Allow extra packages to be installed with ironic

Add a variable ironic_extra_packages, which is a list of pip-installable
packages to be installed alongside ironic. This is especially useful for
out-of-tree drivers.

Change-Id: If918f57ee9c752adb793e3498c1403df5fd4894f

playbooks/roles/bifrost-ironic-install/defaults/main.yml

@@ -97,6 +97,11 @@ enabled_boot_interfaces: "ilo-virtual-media,pxe"
 enabled_management_interfaces: "ilo,ipmitool,ucsm"
 enabled_power_interfaces: "ilo,ipmitool,ucsm"
 
+# Extra pip packages to install with ironic
+# This should be a list of pip-installable references.
+# default: empty list
+ironic_extra_packages: []
+
 # DHCP pool for requests -- ignored if inventory_dhcp is set to True
 # since IP allocation will be static.
 dhcp_pool_start: 192.168.1.200

playbooks/roles/bifrost-ironic-install/tasks/install.yml

@@ -114,6 +114,12 @@
       (ansible_distribution == 'Ubuntu' and ansible_distribution_version|version_compare('14.10', '==')) or
       (ansible_distribution == 'Fedora' and ansible_distribution_version|version_compare('25', '>='))
 
+- name: "Install extra packages for ironic"
+  include: pip_install.yml
+    package={{ item }}
+    extra_args="-c {{ upper_constraints_file }}"
+  with_items: "{{ ironic_extra_packages }}"
+
 - name: "Install Ironic using pip"
   include: pip_install.yml
     package=ironic

releasenotes/notes/ironic-extra-packages-e3ad3e4a85e59049.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Extra packages to install with ironic may be specified as a list in the
+    variable ironic_extra_packages. This is especially useful for out-of-tree
+    drivers.