docker daemon proxy 設定 on CentOS 6

1. 編輯 docker daemon 設定檔，設定 docker daemon 的 proxy
   

   # vim /etc/sysconfig/docker
   other_args=
   export HTTP_PROXY="http://<ip>:<port>"
   export HTTPS_PROXY="https://<ip>:<port>"

2. 重新啟動 docker daemon
   

   # service docker restart

3. 搜尋 coreos image
   

   # docker search coreos
   NAME                                      DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
   tnolet/mesos-on-coreos                                                                    2                    [OK]
   monder/coreos-nginx                                                                       2                    [OK]
   million12/linode-coreos-api               Deploy CoreOS on Linode.                        1                    [OK]
   shift/coreos-ubuntu-etcd                                                                  1                    [OK]

4. 下載 coreos image
   

   # docker pull tnolet/mesos-on-coreos

參考資料：

• [Stack Overflow] Cannot download Docker images behind a proxy
• Running Docker on CentOS behind a proxy

Install Docker on CentOS 6.4

1. 安裝 EPEL repository repository
   

   #  wget http://mirror-fpt-telecom.fpt.net/fedora/epel/6/i386/epel-release-6-8.noarch.rpm
   # rpm -ivh epel-release-6-8.noarch.rpm

2. 執行 yum update 出現錯誤訊息：Error: Cannot retrieve metalink for repository: epel. Please verify its path and try again
   

   # yum update
   Loaded plugins: fastestmirror, security
   Determining fastest mirrors
   Error: Cannot retrieve metalink for repository: epel. Please verify its path and try again

3. 修改「/etc/yum.repos.d/epel.repo」設定
   將 baseurl 前面的 # 拿掉，mirrirlist 前面加上 #
   

   baseurl=http://download.fedoraproject.org/pub/epel/6/$basearch
   #mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-6&arch=$basearch

4. 安裝 Docker
   

   # yum install docker-io

5. 啟動 Docker
   

   # service docker start

6. 設定開機時自動啟動 Docker
   

   # chkconfig docker on

參考資料：

• Installing Docker - CentOS-6
• 在Centos 5.x或6.x上安装RHEL EPEL Repo

利用 chromecast 把 iphone 上的 youtube 影片投放到電視上

1. 開啟 iphone Chromecast app
2. 選取想要連結的 chromecast 裝置
   
   
   
   
3. 開啟 iphone YouTube app，選擇想看的影片，點選影片上的投放標誌
   
   
4. 選擇 chromecast 裝置
   
5. 影片即開始在電視上撥放

用 iphone 啟用 chromecast

參考 chromecast 包裝上的 Getting Started 步驟，將 chromecast 裝置連結電源，插入電視的 HDMI 插槽，切換電視的輸入設定後，開始進行 chromecast 裝置初始設定。

1. 開啟 iphone Chrome app ，網址列輸入「chromecast.com/setup」
2. 安裝 iphone Chromecast app
3. 安裝完成後，開啟 Chromecast app
4. Chromecast app 會自動尋找你的 Chromecast 裝置，第一次設定請選設定新的 CHROMECAST
   
5. 根據提示選擇 chromecast 裝置的 Wi-Fi，與 chromecast 裝置連線
   
   
6. 返回 iphone Chromecast app 會發現已與 chromecast 裝置連線。接著驗證 chromecast，確認手機與電視是否看到一樣的代碼，如是的話，點選「我看到這個驗證碼了」
   
7. 開始 chromecast 裝置初始設定，設定區域「台灣」，設定名稱，設定網路
8. chromecast 裝置連上網路後會進行更新，更新後會重新啟動，需要等待一下
9. 完成後開啟 iphone Chromecast app 選取你的 chromecast 裝置，即可開始投放
10. 更多 chromecast 資訊可以參考「chromecast.com/learn」

Norikra 試用紀錄

Norikra is a open source server software provides "Stream Processing" with SQL, written in JRuby, runs on JVM, licensed under GPLv2.

1. install JRuby (downloads)

# tar xzvf jruby-bin-1.7.15.tar.gz
# mv jruby-1.7.15 /opt
# echo "PATH=$PATH:/opt/jruby-1.7.15/bin" > ~/.bashrc
# jruby -v
jruby 1.7.15 (1.9.3p392) 2014-09-03 82b5cc3 on Java HotSpot(TM) 64-Bit Server VM 1.6.0_33-b04 +jit [linux-amd64]

2. install Norikra (要等個幾分鐘才會開始裝)

# gem install norikra

3. start Norikra (要等個幾分鐘才會啟動成功)

# norikra start

4. Norikra web UI ：http://IP:26578
5. 以 web service 的 log 為例，首先定義 target 的欄位 (minimal fields set for variations of 'www' events)，定義最基本的欄位就好，可再修改

# norikra-client target open www path:string status:integer referer:string agent:string userid:integer
# norikra-client target list
TARGET  AUTO_FIELD
www     true
1 targets found.

6. 加入 query 指令：查詢首頁(path="/")被存取的次數

# norikra-client query add www.toppage 'SELECT count(*) AS cnt FROM www WHERE path="/" AND status=200'

7. 加入 query 指令 with Views (Windows)。Views are used to define time windows or to control timing to fire events. With views, norikra controls the range of events for each queries.

# norikra-client query add www.toppageviews 'SELECT count(*) AS cnt FROM www.win:time_batch(3 sec) WHERE path="/" AND status=200'

8. 開始將資料送到 norikra
• script

#!/bin/sh
for i in `seq 1 1 3`;
do
  data1='{"path":"/", "status":200, "referer":"", "agent":"MSIE", "userid":3}'
  echo `date +"%Y/%m/%d-%H:%M:%S"` $data1
  echo $data1 | norikra-client event send www
  sleep 3
  #
  data2='{"path":"/login", "status":301, "referer":"/", "agent":"MSIE", "userid":3}'
  echo `date +"%Y/%m/%d-%H:%M:%S"` $data2
  echo $data2 | norikra-client event send www
  sleep 3
  #
done

• log

2014/09/17-23:07:58 {"path":"/", "status":200, "referer":"", "agent":"MSIE", "userid":3}
2014/09/17-23:08:13 {"path":"/login", "status":301, "referer":"/", "agent":"MSIE", "userid":3}
2014/09/17-23:08:29 {"path":"/", "status":200, "referer":"", "agent":"MSIE", "userid":3}
2014/09/17-23:08:45 {"path":"/login", "status":301, "referer":"/", "agent":"MSIE", "userid":3}
2014/09/17-23:09:00 {"path":"/", "status":200, "referer":"", "agent":"MSIE", "userid":3}
2014/09/17-23:09:16 {"path":"/login", "status":301, "referer":"/", "agent":"MSIE", "userid":3}

9. 查看 query 結果

# norikra-client event see www.toppage
{"time":"2014/09/17 23:08:10","cnt":1}
{"time":"2014/09/17 23:08:41","cnt":2}
{"time":"2014/09/17 23:09:13","cnt":3}

# norikra-client event see www.toppageviews
{"time":"2014/09/17 23:08:13","cnt":1}
{"time":"2014/09/17 23:08:16","cnt":0}
{"time":"2014/09/17 23:08:43","cnt":1}
{"time":"2014/09/17 23:08:46","cnt":0}
{"time":"2014/09/17 23:09:16","cnt":1}
{"time":"2014/09/17 23:09:19","cnt":0}

10. 取得 query 結果，取到的結果會被刪除，如沒有新的事件發生，再查看 query 結果是沒有資料的

# norikra-client event fetch www.toppageviews
{"time":"2014/09/17 23:08:13","cnt":1}
{"time":"2014/09/17 23:08:16","cnt":0}
{"time":"2014/09/17 23:08:43","cnt":1}
{"time":"2014/09/17 23:08:46","cnt":0}
{"time":"2014/09/17 23:09:16","cnt":1}
{"time":"2014/09/17 23:09:19","cnt":0}

# norikra-client event fetch www.toppageviews

心得：

• 易上手，定義 data set 後，寫少少的程式(SQL)就可開始做資料處理。
• 具備排程功能，資料處理的動作可以 run forever，可設定對全部的資料做處理或者一次處理一段時間內的資料，因資料皆存在 memory 中，對全部的資料做處理時要注意 out of memory 的問題。
• 安裝簡單，單機作業，無資料分散 or 運算分散的架構(ex: storm)。
• 目前無考慮 HA，作者說也不需要考慮。
• 想想適合用在哪裡？複雜多樣的小資料收集與前處理，定期 fetch 處理結果 or 一前處理完就往其他地方匯出，清空主機 memory。

參考資料：

• Norikra 官網
• Installing jRuby for Centos

install python 2.7 & virtualenv on CentOS 6

1. 安裝 gcc

# yum install gcc gcc-c++.x86_64 compat-gcc-34-c++.x86_64 openssl-devel.x86_64 zlib*.x86_64

2. Build Python-2.7 (downloads)

# wget https://www.python.org/ftp/python/2.7.8/Python-2.7.8.tgz
# tar zxvf Python-2.7.8.tgz
# cd Python-2.7.8
# ./configure --enable-shared
# make
# make install

3. 載入動態資料庫

# touch /etc/ld.so.conf.d/python2.7.conf
# vim /etc/ld.so.conf.d/python2.7.conf
/usr/local/lib
# ldconfig

4. install virtualenv

# python-pip install virtualenv

5. 利用 virtualenv 建立 python 2.7 的開發環境 (因為 CentOS 6 預設的 python 版本為 2.6，預設的版本最好不要亂改)

# virtualenv fayeENV --python=python2.7
# source fayeENV/bin/activate
# python
Python 2.7.8 (default, Sep 17 2014, 15:35:06)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>

6. 離開 python 2.7 開發環境

# deactivate

參考資料：

• How to install Python 2.7 and Python 3.3 on CentOS 6
• virtualenv 官網
• Python 開發好幫手 – virtualenv
• Centos 6.4 python 2.6 升级到 2.7

install python-pip on CentOS 6

Python 套件管理工具

1. turn on EPEL repo for CentOS

# wget http://mirror-fpt-telecom.fpt.net/fedora/epel/6/i386/epel-release-6-8.noarch.rpm
# rpm -ivh epel-release-6-8.noarch.rpm

2. install python-pip

# yum install python-pip

3. 完成安裝，之後可用下列指令安裝 python 套件

# python-pip install <package_name>

參考資料：

• Linux: Install pip Client To Install Python Packages
• CentOS / RHEL / Scientific Linux 6 Enable & Install EPEL Repo