. |
| Type string `json:"type"` |
| } |
| |
| // NewContext returns a new Context carrying m. |
| func NewContext(ctx context.Context, m Metadata) context.Context { |
| return context.WithValue(ctx, contextKey{}, m) |
| } |
| |
| // FromContext extracts the Metadata from the Context, if present. |
| func FromContext(ctx context.Context) (Metadata, bool) { |
| if ctx == nil { |
| return Metadata{}, false |
| } |
| m, ok := ctx.Value(contextKey{}).(Metadata) |
| return m, ok |
| } |