搭建Ubuntu Cloud
qemu启动ubuntu
分两种：uefi和正常启动
https://gist.github.com/george-hawkins/16ee37063213f348a17717a7007d2c79
https://gist.github.com/tpaskhalis/1e601200da499508f9a8502493091f52
默认方式无法登陆的，用ssh有两种方式将公钥传递给vm，一种是mount img再复制，另一种是
在cloud.txt中写入
方法一
$ whoami
ghawkins
$ cat ~/.ssh/id_rsa.pub
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC...
$ cat > cloud.txt << EOF
#cloud-config
users:
- name: ghawkins
ssh-authorized-keys:
- ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC...
sudo: ['ALL=(ALL) NOPASSWD:ALL']
groups: sudo
shell: /bin/bash
EOF
$ cloud-localds cloud.img cloud.txt
方法二
# Instructions for working with QEMU image come from
# https://www.kumari.net/index.php/system-adminstration/49-mounting-a-qemu-image
1. Download image http://cloud-images.ubuntu.com/
2. Install qemu, nbd-client
3. Load the module
sudo modprobe nbd max_part=8
4. Connect image
sudo qemu-nbd --connect=/dev/nbd0 Downloads/xenial-server-cloudimg-amd64-disk1.img
5. Mount image
sudo mount /dev/nbd0p1 /mnt/cd
6. Add the content of ~/.ssh/id_rsa.pub to /mnt/cd/home/ubuntu/.ssh/authorized_keys
7. Unmount image
sudo umount /mnt/cd
8. Disconnect the image
sudo nbd-client -d /dev/nbd0
增加img大小
默认的文件系统超级小，所以要增加
https://help.ubuntu.com/community/UEC/Images
## Install a necessary packages
$ sudo apt-get install kvm cloud-utils genisoimage
## URL to most recent cloud image of 12.04
$ img_url="http://cloud-images.ubuntu.com/server/releases/12.04/release"
$ img_url="${img_url}/ubuntu-12.04-server-cloudimg-amd64-disk1.img"
## download the image
$ wget $img_url -O disk.img.dist
## Create a file with some user-data in it
$ cat > my-user-data <<EOF
#cloud-config
password: passw0rd
chpasswd: { expire: False }
ssh_pwauth: True
EOF
## Convert the compressed qcow file downloaded to a uncompressed qcow2
$ qemu-img convert -O qcow2 disk.img.dist disk.img.orig
## Resize the image to 52G from original image of 2G
$ qemu-img resize disk.img.orig +50G
## create the disk with NoCloud data on it.
$ cloud-localds my-seed.img my-user-data
## Create a delta disk to keep our .orig file pristine
$ qemu-img create -f qcow2 -b disk.img.orig disk.img
## Boot a kvm
$ kvm -net nic -net user -hda disk.img -hdb my-seed.img -m 512
