Resource Definitions

Driver

Capability

Flavor

Resource Type

Initcontainers

This section contains example Resource Definitions using the Template Driver for defining an init container on your Pods.

While it is also possible to set init containers via Score , the approach shown here shifts the management of init containers down to the Platform, ensuring consistency and relieving developers of the task to repeat them for each Workload in the Score extension file.

  • custom-workload-with-initcontainer.yaml: Add the required init container to the Workload so it polls for the existence of a Kubernetes service for the Workload. This format is for use with the Humanitec CLI .
  • custom-workload-with-initcontainer.tf: This format is for use with the Humanitec Terraform Provider .

Resource Definitions

custom-workload-with-initcontainer.yaml ( view on GitHub ) :

# This Resource Definition uses the Template Driver to add an init container to a Workload
apiVersion: entity.humanitec.io/v1b1
kind: Definition
metadata:
  id: custom-workload-with-initcontainer
entity:
  name: custom-workload-with-initcontainer
  type: workload
  driver_type: humanitec/template
  driver_inputs:
    values:
      templates:
        outputs: |
          update: 
          - op: add
            path: /spec/pod/initContainers
            value:
            - command:
              - sh
              - -c
              - until nslookup myservice.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for myservice; sleep 2; done
              image: busybox
              name: init-myservice
  # Set matching criteria as required
  criteria:
    - app_id: my-app

custom-workload-with-initcontainer.tf ( view on GitHub ) :

resource "humanitec_resource_definition" "custom-workload-with-initcontainer" {
  driver_type = "humanitec/template"
  id          = "custom-workload-with-initcontainer"
  name        = "custom-workload-with-initcontainer"
  type        = "workload"
  driver_inputs = {
    values_string = jsonencode({
      "templates" = {
        "outputs" = <<END_OF_TEXT
update: 
- op: add
  path: /spec/pod/initContainers
  value:
  - command:
    - sh
    - -c
    - until nslookup myservice.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for myservice; sleep 2; done
    image: busybox
    name: init-myservice
END_OF_TEXT
      }
    })
  }
}

resource "humanitec_resource_definition_criteria" "custom-workload-with-initcontainer_criteria_0" {
  resource_definition_id = resource.humanitec_resource_definition.custom-workload-with-initcontainer.id
  app_id                 = "my-app"
}