Core concept

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

That was nice and easy, but what if you need to deploy the same code on a lot of agents ? You'd 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 for all, 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 iofogctl

$ iofogctl get catalog

NAMESPACE
default

ID		NAME				            DESCRIPTION											                                            REGISTRY	X86					                ARM
4		Diagnostics			            0												                                                remote		iofog/diagnostics			        iofog/diagnostics-arm
5		Hello Web Demo			        A simple web server to test Eclipse ioFog.							                            remote		iofog/hello-web				        iofog/hello-web-arm
6		Open Weather Map Data		    A stream of data from the Open Weather Map API in JSON format					                remote		iofog/open-weather-map			    iofog/open-weather-map-arm
7		JSON REST API			        A configurable REST API that gives JSON output							                        remote		iofog/json-rest-api			        iofog/json-rest-api-arm
8		Temperature Converter		    A simple temperature format converter								                            remote		iofog/temperature-conversion		iofog/temperature-conversion-arm
9		JSON Sub-Select			        Performs sub-selection and transform operations on any JSON messages				            remote		iofog/json-subselect			    iofog/json-subselect-arm
10		Humidity Sensor Simulator	    Humidity Sensor Simulator for Eclipse ioFog							                            remote		iofog/humidity-sensor-simulator		iofog/humidity-sensor-simulator-arm
11		Seismic Sensor Simulator	    Seismic Sensor Simulator for Eclipse ioFog							                            remote		iofog/seismic-sensor-simulator		iofog/seismic-sensor-simulator-arm
12		Temperature Sensor Simulator	Temperature Sensor Simulator for Eclipse ioFog							                        remote		iofog/temperature-sensor-simulator	iofog/temperature-sensor-simulator-arm
13		Common Logging			        Container which gathers logs and provides REST API for adding and querying logs from containers	remote		iofog/common-logging			    iofog/common-logging-arm
14		JSON Generator			        Container generates ioMessages with contentdata as complex JSON object.				            remote		iofog/json-generator			    iofog/json-generator-arm

Instead of specifying the images for each agent type, you can use a catalog ID.

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: iofog.org/v1
kind: Microservice
metadata:
  name: Hello Web Microservice
spec:
  agent:
    name: agent-name
  images:
    catalogId: 5
  config: {}
  rootHostAccess: false
  ports: []
  volumes: []
  env: []
  routes: []
  application: my-application
" > ./hello-web-catalog.yaml

$ iofogctl deploy microservice -f hello-web-catalog.yaml

NB: This assumes you have an iofogctl stack running, with an agent called agent-name and an application called my-application

We can check that the expected images have been used by using iofogctl to describe our newly created microservice:

$ iofogctl describe microservice 'Hello Web Microservice'

apiVersion: iofog.org/v1
kind: Microservice
metadata:
  name: Hello Web Microservice
spec:
  agent:
    name: agent-name
    config:
      dockerUrl: unix:///var/run/docker.sock
      diskLimit: 50
      diskDirectory: /var/lib/iofog-agent/
      memoryLimit: 4096
      cpuLimit: 80
      logLimit: 10
      logDirectory: /var/log/iofog-agent/
      logFileCount: 10
      statusFrequency: 30
      changeFrequency: 60
      deviceScanFrequency: 60
      bluetoothEnabled: false
      watchdogEnabled: false
      abstractedHardwarEenabled: false
  images:
    catalogId: 5
    x86: iofog/hello-web
    arm: iofog/hello-web-arm
    registry: remote
  config: {}
  rootHostAccess: false
  ports: []
  volumes: []
  env: []
  application: my-application

Create your own catalog items

You can also use iofogctl to create your own catalog items.

$ iofogctl create catalogitem Postgresql --registry remote --x86 postgres:latest --arm postgres:latest --description 'Postgresql database'

$ iofogctl get catalog | grep 'Postgresql'

15		Postgresql	Postgresql database		remote		postgres:latest			postgres:latest

We used grep to filter the ouput, but the columns are the same as above. You can now use the images:catalogId field set to 15 in order to deploy postgres databases on your agents.