helm

Helm installation procedure

Overview

In order to be able to use helm to render templates, it has to be installed on a host where a user plans to generate templates.

Helm Installation

On Linux or Mac OS, run these two commands to download and copy helm binary into /usr/local/bin directory.

export HELM_URL=http://storage.googleapis.com/kubernetes-helm/helm-v2.7.2-$(uname | tr A-Z a-z)-amd64.tar.gz
curl "$HELM_URL" | sudo tar --strip-components 1 -C /usr/local/bin -zxf - $(uname | tr A-Z a-z)-amd64/helm

Provisioner's spec generation process has been tested with helm version 2.7.2.

Helm verification

Run the following command:

helm version

This output should be generated:

Client: &version.Version{SemVer:"v2.7.2", GitCommit:"8478fb4fc723885b155c924d1c8c410b7a9444e6", GitTreeState:"clean"}
Error: cannot connect to Tiller

The error on the second line of the output can be ignored, as Tiller, helm's deployment engine has not been installed on the kubernetes cluster as it is not required for template generation.

Provisioner's helm chart

Helm templating is used to generate the provisioner's DaemonSet and ConfigMap specs. The generated specs can be further customized as needed (usually not necessary), and then deployed using kubectl.

helm template uses 3 sources of information:

1. Provisioner's chart template located at helm/provisioner/templates/provisioner.yaml
2. Provisioner's default values.yaml which contains variables used for rendering a template.
3. (Optional) User's customized values.yaml as a part of helm template command. User's provided values will override default values of Provisioner's values.yaml.

Default values.yaml is located in local-volume/helm/provisioner folder, user should not remove variables from this file but can change any values of these variables.

Configurations

The following table lists the configurable parameters of the local volume provisioner chart and their default values.

Parameter	Description	Type	Default
common.rbac	Generating RBAC (Role Based Access Control) objects.	bool	true
common.namespace	Namespace where provisioner runs.	str	default
common.createNamespace	Whether to create namespace for provisioner.	bool	false
common.useAlphaAPI	If running against pre-1.10 k8s version, the useAlphaAPI flag must be enabled.	bool	false
common.useJobForCleaning	If set to true, provisioner will use jobs-based block cleaning.	bool	false
common.useNodeNameOnly	If set to true, provisioner name will only use Node.Name and not Node.UID.	bool	false
common.minResyncPeriod	Resync period in reflectors will be random between minResyncPeriod and 2*minResyncPeriod.	str	5m0s
common.configMapName	Provisioner ConfigMap name.	str	local-provisioner-config
classes.[n].name	StorageClass name.	str	-
classes.[n].hostDir	Path on the host where local volumes of this storage class are mounted under.	str	-
classes.[n].mountDir	Optionally specify mount path of local volumes. By default, we use same path as hostDir in container.	str	-
classes.[n].blockCleanerCommand	List of command and arguments of block cleaner command.	list	-
classes.[n].volumeMode	Optionally specify volume mode of created PersistentVolume object. By default, we use Filesystem.	str	-
classes.[n].fsType	Filesystem type to mount. Only applies when source is block while volume mode is Filesystem.	str	-
classes.[n].storageClass	Create storage class for this class and configure it optionally.	bool/map	false
classes.[n].storageClass.reclaimPolicy	Specify reclaimPolicy of storage class, available: Delete/Retain.	str	Delete
daemonset.name	Provisioner DaemonSet name.	str	local-volume-provisioner
daemonset.image	Provisioner image.	str	quay.io/external_storage/local-volume-provisioner:v2.1.0
daemonset.imagePullPolicy	Provisioner DaemonSet image pull policy.	str	-
daemonset.serviceAccount	Provisioner DaemonSet service account.	str	local-storage-admin
daemonset.kubeConfigEnv	Specify the location of kubernetes config file.	str	-
daemonset.nodeLabels	List of node labels to be copied to the PVs created by the provisioner.	list	-
daemonset.nodeSelector	NodeSelector constraint on nodes eligible to run the provisioner.	map	-
daemonset.tolerations	List of tolerations to be applied to the Provisioner DaemonSet.	list	-
daemonset.resources	Map of resource request and limits to be applied to the Provisioner Daemonset.	map	-
prometheus.operator.enabled	If set to true, will configure Prometheus monitoring	bool	false
prometheus.operator.serviceMonitor.interval	Interval at which Prometheus scrapes the provisioner	str	10s
prometheus.operator.serviceMonitor.namespace	The namespace Prometheus is installed in	str	monitoring
prometheus.operator.serviceMonitor.selector	The Prometheus selector label	map	prometheus: kube-prometheus
Note: classes is a list of objects, you can specify one or more classes.

Examples

To try out one of the examples. you can run, e.g. for gce:

$ helm template ./helm/provisioner -f helm/examples/gce.yaml > ./provisioner/deployment/kubernetes/provisioner_generated.yaml

Currently you can try the following examples:

• examples/baremetal-cleanbyjobs.yaml
• examples/baremetal-resyncperiod.yaml
• examples/baremetal-tolerations.yaml
• examples/baremetal-with-resource-limits.yaml
• examples/baremetal-without-rbac.yaml
• examples/baremetal.yaml
• examples/gce-pre1.9.yaml
• examples/gce-retain.yaml
• examples/gce.yaml
• examples/gke.yaml
• more...