Modified image name not correct generated in container image prepare workflow

[Lars Kellogg-Stedman]

I am trying to build a modified ironic conductor image as part of the container-image-prepare workflow. The input to c-i-p looks like this:

  parameter_defaults:
    ContainerImagePrepare:
    - tag_from_label: rdo_version
      excludes:
        - ironic-conductor
      set:
        name_prefix: centos-binary-
        name_suffix: ''
        namespace: docker.io/tripleomaster
        neutron_driver: null
        [...all the openshift entries elided...]
        tag: current-tripleo

    - tag_from_label: rdo_version
      includes:
        - ironic-conductor
      modify_role: tripleo-modify-image
      modify_append_tag: "-gerrit-640930"
      modify_vars:
        tasks_from: dev_install.yml
        refspecs:
          - project: ironic
            refspec: refs/changes/30/640930/6
      set:
        name_prefix: centos-binary-
        name_suffix: ''
        namespace: docker.io/tripleomaster
        neutron_driver: null
        tag: current-tripleo

I run c-i-p like this:

    sudo openstack tripleo container image prepare \
            ...several -e arguments...
            -e container-prepare-parameters.yaml \
            --output-env container-images.yaml

c-i-p builds and pushes the modified image:

  Trying to pull 192.168.23.1:8787/tripleomaster/centos-binary-ironic-conductor:56eedaf13617f1880ce5b1b268db53a774f453c1_a77b7752...Getting image source signatures
  Copying blob a02a4930cb5d: 71.68 MiB / 71.68 MiB [=========================] 24s
  [...]
  Copying config 86ac93aa6303: 25.68 KiB / 25.68 KiB [========================] 0s
  Writing manifest to image destination
  Storing signatures
  INFO[0007] created - from /var/lib/containers/storage/overlay/a060c4fd8e9b88b19ebe699e3a21f69b5bfe3a7f2e3ab09d6b80d4dc09776843/diff and /var/lib/containers/storage/overlay-layers/a060c4fd8e9b88b19ebe699e3a21f69b5bfe3a7f2e3ab09d6b80d4dc09776843.tar-split.gz (wrote 126750720 bytes)
  Completed modify and upload for image docker.io/tripleomaster/centos-binary-ironic-conductor:56eedaf13617f1880ce5b1b268db53a774f453c1_a77b7752
  Removing local copy of 192.168.23.1:8787/tripleomaster/centos-binary-ironic-conductor:56eedaf13617f1880ce5b1b268db53a774f453c1_a77b7752
  Removing local copy of 192.168.23.1:8787/tripleomaster/centos-binary-ironic-conductor:56eedaf13617f1880ce5b1b268db53a774f453c1_a77b7752-gerrit-640930

But the generated output environment file contains:

  DockerIronicConductorImage: docker.io/tripleomaster/centos-binary-ironic-conductor:56eedaf13617f1880ce5b1b268db53a774f453c1_a77b7752-gerrit-640930

Which is incorrect: it's using the new tag, but it's referencing the wrong repository server (docker.io instead of the local registry).