Salt: `qvm.exists` as a state requisite (`unless`) howto?

User Support General
1

In my salted setup I am trying to use (on dom0) unless analogous to what is shown for file.file_exists in the salt documentation:

# Ensure presence of dedicated named dispVM - not currently achievable using the qvm.vm state 20240108
Ensure presence of dedicated named dispVM:
  cmd.run:
    - name: qvm-create --class DispVM --template={{ dflt_dvm_tmplt }} --label red named-{{ dflt_dvm_tmplt }}
    - unless:
      - fun:  qvm.exists
        name: named-{{ dflt_dvm_tmplt }}

This, however, produces an error, that culminates in

KeyError: 'qvm.exists'

Any pointers on what’s wrong and how to fix that?

1 Like
2

Because it invokes qvm-create, I assume this state is applied in dom0?

If that’s the case, I would expect the qvm.exists function to be found… so I don’t know.

Side note: Given the error message, I’m pretty sure it doesn’t matter, but you’ve got a double space in the -fun: qvm.exists line.

3

Sorry I should have mentioned it from the start, but yes, this is run in dom0. Fixed above.

The double space is for esthetic reasons and indeed tests as irrelevant.

1 Like
4

In this particular example, you could use the command qvm.present directly instead of cmd.run. It will automatically detect the qube’s presence and not create it twice if it’s already there.

Edit: as for the unless requisite, it only accepts commands that you can use on the command line as arguments, such as qvm-ls. Correction: it also accepts modules, see unman’s answer below.

5

Unless is fine. But you have to use a module that actually exists.
This is what the error message is telling you.

What you are probably looking for is qvm.check:

    - unless:
      - fun: qvm.check
        args:
          - named-{{ dflt_dvm_tmplt }}
          - exists

but far better is to use qvm.present instead of that call to cmd.run
qvm.present only creates qube if it is missing.

1 Like
6

Thank you! for that solution! Where would I look up what module any call lets say from this list actually belongs (for future reference)?

And: My infrastructure uses a looped state like this

Assure presence of {{ ca }}:
  qvm.vm:
    - name: {{ ca }}
    - present:
      - template: {{ cstm_appvms[ca]['template']|default(dflt_tmplt) }}
      - label:    {{ cstm_appvms[ca]['label']|default(dflt_lbl) }}
    - features:
      - set:
	    - appmenus-dispvm:	{{ cstm_appvms[ca]['appmenus-dispvm']|default('0') }}
        - menu-items:           {{ cstm_appvms[ca]['menu-items']|default(dflt_menu_items) }}
        - provides_network:     {{ cstm_appvms[ca]['provides_network']|default('False') }}
        - template_for_dispvms: {{ cstm_appvms[ca]['template_for_dispvms']|default('False') }}

I was unable to get that construct to accept any --class DispVM equivalent that I require to create the named dispVM using the cmd.run call above - how would that work? I’m more than happy to (re)integrate the generation of the named dispVM back into the general solution…

7

Those are states - the modules can be found in the repository you linked under
_modules, and in dom0 under /srv/salt/_modules/ext_module_qvm.py

For a disposable you need to specify the disposable template as value
for template - then:

testit:
  qvm.vm:
    - name: test-disp
    - present:
      - class: DispVM
      - template: test
      - label: purple

where test is a disposable template

1 Like
8

This is driving me crazy. Why is this not working?

Shutdown built-dvm:
  cmd.run:
    - name:   qvm-run-vm {{ build_dvm }} -- sudo shutdown now
    - unless:
      - fun: qvm.halted
        args: 
          - {{ build_dvm }}

As far as I can tell, the qvm.halted bit is a module equivalent to what @unman is using above…

9

I apologize for reopening this and will move to a dedicated post.