HostnameMap lookup may return unexpected results if hostname is not in the map

[Harald Jensås]

The use of str_replace to do lookup hostnames in HostnameMap may return unexptected resutls.

The code[1]:
        str_replace:
            template: {get_param: Hostname}
            params: {get_param: HostnameMap}

For example passing this data:

Hostname: overcloud-controller-123 HostnameMap: '{"overcloud-controller-12": "server-b", "overcloud-controller-1": "server-a"}'

Result value: server-b3

The str_replace will match on a substring if a key with the full string is not available in the map.

Most likely there are also other cases where the string matching would pick the wrong value.

[1] https://github.com/openstack/tripleo-heat-templates/blob/master/puppet/role.role.j2.yaml#L363-L365

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/582475

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/582475
Committed: https://git.openstack.org/cgit/openstack/tripleo-heat-templates/commit/?id=aeb783fdcfd40584e00206a947f391f8fc182126
Submitter: Zuul
Branch: master

commit aeb783fdcfd40584e00206a947f391f8fc182126
Author: Harald Jensås <email address hidden>
Date: Fri Jul 13 10:47:28 2018 +0200

    Fix HostnameMap lookup - replace str_replace with yaql

    Using str_replace when looking up hostnames in
    HostnameMap may return unpredictable results.
    For example if the map contain:

    HostnameMap:
      overcloud-compute-12: cmp-12-london
      overcloud-compute-123: cmp-123-berlin

    When we do string replace for a hostname that is
    not in the map (example: 'overcloud-compute-124')
    it will match on the substring. The result would
    be 'cmp-12-london4'.

    This change replaces the str_replace with a yaql
    expression that will return the value of they key
    matching the hostname provided. If the key is not
    in the map, the hostname is returned.

    Closes-Bug: #1781560
    Change-Id: Ia3a6a3539cd566131cd81b4d755190aa5b61a573

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/tripleo-heat-templates 9.0.0.0b4 development milestone.