Build container images using pbrx

Add alpine packages to bindep and the pbrx-build-container-images job.

Depends-On: https://review.openstack.org/582380
Change-Id: I85c6db8d3d51f5df820e60fea8d1fea27eabec49

.zuul.yaml

@@ -135,6 +135,9 @@
         - build-sphinx-docs:
             vars:
               sphinx_python: python3
+        - pbrx-build-container-images:
+            vars:
+              pbrx_prefix: zuul
     gate:
       jobs:
         - tox-pep8
@@ -142,6 +145,9 @@
         - build-sphinx-docs:
             vars:
               sphinx_python: python3
+        - pbrx-build-container-images:
+            vars:
+              pbrx_prefix: zuul
     post:
       jobs:
         - publish-zuul-docs

bindep.txt

@@ -1,8 +1,15 @@
 # This is a cross-platform list tracking distribution packages needed by tests;
 # see http://docs.openstack.org/infra/bindep/ for additional information.
 
+gcc [compile test platform:rpm platform:apk]
 libffi-devel [platform:rpm]
 libffi-dev [platform:dpkg]
-python3-dev [platform:dpkg test]
-python3-devel [platform:rpm test]
+libffi-dev [compile test platform:apk]
+libffi [platform:apk]
+libressl-dev [compile test platform:apk]
+linux-headers [compile test platform:apk]
+make [compile test platform:apk]
+musl-dev [compile test platform:apk]
+python3-dev [compile test platform:dpkg]
+python3-devel [compile test platform:rpm]
 zookeeperd [platform:dpkg test]