SPEKTRA Edge Applications Service API

Applications service manages the applications running on the edge devices. Those applications are typically represented either as a pod or distribution resource, and running as a container.

A standalone executable nor virtual machine based applications are not supported.

Full API Specifications (with resources):

• Version v1alpha2
• Version v1

Application Management (Pod Resources)

A Pod resource delivers an application to a specific SPEKTRA Edge device; a Distribution resource automatically generates a Pod resource for any SPEKTRA Edge device that matches the specified criteria. In other words, a Distribution resource acts as a template for a Pod resource.

In Pod resources, Docker Compose is usually used to define the containers to be run.

Below is a simple Docker Compose example for running an Nginx server. For simplicity, host is used for the network in this example.

version: "3"
services:
  nginx:
    image: "nginx:latest"
    network_mode: host

To use this Docker Compose file as a Pod, create a manifest file like this:

pod:
  name: projects/nttni-test/regions/eu1/pods/nginx-test
  spec:
    node: projects/nttni-test/regions/eu1/devices/device-test
    compose: "version: \"3\"\nservices:\n nginx:\n image: nginx:latest\n network_mode: host\n"

To create a pod resource using the above file (here named $POD_FILE), use the command cuttle applications create pod.

cuttle applications create pod -f $POD_FILE

String escaping with jq command

The jq command can be used to easily perform the escaping process. For example, if the above Docker Compose file is stored in nginx.yaml, the following command will yield the escaped string.

cat nginx.yaml | jq -R -s .

Bulk Distribution of Applications (Distribution Resources)

Although Pod resources are useful for distributing applications to individual devices, resource management becomes complicated when the number of devices is large. To solve this problem, Distribution resources can be used.

The Distribution resource is a template resource for Pod resources, and has a label-matching function for device resources, allowing automatic generation of Pod resources for device resources that match the criteria in a batch. The Distribution resource is a template for the Pod resource.

The following is an example of a Distribution resource to distribute Joki’s Nginx server to all devices present in the project.

Distribution:
  name: projects/ntt-test/distributions/nginx-test
  displayName: Nginx Test
  spec:
    template:
      spec:
        compose: "version: \"3\"\nservices:\n nginx:\n image: nginx:latest\n network_mode: host\n"

To create a Distribution resource from a file, use the cuttle applications create distribution command:

cuttle applications create distribution -f $DIST_FILE

Use the spec.selector field if you want to target only specific Device resources for delivery. If this field is not set, all devices will be targeted for delivery.

The following is an example of how to distribute only to Device resources with {"purpose": "frontend"} set in metadata.labels.

Distribution:
  name: projects/ntt-test/distributions/nginx-test
  displayName: Nginx Test
  spec:
    selector:
      matchLabels:
        purpose: frontend
    template:
      spec:
        compose: >
          version: "3"
          services: {}
          image: "nginx:latest"
          network_mode: host