sap_vm_provision: fix var reference to var lookup

[ja9fuchs]

vars[] lookup is preventing nested variables from being evaluated.
The loop breaks when a custom sap_vm_provision_..._host_specifications_dictionary is used that includes nested variables for flexibility.

All other vars lookups in the role had already been changed to use the lookup plugin some time ago.

Input var:

sap_vm_provision_aws_ec2_vs_host_specifications_dictionary:

  # HANA scale-up minimal
  su_min:

    su1hana01: "{{ aws_host_profile.hana_96m_100s.profile_primary }}"
    su1hana02: "{{ aws_host_profile.hana_96m_100s.profile_secondary }}"

Original syntax and result:

- debug:
    var: vars['sap_vm_provision_' + sap_vm_provision_iac_platform + '_host_specifications_dictionary'][sap_vm_provision_host_specification_plan][scaleout_origin_host_spec | default('su1hana01')].keys() | map('regex_findall', '^sap_.*') | flatten | select() | list
--------------------------------------------------------------------------------------------

ok: [localhost] => 
  ? vars['sap_vm_provision_' + sap_vm_provision_iac_platform + '_host_specifications_dictionary'][sap_vm_provision_host_specification_plan][scaleout_origin_host_spec | default('su1hana01')].keys() | map('regex_findall', '^sap_.*') | flatten | select() | list
  : 'VARIABLE IS NOT DEFINED!: ''ansible.parsing.yaml.objects.AnsibleUnicode object'' has no attribute ''keys''. ''ansible.parsing.yaml.objects.AnsibleUnicode object'' has no attribute ''keys'''

With the fix:

- debug:
    var: lookup('vars', 'sap_vm_provision_' + sap_vm_provision_iac_platform + '_host_specifications_dictionary')[sap_vm_provision_host_specification_plan][scaleout_origin_host_spec | default('su1hana01')].keys() | map('regex_findall', '^sap_.*') | flatten | select() | list 
--------------------------------------------------------------------------------------------

ok: [localhost] => 
  ? lookup('vars', 'sap_vm_provision_' + sap_vm_provision_iac_platform + '_host_specifications_dictionary')[sap_vm_provision_host_specification_plan][scaleout_origin_host_spec | default('su1hana01')].keys() | map('regex_findall', '^sap_.*') | flatten | select() | list
  : - sap_host_type
    - sap_storage_setup_sid
    - sap_storage_setup_host_type

[marcelmamula]

@ja9fuchs I did not have this issue in any of my runs, but change looks good. LGTM

[berndfinger]

LGTM