linux_wiki:os_install_post_install

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linux_wiki:os_install_post_install [2016/05/18 23:32]
billdozor 		linux_wiki:os_install_post_install [2017/09/12 23:07]
billdozor [Post Install Script]
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 After installing an OS via [[linux_wiki:os_install_kickstart|kickstart]] or a [[linux_wiki:os_install_vm_template|VM Template]], there is typically additional standard configuration performed depending upon the environment. After installing an OS via [[linux_wiki:os_install_kickstart|kickstart]] or a [[linux_wiki:os_install_vm_template|VM Template]], there is typically additional standard configuration performed depending upon the environment.
 +
 +This page demonstrates how to create VM templates and kickstarts that will auto-execute scripts one time for a system's first boot.
  
 **Checklist** **Checklist**
   * Distro(s): Enterprise Linux 6/7   * Distro(s): Enterprise Linux 6/7
 +  * Other: NFS Server sharing a post install configuration script
  
 ---- ----
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 ====== Firstboot ====== ====== Firstboot ======
  
-Post install configuration is normally only needed to be completed the first time a system is booted in order to set it up for the type of environment it is in.+  * The firstboot script is executed once. 
 +  * It is baked into the system via a VM template or kickstart. 
 +  * It stays generic and calls other external scripts on remote admin systems to do the actual post install configuration. 
 +  * It also reboots the system and sends an email once it has completed
  
 ---- ----
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 This script is meant to run once and then disable itself. It calls other post install script(s) to do the actual work. This script is meant to run once and then disable itself. It calls other post install script(s) to do the actual work.
  
 +/root/scripts/firstboot.sh
 <code bash> <code bash>
 #!/bin/bash #!/bin/bash
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 nfs_client_mountpoint="/mnt" nfs_client_mountpoint="/mnt"
 post_install_script="${nfs_client_mountpoint}/scripts/postinstall.sh" post_install_script="${nfs_client_mountpoint}/scripts/postinstall.sh"
 +post_install_log="/root/postinstall.log"
  
 # Write a successful run file # Write a successful run file
 firstboot_ran_file="/root/.firstboot-ran" firstboot_ran_file="/root/.firstboot-ran"
 +
 +# System Admins Group Email
 +system_admins_email='sysadmins@example.com'
  
 # Reboot delay in minutes # Reboot delay in minutes
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 #### End of Safeguards #### #### End of Safeguards ####
  
-# Email root notification of completion +# Email notification of completion 
-echo -e "\nfirstboot>> E-mailing root notification that the script completed..." +echo -e "\nfirstboot>> E-mailing notification that the script completed..." 
-echo -e "The firstboot script process has completed for: '$(hostname)' on $(date).\n\nThe following actions have successfully run:\n1) Post install script (System updates, General system configuration)\n2) Other scripts\n\nThe system ($(hostname)) will reboot in ${reboot_delay} minute(s)." | /bin/mail -s "Firstboot Complete: $(hostname)" root+echo -e "The firstboot script process has completed for: '$(hostname)' on $(date).\n\nThe following actions have successfully run:\n1) Post install script (System updates, General system configuration)\n2) Other scripts\n\nThe system ($(hostname)) will reboot in ${reboot_delay} minute(s).\n\n--- Post Install Errors and Warnings ---\n$(grep ERROR ${post_install_log})\n$(grep WARNING ${post_install_log})" | /bin/mail -s "Firstboot Complete: $(hostname)" ${system_admins_email}
  
 # Allow some time for the email to be sent # Allow some time for the email to be sent
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 Firstboot will get executed on CentOS 7 via a custom systemd service unit. Firstboot will get executed on CentOS 7 via a custom systemd service unit.
  
-The following service unit will end up in /etc/systemd/system/firstboot.service+Create the following service unit file: /etc/systemd/system/firstboot.service
 <code bash> <code bash>
 [Unit] [Unit]
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 CentOS 6 will make use of rc.local to execute the script. CentOS 6 will make use of rc.local to execute the script.
  
-/etc/rc.d/rc.local (append)+Append to: /etc/rc.d/rc.local
 <code bash> <code bash>
 /root/scripts/firstboot.sh /root/scripts/firstboot.sh
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 ====== Auto Setup ====== ====== Auto Setup ======
  
-Now that we have a firstboot script and method of executing (CentOS 7 service or CentOS 6 rc.local), the combination of the two can be added to VM templates or kickstarts for unattended execution.+Now that we have a firstboot script and method of executing on boot(CentOS 7 service or CentOS 6 rc.local), the combination of the two can be added to VM templates or kickstarts for unattended execution.
  
 ---- ----
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 ===== Auto Setup: VM Templates ===== ===== Auto Setup: VM Templates =====
  
 +The modifications for auto execution need to be done on a new template that is a modification of your base VM template.
 +
 +**Warning**: Do not delete your base template after you have created an auto setup version! If you ever want to update your auto setup template, you will need to deploy from the base template, make changes, and create a new auto setup version.
 +
 +  * Deploy a new VM from your base template ([[linux_wiki:os_install_vm_template|Create a base template here]])
 +  * Make the following modifications to the new system.
 +    * **CentOS 6**<code bash>## VM deployed from the base template ##
 +
 +## Create a script directory for root
 +mkdir /root/scripts
 +
 +## Mount NFS Server and Copy firstboot.sh to the VM
 +mount -t nfs <nfs-server>:/scripts /mnt
 +cp -v /mnt/firstboot.sh /root/scripts/
 +chown -Rv root:root /root/scripts
 +chmod -Rv 700 /root/scripts
 +
 +## Create line in rc.local to auto execute firstboot script
 +echo "/root/scripts/firstboot.sh" >> /etc/rc.d/rc.local
 +
 +## Unmount NFS server
 +umount /mnt</code>
 +      * [[linux_wiki:os_install_vm_template#centos_6vm_cleanup|Run CentOS 6 clean up commands]] identical to the base template and create a new template.
 +    * **CentOS 7**<code bash>## VM deployed from the base template ##
 +
 +## Create a script directory for root
 +mkdir /root/scripts
 +
 +## Mount NFS Server and Copy firstboot.sh to the VM
 +mount -t nfs <nfs-server>:/scripts /mnt
 +cp -v /mnt/firstboot.sh /root/scripts/
 +chown -Rv root:root /root/scripts
 +chmod -Rv 700 /root/scripts
 +
 +## Copy firstboot.service unit to the VM
 +cp -v /mnt/firstboot.service /etc/systemd/system/
 +chown -v root:root /etc/systemd/system/firstboot.service
 +chmod -v 644 /etc/systemd/system/firstboot.service
 +systemctl enable firstboot.service
 +
 +## Unmount NFS server
 +umount /mnt</code>
 +      * [[linux_wiki:os_install_vm_template#centos_7vm_cleanup|Run CentOS 7 clean up commands]] identical to the base template and create a new template.
  
 ---- ----
  
 ===== Auto Setup: Kickstarts ===== ===== Auto Setup: Kickstarts =====
 +
 +Kickstart files require a post install section to be edited in order for the firstboot script to be placed on a new system.
 +
 +  * [[linux_wiki:os_install_kickstart|Create a kickstart file]] as normal
 +  * Modify the "%post" section at the bottom to include the following:
 +    * **CentOS 6**<code bash>%post --interpreter /bin/sh --log=root/ks-post.log
 +(
 +
 +## Start rpcbind for NFS
 +service rpcbind start
 +
 +## Mount NFS Server
 +mount -vt nfs 10.1.2.3:/scripts /mnt
 +
 +## Create root's scripts directory
 +mkdir /root/scripts
 +
 +## Copy the firstboot script to the new directory
 +cp -v /mnt/firstboot.sh /root/scripts/
 +chown -Rv root:root /root/scripts
 +chmod -Rv 700 /root/scripts
 +
 +## Create rc.local entry for auto execution on boot
 +echo "/root/scripts/firstboot.sh" >> /etc/rc.d/rc.local
 +
 +## Unmount NFS Server
 +umount -v /mnt
 +)
 +%end</code>
 +    * **CentOS 7**<code bash>%post --interpreter /bin/sh --log=root/ks-post.log
 +(
 +
 +## Start rpcbind for NFS
 +systemctl start rpcbind
 +
 +## Mount NFS Server
 +mount -vt nfs 10.1.2.3:/scripts /mnt
 +
 +## Create root's scripts directory
 +mkdir /root/scripts
 +
 +## Copy the firstboot script to the new directory
 +cp -v /mnt/firstboot.sh /root/scripts/
 +chown -Rv root:root /root/scripts
 +chmod -Rv 700 /root/scripts
 +
 +## Copy the firstboot service for auto execution on boot
 +cp -v /mnt/firstboot.service /etc/systemd/system/
 +chown -v root:root /etc/systemd/system/firstboot.service
 +chmod -v 644 /etc/systemd/system/firstboot.service
 +
 +## Enable firstboot service
 +systemctl enable firstboot.service
 +
 +## Unmount NFS Server
 +umount -v /mnt
 +)
 +%end</code>
 +
 +----
 +
 +====== Post Install Script ======
 +
 +  * The post install script is what gets called via the firstboot script.
 +  * This script does all the heavy lifting (system updates, configuration, etc).
 +
 +===== Post Install Script: Parent =====
 +
 +**Post install script**: Provide logging and error checking
 +<code bash postinstall.sh>
 +#!/bin/bash
 +# Title: postinstall.sh
 +# Description: Wrapper script to start the postinstall_worker.sh script with logging.
 +# Last Updated: 2016-10-24
 +# Most Recent Changes:-Initial release
 +#######################################################################################
 +
 +function print_usage
 +{
 +echo
 +echo " Usage: postinstall.sh [-y]"
 +echo
 +echo "   This script(${0}), provides logging for its worker script, worker_postinstall.sh"
 +echo
 +echo "   Recommended action"
 +echo "   1) Mount: mount -t nfs nfs-server:/admin /mnt"
 +echo "   2) Execute parent script: /mnt/deploy/postinstall.sh [-y]"
 +echo "      -y  => Yes, execute script without prompting."
 +echo
 +exit 1
 +}
 +
 +#=====================================
 +# Get Script Arguments
 +#=====================================
 +# Reset POSIX variable in case it has been used previously in this shell
 +OPTIND=1
 +
 +# By default, do not force run script. Prompt for running or not.
 +force_run_script="no"
 +
 +while getopts "hy" opt; do
 +  case "${opt}" in
 +    h) # -h (help) argument
 +      print_usage
 +      exit 0
 +    ;;
 +    y) # -y (yes to running script) argument
 +      force_run_script="yes"
 +    ;;
 +    *) # invalid argument
 +      print_usage
 +      exit 0
 +    ;;
 +  esac
 +done
 +
 +##====================
 +## Pre-req checks
 +##====================
 +
 +## Ensure we are root ##
 +if [[ $(id --user) -ne 0 ]]; then
 +  echo ">>Error; this script must be run as root. Exiting..."
 +  exit 1
 +fi
 +
 +##======================
 +## Set Script Variables
 +##======================
 +
 +# Set base path from executed command (relative or full path works)
 +base_path="$(echo ${0} | sed 's/postinstall.sh//')"
 +
 +# Set log file and script locations
 +postinstall_log="/root/postinstall.log"
 +postinstall_worker="worker_postinstall.sh"
 +
 +##================
 +## Setup Logging
 +##================
 +echo -e ">>Logging output and errors to: ${postinstall_log}\n"
 +
 +# Clear log and timestamp the beginning
 +cat /dev/null > ${postinstall_log}
 +echo -e "---- Log Started: $(date) ----\n" >> ${postinstall_log}
 +
 +##=========================
 +## Execute External Scripts
 +##=========================
 +# Start script, pass base path argument
 +if [[ ${force_run_script} == "no" ]]; then
 +  ${base_path}${postinstall_worker} -d ${base_path} 2>&1 | tee -a ${postinstall_log}
 +elif [[ ${force_run_script} == "yes" ]]; then
 +  ${base_path}${postinstall_worker} -d ${base_path} -y 2>&1 | tee -a ${postinstall_log}
 +else
 +  echo -e ">>Error: Unknown value for force_run_script (${force_run_script}). Exiting..."
 +  exit 1
 +fi
 +
 +##==========================
 +## Close Logs, Show Location
 +##==========================
 +# Ending timestamp
 +echo -e "\n---- Log Completed: $(date) ----" >> ${postinstall_log}
 +
 +# Reminder of where the log file is at
 +echo -e "\n>>Logged output and errors were sent to: ${postinstall_log}\n"
 +echo -e "----> Remember to umount NFS before rebooting <----"
 +</code>
 +
 +===== Post Install Script: Worker =====
 +
 +**Post install worker**: Perform the actual installations/config work
 +<code bash worker_postinstall.sh>
 +</code>
  
 ---- ----
  
  • linux_wiki/os_install_post_install.txt
  • Last modified: 2019/05/25 23:50
  • (external edit)