CSI plugin for ScaleIO []

Description

CSI-ScaleIO is a Container Storage Interface (CSI) plugin that provides ScaleIO support.

This project may be compiled as a stand-alone binary using Golang that, when run, provides a valid CSI endpoint. This project can also be vendored or built as a Golang plug-in in order to extend the functionality of other programs.

Runtime Dependencies

The Node portion of the plugin can be run on any node that is configured as a ScaleIO SDC. This means that the scini kernel module must be loaded. Also, if the X_CSI_SCALEIO_SDCGUID environment variable is not set, the plugin will try to query the SDC GUID by executing the binary /opt/emc/scaleio/sdc/bin/drv_cfg. If that binary is not present, the Node Service cannot be run.

Installation

CSI-ScaleIO can be installed with Go and the following command:

$ go get github.com/thecodeteam/csi-scaleio

The resulting binary will be installed to $GOPATH/bin/csi-scaleio.

If you want to build csi-scaleio with accurate version information, you'll need to run the go generate command and build again:

$ go get github.com/thecodeteam/csi-scaleio
$ cd $GOPATH/src/github.com/thecodeteam/csi-scaleio
$ go generate && go install

The binary will once again be installed to $GOPATH/bin/csi-scaleio.

Start plugin

Before starting the plugin please set the environment variable CSI_ENDPOINT to a valid Go network address such as csi.sock:

$ CSI_ENDPOINT=csi.sock csi-scaleio
INFO[0000] configured com.thecodeteam.scaleio            endpoint="https://10.50.10.100:443" insecure=true password="******" privatedir=/dev/disk/csi-scaleio sdcGUID= systemname=democluster thickprovision=false user=admin
INFO[0000] identity service registered
INFO[0000] controller service registered
INFO[0000] node service registered
INFO[0000] serving                                       endpoint="unix:///csi.sock"

The server can be shutdown by using Ctrl-C or sending the process any of the standard exit signals.

Using plugin

The CSI specification uses the gRPC protocol for plug-in communication. The easiest way to interact with a CSI plugin is via the Container Storage Client (csc) program provided via the GoCSI project:

$ go get github.com/rexray/gocsi
$ go install github.com/rexray/gocsi/csc

Then, have csc use the same CSI_ENDPOINT, and you can issue commands to the plugin. Some examples...

Get the plugin's supported versions and plugin info:

$ ./csc -e csi.sock identity supported-versions
0.1.0

$ ./csc -v 0.1.0 -e csi.sock identity plugin-info
"com.thecodeteam.scaleio"	"0.0.1+1"
"commit"="cd9c538b596db926a3a747c6c219a2ace8f1890b"
"formed"="Fri, 01 Dec 2017 08:33:28 PST"
"semver"="0.0.1+1"
"url"="https://github.com/thecodeteam/csi-scaleio"

Parameters

When using the plugin, some commands accept additional parameters, some of which may be required for the command to work, or may change the behavior of the command. Those parameters are listed here.

• CreateVolume: storagepool The name of a storage pool must be passed in the CreateVolume command
• GetCapacity: storagepool may be passed in GetCapacity command. If it is, the returned capacity is the available capacity for creation within the given storage pool. Otherwise, it's the capacity for creation within the storage cluster.

Passing parameters with csc is demonstrated in this CreateVolume command:

$ ./csc -v 0.1.0 c create --cap 1,mount,xfs --params storagepool=pd1pool1 myvol
"6757e7d300000000"

Configuration

The CSI-ScaleIO SP is built using the GoCSI CSP package. Please see its configuration section for a complete list of the environment variables that may be used to configure this SP.

The following table is a list of this SP's default configuration values:

Name	Value
X_CSI_SPEC_REQ_VALIDATION	true
X_CSI_SERIAL_VOL_ACCESS	true
X_CSI_REQUIRE_NODE_ID	true
X_CSI_REQUIRE_PUB_VOL_INFO	false
X_CSI_SUPPORTED_VERSIONS	0.1.0
X_CSI_PRIVATE_MOUNT_DIR	/dev/disk/csi-scaleio

The following table is a list of this configuration values that are specific to ScaleIO, their default values, and whether they are required for operation:

Name	Description	Default Val	Required
X_CSI_SCALEIO_ENDPOINT	ScaleIO Gateway HTTP endpoint	""	true
X_CSI_SCALEIO_USER	Username for authenticating to Gateway	"admin"	false
X_CSI_SCALEIO_PASSWORD	Password of Gateway user	""	true
X_CSI_SCALEIO_INSECURE	The ScaleIO Gateway's certificate chain and host name should not be verified	false	false
X_CSI_SCALEIO_SYSTEMNAME	The name of the ScaleIO cluster	""	true
X_CSI_SCALEIO_SDCGUID	The GUID of the SDC. This is only used by the Node Service, and removes a need for calling an external binary to retrieve the GUID	""	false
X_CSI_SCALEIO_THICKPROVISIONING	Whether to use thick provisioning when creating new volumes	false	false

Capable operational modes

The CSI spec defines a set of AccessModes that a volume can have. CSI-ScaleIO supports the following modes for volumes that will be mounted as a filesystem:

// Can only be published once as read/write on a single node,
// at any given time.
SINGLE_NODE_WRITER = 1;

// Can only be published once as readonly on a single node,
// at any given time.
SINGLE_NODE_READER_ONLY = 2;

// Can be published as readonly at multiple nodes simultaneously.
MULTI_NODE_READER_ONLY = 3;

This means that volumes can be mounted to either single node at a time, with read-write or read-only permission, or can be mounted on multiple nodes, but all must be read-only.

For volumes that are used as block devices, only the following are supported:

// Can only be published once as read/write on a single node, at
// any given time.
SINGLE_NODE_WRITER = 1;

// Can be published as read/write at multiple nodes
// simultaneously.
MULTI_NODE_MULTI_WRITER = 5;

This means that giving a workload read-only access to a block device is not supported.

In general, volumes should be formatted with xfs or ext4.

Support

For any questions or concerns please file an issue with the csi-scaleio project or join the Slack channel #project-rexray at codecommunity.slack.com.