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This article mainly introduces "what are the new features of kubernetes1.4". In daily operation, I believe many people have doubts about the new features of kubernetes1.4. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful for you to answer the doubts about "what are the new features of kubernetes1.4?" Next, please follow the editor to study!

Background introduction

You can see from the figure that the attribute of the structure PodSpec is Volumes, through which the Volumes attribute can be associated with the structure Volume and the structure VolumeSource, and the Volumes attribute is an array type, which means that the POD can be associated with multiple different types of volumes.

The structure Container represents the container in POD. This structure has an attribute VolumeMounts, which lets the container know the specific storage path to be mounted. This VolumeMounts attribute is also an array type, that is, the container can mount multiple storage paths.

Support for new volume plug-ins

Kubernetes supports a total of 22 volume plug-ins. Two new volume plug-ins have been added to Kubernetes1.4: Quobyte and AzureDisk.

Quobyte

This is a distributed file system launched by Quobyte. To use Quobyte storage in kubernetes, you need to deploy Quobyte software in advance, which must be version 1.3 and later, and deploy Quobyte clients on nodes managed by kubernetes.

Why use 1.3 and later? Because Quobyte provides a feature in these versions: fixed-user mount, this new feature allows all Quobyte volumes to be mounted to a single path and can be used separately according to different users. All access to Quobyte volumes distinguishes between users and groups, of course, without distinction, and the advantage of differentiation is that multi-tenant isolation can be achieved. The following figure shows an example of a fixed-user mount:

Container An is designed to perform operations only through the user wordpress, but for quobyte, container An actually performs the actual read and write operations through the user job; container B is designed to perform operations through the root user, but for quobyte, container B is actually performed through the user mike in the root group. That is to say, a user mapping is made instead of using users in the container to perform read and write operations.

How do I enable the fixed-user mount feature? After installing the Quobyte client, add a line of allow-usermapping-in-volumename to the configuration file / etc/quobyte/client.cfg.

If you use Docker instead of kubernetes, you can also use the Docker plug-in provided by Quobyte instead of installing the Quobyte client. In Docker, all Quobyte volumes are mounted to the / run/docker/quobyte/mnt directory. This plug-in has been tested in the following environment:

However, it is a pity that the Docker plug-in provided by Quobyte does not support fixed-user mount yet, and if you want to use this feature, you must install the Quobyte client.

The following is the structure corresponding to the quobyte volume:

Variable Registry:QuoByte registration service entry, if multiple registration service entries are configured, then each registration service entry can be separated by a semicolon. The variable Volume:QuoByte has already created the volume. Variable ReadOnly: this is a Boolean variable. The default is false, which means that you can read and write to volumes that have been created by QuoByte. If configured as true, it means that only volumes that have been created by QuoByte can be read-only. Variable User: the user who manipulates the QuoByte volume. Variable Group: the group that operates on the QuoByte volume.

The following is an example file, quobyte-pod.yaml, that creates a POD using Quobyte volumes:

Then create the POD with the following command:

After the POD is created successfully, you can check to make sure that the quobyte volume testVolume has been mounted:

AzureDisk

Azure is a public cloud service provided by Microsoft. If the virtual machine above Azure is used as a Kubernetes cluster, the data disk provided by Azure can be mounted through a volume plug-in such as AzureDisk.

The following is an introduction to the data disk on Azure:

A data disk is a VHD attached to a virtual machine to store application data or other data that needs to be retained. The data disk is registered as a SCSI drive and is marked with the selected letter. The maximum capacity of each data disk is 1023 GB. The size of the virtual machine determines the number of disks that can be attached and the type of storage that can be used to host disks. The VHD used in Azure is a .vhd file stored as a page Blob in Azure's standard or advanced storage account.

The core of Azure data disk is that Blob,Blob is to store large binary objects, such as files, pictures, documents and other binary format files.

There are two types of Blob:

1. Block Blob (block Blob). This type is suitable for storing binary files and supports resuming transmission from breakpoints. It can use a maximum of 4m as a block unit, and a single file can store a maximum of 200GB. Chunks are not stored continuously and may be stored in different storage servers. In order to adapt to the upload and download of files, it is specially optimized. Block Blob can be created in two ways. Block Blobs that does not exceed 64MB can be uploaded by calling PutBlob operation. Block Blobs larger than 64m must be uploaded in parts, and the size of each part cannot exceed 4MB. Block Blob can be approximately understood as a network disk.

2. Page Blob (page Blob). This type of storage optimizes random access. It divides a contiguous area in the storage area for applications to store data, which can be used to store VHD, and a single file can store up to 1TB.

The Blob service consists of the Blob itself and its storage container (Container), which can be treated as a folder on the local machine.

You can access Blob through REST API:

Http://.blob.core.chinacloudapi.cn//

Accountname indicates which Azure stores the resources under the account, which is globally unique. Blob.core.chinacloudapi.cn represents an azure chinablob storage resource and is fixed. Containername represents the name of the container, can be thought of as accessing a resource under a folder blobname represents the name of the resource to be accessed, can be thought of as a mp3 file, or a jpg file.

Examples are as follows:

Save it under the leizhangstorage storage account, and containername is photo,blobname and myphoto.jpg. Then the URL address is:

Http://leizhangstorage.blob.core.chinacloudapi.cn/photo/myphoto.jpg

Save it under the leizhangstorage storage account, and containername is vhd,blobname and myvm.vhd. Then the URL address is:

Http://leizhangstorage.blob.core.chinacloudapi.cn/vhd/myvm.vhd

Naming rules for Container:

Containername can only be a first-level directory. There is no way to set the next level under containername. Containername must start with English or numbers, and the name can only contain English, numbers and dash (-). It cannot start or end with dash (-). Dash (-) cannot appear continuously. All English characters must be between 3-63 in lowercase length.

Naming rules for Blob:

Except for the reserved characters of url, other character combinations can use a length of 1-1024 characters to avoid using dot (.) Or the end of forward slash (/). Otherwise, it will cause Blob Service misjudgment.

The following is the structure corresponding to the AzureDisk volume in Kubernetes:

Variable DiskName: a required parameter that represents the name of the data disk. Variable DataDiskURI: a required parameter that represents the access path to the data disk. Variable CachingMode: optional parameter, indicating the data disk buffering mode. You can choose None, ReadOnly, and ReadWrite. The default is None. Variable FSType: optional parameter that represents the file system type formatted after the data disk is mounted on the operating system, such as "ext4", "xfs", "ntfs". The default is "ext4". Variable ReadOnly: optional parameter, which is a Boolean variable indicating whether the data disk is read-only. The default is false, indicating that read and write operations can be performed. At this point, the study on "what are the new features of kubernetes1.4" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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