LXC - Linux Containers

2014-01-11

• <參考> ​Creating a virtualized fully-distributed Hadoop cluster using Linux Containers
• 測試環境：Debian Wheezy 7.1 netinstall ISO with ​preseed

  jazz@debian:~$ lsb_release -a
  No LSB modules are available.
  Distributor ID:	Debian
  Description:	Debian GNU/Linux 7.3 (wheezy)
  Release:	7.3
  Codename:	wheezy
  

• 安裝 LXC

  jazz@debian:~$ sudo apt-get install lxc
  

• 產生虛擬機器

  jazz@debian:~$ sudo lxc-create -t debian -n test1
  jazz@debian:~$ sudo lxc-start -d -n test1
  

• 安裝 LXC Web Panel

  root@debian:~# wget http://lxc-webpanel.github.io/tools/install.sh -O - | bash
  

• <狀況> 指令可以建立 LXC VM, 但網頁似乎不太靈光。

2014-01-12

• 測試環境：Ubuntu 12.04 LTS

  jazz@jazzbook:~$ lsb_release -a
  No LSB modules are available.
  Distributor ID:	Ubuntu
  Description:	Ubuntu 12.04.2 LTS
  Release:	12.04
  Codename:	precise
  

• 感覺上 LXC 1.0 的功能比較齊全(Ex. 支援根據 DNS 分配 IP 的機制)，因此直接採用 precise-backports 套件庫中的 lxc 1.0 版本

  echo "deb http://free.nchc.org.tw/ubuntu precise-backports main universe" > /tmp/precise-backport.list
  sudo mv /tmp/precise-backport.list /etc/apt/sources.list.d/
  sudo apt-get update
  

• 安裝 LXC 1.0 版本

  sudo apt-get install lxc
  

  jazz@jazzbook:~$ lxc-version 
  lxc version: 1.0.0.alpha1
  

• 根據 /etc/default/lxc-net 的說明，可以設定一個檔案，來根據 hostname 決定 IP 分配

  # Uncomment the next line if you'd like to use a conf-file for the lxcbr0
  # dnsmasq.  For instance, you can use 'dhcp-host=mail1,10.0.3.100' to have
  # container 'mail1' always get ip address 10.0.3.100.
  #LXC_DHCP_CONFILE=/etc/lxc/dnsmasq.conf
  

  jazz@jazzbook:~$ sudo su -
  root@jazzbook:~# echo "LXC_DHCP_CONFILE=/etc/lxc/dnsmasq.conf" >> /etc/default/lxc-net
  root@jazzbook:~# cat > /etc/lxc/dnsmasq.conf << EOF
  dhcp-host=hdp11,10.0.1.111
  dhcp-host=hdp12,10.0.1.112
  dhcp-host=hdp13,10.0.1.113
  dhcp-host=hdp14,10.0.1.114
  dhcp-host=hdp15,10.0.1.115
  dhcp-host=hdp16,10.0.1.116
  dhcp-host=hdp17,10.0.1.117
  dhcp-host=hdp18,10.0.1.118
  dhcp-host=hdp19,10.0.1.119
  dhcp-host=hdp20,10.0.1.120
  dhcp-host=hdp21,10.0.1.121
  dhcp-host=hdp22,10.0.1.122
  dhcp-host=hdp23,10.0.1.123
  dhcp-host=hdp24,10.0.1.124
  dhcp-host=hdp25,10.0.1.125
  dhcp-host=hdp26,10.0.1.126
  dhcp-host=hdp27,10.0.1.127
  dhcp-host=hdp28,10.0.1.128
  dhcp-host=hdp29,10.0.1.129
  dhcp-host=hdp30,10.0.1.130
  EOF
  

• 建立 20 個 VM 的主機名稱對應(hostname)

  root@jazzbook:~# cat >> /etc/hosts << EOF
  # for LXC
  10.0.1.111	hdp11
  10.0.1.112      hdp12
  10.0.1.113      hdp13
  10.0.1.114      hdp14
  10.0.1.115      hdp15
  10.0.1.116      hdp16
  10.0.1.117      hdp17
  10.0.1.118      hdp18
  10.0.1.119      hdp19
  10.0.1.120      hdp20
  10.0.1.121      hdp21
  10.0.1.122      hdp22
  10.0.1.123      hdp23
  10.0.1.124      hdp24
  10.0.1.125      hdp25
  10.0.1.126      hdp26
  10.0.1.127      hdp27
  10.0.1.128      hdp28
  10.0.1.129      hdp29
  10.0.1.130      hdp30
  EOF
  

• 為了讓根據 DNS 主機名稱對應分配 IP 的機制生效，必須重新啟動 lxc-net

  root@jazzbook:~# /etc/init.d/lxc restart
  root@jazzbook:~# /etc/init.d/lxc-net restart
  

• 先建立五個 LXC VM 試試看

  root@jazzbook:~# for ((i=11;i<=15;i++)); do lxc-create -t ubuntu -n hdp$i; done
  
  Checking cache download in /var/cache/lxc/precise/rootfs-i386 ... 
  Copy /var/cache/lxc/precise/rootfs-i386 to /usr/lib/i386-linux-gnu/lxc ... 
  Copying rootfs to /usr/lib/i386-linux-gnu/lxc ...
  /bin/bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8)
  Generating locales...
    en_US.UTF-8... done
  Generation complete.
  Creating SSH2 RSA key; this may take some time ...
  Creating SSH2 DSA key; this may take some time ...
  Creating SSH2 ECDSA key; this may take some time ...
  
  ##
  # The default user is 'ubuntu' with password 'ubuntu'!
  # Use the 'sudo' command to run tasks as root in the container.
  ##
  

• 從以上訊息可以得知，預設的帳號密碼都是 ubuntu
• 啟動 5 個 LXC VM

  root@jazzbook:~# for ((i=11;i<=15;i++)); do lxc-start -d -n hdp$i; done
  

• 用 lxc-ls 查詢分配到的 IP 位置，看樣子 LXC_DHCP_CONFILE 的設定沒啥用 :P

  root@jazzbook:~# lxc-ls --fancy
  NAME   STATE    IPV4        IPV6  AUTOSTART  
  -------------------------------------------
  hdp11  RUNNING  10.0.3.232  -     NO         
  hdp12  RUNNING  10.0.3.119  -     NO         
  hdp13  RUNNING  10.0.3.201  -     NO         
  hdp14  RUNNING  10.0.3.210  -     NO         
  hdp15  RUNNING  10.0.3.243  -     NO       
  

• 看樣子跟 /var/lib/misc/dnsmasq.lxcbr0.leases 有關，因此清除該檔案，再重來一次

  service lxc-net stop
  rm /var/lib/misc/dnsmasq.lxcbr0.leases 
  service lxc-net start
  

  root@jazzbook:~# for ((i=11;i<=15;i++)); do lxc-stop -n hdp$i; done
  root@jazzbook:~# for ((i=11;i<=15;i++)); do lxc-destroy -n hdp$i; done
  root@jazzbook:~# for ((i=11;i<=15;i++)); do lxc-create -t ubuntu -n hdp$i; done
  root@jazzbook:~# for ((i=11;i<=15;i++)); do lxc-start -d -n hdp$i; done
  

• <結果> 一樣還是沒有照 hostname 分配 IP ..... XD

  root@jazzbook:~# lxc-ls --fancy
  NAME   STATE    IPV4        IPV6  AUTOSTART  
  -------------------------------------------
  hdp11  RUNNING  10.0.3.238  -     NO         
  hdp12  RUNNING  10.0.3.36   -     NO         
  hdp13  RUNNING  10.0.3.72   -     NO         
  hdp14  RUNNING  10.0.3.214  -     NO         
  hdp15  RUNNING  10.0.3.9    -     NO   
  

• 安裝 LXC Web Panel

  root@jazzbook:~# wget http://lxc-webpanel.github.io/tools/install.sh -O - | bash
  

• 金鑰交換

  root@jazzbook:~# ssh-keygen
  root@jazzbook:~# for ((i=11;i<=15;i++)); do mkdir -p /var/lib/lxc/hdp$i/rootfs/root/.ssh; done
  root@jazzbook:~# for ((i=11;i<=15;i++)); do cp /root/.ssh/id_rsa.pub /var/lib/lxc/hdp$i/rootfs/root/.ssh/authorized_keys; done
  

• 安裝與設定 dsh

  root@jazzbook:~# apt-get install dsh
  root@jazzbook:~# mkdir -p .dsh
  root@jazzbook:~# lxc-ls --fancy | grep hdp | awk '{ print $3 }' > .dsh/machines.list
  root@jazzbook:~# dsh -a hostname
  hdp11
  hdp12
  hdp13
  hdp14
  hdp15
  

LXC PXE Boot ?

• <問題> LXC 可以支援 PXE 開機嘛？
• 找了些參考資料，似乎多半都是讓 LTSP 或讓 PXE Boot Client 可以支援 lxc