Friday, 28 February 2020

Vagrant box with Oracle Linux 77 basebox - additional fiddlings

Last year on the way home from the UK OUG TechFest 19, I wrote about creating a Vagrant box from the Oracle provided basebox in this article.

Lately I wanted to use it but I stumbled upon some nasty pitfalls.

Failed to load SELinux policy

For starters, as described in the article, I added the 'Server with GUI' package and packaged the box in a new base box. This is handy, because the creation of the GUI box is quite time-consuming and requires an intermediate restart. But if I use the new Server-with-GUI basebox, the new VM fails to start with the message: "Systemd: Failed to load SELinux policy. Freezing.".

This I could solve using the support document 2314747.1. I have to add it to my provision scripts, but before packaging the box, you need to edit the file /etc/selinux/config:
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
# enforcing - SELinux security policy is enforced.
# permissive - SELinux prints warnings instead of enforcing.
# disabled - No SELinux policy is loaded.


# SELINUXTYPE= can take one of three two values:
# targeted - Targeted processes are protected,
# minimum - Modification of targeted policy. Only selected processes are protected.
# mls - Multi Level Security protection.


The option SELINUX turned out to be set on enforcing.

Vagrant unsecure keypair

When  you first start your VM, you'll probably see messages like:
The working of this is described in the Vagrant documentation about creating a base box under the chapter "vagrant" User. I think when I started with Vagrant, I did not fully grasped this part. Maybe the documentation changed. Basically you need to download the Vagrant insecure keypair from GitHub. Then  in the VM, you'll need to update the file authorized_keys in the .ssh folder of the vagrant user:
[vagrant@localhost ~]$ cd .ssh/
[vagrant@localhost .ssh]$ ls
[vagrant@localhost .ssh]$ pwd
[vagrant@localhost .ssh]$

The contents look like:
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDGn8m1kC2mHfPx0dno+HNNYfhgXUZHn8Rt7orIm2Hlc7g4JkvCN6bO7mrYhUbdN2qjy2TziPdlndTAI0E1HK2GbwRM8+N02CNzBg5zvJosMQhweU7EXsDZjYRNJ/SAgVlU5EqIPzmznFjp08uzvBAe2u+L4dZ9kIZ23z/GVWupNpTJmem6LsqS3xg/h0qKf2LFv55SqtLVLlC1sAxL4fvBi3fFIsR9+NLf0fxb+tV/xrprn3yYXT1GyRPVtYAbiOzE3gUOWLKQZVkCXN8R69JeY8P5YgPGx9gSLCiNyLLmqCdF4oLIBMg82lZ0a3/BXG7AoAHVxh7caOoWJrFAjVK9 vagrant

This is now a generated public key matching with a newly generated private key, matching with this file in my .vagrant folder:
As shown, it is the private_key file in the .vagrant\machines\darwin\virtualbox\ folder.
If you update the authorized_keys file of the vagrant user with the public key of the Vagrant insecure keypair, then you need to remove the private_key file. Vagrant will notice that it finds the insecure key and replaces the insecure file with a newly generated private one. By the way, I noticed that sometimes Vagrant won't remove the insecure public key. That means that someone could login to your box using the insecure keypair. You might not want that, so remove that public key from the file.
For convenience, the insecure public key is:
ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA6NF8iallvQVp22WDkTkyrtvp9eWW6A8YVr+kz4TjGYe7gHzIw+niNltGEFHzD8+v1I2YJ6oXevct1YeS0o9HZyN1Q9qgCgzUFtdOKLv6IedplqoPkcmF0aYet2PkEDo3MlTBckFXPITAMzF8dJSIFo9D8HfdOV0IAdx4O7PtixWKn5y2hMNG0zQPyUecp4pzC6kivAIhyfHilFR61RGL+GPXQ2MWZWFYbAGjyiYJnAmCP3NOTd0jMZEnDkbUvxhMmBYSdETk1rRgm+R4LOzFUGaHqHDLKLX+FIPKcF96hrucXzcWyLbIbEgE98OHlnVYCzRdK8jlqm8tehUc9c9WhQ== vagrant

It's this file on GitHub:

Oracle user

For my installations I allways use an Oracle user. And it is quite safe to say I always use the password 'welcome1', for demo and training boxes that is (fieeewww).

But I found out that I could not logon to that user using ssh with a simple password.
That is because in the Oracle vagrant basebox this option is set to no. To solve it, edit the following file /etc/ssh/sshd_config and find the option PasswordAuthentication:
# To disable tunneled clear text passwords, change to no here!
PasswordAuthentication yes
#PermitEmptyPasswords no
#PasswordAuthentication no

Comment the line with value no and uncomment the one with yes.

You can add this to your script to enable it:
echo 'Allow PasswordAuthhentication'
sudo cp /etc/ssh/sshd_config /etc/ssh/
sudo sed -i 's/PasswordAuthentication no/#PasswordAuthentication no/g' /etc/ssh/sshd_config
sudo sed -i 's/#PasswordAuthentication yes/PasswordAuthentication yes/g' /etc/ssh/sshd_config
sudo service sshd restart

You need to restart the sshd as shown in the last line, to have this take effect.


I'll need to add the changes above to my Vagrant scripts, at least the one creating the box based on the one from Oracle. And now I need to look into the file systems created in the Oracle box, to be able to extend them with mine... But that might be input for another story.

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