Mount a disk to an elastic container instance - Elastic Container Instance

Disks are block storage products provided by Alibaba Cloud that feature low latency, high performance, durability, and high reliability. You can use the FlexVolume plug-in to mount disks to an elastic container instance as volumes. This topic describes how to mount a disk as a volume on an elastic container instance.

Limitations

Only pay-as-you-go disks can be mounted. For more information, see Block storage billing.
Disks cannot be shared. A disk can be mounted to only one instance.
A maximum of six disk volumes can be mounted to an elastic container instance.
A disk can only be mounted to an instance in the same availability zone. Cross-zone mounting is not supported.
You cannot mount NVMe disks that have the multi-mount feature enabled (also known as NVMe shared disks).
You cannot mount a disk that has partitions.

Configuration description

When you call the CreateContainerGroup API operation to create an elastic container instance, you can use Volume-related parameters to specify volumes, and then use Container.VolumeMount-related parameters to mount the volumes to containers. The relevant parameters are described below. For more information, see CreateContainerGroup.

Declare a volume

When you use Volume-related parameters to specify volumes, you must first specify the types and names of the volumes. Then, you must configure other Volume-related parameters based on the value of the Volume.N.Type parameter.

Parameter	Type	Example	Description
Volume.N.Name	String	disk-demo	The name of the volume N.
Volume.N.Type	String	FlexVolume	Set the value to FlexVolume. The value specifies a volume that is mounted by using the FlexVolume plug-in.
Volume.N.FlexVolume.Driver	String	alicloud/disk	The driver type when you use the FlexVolume plug-in to mount a volume. Set the value to `alicloud/disk`, which specifies to mount Alibaba Cloud disks.
Volume.N.FlexVolume.FsType	String	ext4	The type of the file system. Select the file system type of the disk. Valid values: ext4, ext3, xfs, and vfat. Default value: ext4.
Volume.N.FlexVolume.Options	String	{"volumeSize":"50","tags":"test:eci"}	The options when you set the Volume.N.Type parameter to FlexVolume. Each option is a key-value pair in the JSON string. When you use the FlexVolume plug-in to mount a disk, this parameter represents the configuration parameters of the disk volume. The following parameters can be configured: Important If you do not specify the volumeId parameter, you must specify the volumeSize parameter. If you specify the volumeId parameter, the values of the attribute parameters of the disk, such as volumeSize, are ignored. To use an existing disk (static provisioning) volumeId: the ID of the disk. To create a new disk (dynamic provisioning) volumeSize: the disk size in GiB. Valid values: 20 to 32768. Note If the disk to be amounted is created based on a snapshot (you use the snapshotId parameter to specify the snapshot), the actual size of the created disk is the greater of the following two values: The value of the volumeSize parameter The size of the disk that is created based on a snapshot. performanceLevel: the performance level of the disk. The system automatically uses an enhanced SSD (ESSD) as the volume. You cannot specify the category of the disk. For more information, see ESSDs. deleteWithInstance: specifies whether to release the disk when the elastic container instance is released. Default value: true. encrypted: specifies whether to encrypt the disk. Default value: false. For more information, see Encryption overview. kmsKeyId: the ID of the Key Management Service (KMS) key that is used to encrypt the disk. tags: the tags to be bound to the disk. You can bind up to 20 tags. Format: `"tagkey1:tagvalue1,tagkey2:tagvalue2"`. snapshotId: the ID of the snapshot. A snapshot is a stateful data file of a disk at a specific point in time. You can obtain the data on a disk that is created based on a snapshot. For more information about snapshots, see Overview. Note If a disk that is created based on a snapshot has partitions, you cannot mount the disk to an elastic container instance.

Mount volumes

After you specify volumes, you can use VolumeMount-related parameters to mount the volumes to containers.

Parameter	Type	Example	Description
Container.N.VolumeMount.N.Name	String	test-volume	The name of volume N to be mounted to container N. This value is the value of Volume.N.Name.
Container.N.VolumeMount.N.MountPath	String	/usr/share	The path within the container at which to mount the volume. Data in this directory is obscured by the data on the volume.
Container.N.VolumeMount.N.SubPath	String	/usr/sub	The subdirectory of the volume. This parameter specifies different subdirectories of the same volume that the instance can mount to different subdirectories of containers.
Container.N.VolumeMount.N.ReadOnly	Boolean	false	Specifies whether the mount directory is read-only. Default value: false.
Container.N.VolumeMount.N.MountPropagation	String	None	The mount propagation setting of volume N. Mount propagation allows you to share volumes that are mounted to one container to other containers in the same elastic container instance, or even to other elastic container instances on the same host. Valid values: None: The volume mount does not receive subsequent mounts that are mounted to this volume or its subdirectories. HostToContainer: The volume mount receives all subsequent mounts that are mounted to this volume or its subdirectories. Bidirectional: This value has a similar effect as HostToContainer. The volume mount receives all subsequent mounts that are mounted to this volume or its subdirectories. In addition, all volume mounts created by container N are propagated back to the host and to all containers of all elastic container instances that use the same volume. Default value: None.

Note

Volumes can also be mounted to init containers. The required parameters are similar to the parameters in the preceding table. You only need to change Container to InitContainer.

Configuration examples

The following examples show the parameters used when you call the CreateContainerGroup operation to create an elastic container instance and mount a disk as a volume. For more information, see CreateContainerGroup.

Example 1: Statically mount an existing disk

ContainerGroupName=test-disk1
SecurityGroupId=sg-bp1daxpbz9lzpvvc****
VSwitchId=vsw-bp1gds63lmlm7ib05****
# Specify the volume to be mounted.
Volume.1.Name=disk-demo
Volume.1.Type=FlexVolume
Volume.1.FlexVolume.Driver=alicloud/disk
Volume.1.FlexVolume.FsType=ext4
Volume.1.FlexVolume.Options={"volumeId":"d-2zebuamrpar7xnj****"}
# Mount the volume to a container.
Container.1.Name=nginx
Container.1.Image=registry-vpc.cn-hangzhou.aliyuncs.com/eci_open/nginx:1.14.2
Container.1.VolumeMount.1.Name=disk-demo
Container.1.VolumeMount.1.MountPath=/data

Note

When you statically mount an existing disk, it must be in the Pending state and in the same availability zone as the elastic container instance.

Example 2: Dynamically create a new disk

ContainerGroupName=test-disk2
# Specify the volume to be mounted.
Volume.1.Name=disk-demo
Volume.1.Type=FlexVolume
Volume.1.FlexVolume.Driver=alicloud/disk
Volume.1.FlexVolume.FsType=ext4
Volume.1.FlexVolume.Options={"volumeSize":"50","tags":"test:eci"}
# Mount the volume to a container.
Container.1.Name=nginx
Container.1.Image=registry-vpc.cn-hangzhou.aliyuncs.com/eci_open/nginx:1.14.2
Container.1.VolumeMount.1.Name=disk-demo
Container.1.VolumeMount.1.MountPath=/data