TranslateProject/sources/tech/20210119 Set up a Linux cloud on bare metal.md

[#]: collector: (lujun9972)
[#]: translator: ( )
[#]: reviewer: ( )
[#]: publisher: ( )
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[#]: subject: (Set up a Linux cloud on bare metal)
[#]: via: (https://opensource.com/article/21/1/cloud-image-virt-install)
[#]: author: (Sumantro Mukherjee https://opensource.com/users/sumantro)

Set up a Linux cloud on bare metal
======
Create cloud images with virt-install on Fedora.
![Sky with clouds and grass][1]

Virtualization is one of the most used technologies. Fedora Linux uses [Cloud Base images][2] to create general-purpose virtual machines (VM), but there are many ways to set up Cloud Base images. Recently, the virt-install command-line tool for provisioning VMs added support for **cloud-init**, so it can now be used to configure and run a cloud image locally.

This article walks through how to set up a base Fedora cloud instance on bare metal. The same steps can be used with any raw or Qcow2 Cloud Base image.

### What is --cloud-init?

The **virt-install** command creates a KVM, Xen, or [LXC][3] guest using **libvirt**. The `--cloud-init` option uses a local file (called a **nocloud datasource**) so you don't need a network connection to create an image. The **nocloud** method derives user data and metadata for the guest from an iso9660 filesystem (an `.iso` file) during the first boot. When you use this option, **virt-install** generates a random (and temporary) password for the root user account, provides a serial console so you can log in and change your password, and then disables the `--cloud-init` option for subsequent boots. 

### Set up a Fedora Cloud Base image

First, [download a Fedora Cloud Base (for OpenStack) image][2].

![Fedora Cloud website screenshot][4]

(Sumantro Mukherjee, [CC BY-SA 4.0][5])

Then install the **virt-install** command:


```
`$ sudo dnf install virt-install`
```

Once **virt-install** is installed and the Fedora Cloud Base image is downloaded, create a small YAML file named `cloudinit-user-data.yaml` to contain a few configuration lines that virt-install will use.


```
#cloud-config
password: 'r00t'
chpasswd: { expire: false }
```

This simple cloud-config sets the password for the default **fedora** user. If you want to use a password that expires, you can set it to expire after logging in.

Create and boot the VM:


```
$ virt-install --name local-cloud18012709 \
\--memory 2000 --noreboot \
\--os-variant detect=on,name=fedora-unknown \
\--cloud-init user-data="/home/r3zr/cloudinit-user-data.yaml" \
\--disk=size=10,backing_store="/home/r3zr/Downloads/Fedora-Cloud-Base-33-1.2.x86_64.qcow2"
```

In this example, `local-cloud18012709` is the name of the virtual machine, RAM is set to 2000MiB, disk size (the virtual hard drive) is set to 10GB, and `--cloud-init` and `backing_store` contain the absolute path to the YAML config file you created and the Qcow2 image you downloaded.

### Log in

After the image is created, you can log in with the username **fedora** and the password set in the YAML file (in my example, this is **r00t**, but you may have used something different). Change your password once you've logged in for the first time.

To power off your virtual machine, execute the `sudo poweroff` command, or press **Ctrl**+**]** on your keyboard.

### Start, stop, and kill VMs

The `virsh` command is used to start, stop, and kill VMs.

To start any VM that is running:


```
`$ virsh start <vm-name>`
```

To stop any running VM:


```
`$ virsh shutdown <vm-name>`
```

To list all VMs that are in a running state:


```
`$ virsh list`
```

To destroy the VMs:


```
`$ virsh destroy <vm-name>`
```

![Destroying a VM][6]

(Sumantro Mukherjee, [CC BY-SA 4.0][5])

### Fast and easy

The **virt-install** command combined with the `--cloud-init` option makes it fast and easy to create cloud-ready images without worrying about whether you have a cloud to run them on yet.  Whether you're preparing for a a major deployment or just learning about containers, give `virt-install --cloud-init` a try.

Do you have a favourite tool for your work in the cloud? Tell us about them in the comments.

--------------------------------------------------------------------------------

via: https://opensource.com/article/21/1/cloud-image-virt-install

作者：[Sumantro Mukherjee][a]
选题：[lujun9972][b]
译者：[译者ID](https://github.com/译者ID)
校对：[校对者ID](https://github.com/校对者ID)

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[a]: https://opensource.com/users/sumantro
[b]: https://github.com/lujun9972
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/bus-cloud.png?itok=vz0PIDDS (Sky with clouds and grass)
[2]: https://alt.fedoraproject.org/cloud/
[3]: https://www.redhat.com/sysadmin/exploring-containers-lxc
[4]: https://opensource.com/sites/default/files/uploads/fedoracloud.png (Fedora Cloud website)
[5]: https://creativecommons.org/licenses/by-sa/4.0/
[6]: https://opensource.com/sites/default/files/uploads/destroyvm.png (Destroying a VM)