KDE Dolphin Add Context Menu

Following are the instructions to a create context menu "Open with GVim" entry in KDE Dolphin file manager.

Create a service menu file with the following contents. Give the file any meaningful name. I named it "open_with_gvim.desktop".

[Desktop Entry]
Type=Service
ServiceTypes=KonqPopupMenu/Plugin
MimeType=all/all;
Actions=OpenWithGVim
X-KDE-Priority=TopLevel

[Desktop Action OpenWithGVim]
Name=Open with GVim
Icon=gvim
Exec=gvim %u

To install this service menu for all users copy the file to the following location.

Fedora 23 (KDE 5)

# cp open_with_gvim.desktop /usr/share/kservices5/ServiceMenus/

Fedora 20 (KDE 4)

# cp open_with_gvim.desktop /usr/share/kde4/services/ServiceMenus/

Restart Dolphin and when you right click on any file "Open with GVim" context menu will be displayed.

References

• [1] https://techbase.kde.org/Development/Tutorials/Creating_Konqueror_Service_Menus

Building Go 1.5 from source

I was trying to build Go v1.5 from source and ran it to the following error.

$ git clone https://go.googlesource.com/go
$ git checkout -b v1.5.1 go1.5.1
$ cd src
$ ./all.bash
##### Building Go bootstrap tool.
cmd/dist
ERROR: Cannot find /home/arun/go1.4/bin/go.
Set $GOROOT_BOOTSTRAP to a working Go tree >= Go 1.4.
./make.bash: line 121: /home/arun/go1.4/bin/go: No such file or directory

After some googling [1] [2], it turns out starting with version 1.5 Go requires Go to build itself.

Bootstrapping Go 1.4

We cannot use Go 1.5 to bootstrap itself. So, first build Go 1.4 which will be used to build Go 1.5.

$ mkdir build
$ cd build
$ git clone https://go.googlesource.com/go go-1.4
$ cd go-1.4
$ git checkout -b v1.4.3 go1.4.3
$ cd src
$ ./make.bash

Building Go 1.5

Use Go 1.4 we built in the earlier step to build Go 1.5.

$ cd ~/go/src
$ GOROOT_BOOTSTRAP=~/build/go-1.4 ./make.bash

Go v1.5 is now installed in ${HOME}/go.

$ go version
go version go1.5.1 linux/amd64

Test Installation

Add the location of go binaries (${HOME}/go/bin) to the PATH. I have the following in ${HOME}/.bash_profile file.

export GOROOT=$HOME/go
export PATH=$PATH:$GOROOT/bin

Write a customary "helloworld" program and run it to ensure that the Go build is working.

$ go run helloworld.go
Hello, world!

Notes

When building Go from source, we can run ./all.bash instead of ./make.bash to build and run all the unit tests. Only downside is it increases the build time.

References

• [1] https://golang.org/doc/install/source

• [2] http://dave.cheney.net/2015/10/16/bootstrapping-go-1-5-on-non-intel-platforms

Getting started with Puppet on CentOS 6

This is a how to for setting up Puppet on machines running CentOS 6. Instructions were tested on CentOS 6.2 machines.

Introduction

Instructions below assume you have two machines named master.example.com which will be the Puppet master and client.example.com which will be the Puppet client.
Puppet requires machines to have full qualified domain names (FQDN). Also, the clocks on machines must be in sync. Enable NTP daemon on both machines to sync the machine clock to NTP servers.

# service ntpd start

Prerequisites

Puppet requires "ruby" and "ruby-lib" packages installed.
To view puppet command-line help, you need "ruby-rdoc" package installed.

# yum ruby ruby-lib ruby-rdoc

Puppet is not available in CentOS "base" repository. PuppetLabs provides a Yum repository for puppet. You can install a RPM provided by PuppetLabs to configure the Yum repository.

# wget -c http://yum.puppetlabs.com/el/6/products/x86_64/puppetlabs-release-6-1.noarch.rpm
# yum install puppetlabs-release-6-1.noarch.rpm

Puppet Server

Install Puppet server package on master.example.com

[root@master ~]# yum install puppet-server

Start the Puppet master daemon.

[root@master ~]# service puppetmaster start

Puppet and SSL

Puppet clients uses HTTPS to communicate with the server. In order to communicate with the server Puppet clients require valid SSL certificate. Puppet master daemon acts as CA (certificate authority) for SSL certificates.
During the first run of the puppet client it generates a SSL certificate and sends to puppet master.

[root@client ~]# puppet agent --no-daemonize --onetime --verbose --debug --server=master.example.com

Before the client can successfully connect to the master, master has to sign the client certificate.

[root@master ~]# puppet cert list --all
[root@master ~]# puppet cert --sign client.example.com

Puppet Client

Install Puppet client package on client.example.com

[root@client ~]# yum install puppet

Test Puppet client from the command-line. We will assume that the master has valid signed certificate for client.example.com.

[root@client ~]# puppet agent --help
[root@client ~]# puppet agent --no-daemonize --onetime --verbose --debug --server=master.example.com

See the "puppet agent --help" to understand the command line flags.

In the next post, we will see how to setup a "helloworld" example for Puppet.

Location of userContent.css in Linux and Windows 7

Windows 7

C:\Users\{username}\AppData\Roaming\Mozilla\Firefox\Profiles\{profile-directory}\chrome

E.g.

C:\Users\arun\AppData\Roaming\Mozilla\Firefox\Profiles\4s7v2bl8.default\chrome

Linux

/home/{username}/.mozilla/firefox/{profile-directory}/chrome

E.g.

/home/arun/.mozilla/firefox/4s7v2bl8.default/chrome

View Gmail conversations in fixed width font using Firefox

Add the following lines to "$HOME/.mozilla/firefox/{profile-directory}/chrome/userContent.css" to view Gmail emails in fixed width font using Firefox.

@-moz-document domain(mail.google.com)
{
    /* GMail messages and textarea should use fixed-width font */
    .gs .ii, textarea.Ak {
        font-family: MonoSpace !important;
        font-size: 10pt !important;
    }
}

That's it. Enjoy.
Edit: 13 Feb 2016 (Originally published on 09 Oct 2011)
This still works on Firefox 44 on Fedora 23. The "chrome" directory was missing in profiles directory. Just create the directory and put "userContent.css" file inside it.

Google Yum repository configuration on Fedora

To install and update Google programs like Chrome and Picasa using Yum, create a new configuration file named "google.repo" under /etc/yum.repos.d/. The contents of "google.repo" would like below.

[google]
name=Google - i386
baseurl=http://dl.google.com/linux/rpm/stable/i386
enabled=1
gpgcheck=1
gpgkey=https://dl-ssl.google.com/linux/linux_signing_key.pub 

With this setup in place, you should be able to install Google Chrome using the following command.

# yum install google-chrome-unstable
or
# yum install google-chrome-stable

For more information, refer to [1].
1. http://www.google.com/linuxrepositories/yum.html

Accessing Microsoft Exchange with Evolution on Fedora

Install Evolution if it not already installed. To make Evolution work with Microsoft Exchange you will need to install "evolution-exchange" package.

$ yum install evolution-exchange

Launch Evolution.
Go to Edit->Preferences->Mail Accounts
To create a new account choose "Add"
"Mail Configuration" window click "Forward"
"Identity" enter your name and email address
"Receiving Email": Choose Server Type: Microsoft Exchange
User Name: domain/username
OWA URL: https://webmail.example.com/exchange/ Click Authenticate. Click Forward.
"Receiving Options": The defaults are fine. If you want to customize them you can do so later. Click Forward
"Account Management": The defaults are fine. If not, choose a name. Click Forward
In the next screen, once you click "Apply" your account will be setup.