okd/roles/openshift_storage_glusterfs

OpenShift GlusterFS Cluster

OpenShift GlusterFS Cluster Configuration

This role handles the configuration of GlusterFS clusters. It can handle two primary configuration scenarios:

• Configuring a new, natively-hosted GlusterFS cluster. In this scenario, GlusterFS pods are deployed on nodes in the OpenShift cluster which are configured to provide storage.
• Configuring a new, external GlusterFS cluster. In this scenario, the cluster nodes have the GlusterFS software pre-installed but have not been configured yet. The installer will take care of configuring the cluster(s) for use by OpenShift applications.
• Using existing GlusterFS clusters. In this scenario, one or more GlusterFS clusters are assumed to be already setup. These clusters can be either natively-hosted or external, but must be managed by a heketi service.

As part of the configuration, a particular GlusterFS cluster may be specified to provide backend storage for a natively-hosted Docker registry.

Unless configured otherwise, a StorageClass will be automatically created for each non-registry GlusterFS cluster. This will allow applications which can mount PersistentVolumes to request dynamically-provisioned GlusterFS volumes.

Requirements

• Ansible 2.2

Host Groups

The following group is expected to be populated for this role to run:

• [glusterfs]

Additionally, the following group may be specified either in addition to or instead of the above group to deploy a GlusterFS cluster for use by a natively hosted Docker registry:

• [glusterfs_registry]

Host Variables

For configuring new clusters, the following role variables are available.

Each host in either of the above groups must have the following variable defined:

Name	Default value	Description
glusterfs_devices	None	A list of block devices that will be completely managed as part of a GlusterFS cluster. There must be at least one device listed. Each device must be bare, e.g. no partitions or LVM PVs. Example: '[ "/dev/sdb" ]' NOTE: You MUST set this as a host variable on each node host. For some reason, if you set this as a group variable it gets interpreted as a string rather than an array. See https://github.com/openshift/openshift-ansible/issues/5071

In addition, each host may specify the following variables to further control their configuration as GlusterFS nodes:

Name	Default value	Description
glusterfs_cluster	1	The ID of the cluster this node should belong to. This is useful when a single heketi service is expected to manage multiple distinct clusters. NOTE: For natively-hosted clusters, all pods will be in the same OpenShift namespace
glusterfs_hostname	openshift.node.nodename	A hostname (or IP address) that will be used for internal GlusterFS communication
glusterfs_ip	openshift.common.ip	An IP address that will be used by pods to communicate with the GlusterFS node. NOTE: Required for external GlusterFS nodes
glusterfs_zone	1	A zone number for the node. Zones are used within the cluster for determining how to distribute the bricks of GlusterFS volumes. heketi will try to spread each volumes' bricks as evenly as possible across all zones

Role Variables

This role has the following variables that control the integration of a GlusterFS cluster into a new or existing OpenShift cluster:

Name	Default value	Description
openshift_storage_glusterfs_timeout	300	Seconds to wait for pods to become ready
openshift_storage_glusterfs_namespace	'glusterfs'	Namespace/project in which to create GlusterFS resources
openshift_storage_glusterfs_is_native	True	GlusterFS should be containerized
openshift_storage_glusterfs_name	'storage'	A name to identify the GlusterFS cluster, which will be used in resource names
openshift_storage_glusterfs_nodeselector	'glusterfs=storage-host'	Selector to determine which nodes will host GlusterFS pods in native mode. NOTE: The label value is taken from the cluster name
openshift_storage_glusterfs_use_default_selector	False	Whether to use a default node selector for the GlusterFS namespace/project. If False, the namespace/project will have no restricting node selector. If True, uses pre-existing or default (e.g. osm_default_node_selector) node selectors. NOTE: If True, nodes which will host GlusterFS pods must already have the additional labels.
openshift_storage_glusterfs_storageclass	True	Automatically create a StorageClass for each GlusterFS cluster
openshift_storage_glusterfs_image	'gluster/gluster-centos'	Container image to use for GlusterFS pods, enterprise default is 'rhgs3/rhgs-server-rhel7'
openshift_storage_glusterfs_version	'latest'	Container image version to use for GlusterFS pods
openshift_storage_glusterfs_block_deploy	True	Deploy glusterblock provisioner service
openshift_storage_glusterfs_block_image	'gluster/glusterblock-provisioner'	Container image to use for glusterblock-provisioner pod, enterprise default is 'rhgs3/rhgs-gluster-block-prov-rhel7'
openshift_storage_glusterfs_block_version	'latest'	Container image version to use for glusterblock-provisioner pod
openshift_storage_glusterfs_block_host_vol_create	True	Automatically create GlusterFS volumes to host glusterblock volumes. NOTE: If this is False, block-hosting volumes will need to be manually created before glusterblock volumes can be provisioned
openshift_storage_glusterfs_block_host_vol_size	100	Size, in GB, of GlusterFS volumes that will be automatically create to host glusterblock volumes if not enough space is available for a glusterblock volume create request. NOTE: This value is effectively an upper limit on the size of glusterblock volumes unless you manually create larger GlusterFS block-hosting volumes
openshift_storage_glusterfs_block_host_vol_max	15	Max number of GlusterFS volumes to host glusterblock volumes
openshift_storage_glusterfs_s3_deploy	True	Deploy gluster-s3 service
openshift_storage_glusterfs_s3_image	'gluster/gluster-object'	Container image to use for gluster-s3 pod, enterprise default is 'rhgs3/rhgs-gluster-s3-server-rhel7'
openshift_storage_glusterfs_s3_version	'latest'	Container image version to use for gluster=s3 pod
openshift_storage_glusterfs_s3_account	Undefined	S3 account name for the S3 service, required for S3 service deployment
openshift_storage_glusterfs_s3_user	Undefined	S3 user name for the S3 service, required for S3 service deployment
openshift_storage_glusterfs_s3_password	Undefined	S3 user password for the S3 service, required for S3 service deployment
openshift_storage_glusterfs_s3_pvc	Dynamic	Name of the GlusterFS-backed PVC which will be used for S3 object data storage, generated from the cluster name and S3 account by default
openshift_storage_glusterfs_s3_pvc_size	"2Gi"	Size, in Gi, of the GlusterFS-backed PVC which will be used for S3 object data storage
openshift_storage_glusterfs_s3_meta_pvc	Dynamic	Name of the GlusterFS-backed PVC which will be used for S3 object metadata storage, generated from the cluster name and S3 account by default
openshift_storage_glusterfs_s3_meta_pvc_size	"1Gi"	Size, in Gi, of the GlusterFS-backed PVC which will be used for S3 object metadata storage
openshift_storage_glusterfs_wipe	False	Destroy any existing GlusterFS resources and wipe storage devices. WARNING: THIS WILL DESTROY ANY DATA ON THOSE DEVICES.
openshift_storage_glusterfs_heketi_is_native	True	heketi should be containerized
openshift_storage_glusterfs_heketi_cli	'heketi-cli'	Command/Path to invoke the heketi-cli tool NOTE: Change this only for non-native heketi if heketi-cli is not in the global $PATH of the machine running openshift-ansible
openshift_storage_glusterfs_heketi_image	'heketi/heketi'	Container image to use for heketi pods, enterprise default is 'rhgs3/rhgs-volmanager-rhel7'
openshift_storage_glusterfs_heketi_version	'latest'	Container image version to use for heketi pods
openshift_storage_glusterfs_heketi_admin_key	auto-generated	String to use as secret key for performing heketi commands as admin
openshift_storage_glusterfs_heketi_user_key	auto-generated	String to use as secret key for performing heketi commands as user that can only view or modify volumes
openshift_storage_glusterfs_heketi_topology_load	True	Load the GlusterFS topology information into heketi
openshift_storage_glusterfs_heketi_url	Undefined	When heketi is native, this sets the hostname portion of the final heketi route URL. When heketi is external, this is the FQDN or IP address to the heketi service.
openshift_storage_glusterfs_heketi_port	8080	TCP port for external heketi service NOTE: This has no effect in native mode
openshift_storage_glusterfs_heketi_executor	'kubernetes'	Selects how a native heketi service will manage GlusterFS nodes: 'kubernetes' for native nodes, 'ssh' for external nodes
openshift_storage_glusterfs_heketi_ssh_port	22	SSH port for external GlusterFS nodes via native heketi
openshift_storage_glusterfs_heketi_ssh_user	'root'	SSH user for external GlusterFS nodes via native heketi
openshift_storage_glusterfs_heketi_ssh_sudo	False	Whether to sudo (if non-root user) for SSH to external GlusterFS nodes via native heketi
openshift_storage_glusterfs_heketi_ssh_keyfile	Undefined	Path to a private key file for use with SSH connections to external GlusterFS nodes via native heketi NOTE: This must be an absolute path
openshift_storage_glusterfs_heketi_fstab	'/var/lib/heketi/fstab'	When heketi is native, sets the path to the fstab file on the GlusterFS nodes to update on LVM volume mounts, changes to '/etc/fstab/' when the heketi executor is 'ssh' NOTE: This should not need to be changed
openshift_storage_glusterfs_heketi_wipe	False	Destroy any existing heketi resources, defaults to the value of openshift_storage_glusterfs_wipe

Each role variable also has a corresponding variable to optionally configure a separate GlusterFS cluster for use as storage for an integrated Docker registry. These variables start with the prefix openshift_storage_glusterfs_registry_ and, for the most part, default to the values in their corresponding non-registry variables. The following variables are an exception:

Name	Default value	Description
openshift_storage_glusterfs_registry_namespace	registry namespace	Default is to use the hosted registry's namespace, otherwise 'glusterfs'
openshift_storage_glusterfs_registry_name	'registry'	This allows for the logical separation of the registry GlusterFS cluster from other GlusterFS clusters
openshift_storage_glusterfs_registry_storageclass	False	It is recommended to not create a StorageClass for GlusterFS clusters serving registry storage, so as to avoid performance penalties
openshift_storage_glusterfs_registry_heketi_admin_key	auto-generated	Separate from the above
openshift_storage_glusterfs_registry_heketi_user_key	auto-generated	Separate from the above

Additionally, this role's behavior responds to several registry-specific variables in the openshift_hosted role:

Name	Default value	Description
openshift_hosted_registry_storage_glusterfs_endpoints	glusterfs-registry-endpoints	The name for the Endpoints resource that will point the registry to the GlusterFS nodes
openshift_hosted_registry_storage_glusterfs_path	glusterfs-registry-volume	The name for the GlusterFS volume that will provide registry storage
openshift_hosted_registry_storage_glusterfs_readonly	False	Whether the GlusterFS volume should be read-only
openshift_hosted_registry_storage_glusterfs_swap	False	Whether to swap an existing registry's storage volume for a GlusterFS volume
openshift_hosted_registry_storage_glusterfs_swapcopy	True	If swapping, copy the contents of the pre-existing registry storage to the new GlusterFS volume

Dependencies

• os_firewall
• openshift_hosted_facts
• openshift_repos
• lib_openshift

Example Playbook

- name: Configure GlusterFS hosts
  hosts: oo_first_master
  roles:
  - role: openshift_storage_glusterfs
    when: groups.oo_glusterfs_to_config | default([]) | count > 0

License

Apache License, Version 2.0

Author Information

Jose A. Rivera (jarrpa@redhat.com)