Resource Definitions

Driver

Capability

Flavor

Resource Type

Volumes

This section contains Resource Definition examples for handling Kubernetes Volumes by using the template Driver to configure your own PersistentVolume implementation. You can see this other example if you want to use the volume-pvc Driver.

You will find two examples:

  • volume-emptydir - in order to inject an emptyDir volume in a Workload for any request of a volume resource with the class ephemeral.
  • volume-nfs - in order to create the associated PersistentVolumeClaim, PersistentVolume and volume in a Workload for any request of a volume resource with the class nfs.

You can find a Score file example using the volume resource type here .

Resource Definitions

volume-emptydir.yaml ( view on GitHub ) :

apiVersion: entity.humanitec.io/v1b1
kind: Definition
metadata:
  id: volume-emptydir
entity:
  name: volume-emptydir
  type: volume
  driver_type: humanitec/template
  driver_inputs:
    values:
      templates:
        manifests:
          emptydir.yaml:
            location: volumes
            data: |
              name: ${context.res.guresid}-emptydir
              emptyDir:
                sizeLimit: 1024Mi
  criteria:
  - class: ephemeral

volume-nfs.yaml ( view on GitHub ) :

# Using the Template Driver for the static provisioning of
# a Kubernetes PersistentVolume and PersistentVolumeClaim combination,
# then adding the volume into the Pod of the Workload.
# The volumeMount in the container is defined in the "workload" type Resource Definition.
apiVersion: entity.humanitec.io/v1b1
kind: Definition
metadata:
  id: volume-nfs
entity:
  name: volume-nfs
  type: volume
  driver_type: humanitec/template
  driver_inputs:
    values:
      templates:
        init: |
          # Generate a unique id for each pv/pvc combination.
          # Every Workload will have a separate pv and pvc created for it,
          # but pointing to the same NFS server endpoint.
          volumeUid: {{ randNumeric 4 }}-{{ randNumeric 4 }}
          pvBaseName: pv-tmpl-
          pvcBaseName: pvc-tmpl-
          volBaseName: vol-tmpl-
        manifests:
          ####################################################################
          # This template creates the PersistentVolume in the target namespace
          # Modify the nfs server and path to address your NFS server
          ####################################################################
          app-pv-tmpl.yaml:
            location: namespace
            data: |
              apiVersion: v1
              kind: PersistentVolume
              metadata:
                name: {{ .init.pvBaseName }}{{ .init.volumeUid }}
              spec:
                capacity:
                  storage: 1Mi
                accessModes:
                  - ReadWriteMany
                nfs:
                  server: nfs-server.default.svc.cluster.local
                  path: "/"
                mountOptions:
                  - nfsvers=4.2
          
          #########################################################################
          # This template creates the PersistentVolumeClaim in the target namespace
          #########################################################################
          app-pvc-tmpl.yaml:
            location: namespace
            data: |
              apiVersion: v1
              kind: PersistentVolumeClaim
              metadata:
                name: {{ .init.pvcBaseName }}{{ .init.volumeUid }}
              spec:
                accessModes:
                  - ReadWriteMany
                storageClassName: ""
                resources:
                  requests:
                    storage: 1Mi
                volumeName: {{ .init.pvBaseName }}{{ .init.volumeUid }}

          ########################################################
          # This template creates the volume in the Workload's Pod
          ########################################################
          app-vol-tmpl.yaml:
            location: volumes
            data: |
              name: {{ .init.volBaseName }}{{ .init.volumeUid }}
              persistentVolumeClaim:
                claimName: {{ .init.pvcBaseName }}{{ .init.volumeUid }}

        # Make the volume name and pvc name available for other Resources
        outputs: |
          volumeName: {{ .init.volBaseName }}{{ .init.volumeUid }}
          pvcName: {{ .init.pvcBaseName }}{{ .init.volumeUid }}
  criteria:
  - class: nfs

volume-emptydir.tf ( view on GitHub ) :

resource "humanitec_resource_definition" "volume-emptydir" {
  driver_type = "humanitec/template"
  id          = "volume-emptydir"
  name        = "volume-emptydir"
  type        = "volume"
  driver_inputs = {
    values_string = jsonencode({
      "templates" = {
        "manifests" = {
          "emptydir.yaml" = {
            "location" = "volumes"
            "data"     = <<END_OF_TEXT
name: $${context.res.guresid}-emptydir
emptyDir:
  sizeLimit: 1024Mi
END_OF_TEXT
          }
        }
      }
    })
  }
}

resource "humanitec_resource_definition_criteria" "volume-emptydir_criteria_0" {
  resource_definition_id = resource.humanitec_resource_definition.volume-emptydir.id
  class                  = "ephemeral"
}

volume-nfs.tf ( view on GitHub ) :

resource "humanitec_resource_definition" "volume-nfs" {
  driver_type = "humanitec/template"
  id          = "volume-nfs"
  name        = "volume-nfs"
  type        = "volume"
  driver_inputs = {
    values_string = jsonencode({
      "templates" = {
        "init" = <<END_OF_TEXT
# Generate a unique id for each pv/pvc combination.
# Every Workload will have a separate pv and pvc created for it,
# but pointing to the same NFS server endpoint.
volumeUid: {{ randNumeric 4 }}-{{ randNumeric 4 }}
pvBaseName: pv-tmpl-
pvcBaseName: pvc-tmpl-
volBaseName: vol-tmpl-
END_OF_TEXT
        "manifests" = {
          "app-pv-tmpl.yaml" = {
            "location" = "namespace"
            "data"     = <<END_OF_TEXT
apiVersion: v1
kind: PersistentVolume
metadata:
  name: {{ .init.pvBaseName }}{{ .init.volumeUid }}
spec:
  capacity:
    storage: 1Mi
  accessModes:
    - ReadWriteMany
  nfs:
    server: nfs-server.default.svc.cluster.local
    path: "/"
  mountOptions:
    - nfsvers=4.2
END_OF_TEXT
          }
          "app-pvc-tmpl.yaml" = {
            "location" = "namespace"
            "data"     = <<END_OF_TEXT
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: {{ .init.pvcBaseName }}{{ .init.volumeUid }}
spec:
  accessModes:
    - ReadWriteMany
  storageClassName: ""
  resources:
    requests:
      storage: 1Mi
  volumeName: {{ .init.pvBaseName }}{{ .init.volumeUid }}
END_OF_TEXT
          }
          "app-vol-tmpl.yaml" = {
            "location" = "volumes"
            "data"     = <<END_OF_TEXT
name: {{ .init.volBaseName }}{{ .init.volumeUid }}
persistentVolumeClaim:
  claimName: {{ .init.pvcBaseName }}{{ .init.volumeUid }}
END_OF_TEXT
          }
        }
        "outputs" = <<END_OF_TEXT
volumeName: {{ .init.volBaseName }}{{ .init.volumeUid }}
pvcName: {{ .init.pvcBaseName }}{{ .init.volumeUid }}
END_OF_TEXT
      }
    })
  }
}

resource "humanitec_resource_definition_criteria" "volume-nfs_criteria_0" {
  resource_definition_id = resource.humanitec_resource_definition.volume-nfs.id
  class                  = "nfs"
}