Quick Tip : Installing Ruby 2.7 and Node 12 on RH8

Installing Ruby and Node on Redhat 8

Quick tip on how to install Ruby 2.7 and Nodejs 12 on Redhat 8, as it can default to older versions.

# Enable new versions
dnf -y module reset ruby nodejs
dnf -y module enable ruby:2.7 nodejs:12

# Install
dnf install nodejs ruby

# Check installed versions
ruby --version
node --version
npm --version

Installing Ruby Rails on Manjaro Linux

Thought I'd give Rails another go on my newly created Manjaro Linux VM.

After filling in a couple of required packages the above screenshot shows it firing through the Rails install.

To get to this stage I did the following;

sudo pacman -S base-devel ruby sqlite3 nodejs
Added /home/alastair/.gem/ruby/2.1.0/bin to my path in .bashrc
gem install rails
gem install execjs

After a few minutes got the following successful install

Now to dig out that Rails tutorial I was working through.

Update,
Turns out can't start a rails server do it a missing JavaScript Runtime, bit more searching require.

Update2,
Found the answer on the Arch Linux Wiki which worked updated the instructions above.

sudo pacman -S nodejs

Success

Doodle's Geek Monkey by Alastair Montgomery

No static external IP on Raspberry Pi

My Internet provider doesn't supply me with a static IP address with my broadband, so my Raspberry Pi external web address can wander if my router or connectigets reset. There are third party sites which will provide you with a static URL which follows your wandering IP address but its fun to do it yourself.

To keep me updated on the current IP I wrote a Ruby script which I run via crontab to check and Tweet me is the IP address changes.


#!/usr/bin/ruby

require 'open-uri'

require 'twitter'



twitDM = "twitter_username"



remote_ip = open('http://whatismyip.akamai.com').read

old_ip = File.open('remote_ip.txt', 'r').read



if (remote_ip != old_ip) then

    File.open('remote_ip.txt', "w") { |file|  file.write(remote_ip)}



    client = Twitter::REST::Client.new do |config|

      config.consumer_key        = "xxxx"

      config.consumer_secret     = "xxxx"

      config.access_token        = "xxxx"

      config.access_token_secret = "xxxx"

    end



    client.update("D #{twitDM} My IP address is now #{remote_ip}")



else

    puts "IP addresses match"

end

You can clone the script at Github https://github.com/alastairhm/myip it uses a Ruby Twitter API library which can be found at https://github.com/sferik/twitter to do the direct message with the new IP.
Full details about getting your Twitter API keys can be found at https://dev.twitter.com/

Doodle's Geek Monkey by Alastair Montgomery

Ruby Script to send Twitter mentions over serial port

Short script to send Twitter mention messages to a serial port using Ruby and the gems twitter and serialport.

# Find your Twitter Mentions and send them to Arduino on Serial Port
require “rubygems”
require “twitter” #https://github.com/sferik/twitter for config details
require “serialport” #http://rubygems.org/gems/serialport
require “pp”
prevID = 0
puts “Setting Up Serial Port”
myport = SerialPort.new("/dev/ttyACM0",“9600”.to_i)
sleep(10)
while true
puts “Checking for mentions”
latestMention = Twitter.mentions(:count => 1)[0]
if prevID != latestMention.id
msg = latestMention.user.screen_name + " " + latestMention.text
puts “-” + msg
bytes = myport.write(msg)
puts “-” + bytes.to_s
prevID = latestMention.id
else
puts “-No new updates”
end
sleep 60
end
myport.close

Doodle’s Geek Monkey by Alastair Montgomery

Some Debug Required

First test of Twitter updates getting written to the Arduino from Ruby didn't go quite right as seen from the video below, some debugging required.

Testing writing the same message from the Arduino IDE gives the same results so looks like problem is in the Arduino code. Maybe the message is too long for the LCD's buffer?

The Twitter to Serial port Ruby script can be found at https://github.com/alastairhm/arduino/tree/master/SerialMessage

Doodle's Geek Monkey by Alastair Montgomery

Ruby Script to get Twitter mentions

Here is a short Ruby script to check for mentions on Twitter, it uses the Twitter Gem.

Plan to use this to send messages to my Arduino, looking for a good Ruby Serial Port Gem now.

# Find your Twitter Mentions
require “rubygems”
require “twitter” #https://github.com/sferik/twitter for config details
require “pp”
prevID = 0
while true
latestMention = Twitter.mentions(:count => 1)[0]
if prevID != latestMention.id
msg = latestMention.user.screen_name + " " + latestMention.text
#puts msg.size
puts msg
prevID = latestMention.id
else
puts “No new updates”
end
sleep 60
end

Sending Arduino messages over serial port

Note: 1 of this post’s 6 links are now broken — mostly dead 2008–2013 feed-syndication infrastructure (FeedBurner, Gawker, AOL’s old blog network, Pheedo, Yahoo Pipes). Left as originally published.

Video of sending a message to the Arduino over the serial port which then gets scrolled on a SainSmart LCD shield.

Idea was to use it to display tweets, just need to write the Ruby code to get the tweet and send it over the serial port now.

Here is the first version of the sketch uploaded to the Arduino.
All code can be found at https://github.com/alastairhm/arduino.git

// Auto scroll a message on the LCD and receive new messages via Serial port. // Alastair Montgomery (c) 2013 // Version 1.00 // include the library code: #include <LiquidCrystal.h> #include <string.h>

// initialize the library with the numbers of the interface pins // below for SainSmart LCD Shield LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

Creating a Ruby/ Sinatra dev environment

Note: 1 of this post’s 8 links are now broken — mostly dead 2008–2013 feed-syndication infrastructure (FeedBurner, Gawker, AOL’s old blog network, Pheedo, Yahoo Pipes). Left as originally published.

To work my way through the book Cloning Internet Applications with Ruby I've created a development environment using Vagrant and Puppet.

You will need the following installed;

VirtualBox VM https://www.virtualbox.org/
Vagrant http://www.vagrantup.com/

These pages are also helpful
http://net.tutsplus.com/tutorials/php/vagrant-what-why-and-how/
http://titusd.co.uk/2010/04/07/a-beginners-sinatra-tutorial/

You can see my setup files at https://github.com/alastairhm/vagrant.git

Doodle's Geek Monkey by Alastair Montgomery

Using Ruby to send commands over SSH

Doing a lot of work on remote Linux servers lately, lots of login in over SSH running commands logging out.

So wrote this simple script to use Ruby to send a single command or a file of commands to a Linux server over SSH. Needs some error trapping etc but functional at the moment.

It requires the Ruby Gem net-ssh installed.

#!/usr/bin/ruby
require 'rubygems'
require 'net/ssh'
require 'optparse'

opts = OptionParser.new
opts.on("-h HOSTNAME", "--hostname NAME", String, "Hostname of Server") { |v| @hostname = v }
opts.on("-u SSH USERNAME", "--username SSH USERNAME", String, "SSH Username of Server") { |v| @username = v }
opts.on("-p SSH PASSWORD", "--password SSH PASSWORD", String, "SSH Password of Server") { |v| @password = v }
opts.on("-c SHELL_COMMAND", "--command SHELL_COMMAND", String, "Shell Command to Execute") { |v| @cmd = v }
opts.on("-f FILE_COMMAND", "--command FILE_COMMAND", String, "File containing shell Commands to Execute") { |v| @fileCmd = v }
begin
opts.parse!(ARGV)
rescue OptionParser::ParseError => e
puts e
end
raise OptionParser::MissingArgument, "Hostname [-h]" if @hostname.nil?
raise OptionParser::MissingArgument, "SSH Username [-u]" if @username.nil?
raise OptionParser::MissingArgument, "SSH Password [-p]" if @password.nil?
raise OptionParser::MissingArgument, "Command to Execute [-c/-f]" if @cmd.nil? and @fileCmd.nil?

begin
ssh = Net::SSH.start(@hostname, @username, :password => @password)
if @cmd != nil then
ssh.exec!(@cmd) do |ch, stream, data|
if stream == :stderr
puts "ERROR: #{data}"
else
puts data
end
end
else
puts "Processing file #{@fileCmd}"
file = File.new(@fileCmd, "r")
file.each {|line|
ssh.exec!(line) do |ch, stream, data|
if stream == :stderr
puts "ERROR: #{data}"
else
puts data
end
end
}
file.close
end
ssh.close
rescue Exception => e
puts "Unable to connect to #{@hostname} using #{@username}/#{@password}"
puts e
end

Doodle's Geek Monkey by Alastair Montgomery

Ruby and RSS

Note: 1 of this post’s 4 links are now broken — mostly dead 2008–2013 feed-syndication infrastructure (FeedBurner, Gawker, AOL’s old blog network, Pheedo, Yahoo Pipes). Left as originally published.

Started looking into access RSS from Ruby discovered it pretty much already built in as described in this article Consuming RSS Feeds with Ruby, full docs are available in the Ruby Standard Library.

Accessing an RSS Feed is as simple as the following code snippet.

require "rss"
rss_feed = "http://meekgonkey.blogspot.com/feeds/posts/default?alt=rss"
rss_content = ""
open(rss_feed) { |f|
rss_content = f.read
}
puts "Bytes read #{rss_content.length} from feed"
rss = RSS::Parser.parse(rss_content,false)
puts "Title: #{rss.channel.title}"
puts "RSS URL: #{rss.channel.link}"
puts "Total entries: #{rss.items.size}"
rss.items.each { |item|
puts item.title
puts item.link
puts item.date
puts "---"
}

Which when run produces something along the lines of;
Bytes read 115009 from feed
Title: Geek Monkey
RSS URL: http://meekgonkey.blogspot.com/
Total entries: 25
Twitter from Ruby
http://meekgonkey.blogspot.com/2011/07/twitter-from-ruby.html
Thu, 21 Jul 2011 13:20:00 +0100
---
Github
http://meekgonkey.blogspot.com/2011/07/github.html
Mon, 18 Jul 2011 13:59:00 +0100
---
Google Plus
http://meekgonkey.blogspot.com/2011/07/google-plus.html
Fri, 01 Jul 2011 10:50:00 +0100
---
WATIR makes a tester's life easier.
http://meekgonkey.blogspot.com/2011/06/watir-makes-testers-life-easier.html
Wed, 29 Jun 2011 14:36:00 +0100
---
Setting browser size and position with watir-webdriver
http://meekgonkey.blogspot.com/2011/06/setting-browser-size-and-position-with.html
Thu, 23 Jun 2011 09:22:00 +0100
---

Doodle's Geek Monkey by Alastair Montgomery

Twitter from Ruby

Just been looking at Ruby Twitter gem by John Nunemaker during my lunch break.
Looking good so far, got my Twitter Dev key setup and have made a test post from a Ruby script.

1. Tweeting from Ruby
2......
3. Profit!!!

Doodle's Geek Monkey by Alastair Montgomery

Github

Finally got round to uploading some of my stuff to the GitHub site.
If you want a laugh have a look at my code alastairhm@github ;)

Doodle’s Geek Monkey by Alastair Montgomery

WATIR makes a tester's life easier.

I am constantly amazed that Watir and Ruby make software testing a web application so easy.
For example finding all the links in a table based on their text starting with a string.

stub = "0 Text"
browser.table(:id,"myTable").links(:text,/#{stub}/).each { |link| puts link.text }

This will return all the links in the table "myTable" with text starting with "0 Text"

Doodle's Geek Monkey by Alastair Montgomery

Setting browser size and position with watir-webdriver

In working on my automated web app test using watir-webdriver I need to change the window size and move it on the screen.

From asking the question at StackOverFlow.com you can do this with the following commands;

browser = Watir::Browser.new(:firefox)
browser.execute_script('window.resizeTo(800,600)')
browser.execute_script('window.moveTo(0,0)')

Doodle's Geek Monkey by Alastair Montgomery

Converting scripts from Watir to Webdriver, Table size

I am starting the process of converting my WATIR scripts to use WATIR webdriver.

There a couple of table methods I was using in my WATIR scripts to check the size (rows and columns) of a HTML table.

myTable.row_count
myTable.column_count

These methods don't exist in webdriver so I was looking for a good way of doing the same check.

For rows this seems to give the same result as the row_count method

myTable.rows.length

For column count of the table I've tried converting the table to an array of strings and getting the length of the first row, but the conversion to the string array is taking a while.

myCols = myTable.strings[0].length

After asking the question on StackOverFlow the solution to find the number of columns in the table was to use;

myCols = myTable.row.cells.length

This assumes that the first row has the correct number of columns, which in our application should always be the case.

To avoid rewriting all the unit tests I've extended the Watir::Table class at the start of the script so that it contains the missing row_count and column_count methods.

class Watir::Table
    def row_count
        return self.rows.length
    end
    def column_count
        return self.row.cells.length
    end
end

The unit tests now run unaltered.

If your table has a uniform number of columns for each row then you could check the whole table by doing something like.

        myTable.rows.each { |myRow|
            myCols = myRow.cells.length
            assert_equal(validColumnCount,myCols,"Column count mismatch")
        }

Doodle's Geek Monkey by Alastair Montgomery

#Ruby

Installing Ruby and Node on Redhat 8