Introduction
Please see the article “Build a Linux-based Infrastructure Solution Demonstration Series” (https://blogs.czapski.id.au/2016/10/build-a-linux-based-infrastructure-solution-demonstration-series) for rationale, introduction and links to articles in this series.
In this article a script which will add GEyes, ShowDesktop and GnomeMonitor applests and configure the GnomeMonitor applet will be developed and executed.
Pre-Requisites
This article assumes that
- The work is done in the Virtual Box Machine Image created in accordance with the instructions in the blog article to be found at https://blogs.czapski.id.au/2016/10/configure-virtual-box-virtual-machine-and-install-centos-6-8-base-image.
The instructions should work in other RedHat 6-like OS’ and OS versions.
Script Adding Applets to Top Panel
I typically set up my environment to my taste, which does not mean that everybody needs to do this the same way or at all.
The discussion below shows how one can script adding and configuration of top panel applets.
Remember that all this can be done using the relevant UIs but my objective is to create configuration scripts which I can execute and have the demo image configured without having to tediously manipulate various UIs.
Let’s have a look at some applets-related commands and outputs, and then create and execute a script to add three applets to the top panel using a script.
After CentOS installation the top panel looks like that shown in the figure below.
Let’s list top level panels so as to see which ones we have – top and bottom is what is expected.
/usr/bin/gconftool-2 --all-dirs /apps/panel/toplevels /apps/panel/toplevels/top_panel /apps/panel/toplevels/bottom_panel
List applets in the two panels
/usr/bin/gconftool-2 --all-dirs /apps/panel/applets /apps/panel/applets/trash_applet /apps/panel/applets/workspace_switcher /apps/panel/applets/window_list /apps/panel/applets/fast_user_switch_applet /apps/panel/applets/systray /apps/panel/applets/gnote /apps/panel/applets/clock
List all available applets which can be added to the panels
/usr/bin/activation-client -q --spec="has (repo_ids,'IDL:Bonobo/Control:1.0')" | grep '^IID' | cut -d ',' -f1-1 | cut -d ' ' -f2-2 | more OAFIID:GNOME_MixerApplet OAFIID:DwellClickApplet OAFIID:GNOME_SystemTrayApplet OAFIID:GNOME_NotificationAreaApplet OAFIID:GNOME_Panel_TrashApplet OAFIID:GNOME_ClockApplet OAFIID:GNOME_AccessxStatusApplet OAFIID:Invest_Applet OAFIID:GnoteApplet OAFIID:GNOME_MailcheckApplet OAFIID:GNOME_CDPlayerApplet OAFIID:GNOME_FishApplet OAFIID:GNOME_GeyesApplet OAFIID:GNOME_GtikApplet OAFIID:GNOME_WindowMenuApplet OAFIID:GNOME_KeyboardApplet OAFIID:GNOME_GWeatherApplet OAFIID:GNOME_BattstatApplet OAFIID:GNOME_PagerApplet OAFIID:GNOME_WorkspaceSwitcherApplet OAFIID:GNOME_TasklistApplet OAFIID:GNOME_MultiLoadApplet OAFIID:GNOME_StickyNotesApplet OAFIID:GNOME_ShowDesktopApplet OAFIID:GNOME_WindowListApplet OAFIID:GNOME_DriveMountApplet OAFIID:GNOME_CharpickerApplet OAFIID:GNOME_DictionaryApplet OAFIID:GNOME_FastUserSwitchApplet OAFIID:GNOME_GDictApplet OAFIID:PointerCaptureApplet OAFIID:GNOME_BrightnessApplet OAFIID:Square_Controller OAFIID:Circle_Controller OAFIID:Bonobo_Sample_Entry OAFIID:GNOME_CPUFreqApplet OAFIID:GNOME_MiniCommanderApplet
Create the script to update property values in the applet dump file. This script will be used later to update specific key values. If you are curious, execute the script lines one at a time to see what they do.
mkdir -p /media/sf_distros/scripts
cat <<-'EODECK' > /media/sf_distros/scripts/z_update_upplet_config_key.sh
#!/bin/bash
# update value for key in applet dump for a particular applet
# expect applet dump file, key and value pair as $1, $2 and $3
fileName=${1}
keyName=${2}
valueName=${3}
echo -- before : processing ${fileName}, key: ${keyName}, for value ${valueName}
cat ${fileName} | grep -A 2 "${keyName}<"
matchedLine=$(cat ${fileName} | grep -n "${keyName}<")
matchedLineNum=$(echo ${matchedLine} | cut -d ':' -f 1)
replaceLineNum=$(echo $(( ${matchedLineNum} + 3)))
sed -i "${replaceLineNum}s|<\([a-z]*\)>.*</\([a-z]*\)>|<\1>${valueName}</\1>|" ${fileName}
echo ++ after
cat ${fileName} | grep -A 2 "${keyName}<"
EODECK
chmod ug+x /media/sf_distros/scripts/z_update_upplet_config_key.sh
Create a script which will add three applets to the top bar and configure the monitor applet
mkdir -p /media/sf_distros/scripts cat <<-'EODECK' > /media/sf_distros/scripts/005_add_applets_to_top_panel.sh # Add GEyes to the top bar /usr/libexec/gnome-panel-add --applet=OAFIID:GNOME_GeyesApplet --panel=top_panel --position=849 --copy-launcher # Add Show Desktop Applet to the top bar /usr/libexec/gnome-panel-add --applet=OAFIID:GNOME_ShowDesktopApplet --panel=top_panel --position=400 --copy-launcher # Add Monitor Applet to the top bar /usr/libexec/gnome-panel-add --applet=OAFIID:GNOME_MultiLoadApplet --panel=top_panel --position=980 --copy-launcher # Dump applet_2 configuration - that will be the last applet added above - MultiLoadApplet sleep 2 gconftool-2 --dump /apps/panel/applets/applet_2 > ~/applet_2_fix.entries sleep 2 # Update property values and load the updated entries /media/sf_distros/scripts/z_update_upplet_config_key.sh ~/applet_2_fix.entries view_netload true /media/sf_distros/scripts/z_update_upplet_config_key.sh ~/applet_2_fix.entries view_diskload true /media/sf_distros/scripts/z_update_upplet_config_key.sh ~/applet_2_fix.entries view_loadavg true /media/sf_distros/scripts/z_update_upplet_config_key.sh ~/applet_2_fix.entries view_swapload true /media/sf_distros/scripts/z_update_upplet_config_key.sh ~/applet_2_fix.entries view_memload true /media/sf_distros/scripts/z_update_upplet_config_key.sh ~/applet_2_fix.entries size 30 gconftool-2 --load ~/applet_2_fix.entries killall gnome-panel EODECK chmod ug+x /media/sf_distros/scripts/005_add_applets_to_top_panel.sh
Execute the commands
/bin/bash -v /media/sf_distros/scripts/005_add_applets_to_top_panel.sh
After script execution the top panel looks like the following
List the applets now in the panels
/usr/bin/gconftool-2 --all-dirs /apps/panel/applets /apps/panel/applets/clock /apps/panel/applets/applet_0 /apps/panel/applets/applet_1 /apps/panel/applets/applet_2 /apps/panel/applets/trash_applet /apps/panel/applets/window_list /apps/panel/applets/systray /apps/panel/applets/workspace_switcher /apps/panel/applets/gnote /apps/panel/applets/fast_user_switch_applet
It is expected that the image being configured a bit at a time will be created multiple times. With this assumptions the individual scripts are appended to a single script so that the second and subsequent images can be configured by a single script rather than having lots of scripts to execute manually.
Append “add applets to top panel and configure monitor” script execution commands to the initial bulk configuration script. This script is intended to collect all automated configuration commands and scripts so that they can be all executed in one go on a brand new image if one gets to do this the second and subsequent times.
Don’t actually execute this script while you are building the first image.
cat <<-'EODECK' >> /media/sf_distros/scripts/000_initial_bulk_configuration.sh # add and configure top panel applets /bin/bash -v /media/sf_distros/scripts/005_add_applets_to_top_panel.sh EODECK chmod ug+x /media/sf_distros/scripts/000_initial_bulk_configuration.sh
