Openstack之路（八）創建雲主機鏡像

• 準備CentOS-7.x鏡像，可以從網上直接下載，我這裏準備的鏡像是CentOS-7.2-x86_64

[root@linux-node1 ~]# ls -l /tmp/CentOS-7-x86_64-DVD-1511.iso
-rw-r--r-- 1 root root 4329570304 Jan  7  2016 /tmp/CentOS-7-x86_64-DVD-1511.iso

• 安裝相關軟件

[root@linux-node1 ~]# yum -y install qemu-kvm libvirt virt-install
[root@linux-node1 ~]# rpm -qa qemu-kvm libvirt virt-install
libvirt-3.2.0-14.el7_4.5.x86_64
qemu-kvm-1.5.3-141.el7_4.4.x86_64
virt-install-1.4.1-7.el7.noarch

• 啓動libvirtd，會自動創建虛擬網卡virbr0，默認地址爲192.168.122.1

[root@linux-node1 ~]# systemctl start libvirtd
[root@linux-node1 ~]# systemctl status libvirtd
[root@linux-node1 ~]# ifconfig virbr0
virbr0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        inet 192.168.122.1  netmask 255.255.255.0  broadcast 192.168.122.255
        ether 00:00:00:00:00:00  txqueuelen 0  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

• 創建虛擬磁盤，”-f”指定磁盤格式qcow2，存放路徑/opt/CentOS-7.2_x86_64.qcow2，磁盤大小10G

[root@linux-node1 ~]# qemu-img create -f qcow2 /opt/CentOS-7.2-x86_64.qcow2 10G
Formatting '/opt/CentOS-7.2-x86_64.qcow2', fmt=qcow2 size=10737418240 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
[root@linux-node1 ~]# ls -l /opt/CentOS-7.2-x86_64.qcow2
-rw-r--r-- 1 root root 196768 Jan 23 14:39 /opt/CentOS-7.2-x86_64.qcow2

• 創建雲主機

[root@linux-node1 ~]# virt-install --virt-type kvm --name CentOS-7.2 --ram 1024 \
--disk /opt/CentOS-7.2-x86_64.qcow2,format=qcow2 \
--network network=default \
--graphics vnc,listen=0.0.0.0 --noautoconsole \
--os-type=linux --os-variant=centos7.0 \
--location=/tmp/CentOS-7-x86_64-DVD-1511.iso

• 通過TightVNS工具連接192.168.56.11:5900（默認端口是5900），接下來的步驟和我們平時安裝系統沒有什麼區別，注意，只分根分區，不需要分交換分區。

• 啓動雲主機，並查看狀態

[root@linux-node1 ~]# virsh start CentOS-7.2
Domain CentOS-7.2 started
[root@linux-node1 ~]# virsh list --all
 Id    Name                           State
----------------------------------------------------
 2     CentOS-7.2                     running

• 通過TightVNS工具連接192.168.56.11:5900，配置雲主機網絡

DNS配置

[root@localhost ~]# echo -e "nameserver 114.114.114.114\nnameserver 202.96.128.86" > /etc/resolv.conf
[root@localhost ~]# cat /etc/resolv.conf
nameserver 114.114.114.114
nameserver 202.96.128.86

網卡配置

[root@localhost ~]# vi /etc/sysconfig/network-scripts/ifcfg-eth0
TYPE=Ethernet
BOOTPROTO=dhcp
IPV4_FAILURE_FATAL=no
NAME=eth0
DEVICE=eth0
ONBOOT=yes

[root@localhost ~]# systemctl stop NetworkManager
[root@localhost ~]# systemctl status NetworkManager
[root@localhost ~]# systemctl disable NetworkManager

[root@localhost ~]# systemctl restart netwrok
[root@localhost ~]# systemctl status netwrok

• 關閉firewalld，selinux，postfix等服務

[root@localhost ~]# systemctl stop firewalld
[root@localhost ~]# systemctl status firewalld
[root@localhost ~]# systemctl disable firewalld

[root@localhost ~]# setenforce 0
[root@localhost ~]# getenforce
Permissive
[root@localhost ~]# sed -i 's#SELINUX=enforcing#SELINUX=disabled#g' /etc/selinux/config

[root@localhost ~]# systemctl stop postfix
[root@localhost ~]# systemctl status postfix
[root@localhost ~]# systemctl disable postfix

• 設置系統文件描述符數

[root@localhost ~]# ulimit -SHn 65535
[root@localhost ~]# ulimit -n
65535
[root@localhost ~]# echo "*               -       nofile          65535" >> /etc/security/limits.conf

• 設置系統字符集

[root@localhost ~]# vi /etc/locale.conf
LANG="en_US.UTF-8"

• 更新國內yum源

aliyun

[root@localhost ~]# curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

epel

[root@localhost ~]# wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo

• 安裝必要的軟件包

[root@localhost ~]# yum -y install lrzsz vim dos2unix telnet nmap nc net-tools ntpdate wget screen tree

• 安裝ACPI服務，支持關閉和重啓雲主機實例

[root@localhost ~]# yum -y install acpid
[root@localhost ~]# systemctl enable acpid

• 同步網絡時間服務器

[root@localhost ~]# ntpdate 0.pool.ntp.org
[root@localhost ~]# hwclock
[root@localhost ~]# crontab -e
####Synchronization Network Time Server####
*/5 * * * * /usr/sbin/ntpdate 0.pool.ntp.org &>/dev/null

• 編寫鏡像初始化腳本

[root@localhost ~]# vim /tmp/system_init.sh
#!/bin/bash
# Name：system_init.sh
# Version：V1.0
# Type：system_init
# Language：Bash Shell
# Date：2018-01-25
# Author：LinBin
# Email：[email protected]

set_key() {
# Determine whether the file exists
if [ ! -d /root/.ssh ]
  then
    mkdir -p /root/.ssh
    chmod 700 /root/.ssh
fi

# Fetch public key using HTTP
for ((i=1;i<6;i++))
do
  if [ ! -f /root/.ssh/authorized_keys ]
    then
      curl -f http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key > /tmp/metadata-key 2>/dev/null
      if [ $? -eq 0 ]
        then
          cat /tmp/metadata-key >> /root/.ssh/authorized_keys
          chmod 0600 /root/.ssh/authorized_keys
          restorecon /root/.ssh/authorized_keys
          rm -f /tmp/metadata-key
          echo "Successfully retrieved public key from instance metadata"
          echo "*****************"
          echo "AUTHORIZED KEYS"
          echo "*****************"
          cat /root/.ssh/authorized_keys
          echo "*****************"
     fi
  else
    break;
  fi
done
}

# Set the system host name
set_hostname() {
    Hostname=$(curl -s http://169.254.169.254/latest/meta-data/hostname)
    echo "$Hostname" > /etc/hostname
    hostnamectl set-hostname $(echo "$Hostname")
}

# Set static ip address
set_static_ip() {
    IP=$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)
    cat > /etc/sysconfig/network-scripts/ifcfg-eth0 <<EOF
TYPE=Ethernet
BOOTPROTO=static
NAME=eth0
DEVICE=eth0
ONBOOT=yes
IPADDR=$IP
PREFIX=24
GATEWAY=192.168.56.2
DNS1=114.114.114.114
DNS2=202.96.128.86
EOF
}

# Reboot the instance
reboot_instance() {
    rm -f /tmp/system_init.sh
    sed -i '$d' /etc/rc.local
    reboot
}

# Main function
main() {
    set_key;
    set_hostname;
    set_static_ip;
    reboot_instance;
}

# Executive main function
main

• 設置/etc/rc.local文件的執行權限，並添加鏡像初始化腳本

[root@localhost ~]# ls -l /etc/rc.local
lrwxrwxrwx 1 root root 13 Jan 20 13:24 /etc/rc.local -> rc.d/rc.local
[root@localhost ~]# ls -l /etc/rc.d/rc.local
-rw-r--r-- 1 root root 473 Oct 20 11:07 /etc/rc.d/rc.local
[root@localhost ~]# chmod +x /etc/rc.d/rc.local
[root@localhost ~]# ls -l /etc/rc.d/rc.local
-rwxr-xr-x 1 root root 473 Oct 20 11:07 /etc/rc.d/rc.local

[root@localhost ~]# echo "/bin/bash /tmp/system_init.sh" >> /etc/rc.local
[root@localhost ~]# tail -1 /etc/rc.local
/bin/bash /tmp/system_init.sh

• 關閉雲主機，並查看狀態

[root@linux-node1 ~]# virsh shutdown CentOS-7.2
Domain CentOS-7.2 is being shutdown

[root@linux-node1 ~]# virsh list --all
 Id    Name                           State
----------------------------------------------------
 -     CentOS-7.2                     shut off

• 獲得admin憑證來獲取只有管理員能執行的命令的訪問權限

[root@linux-node1 ~]# source admin-openrc

• 上傳鏡像到鏡像服務並設置公共可見，這樣所有的項目都可以訪問它

[root@linux-node1 ~]# openstack image create "CentOS-7.2-x86_64" \
--file /opt/CentOS-7.2-x86_64.qcow2 \
--disk-format qcow2 --container-format bare \
--public
+------------------+------------------------------------------------------+
| Field            | Value                                                |
+------------------+------------------------------------------------------+
| checksum         | 9a6d3efdd6874d4aa8ad555e9752b012                     |
| container_format | bare                                                 |
| created_at       | 2018-01-25T11:44:35Z                                 |
| disk_format      | qcow2                                                |
| file             | /v2/images/18587404-efaa-4c9d-bd88-682a835933db/file |
| id               | 18587404-efaa-4c9d-bd88-682a835933db                 |
| min_disk         | 0                                                    |
| min_ram          | 0                                                    |
| name             | CentOS-7.2-x86_64                                    |
| owner            | 14055178975d417987c5a94f030c7acf                     |
| protected        | False                                                |
| schema           | /v2/schemas/image                                    |
| size             | 1196359680                                           |
| status           | active                                               |
| tags             |                                                      |
| updated_at       | 2018-01-25T11:44:57Z                                 |
| virtual_size     | None                                                 |
| visibility       | public                                               |
+------------------+------------------------------------------------------+

• 確認鏡像的上傳並驗證屬性

[root@linux-node1 ~]# openstack image list
+--------------------------------------+-------------------+--------+
| ID                                   | Name              | Status |
+--------------------------------------+-------------------+--------+
| 18587404-efaa-4c9d-bd88-682a835933db | CentOS-7.2-x86_64 | active |
| cd96090c-87ca-4eb3-b964-a7457639bc1e | cirros            | active |
+--------------------------------------+-------------------+--------+