Add --no-binary option to wheel compile task

There are situations where you may wish to ensure that a package
is always built from source, regardless of whether a pre-compiled
wheel is available on one of the indexes.

This patch adds the ability to set a list of packages which must
always be compiled from source.

Change-Id: I2f47d94c58503514a3f9a0a62081cbc1ca53613b

defaults/main.yml

@@ -33,6 +33,12 @@ repo_build_release_tag: "untagged"
 #repo_build_pip_extra_indexes:
 #  - "https://pypi.python.org/simple"
 
+# Optionally set this to a list of packages which must always have the wheel
+# compiled from source. This will ensure that a pre-compiled wheel is not
+# downloaded from any of the indexes.
+#repo_build_pip_no_binary:
+#  - libvirt-python
+
 # TODO(odyssey4me): Deprecate this var for Mitaka & mark for removal
 #                   in Newton.
 # repo_build_pip_extra_index: "https://pypi.python.org/simple"

tasks/repo_build.yml

@@ -35,6 +35,7 @@
     --find-links {{ repo_build_global_links_path }}
     --find-links {{ repo_build_output }}
     --constraint {{ repo_build_release_path }}/{{ repo_build_release_tag }}/requirements_constraints.txt
+    {% if repo_build_pip_no_binary is defined %}--no-binary {{ repo_build_pip_no_binary | join(',') }}{% endif %}
     {% if repo_build_pip_default_index is defined %}--index-url {{ repo_build_pip_default_index }}
     --trusted-host {{ repo_build_pip_default_index | netloc_no_port }}{% endif %}
     {% if repo_build_pip_extra_index is defined %}--extra-index-url {{ repo_build_pip_extra_index }}