MQTT 安裝及web socket設定

MQTT：是一個client server的publish/subscribe訊息交換協定

安裝過程：

wget http://repo.mosquitto.org/debian/mosquitto-repo.gpg.key

sudo apt-key add mosquitto-repo.gpg.key

rm mosquitto-repo.gpg.key

cd /etc/apt/sources.list.d/

sudo wget http://repo.mosquitto.org/debian/mosquitto-jessie.list

sudo apt-get update

sudo apt-get install mosquitto mosquitto-clients
安裝好之後，
其實就會隨著開機啟動MQTT把這台機器也當作Topic Server，
可以做本地端測試

開啟兩個終端機，分別執行下面的1以及2

1.建立Subscriber(訂閱者)，訂閱topic名稱為 TEST_TOPIC
mosquitto_sub -d -t TEST_TOPIC

2.建立Publisher(發布者)，發佈到topic名稱為TEST_TOPIC
mosquitto_pub -d -t TEST_TOPIC -m "Test message. Test message. Test message."

此時在1號終端機，Subscriber應該會看到來自Publisher的訊息

而2號終端機所key的那行指令，若預設沒有加上-h指定topic server，則會以自身當作topic server以及一個publisher的腳色

※ 如果要指定port的話 使用-p 8888 參數
※ console使用的port 和 websocket的port不同
=============================================================

使用js與MQTT溝通
sudo vim /etc/mosquitto/mosquitto.conf

修改內容：
 bind_address localhost
port 9999  #預設MQTT的port

#下面2行是設定給websockets的port
listener 8888
protocol websockets



設完重開
sudo service mosquitto restart

server部份設定完成
===============================================================


sample code: https://github.com/xms/MQTT-Client-with-web-socket

Install mongoDB on ubuntu 14.04 LTS

MongoDB is a NoSQL database intended for storing large amounts of data in document-oriented storage with dynamic schemas. NoSQL refers to a database with a data model other than the tabular format used in relational databases such as MySQL, PostgreSQL, and Microsoft SQL. MongoDB features include: full index support, replication, high availability, and auto-sharding.

Pre-Flight Check

• These instructions are intended for installing MongoDB on a single Ubuntu 14.04 LTS node.
• I’ll be working from a Liquid Web Core Managed Ubuntu 14.04 LTS server, and I’ll be logged in as a non-root user, but with sudo access. For information on giving a user sudo access visit our page on How to Add a User and Grant Root Privileges on Ubuntu 14.04.

Step #1: Setup a the Package Database

First we’ll import the MongoDB public key used by the package management system:

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10

Then we’ll create a list file for MongoDB:

echo 'deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen' | sudo tee /etc/apt/sources.list.d/mongodb.list

Now reload the package database:

sudo apt-get update

Step #2: Install Latest Stable Version MongoDB

At this point, installing MongoDB is as simple as running just one command:

sudo apt-get install -y mongodb-org

If you’d like MongoDB to auto-update with apt-get than you’re done with the installation. But, it’s possible to ‘pin’ the version of MongoDB you just installed to prevent apt-get from auto-updating.

echo "mongodb-org hold" | sudo dpkg --set-selections
echo "mongodb-org-server hold" | sudo dpkg --set-selections
echo "mongodb-org-shell hold" | sudo dpkg --set-selections
echo "mongodb-org-mongos hold" | sudo dpkg --set-selections
echo "mongodb-org-tools hold" | sudo dpkg --set-selections

Step #3: Get MongoDB Running

Start-Up MongoDB

sudo service mongod start

Check MongoDB Service Status

sudo service mongod status

Summary List of Status Statistics (Continuous)

mongostat

Summary List of Status Statistics (5 Rows, Summarized Every 2 Seconds)

mongostat --rowcount 5 2

Enter the MongoDB Command Line

mongo

By default, running this command will look for a MongoDB server listening on port 27017 on the localhost interface.

If you’d like to connect to a MongoDB server running on a different port, then use the –port option. For example, if you wanted to connect to a local MongoDB server listening on port 22222, then you’d issue the following command:

mongo --port 22222

Shutdown MongoDB

sudo service mongod stop

Restart MongoDB

sudo service mongod restart

[ubuntu] nodejs & glup installation guide

ubuntu LTS 14.04

NodeJS: https://tw-hkt.gitbooks.io/blog/content/zai_ubuntu_14__04_shang_an_zhuang_node__js.html

gulp: https://kejyuntw.gitbooks.io/gulp-learning-notes/content/install/Install-README.html

[ubuntu][npm] 安裝node時出現failure might be due to the use of legacy binary "node"

sh: 1: node: not found
npm WARN This failure might be due to the use of legacy binary "node"
npm WARN For further explanations, please read /usr/share/doc/nodejs/README.Debian

解法

sudo apt-get install nodejs-legacy

收工