[Ubuntu] 解决 E: Sub-process /usr/bin/dpkg returned an error code (1)

#mv /var/lib/dpkg/info /var/lib/dpkg/info_old
#mkdir /var/lib/dpkg/info
#apt-get update && apt-get -f install
#mv /var/lib/dpkg/info_old/* /var/lib/dpkg/info

[Linux] 重建SSH服務器 Key

方法如下：

• 刪除ssh_host_*
  
  #rm -rf /etc/ssh/ssh_host*
• 重建ssh_host_key*
  
  #dpkg-reconfigure openssh-server
• 重啟SSH Server
  
  #/etc/init.d/ssh restart

Reference：
[1] 重新生成SSH服务器端密钥方法

[Ubuntu] Ubuntu中QtCreator 使用搜狗輸入法

• 安装
  
  #apt-get install sogoupinyin fcitx-frontend-qt5  fcitx-libs-dev
  #dpkg -i sogoupinyin_2.1.0.0082_amd64.deb

• 重新編譯 fcitx-qt5
  
  #apt-get install cmake
  #export PATH="/opt/Qt5.7.1/5.7/gcc_64/bin":$PATH
  #git clone https://github.com/fcitx/fcitx-qt5
  #cd fcitx-qt5
  #make
  #cp ./platforminputcontext/libfcitxplatforminputcontextplugin.so /opt/Qt5.7.0/Tools/QtCreator/lib/Qt/plugins/platforminputcontexts
• 錯誤處理
• ECMConfig.cmake
  
  #apt install extra-cmake-modules
• Failed to find "GL/gl.h" in "/usr/include/libdrm
  
  #apt-get install libgl1-mesa-dev libglu1-mesa-dev
• Could NOT find XKBCommon
  
  # apt-get install libxcb-xkb-dev
  #wget http://xkbcommon.org/download/libxkbcommon-0.5.0.tar.xz
  #tar -xvf libxkbcommon-0.5.0.tar.xz
  #cd libxkbcommon-0.5.0
  #./configure
  #make
  #make install
• package ‘fcitx-utils’ not found
  
  #apt-get install fcitx-libs-dev

Reference
[1]http://www.codes51.com/article/detail_1465512_6.html

[Ubuntu] Ubuntu 16.04 Server 安裝 desktop

1. 安装 Desktop
#apt-get install xorg lxde-core lterminal

2. 安装字形
#apt-get install xfonts-wqy xfonts-intl-chinese  xfonts-wqy

3. 安装HostOS与GuestOS 复制贴上
#apt-get install open-vm-tools-desktop

[Ubuntu] 將Ubuntu 15.04的網卡(eno1677XXX) 修改回eth0

• 修改grub
#vim /etc/default/grub

GRUB_CMDLINE_LINUX=""
change to
GRUB_CMDLINE_LINUX="net.ifnames=0 biosdevname=0"


• 更新grub
#grub-mkconfig -o /boot/grub/grub.cfg


• 修改interface
#vim /etc/network/interface

auto enoXXXXX
iface enoXXXX inet static

auto eth0
iface eth0 inet static

Reference:
[1] Change default network name (ens33) to old “eth0” on Ubuntu 16.04

[Linux] 常用來監控系統的相關指令

• top / htop
  
  description : 列出Procces/CPU/Memory的使用率
  show items : CPU usage, Memory usage, Swap Memory, Cache Size, Buffer Size, Process PID, User, Commands
• vmstat
  
  //description : Virtual Memory Statistics
  //show items : virtual memory, kernerl threads, disks, system processes, I/O blocks, interrupts, CPU activity
• lsof
  
  //description : 可列出Process所使用的的檔案(fd)
  //show items : disk files, network sockets, pipes, devices and processes
• iotop
  
  //description : 列出Process對IO使用狀態 //show items : DISK READ, DISK WRITE, SWAPIN
• iostat
  
  //description : 列出每顆Disk的IO使用狀態 //show items : tps, read/s, write/s, read, write
• iftop
  
  //description : 列出所有session的網路使用率 //show items : src ip , dst ip , rate( 2s 10s 40s 的平均值 )

Reference:
[1] 20 Command Line Tools to Monitor Linux Performance

[Linux] Monitor Linux系統的各種資源狀態

• 計算網路卡的流量
  
  #cat /sys/class/net/$nic_dev/statistics/$file
  
  $file :
  rx_bytes : 目前已接收的bytes
  tx_bytes : 目前已傳輸的bytes
  rx_packets : 目前已接收的packets
  tx_packets : 目前已傳輸的packets


• 計算網路卡的流量 - Script
  
  #!/bin/sh
  
  INTERVAL=1
  
  nic=$1
  
  while true
  do
      R1=`cat /sys/class/net/$nic/statistics/rx_bytes`
      T1=`cat /sys/class/net/$nic/statistics/tx_bytes`
      sleep $INTERVAL
      R2=`cat /sys/class/net/$nic/statistics/rx_bytes`
      T2=`cat /sys/class/net/$nic/statistics/tx_bytes`
  
      RKBPS=$((($R2 - $R1) / 1024))
      TKBPS=$((($T2 - $T1) / 1024))
  
      echo "TX $nic: $TKBPS kB/s RX $nic: $RKBPS kB/s"
   
  done


• 計算IO的讀寫量
  #cat /proc/PID/io
  
  欄位:
  rchar: number of bytes the process read, using any read-like system call (from files, pipes, tty...).
  wchar: number of bytes the process wrote using any write-like system call.
  syscr: number of read-like system call invocations that the process performed.
  syscr: number of write-like system call invocations that the process performed.
  read_bytes: number of bytes the process directly read from disk.
  write_bytes: number of bytes the process originally dirtied in the page-cache (assuming they will go to disk later).
  cancelled_write_bytes: number of bytes the process "un-dirtied" - e.g. using an "ftruncate" call that truncated pages from the page-cache.

[Ubuntu] KVM啟用SR-IOV功能

Virtual Function I/O - VFIO 

Single Root I/O Virtualization (SR-IOV)

• 確認網卡支援SR-IOV
  
  //選擇要確認的網卡
  #lspci
  ...(省略)
  05:00.0 Ethernet controller: Intel Corporation Ethernet Controller 10-Gigabit X540-AT2 (rev 01)
  ...(省略)
  
  #lspci -s 05:00.0 -vvv | grep "Single Root I/O Virtualization"


• 啟動IOMMU
  
  //編輯 grub (vim /etc/default/grub)
  
  //Intel CPU
  GRUB_CMDLINE_LINUX_DEFAULT="intel_iommu=on"
  
  //AMD CPU
  GRUB_CMDLINE_LINUX_DEFAULT="amd_iommu=on"
  #update-grub
  
  //啟動匯入
  //編輯 ixgbe.conf(/etc/modprobe.d/ixgbe.conf)
  #


• 匯入Driver
  
  //匯入vxlan
  #modprobe vxlan
  
  //匯入pci-stub
  #modprobe pci_stub
  
  // 啟動Virtual Function
  // 方法一：
  // 匯入1G的ko檔，開啟Function。成功開啟後可從ip a看到新的網卡。
  #modprobe -r ixgbe // 移除ixgbe
  #modprobe ixgbe max_vfs=<int> //啟動Virtual Functions功能，<int>根據網卡而定。
  
  //匯入10G的ko檔，開啟Function。成功開啟後可從ip a看到新的網卡。
  #modprobe -r igb // 移除ixgbe
  #modprobe igb max_vfs=<int> //啟動Virtual Functions功能，<int>根據網卡而定。
  
  // 方法二：
  // 取得該張網卡可使用的最大VFS
  // 指令：
  #cat /sys/bus/pci/devices/<DOMAIN:BUS:DEVICE.FUNCTION>/sriov_totalvfs
  

  Ex:
  #cat /sys/bus/pci/devices/0000\:01\:00.0/sriov_totalvfs
  
  取得 01\:00.0 方式：
  #lspci
  
  顯示：
  ...(省略)
  
  01:00.0 Ethernet controller: Intel Corporation I350 Gigabit Network Connection (rev 01)
  
  ...(省略)
  
  // 指定對某實體開啟VF
  // 指令：
  #echo 8 > /sys/bus/pci/devices/<DOMAIN:BUS:DEVICE.FUNCTION>/sriov_numvfs
  
  Ex:
  #echo 8 > /sys/bus/pci/devices/0000\:01\:00.0/sriov_numvfs
  
  

  
  

  
  
  


• 初始化PCI相關設定
  
  //本機器共有兩張支援SR-IOV功能的網卡，假設使用第二張網卡做為本次實驗。
  #lspci | grep "Virtual Function"
  
  顯示：
  ...(省略)
  
  01:00.0 Ethernet controller: Intel Corporation I350 Gigabit Network Connection (rev 01)
  01:00.1 Ethernet controller: Intel Corporation I350 Gigabit Network Connection (rev 01)
  01:10.0 Ethernet controller: Intel Corporation I350 Ethernet Controller Virtual Function (rev 01)
  01:10.1 Ethernet controller: Intel Corporation I350 Ethernet Controller Virtual Function (rev 01)
  ...(省略)
  取得 01:10.1，再取的 vendor和device ID
  #lspci -s 01:10.1 -n
  
  顯示：
  01:10.3 0200: 8086:1520 (rev 01)


• 匯入至 pci-stub
  
  echo "8086 1520" > /sys/bus/pci/drivers/pci-stub/new_id
  echo "0000:01:10.1" > /sys/bus/pci/drivers/igbvf/unbind
  echo "0000:01:10.1" > /sys/bus/pci/drivers/pci-stub/bind
  
  若要取消功能則執行
  
  

  echo "8086 1520" > /sys/bus/pci/drivers/pci-stub/remove_id


• 啟動KVM
  
  #brctl addbr br0
  #tunctl -t tap0
  
  #qemu-system-x86_64 test.img --enable-kvm -netdev tap,id=hostnet0,ifname=vnet0,script=/etc/qemu-ifup -device pci-assign,host=01:10.1 -vnc :0,password -k en-us -monitor stdio
  
  Note :
  /etc/qemu-ifup的功能是綁定default gw的那張網卡，若不是要綁定那張網卡，需修改該script


• 指定某個Virtual Function tagged vlan
  
  //假設 eth0是Physical function，並且 virtual function 1 tagged vlan 2
  //指令：
  #ip link set <pf> vf <vf_index> vlan <vlan id>  qos <pirority> mac  <macaddr>
  
  #ip link set eth0 down
  #ip link set eth0 vf 1 vlan 2
  #ip link set eth0 up
  
  //顯示vf狀態 #ip link show dev eth0
  
  顯示：
  link/ether a0:36:9f:41:8b:e3 brd ff:ff:ff:ff:ff:ff
    vf 0 MAC 9e:21:26:cb:dc:47, vlan 2, spoof checking on, link-state auto
    vf 1 MAC 5e:8c:75:69:c3:19, spoof checking on, link-state auto
    vf 2 MAC 00:00:00:00:00:00, spoof checking on, link-state auto ...(省略)
  
  //啟動KVM，假設virtual function 1 , host=01:10.3
  # qemu-system-x86_64 test.img --enable-kvm -netdev tap,id=hostnet0,script=/etc/qemu-ifup -device pci-assign,host=01:10.3 -vnc :0,1qazxcvb -k en-us -monitor stdio

Reference: 
[1] 英特爾的VT-x、VT-d、VT-c技術概述
[2] KVM 介绍（4）：I/O 设备直接分配和 SR-IOV [KVM PCI/PCIe Pass-Through SR-IOV]
[3] SR-IOV Mode Utilization in a DPDK Environment
[4] PCI_EXPRESS_PASSTHROUGHb
[5] HowTo Set Virtual Network Attributes on a Virtual Function (SR-IOV)

[Ubuntu] There was a problem reading data from the CD-ROM. Please make sure it is in the drive. If retrying does not work, you should check the integrity of your CD-ROM. Failed to copy file from CD-ROM. Retry?

今天使用usb安裝 Ubuntu 14.04到Server一直失敗，且安裝過程一直出現這個錯誤訊息

There was a problem reading data from the CD-ROM. Please make sure it is in the drive. If retrying does not work, you should check the integrity of your CD-ROM.  Failed to copy file from CD-ROM. Retry?

後來發現是 unetbootin搞的鬼，不知道它中間做了什麼事？故只要改用linux dd即可解決該問題。

指令：

dd if=ubuntu-14.04-server-amd64.iso of=/dev/sdb bs=16M

[Ubuntu] KVM+QEMU 使用筆記 (Ubuntu 14.04)

• 安裝指令
  
  #apt-get install qemu-kvm qemu-system libvirt-bin bridge-utils


• 建立Image檔
  qemu-img
  
  check[-q] [-f fmt] [--output=ofmt] [-r [leaks | all]] filename
  
  create [-q] [-f fmt] [-o options] filename [size]
  
  commit [-q] [-f fmt] [-t cache] filename
  
  compare [-f fmt] [-F fmt] [-p] [-q] [-s] filename1 filename2
  
  convert [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-O output_fmt] [-o options] [-s snapshot_id_or_name] [-l snapshot_param] [-S sparse_size] filename [filename2 [...]] output_filename
  
  info [-f fmt] [--output=ofmt] [--backing-chain] filename
  
  map [-f fmt] [--output=ofmt] filename
  
  snapshot [-q] [-l | -a snapshot | -c snapshot | -d snapshot] filename
  
  rebase [-q] [-f fmt] [-t cache] [-p] [-u] -b backing_file [-F backing_fmt] filename
  
  resize [-q] filename [+ | -]size
  
  amend [-q] [-f fmt] -o options filename
  
  [-f fmt] : raw|qcow2|qcow|vmk|cloop
  
  Example:
  qemu-img create -f qcow2 linux.img 5G


• Create Virtual Machine
  qemu-system-{cpu-architecute} [--enable-kvm]  [-smp options] [-boot dev] [-m size] [-cdrom iso] [-soundhw sdev] [-net nic] [-vnc conn] [-k keyboard] [-netdev options] [disk options] [-monitor options] [--enable-kvm]
  
  [--enable-kvm] : 啟動KVM能力，該功能CPU必須支援
      1. #egrep 'vmx|svm' /proc/cpuinfo
  
  [--smp options] :
      1. -smp [current allocation] [,maxcpus=n] [,sockets=n] [,cores=n] [,threads=n]     ( Example : -smp 2,maxcpus=4,sockets=4,cores=2,threads=2 )
  
  [-boot dev] : a, b (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot from network adapter 1-4)
  
  [-m size] : memory size , default M
  
  [-cdrom iso] : 加入 cdrom
  
  [-soundhw sdev] : 加入 sound card
  
  [-vnc conn] :
      1. conn = host:port,password
      2. conn = host:port,tls,x509=/path
      3. conn = host:port,tls,x509verify=/path
  
  [-k keyboard]  keyboard layout
  
  [-netdev options]    
      1. -netdev nic [,vlan=n] [,macaddr=mac] [,model=type] [,name=name] [,addr=addr]
      2. -netdev tap [,vlan=n][,name=name][,fd=h][,ifname=name][,script=file][,downscript=dfile][,helper=helper]
      3. -netdev bridge ,id=id[,br=bridge][,helper=helper] -net bridge[,vlan=n][,name=name][,br=bridge][,helper=helper]
      4. -netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]
      5. -netdev none
   
  [nic] : 建立一個網路卡，並且連接至VLAN n ( n預設為0 )
  [tap] : 連接到host TAP的網路介面
  [bridge] : Bridge 模式，
  [vhost-user]
  [type] : [virtio|i82551|i82557b|i82559er|ne2k_pci|ne2k_isa|pcnet|rtl8139|e1000| smc91c111|lance|mcf_fec]
  
  [disk options] :
      1. -drive file=[path] ,if=none [,id=id_name] [,format=qow2] -device virtio-blk-pci,drive-virtio-disk0,id=virtio-disk0 [,bootindex=1]
      ( Example : -drive file=/images/ubuntu-14.04.img,if=none,id=drive-virtio-disk0,format=qcow2 -device virtio-blk-pci,drive=drive-virtio-disk0,id=virtio-disk-0,bootindex=1 )
  
  
  [-monitor options] :
      1. -monitor stdio
      2. -monitor telnet:[bind_ip]:[port] [,server] [,nowait] [,nodelay]
      ( Example : -monitor telnet::7000, server, nowait, nodelay )
     
  Example 1 : (安裝 Guest OS )
  qemu-system-x86_64 --enable-kvm -smp 2,maxcpus=4,sockets=4,cores=2,threads=2 linux.img -cdrom ubuntu-14.04-server-amd64.iso -boot d -vnc :0,password -k en-us -netdev nic -monitor stdio
  
  


• Virtual Machine相關指令
  
  #telnet  host  port
  
  // 暫停/恢復/重置
  (qemu) stop  #暫停VM
  (qemu) cont #恢復VM
  (qemu) system_reset #重新啟動 VM
  (qemu) system_poweddown  #送ACPI Shutdown request
  (qemu) quit #關閉
  
  // Memory 相關
  (qemu) memsave    #儲存 Virutal memory 資料
  (qemu) pmemsave    #儲存 Physical memory 資料
  
  // Snapshot 相關
  (qemu) savevm name    #建立Snapshot
  (qemu) loadvm name    #恢復Snapshot
  (qemu) delvm    #刪除Snapshot
  (qemu) info snapshot    #顯示可用的Snapshot


• NAT網路設定
  
  //-------Host OS 設定-------
  //安裝 tap tool
  #apt-get install uml-utilities
  
  //KVM Command
  #qemu-system-x86_64 linux.img --enable-kvm -vnc :0,password -k en-us -netdev nic -monitor stdio
  
  // 建立通道
  #tunctl -t tap0
  
  // 設定iptables
  #echo 1 > /proc/sys/net/ipv4/ip_forward
  #iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
  #iptables -I FORWARD 1 -i tap0 -j ACCEPT
  #iptables -I FORWARD 1 -o tap0 -m state --state RELATED,ESTABLISHED -j ACCEPT
  
  //-------Guest OS 設定-------
  ip address : 192.168.100.2
  gateway : 192.168.100.1
  dns : 192.168.100.1


• Bridge網路設定
  
  //-------Host OS 設定-------
  //安裝Bridge
  #apt-get install bridge-utils
  
  //建立Bridge
  #brctl addbr br0
  #brctl addif br0 eth0
  
  //KVM Command
  #qemu-system-x86_64 linux.img --enable-kvm -netdev tap,id=hostnet0,ifname=vnet0,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,id=net0 -vnc :0,password -k en-us -monitor stdio


• 設定VLAN(802.1Q)

  

  VLAN示意圖

  要對某VM送出或進來的封包執行802.1Q，方法很簡單，只需要將VLAN和VNet0以起綁定至br0.2即可，如VLAN示意圖所示。
  
  
  //安裝vlan tools
  #apt-get install vlan
  
  //設定VLAN，假設VLAN為2
  #vconfig add eth0 2
  
  //建立新的Bridge，並且綁定eth0.2
  #brctl addbr br0.2
  #brctl addif br0.2 eth0.2
  
  //修改 /etc/qemu-ifup
  switch=br0.2
  for br in $switch; do
    if [ -d /sys/class/net/$br/bridge/. ];then
      brctl addif $br vnet0
    fi
  done
  
  //KVM Command
  #qemu-system-x86_64 linux.img --enable-kvm -netdev tap,id=hostnet0,ifname=vnet0,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,id=net0 -vnc :0,password -k en-us -monitor stdio

Reference:
[1] 架設Linux KVM虛擬化主機 (Set up Linux KVM virtualization host)
[2] QEMU Emulator User Documentation
[3] Chapter 14. Administrating Virtual Machines with QEMU Monitor
[4] 使用 monitor command 监控 QEMU 运行状态 
[5] Setting up QEMU with a NAT
[6] CentOS + KVM 建立 VLAN 的方式
[7]  KVM虚拟化技术之使用Qemu-kvm创建和管理虚拟机

[Ubuntu] Ubuntu14.04 安裝 Java + Tomcat + Mysql

安裝步驟

• 安裝Java
#apt-get install openjdk-7-jdk


• 安裝Tomcat
#apt-get install tomcat7


• 安裝Mysql
#apt-get install mysql-server libmysql-java


• tomcat7設定檔
#vim /etc/default/tomcat7
JAVA_OPTS="-Djava.security.egd=file:/dev/./urandom -Djava.awt.headless=true -Xmx512m -XX:MaxPermSize=256m -XX:+UseConcMarkSweepGC"


• 預設Tomcat開啟的Port 8080，若想改接收Port 80，可加入以下iptables command
#iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080

Reference :
[1] How To Install Apache Tomcat 7 on Ubuntu 14.04 via Apt-Get

[Ubuntu] Linux 指令筆記

• 將使用者加入Sudoer檔
#sudo adduser sudo


• 使用指定的使用者執行程式
#su -c '${program_name}' ${username}
example:
#su -c 'php test.php' www-data


• 針對某Program發Signal
#ps -aux | grep ${program_name} | grep "grep" -v | awk '{print $2}' | xargs kill -${signal_num}
example:
#ps -aux | grep test.php | grep "grep" -v | awk '{print $2}' | xargs kill -15


• 找尋大於某Size的檔案
#find . -type f -size -4096c
Parameter:
`b' for 512-byte blocks (this is the default if no suffix is used)
`c' for bytes
`w' for two-byte words
`k' for Kilobytes (units of 1024 bytes)
`M' for Megabytes (units of 1048576 bytes)
`G' for Gigabytes (units of 1073741824 bytes)



• 查詢硬體與系統設定的關係
  #lshw
  
  // 查詢網路卡
  #lshw -class network

[STM32] 如何取到STM32 MCU的Serial ID

unsigned int serial_id[3];

serial_id[0] = *((unsigned int *)0x1FFFF7E8));
serial_id[1] = *((unsigned int *)0x1FFFF7EC));
serial_id[2] = *((unsigned int *)0x1FFFF7F0));

Reference:
[1] http://www.keil.com/forum/58081/read-unique-id/

[Network] Routing Table其實不只一個

    最近設計的一套系統，有兩張網卡A、B。而由於使用者的環境因素導致我的Routing Rule不論怎麼設定，封包可能從網卡A進來，但卻從網卡B進到另一個網段，而導致封包回不來之窘境。


這個問題卡好久啊，總算找到解法了。概念其實很簡單，從A網卡進來的封包就走A網卡的Routing Table，而從B網卡進來的封包就走B網卡的Routing Table。而實作方式使用 iproute2。(Ubuntu Linux預設就有這個套件)

以下範例則是參考[1]。假設兩線路ADSL和Cable，希望從ADSL進來的封包就從ADSL的路徑回去，反之一樣，從Cable進來的封包則從Cable回去。

網路環境設定如下：
eth1 192.168.100.50 Gateway 192.168.100.254 --> ADSL
eth2 192.168.200.100 Gateway 192.168.200.254 --> CABLE

設定方式：

1. 新增 Table
   #vim /etc/iproute2/rt_tables
   
   1    ADSL
   2    Cable


2. 各至設定routing rule
   
   // 設定ADSL Routing Table
   #ip route add 192.168.100.0/24 dev eth1 src 192.168.100.50 table ADSL
   #ip route add default via 192.168.100.254 table ADSL
   
   // 設定CABLE Routing Table
   #ip route add 192.168.100.0/24 dev eth1 src 192.168.100.50 table CABLE
   #ip route add default via 192.168.100.254 table CABLE
   
   // 指定從哪張網卡來的封包走哪個Routing Table
   #ip rule add from 192.168.100.50 table ADSL
   #ip rule add from 192.168.200.100 table CABLE
   
   
   // Delete routing rule
   #ip rule del from 192.168.100.50 table ADSL
   #ip rule del from 192.168.200.100 table CABLE
   
   // Show routing by table
   #ip rule show table ADSL
   #ip rule show table CABLE

Reference :
[1] LINUX上的雙網路共享

[Linux] Parser JSON Parser For Linux Command-Line

jq command是一個command-line的processor。

Ubuntu安裝方式如下：

#apt-get install jq

使用方法：

• 取得物件裡的值，Ex1 : {"obj":1, "desc": "object1", "inobj":{"desc":"in-object1"}}
  //取得obj
  #jq '.obj'
  =>1
  
  //取得obj1
  #jq '.obj1'
  =>null
  
  //取得inobj1.desc
  #jq '.inobj.desc'
  =>in-object1
  
  //取得key
  #jq 'keys'
  =>["obj","desc","inobj"]
  
  
  
  
• 取得陣列，Ex2 : [{"obj":1, "desc": "object1"},{"obj":2, "desc": "object2"},{"obj":3, "desc": "object3"}]
  // 取得第一個物件.[0]
  #jq '.[0]'
  =>{"obj":1, "desc": "object1"}
  
  // 取得所有物件.[]
  #jq '.[]'
  =>{"obj":1, "desc": "object1"},{"obj":2, "desc": "object2"},{"obj":3, "desc": "object3"}
  
  // 取得1~2物件.[1:2]
  #jq '.[1:2]'
  =>{"obj":2, "desc": "object2"},{"obj":3, "desc": "object3"}
  
  
  
  

Reference:
[1] https://stedolan.github.io/jq
[2] #man jq

[Python] 在Ubuntu 14.04，使用Python撰寫MySql程式

• 安裝Python 套件
#apt-get install python-mysqldb


• Sample Code
import MySQLdb

try :
    db = MySQLdb.connect("host", "username", "password", "db_name", charset='utf-8')

    sql = "SELECT field1, field2 FROM table"
    cursor = db.cursor()
    cursor.execute(sql)

    results = cursor.fetchall()
    for record in results:
       col1 = record[0]
       col2 = record[1]
       print "%s, %s" % (col1, col2)

    db.close()
except MySQLdb.Error as e:
    print "Error %d: %s" % (e.args[0], e.args[1])

Reference :
[1] 實作Python 連接MySQL 資料庫

[LDAP] 使用 LDAP 管理 Account on Ubuntu 14.04 (使用phpldapadmin)

• 簡介
  LDAP的概念與DNS類似，都是以階層(hierarchical)概念來進行操作與處理。因此，設計一透合適的階層架構圖(Schema)是非常重要的，Schema可以讓LDAP Client知道該如何存取資訊，以及可以定義哪些人符合擁有哪些權限等等資訊。圖一為我所設計的Schema，圖中個縮寫定義如下：
  DIT（Directory Information Tree；目錄資訊樹）
  DC（Domain Country；區域網域）
  OU（Organization Unit；組織單位）
  CN（Common Name；使用者名稱）
  DN（Distinguish Name；識別名稱）
  

圖一 : Schema

• 安裝LDAP和phpldapadmin
  
  #apt-get install slapd ldap-utils
  #apt-get install phpldapadmin apache2 php5 php5-mysql


•  設定sldapd
  
  #dpkg-reconfigure slapd
  
   以下為我採用的設定
  

  • Omit OpenLDAP server configuration? No
  • DNS domain name? example.com.tw
    
  • Organization name? company (or example)
    
  • Administrator password? (phpldapadmin登入用)
    
  • Database backend to use? HDB
  • Remove the database when slapd is purged? Yes
  • Allow LDAPv2 protocol? No

  
  Note: db path : /var/lib/ladp


•  設定 phpldapadmin
  #vim /etc/phpldapadmin/config.php
  
  #指定Host
  $servers->setValue('server','host','127.0.0.1');
  
  #指定DIT
  $servers->setValue('server','base',array('dc=example,dc=com,dc=tw'));
  
  #指定admin
  $servers->setValue('login','bind_id','cn=admin,dc=example,dc=com,dc=tw');


• Connect to phpldapadmin
  
  • WebSite : http://127.0.0.1/phpldapadmin
  • 帳號：cn=admin,dc=example›‹,dc=com,dc=tw
  • 密碼：執行dpkg-reconfiguration時所設定的那組

  

  phpldapadmin



• 安裝並設定 LDAP Client
  #apt-get install libpam-ldap nscd
  #dpkg-reconfigure ldap-auth-config
      注意：LDAP server Uniform Resource Identifier: ldap://{LDAP SERVER}
  #auth-client-config -t nss -p lac_ldap
  #pam-auth-update

• 如果需要使用者登入時，沒有家目錄要自動建立，則設定以下動作
  #vim /etc/pam.d/common-session
  session required pam_mkhomedir.so umask=0022 skel=/etc/skel
  
  
• 重啟Service
  /etc/init.d/nscd restart

Reference :
[1] How To Install and Configure OpenLDAP and phpLDAPadmin on an Ubuntu 14.04 Server

[Ubuntu] 安裝Redmine on Ubuntu14.04

• 安裝Redmine依賴之相關套件
#apt-get install apache2 libapache2-mod-passenger mysql-server mysql-client




設定mysql password

• 安裝Redmine
#apt-get install redmine redmine-mysql


設定Redmine (Yes)



設定Redmine資料庫(MySql)

設定MySql Password

• 安裝Bundler
#gem install bundler

• vim /etc/apache2/mods-available/passenger.conf  



設定內容

• vim /etc/apache2/sites-available/000-default.conf



設定內容

• link redmine source code to web root
#ln -s /usr/share/redmine/public /var/www/html/redmine

• 更改權限
#chown -R www-data:www-data /usr/share/redmine/

• 重啟Apache
#/etc/init.d/apache2 restart

• 開啟Redmine網頁



帳號 : admin
密碼:  admin

Reference :
[1] redmine
[2] installing-redmine-on-ubuntu-14-04

[Ubuntu] Ubuntu 安裝字型

常用的字型:
*中文
ttf-arphic-bkai00mp - 文鼎PL細上海宋 (AR PL Mingti2L Big5)
ttf-arphic-bsmi00lp - 文鼎PL中楷 (AR PL KaitiM Big5)
ttf-arphic-gbsn00lp - 文鼎PL簡報宋 (AR PL SungtiL GB)
ttf-arphic-gkai00mp - 文鼎PL簡中楷 (AR PL KaitiM GB)
ttf-arphic-uming - 文鼎PL上海宋Uni (AR PL ShanHeiSun Uni)
ttf-arphic-ukai- 文鼎PL中楷Uni (AR PL ZenKai Uni)
ttf-arphic-uming - 文鼎 PL 上海宋 Uni, AR PL ShanHeiSun Uni
xfonts-intl-chinese
xfonts-intl-chinese
xfonts-wqy

*日文
ttf-vlgothic
ttf-kochi-gothic
ttf-kochi-mincho

*韓文
ttf-baekmuk
x-ttcidfont-conf


指令:
$ apt-get install ttf-arphic-bkai00mp ttf-arphic-bsmi00lp ttf-arphic-gbsn00lp ttf-arphic-gkai00mp ttf-arphic-uming ttf-arphic-ukai xfonts-intl-chinese xfonts-intl-chinese xfonts-wqy

[Ryu] unsupported version 0x1. If possible, set the switch to use one of the versions [4]

 這個錯誤的意思就是OpenFlow的版本有誤，解決方法就是要設定OVS支援OpenFlow
 

#mn --controller=remote,ip=CTR_IP --topo linear,2 --switch ovsk,protocols=OpenFlow13 
or
#ovs-vsctl set bridge s1 protocols=OpenFlow10,OpenFlow13
#ovs-vsctl set bridge s2 protocols=OpenFlow10,OpenFlow13

而如果執行 ovs-vsctl發以下訊息，那表示你的OVS版本太低了，必須更新OVS。
Bridge does not contain a column whose name matches "protocols"

更新方法：

#wget http://openvswitch.org/releases/openvswitch-2.3.1.tar.gz
#tar -zxvf openvswitch-2.3.1.tar.gz
#cd openvswitch-2.3.1
#./configure --prefix=/usr --with-linux=/lib/modules/`uname -r`/build
#make
#make install
#make modules_install
#rmmod openvswitch
#depmod -a
#/etc/init.d/openvswitch-switch restart

Reference:
[1] Upgrading Open vSwitch