ec2_tag module: unable to delete tags using variable names

[Bruce Pennypacker]

I'm trying to do something that I thought was fairly straightforward but I'm not having any luck.  In a nutshell I need to delete a tag from an EC2 instance, but the name is a concatenation of a variable and a constant.  What I'm trying is basically this:

      vars:

         - foo: sometag

    - name: Delete tag

      local_action: ec2_tag state=absent

                            aws_access_key={{ AWS_ACCESS_KEY_ID }}

                            aws_secret_key={{ AWS_SECRET_ACCESS_KEY }}

                            region={{ AWS_REGION }}

                            resource={{ instanceId }}

      args:

          tags:

              "{{ foo }}-bar": some_value

The problem is that "{{ foo }}-bar" doesn't seem to get converted into "sometag-bar" before the module is called.  (foo is actually a fact of the host, so I can't just statically set the tag name) Bug? Feature?

Unrelated issue (or maybe not), but also dealing with the ec2_tag module: What's the correct way to reference the value of a tag when trying to delete it?  For whatever reason when using "state=absent" the ec2_module will only remove a tag if you specify both the name and the current value of the tag.  In other words, if you have an instance with a tag named foo that has a value of "bar" then the following will not remove the tag:

   - name: Delete tag

      local_action: ec2_tag state=absent

                            aws_access_key={{ AWS_ACCESS_KEY_ID }}

                            aws_secret_key={{ AWS_SECRET_ACCESS_KEY }}

                            region={{ AWS_REGION }}

                            resource={{ instanceId }}

      args:

          tags:

              foo: ''

The only way to get the ec2_tag module to actually delete the tag is to specify both the name & value of the tag, so you need to set the args as:

      args:

          tags:

              foo: bar

Because of this, and the fact that some of our tags have dynamic values, I'm trying to do something like this:

    - name: Get tags

      local_action: ec2_tag state=list

                            aws_access_key={{ AWS_ACCESS_KEY_ID }}

                            aws_secret_key={{ AWS_SECRET_ACCESS_KEY }}

                            region={{ AWS_REGION }}

                            resource={{ instanceId }}

      register: mytags

    - name: Delete env tag

      local_action: ec2_tag state=absent

                            aws_access_key={{ AWS_ACCESS_KEY_ID }}

                            aws_secret_key={{ AWS_SECRET_ACCESS_KEY }}

                            region={{ AWS_REGION }}

                            resource={{ instanceId }}

      args:

          tags:

              foo: mytags[ foo ]

But I'm unable to get anything here to work either, even if I set the name of the tag to a static value.  What's the proper way to reference the tags from "state=list" so that you can do something like delete a tag?

-Bruce