Custom config / cloud-init

bvitnik

@acebmxer said in Custom config / cloud-init:

If convert this newly created vm to a template. Then create another vm from this template. Even though the VM is generating a new mac address when the vm boots its still getting / using the same ip from vm used to create the template.

You will have to carefully read cloud-init documentation to understand how it works and what phases it has.

Short answer is that VM template creation is a bit more work than just preparing some base VM and than converting it to the template or use it to clone other VMs. For a start, cloud-init has to be "cleaned" so that it is reset to the initial state.

cloud-init, or better said most of it's modules, run only once - just on first boot. So... when you create a VM from a hub template, cloud-init will run but if you use that VM to clone another VM, cloud-init will not run like on first boot of the original VM. Aside from that, to prepare some VM to be a template for other VMs, other "stuff" beside cloud-init has to be cleaned up like machine-id, SSH host keys, network configuration, logs... There is some official documentation on this here:

https://docs.xcp-ng.org/guides/create-use-custom-xcpng-ubuntu-templates/

and some forum addendum here:

https://xcp-ng.org/forum/topic/11008/ubuntu-22.04.5-custom-template-additional-steps-missing-from-documentation

read carefully

acebmxer

@bvitnik thanks for that info. There is so much to learn with linux. Not that there is alot to learn with windows. I am still learning new stuff every day but still know just enough to get myself in trouble with Linux.

Pilow

@bvitnik said in Custom config / cloud-init:

https://docs.xcp-ng.org/guides/create-use-custom-xcpng-ubuntu-templates/

I noticed in the documentation, they put "password:" for user password creation.

what is working for me :

plain_text_passwd: 'myverysecureplaintextpassword'

more secure, use a SHA 512 encrypted password, but with :

passwd: QChUQYy14yOv_encrypted_password_mgnEFL6TRPIsJ/4

make it encrypted with

# mkpasswd --method=SHA-512

bvitnik

@Pilow password: as a global option and passwd: or plain_text_passwd: under users: key are two different things. The first one sets the password for the default user, ubuntu on Ubuntu if I recall correctly, while the others set password for the user specified in the users: key.

Read the docs people

Pilow

@bvitnik indeed, RTFM

i'm a newb on cloud-init, and should follow more this good advice !

acebmxer

So I have had some more time to play around with this, and I think I got it working except for one part.

After I convert the vm to a template and go deploy new vm with newly created template. Even if i put in the network config as such.

#cloud-config
network:                                                                                                                                              
   version: 2                                                                                                                                          
   ethernets:
    enX0:
      dhcp4: true
      dhcp6: false
      set-name: "enX0"

The new vm does not get IP address. When i log into new vm it does not have /etc/netplan/50-cloud-init.yaml with the above network config.

If i manually create the file with the above config and reboot the vm gets an IP address and a different one then previous vm

bvitnik

@acebmxer Did you do:

cloud-init clean --logs --seed

before converting the VM to template?

Also, network configuration is not part of the cloud-config (aka user data). In XO, there is a separate field called "Network config" where it should be specified. See examples at the end of the guide I pasted earlier. network: key should also be removed (commented in the examples).

acebmxer

@bvitnik
This is creating new vm from Hub template. If i try the below network config the VM hangs on boot. Think previously it would eventually boot but have not networking as stated previously.

#cloud-config
# network:                                                                                                                                              
   version: 2                                                                                                                                          
   ethernets:
    enX0:
      dhcp4: true
      dhcp6: false
      set-name: "enX0"

This is copy pasted from the link you provided about additional infomation to add to documentation. does not show network: commented out. When i use this with ips corrected to my network the vm boots fast but again still no networking. Even if i comment out network. Still no networking. I have to leave blank during vm creation. Can you past your working network config?

#cloud-config
network:
  version: 2
  ethernets:
    eth0:
      dhcp4: false
      addresses:
        - 10.0.2.6/27
      gateway4: 10.0.2.1
      nameservers:
        addresses:
          - 10.0.2.1
          - 1.1.1.1

EDIT -

This is a working config for new vm from Ubuntu Hub template. VM boots and gets IP address. Its not much different then my original. I dont know. Still learning this stuff.

network:
  version: 2
  ethernets:
    enX0:      # or whatever your interface name is
      dhcp4: true

Edit -2 while the above works for dhcp the below does not work for static. VM does not get static ip

network:
  version: 2
  ethernets:
    enX0:      # or whatever your interface name is
      dhcp4: false
      addresses: - 10.100.10.206/24
      gateway4: 10.100.10.254
      nameservers:
          addresses:
               - 10.100.10.254
               - 1.1.1.1

acebmxer

@bvitnik said in Custom config / cloud-init:

@acebmxer Did you do:
cloud-init clean --logs --seed
before converting the VM to template?

Also, network configuration is not part of the cloud-config (aka user data). In XO, there is a separate field called "Network config" where it should be specified. See examples at the end of the guide I pasted earlier. network: key should also be removed (commented in the examples).

besides getting it working on fresh vm from the ubuntu template from the Hub. I do have that command in script to prepare the vm to create a template from it. AI says this will cause the vm not to recreate the 50-cloud-init.yaml file. So how do I work around that also.

bvitnik

@acebmxer said in Custom config / cloud-init:

...

network:
  version: 2
  ethernets:
    enX0:      # or whatever your interface name is
      dhcp4: false
      addresses: - 10.100.10.206/24
      gateway4: 10.100.10.254
      nameservers:
          addresses:
               - 10.100.10.254
               - 1.1.1.1

Address should be on the next line:

      addresses:
      - 10.100.10.206/24

Regarding 50-cloud-init.yaml, AI is lying .

acebmxer

@bvitnik that worked.

bvitnik

@acebmxer Great. These are some YAML basics. You should read more about it . Following AI instructions without understanding is not going to take you far.