OsImages related activities

Updating an osimage

Updating and maintaining software is a good practice. Software provided by the controller nodes (over NFS and the modules environment) is centralized on the controller node; this only needs to be updated once.

Linux distribution software will need to be updated in the osimage. This article will provide the steps.

NOTE: it's a good rule of thumb to have a backup of the osimage before changing it. The most common way is to clone the original and either work on the clone or the original.

Step-by-step guide

Check which osimages you have. Multiple groups may share the same osimage.

1. List the image(s):

# luna osimage list
+------------+----------------------------+-------------------------------+
| Name       | Path                       | Kernel version                |
+------------+----------------------------+-------------------------------+
| compute    | /trinity/images/compute    | 3.10.0-957.27.2.el7.x86_64    |
+------------+----------------------------+-------------------------------+

2. Manual changes:

a. Using lchroot you can enter a chroot environment where the modifications to the image can be made. We assume 'compute' as the image used.

# lchroot compute
IMAGE PATH: /trinity/images/compute
chroot [root@compute /]$

b. After updating the software in the image, using yum or any other method, typing exit will get you back to your shell.

Complete!
chroot [root@compute /]$ exit
exit

if the kernel was updated, make sure to set the desired kernel in luna prior to packing.

# luna osimage change --kernelversion <version> compute

Note: in most cases the kernels installed can be obtained from 'ls /lib/modules' inside the image.

c. After the modifications, the image will need to be (re)packed.

# luna osimage pack compute
osimage pack for compute queued
2024-06-14 12:27:26 :: queued pack osimage compute with id 1077
2024-06-14 12:27:26 :: assembling kernel and ramdisk for osimage compute
2024-06-14 12:28:09 :: finished assembling kernel and ramdisk for osimage compute
2024-06-14 12:28:09 :: building osimage compute
2024-06-14 12:29:09 :: finished building osimage compute
2024-06-14 12:29:09 :: creating provisioning for osimage compute
2024-06-14 12:29:13 :: created torrent provisioning for osimage compute
2024-06-14 12:29:14 :: created http provisioning for osimage compute
[========] Image compute Packed.

d. After this, reboot the nodes to have them updated.

-- OR --

3. Use the ansible-playbook to add a new roles or software: This will overwrite changes which are managed by ansible.

# ansible-playbook compute-redhat.yml