Add Infrastructure

With Monk you can grow your cluster manually by issuing the grow command. This is not the only way to add instances to your cluster as the Kits can also carry instructions instance definitions. Monk will create instances when running a Kit containing such a definition.

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Requirements

You need to create a cluster or join already existing cluster in order to deploy your runnable with embedded instances.

note

Please follow this guide if you need to create a new cluster.

Defining nodes

Any runnable can define nodes like this:

namespace: foos

foo:
    defines: runnable

    nodes:
        my-node:
            provider: gcp
            tag: my-magical-cluster
            instance-type: n1-standard-1
            region: us-central1
            disk-size: 128

    affinity:
        name: my-node

    containers:
        some-service:
            image: some/image
            image-tag: latest

When running foos/foo, MonkOS will create an instance named my-node using the GCP provider if it's available. The some-service container will be then scheduled to run on that new instance thanks to the affinity directive.

Nodes section

The nodes definition is applicable in any runnable.

my-node:
    provider: gcp
    tag: auto-grown
    instance-type: n1-standard-1
    region: us-central1
    disk-size: 128

The fields here match the arguments in the monk grow command.

Instance affinity

Use affinity field in runnable definition in order to tell MonkOS where to start this runnable.

affinity:
    name: my-instance

Using name will look for a concrete instance by name and pin the runnable there so it always run on that instance.

affinity:
    tag: some-tag

Using tag will look for any instance with the specified tag and pin the runnable on that instance. Both can be used at the same time but name takes precedence.