Rabi, Good point. I suppose, that the root cause of it is gap in our documentation. Unfortunately I can not find any clear description what's the differences or how it should work (especially with examples) in our documentation. [1]
May be we need to improve it by adding more examples ? [1] http://docs.openstack.org/developer/heat/template_guide/hot_spec.html#get-attr On 24 March 2016 at 08:39, Rabi Mishra <ramis...@redhat.com> wrote: >> On Wed, Mar 23, 2016 at 05:25:57PM +0300, Sergey Kraynev wrote: >> > Hello, >> > It looks similar on issue, which was discussed here [1] >> > I suppose, that the root cause is incorrect using get_attr for your >> > case. >> > Probably you got "list" instead of "string". >> > F.e. if I do something similar: >> > outputs: >> > rg_1: >> > value: {get_attr: [rg_a, rg_a_public_ip]} >> > rg_2: >> > value: {get_attr: [rg_a, rg_a_public_ip, 0]} >> > >> > rg_3: >> > value: {get_attr: [rg_a]} >> > rg_4: >> > value: {get_attr: [rg_a, resource.0.rg_a_public_ip]} >> > where rg_a is also resource group which uses custom template as >> > resource. >> > the custom template has output value rg_a_public_ip. >> > The output for it looks like [2] >> > So as you can see, that in first case (like it is used in your example), >> > get_attr returns list with one element. >> > rg_2 is also wrong, because it takes first symbol from sting with IP >> > address. >> >> Shouldn't rg_2 and rg_4 be equivalent? > > They are the same for template version 2013-05-23. However, they behave > differently > from the next version(2014-10-16) onward and return a list of characters. I > think > this is due to the fact that `get_attr` function mapping is changed from > 2014-10-16. > > > 2013-05-23 - > https://github.com/openstack/heat/blob/master/heat/engine/hot/template.py#L70 > 2014-10-16 - > https://github.com/openstack/heat/blob/master/heat/engine/hot/template.py#L291 > > This makes me wonder why would a template author do something like > {get_attr: [rg_a, rg_a_public_ip, 0]} when he can easily do > {get_attr: [rg_a, resource.0.rg_a_public_ip]} or {get_attr: [rg_a, > resource.0, rg_a_public_ip]} > for specific resource atrributes. > > I understand that {get_attr: [rg_a, rg_a_public_ip]} cane be useful when we > just want to use > the list of attributes. > > >> >> {get_attr: [rg_a, rg_a_public_ip]} should return a list of all >> rg_a_public_ip attributes (one list item for each resource in the group), >> then the 0 should select the first item from that list? >> >> If it's returning the first character of the first element, that sounds >> like a bug to me? >> >> Steve >> >> __________________________________________________________________________ >> OpenStack Development Mailing List (not for usage questions) >> Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >> > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Regards, Sergey. __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev