Microservice Registry and Catalog Management

During the Quickstart and the tutorial, we specified images to be used for each microservice, for each type of Agent.

That was nice and easy, but what if we need to deploy the same code on a lot of Agents? We would need to specify the images for each Microservice. Wouldn't it be nice to have a way to specify the images to be used for each type of Agent once and then reuse this configuration? That's where the Controller Microservice catalog comes into play!

Each ioFog Controller comes with a built-in microservice catalog. You can see the list of preconfigured Microservices images using potctl:

potctl get catalog

NAMESPACE
default

ID		NAME		DESCRIPTION									REGISTRY	X86		                        ARM					
1		NATs		NATs server microservice for Datasance PoT					remote		ghcr.io/datasance/nats:latest		ghcr.io/datasance/nats:latest		
4		EdgeGuard	Security and monitoring component for edge devices running ioFog Agents.	remote		ghcr.io/datasance/edge-guard:latest	ghcr.io/datasance/edge-guard:latest	

Instead of specifying the images for each Agent type, we can refer to catalog ID in your Microservice specification. We can see that there is a Hello Web Demo catalog item that is configured with the iofog/hello-web image for x86 Agents, and iofog/hello-web-arm for ARM Agents. So, to deploy a Microservice running those images, we can use the following YAML:

echo "---
apiVersion: 'datasance.com/v3'
kind: Application
metadata:
name: edge-guard
spec:
---
apiVersion: 'datasance.com/v3'
kind: Microservice # Or application, as application uses the same spec for its microservices
metadata:
  name: edge-guard
spec:
  agent:
    name: my-agent-name
    config: {}
  images:
    catalogId: 4
  container:
    env: []
    ports: []
    rootHostAccess: false
    volumes:
      - hostDestination: /etc/iofog-agent/local-api
        containerDestination: /local-api
        accessMode: ro
        type: bind
      - hostDestination: hw-id
        containerDestination: /id
        accessMode: rw
        type: volume
    commands: []
  config: {}
  application: edge-guard
" > /tmp/edge-guard.yaml
potctl deploy microservice -f /tmp/edge-guard.yaml

Note that this YAML snippet assumes we have a running ECN in the current Namespace with an Agent called my-agent-name.

We can check that the expected images have been used by describing our Microservice with potctl:

potctl describe microservice edge-guard/edge-guard

Create our own Catalog Items

We can also use potctl to create our own Catalog Items. The YAML spec reference can be found here.

echo "---
apiVersion: 'datasance.com/v3'
kind: CatalogItem
metadata:
  name: 'my-multiplatform-microservice'
spec:
  description: 'Alpine Linux'
  x86: 'amd64/alpine:latest'
  arm: 'arm32v6/alpine:latest'
  registry: 'remote'

" > /tmp/my-catalog-item.yaml
potctl deploy -f /tmp/my-catalog-item.yaml

We can verify that our new Catalog Item was added to the Catalog:

potctl get catalog | grep my-multiplatform-microservice

17		my-multiplatform-microservice	Alpine Linux											remote		amd64/alpine:latest			arm32v6/alpine:latest

We used grep to filter the ouput, but the columns are the same as above. You can now use the spec.images.catalogId field on Microservice kind set to 17 in order to deploy you microservice.

Registries

During the tutorial, we saw that the images are being pulled from a repository specified in the YAML. The two values we have used so far are remote (public docker hub) and local (image locally present on the Agent). There is a third value available, which is a repository ID.

NB: remote and local are aliases for values 1 and 2, which are the repository seeded in your Controller database.

We can list our current registries using potctl get registries

ID              URL                     USERNAME        PRIVATE         SECURE
1               registry.hub.docker.com                 false           true
2               from_cache                              false           true

We can add a new registry using the Registry deploy kind

echo "---
apiVersion: datasance.com/v3
kind: Registry
spec:
  url: registry.hub.docker.com # This will create a registry that can download your private docker hub images
  username: john
  password: q1u45ic9kst563art
  email: user@domain.com
" > /tmp/my-private-registry.yaml
potctl deploy -f /tmp/my-private-registry.yaml

After running this, you should now have 3 registries and you can use the ID in the microservice images registry field

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Create our own Catalog Items​

Registries

Create our own Catalog Items