Cloud Application Framework
This library aims to expose a common set of interfaces for handling common cloud platform tasks. Such as queuing messages, publishing events, calling cloud functions etc.
This library is AWS centric, however, can by modified and extended to support others. Using the interfaces and configuration options shown below.
Being AWS centric, the default options are:
- Locator / Service Discovery: AWS Cloudmap
- Request: AWS Lambda
- Pubsub: AWS SNS
- Queue: AWS SQS
- Automate: AWS SSM
Registering a service - Cloudformation
For the Cloudmap locator, the easiest way to register a service is through Cloudformation (or Terraform etc):
CloudMapService:
Type: AWS::ServiceDiscovery::Service
Properties:
Description: User service
Name: users
NamespaceId: <namespace-id-here>
CreateUserInstance:
Type: "AWS::ServiceDiscovery::Instance"
Properties:
InstanceAttributes:
arn: create-user
handler: create-job-run
type: function
InstanceId: create-user
ServiceId:
Ref: CloudMapServiceUse with default settings
func main() {
d := discover.NewDiscovery()
token, err := d.Queue("acme-prod.my-service->my-queue", types.Request{
Body: []byte("{}"),
})
...
}Use with custom integrations
func main() {
...
d := discover.NewDiscovery(
discover.SetQueue(NewKafkaAdapter(kafkaClient)),
discover.SetPubsub(NewNATSAdapter(natsClient)),
discover.SetLocator(NewConsulLocator(consul)),
)
}Request
d := discover.NewDiscovery()
d.Request("my-namespace.users->create-user", types.Request{
Body: []byte("{ \"hello\": \"world\" }"),
})Queue
d := discover.NewDiscovery()
d.Queue("my-namespace.my-service->my-queue", types.Request{
Body: jsonString,
})
go func() {
messages, err := d.Listen("my-namespace.my-service->my-queue")
for message := range message {
log.Println(string(message.Body))
}
}()Pubsub
d := discovery.NewDiscovery()
d.Publish("my-namespace.my-service->my-event", types.Request{
Body: jsonEvent,
})Automate
d := discovery.NewDiscovery()
d.Automate("my-namespace.my-service->my-script", types.Request{
Body: jsonEvent,
})Custom integrations
You can customise the behaviour and create your own integrations by conforming to the following interfaces, and use the SetLocator, SetQueue, SetPubsub, SetAutomate and SetFunction methods when creating an instance of the Discovery library.
Locator interface
Discover(signature *types.Signature) (*types.Service, error)Queue interface
// QueueAdapter -
type QueueAdapter interface {
// Queue a message, return a token or message id
QueueWithOpts(service *types.Service, request types.Request, opts types.Options) (string, error)
ListenWithOpts(service *types.Service, opts types.Options) (<-chan *types.Response, error)
}Function interface
// FunctionAdapter -
type FunctionAdapter interface {
CallWithOpts(service *types.Service, request types.Request, opts types.Options) (*types.Response, error)
}AutomateAdapter interface
// AutomateAdapter -
type AutomateAdapter interface {
ExecuteWithOpts(service *types.Service, request types.Request, opts types.Options) (*types.Response, error)
}PubsubAdapter interface
// PubsubAdapter -
type PubsubAdapter interface {
PublishWithOpts(service *types.Service, request types.Request, opts types.Options) error
SubscribeWithOpts(service *types.Service, opts types.Options) (<-chan *types.Response, error)
}Acknowledgements: inspired by the amazing work at Micro