(feat) Listen to NATS/JetStream for CloudEvents

[gianlucam76]

Sveltos-agent gets NATS/JetStream configuration from a Secret in the projectsveltos namespace. The Secret name is sveltos-nats. The key in the Secret with configuration is named ``sveltos-nats`.

This is a configuration example

  "nats":
   {
     "configuration":
        {
            "url": "nats://nats.nats.svc.cluster.local:4222",
            "subjects": [
                "test",
                "foo"
            ],
            "authorization": {
                "user": {
                    "user": "admin",
                    "password": "password"
                }
            }
        }
   }
}

JetStream can also be configured. Create a section jetstream with same fields as NATS.

Authorization also allows specifying:

• token
• clientCert _ root CA

Here is the golang structures

type messagingUser struct {
	User     string `json:"user"`
	Password string `json:"password"`
}

type clientCert struct {
	CertPem []byte `json:"certPem"`
	KeyPem  []byte `json:"keyPem"`
}

type messagingAuthorization struct {
	User       *messagingUser `json:"user,omitempty"`
	Token      *string        `json:"token,omitempty"`
	ClientCert *clientCert    `json:"clientCert,omitempty"`
	RootCA     []byte         `json:"rootCA,omitempty"`
}

type configuration struct {
	URL           string                 `json:"url"`
	Subjects      []string               `json:"subjects"`
	Authorization messagingAuthorization `json:"authorization,omitempty"`
}

type natsConfiguration struct {
	Configuration configuration `json:"configuration"`
}

type jetstreamConfiguration struct {
	Configuration configuration `json:"configuration"`
}

type messagingConfig struct {
	Nats      *natsConfiguration      `json:"nats,omitempty"`
	Jetstream *jetstreamConfiguration `json:"jetstream,omitempty"`
}