ansible_local: Add `pip_args` option

With this new option, it is now possible to pass additional arguments to
pip command when the `install_mode` is "pip".

(@gildegoma reworded the original commit message of pull request GH-8170)

plugins/provisioners/ansible/cap/guest/arch/ansible_install.rb

@@ -7,7 +7,7 @@ module VagrantPlugins
         module Arch
           module AnsibleInstall
 
-            def self.ansible_install(machine, install_mode, ansible_version)
+            def self.ansible_install(machine, install_mode, ansible_version, pip_args)
               if install_mode == :pip
                 raise Ansible::Errors::AnsiblePipInstallIsNotSupported
               else

plugins/provisioners/ansible/cap/guest/debian/ansible_install.rb

@@ -8,17 +8,17 @@ module VagrantPlugins
           module AnsibleInstall
 
 
-            def self.ansible_install(machine, install_mode, ansible_version)
+            def self.ansible_install(machine, install_mode, ansible_version, pip_args)
               if (install_mode == :pip)
-                ansible_pip_install machine, ansible_version
+                ansible_pip_install machine, ansible_version, pip_args
               else
                 ansible_apt_install machine
               end
             end
 
-            def self.ansible_pip_install(machine, ansible_version)
+            def self.ansible_pip_install(machine, ansible_version, pip_args)
               pip_setup machine
-              Pip::pip_install machine, "ansible", ansible_version
+              Pip::pip_install machine, "ansible", ansible_version, pip_args
             end
 
             private

plugins/provisioners/ansible/cap/guest/fedora/ansible_install.rb

@@ -8,12 +8,12 @@ module VagrantPlugins
         module Fedora
           module AnsibleInstall
 
-            def self.ansible_install(machine, install_mode, ansible_version)
+            def self.ansible_install(machine, install_mode, ansible_version, pip_args)
               rpm_package_manager = Facts::rpm_package_manager(machine)
 
               if install_mode == :pip
                 pip_setup machine
-                Pip::pip_install machine, "ansible", ansible_version
+                Pip::pip_install machine, "ansible", ansible_version, pip_args
               else
                 machine.communicate.sudo "#{rpm_package_manager} -y install ansible"
               end

plugins/provisioners/ansible/cap/guest/pip/pip.rb

@@ -5,7 +5,7 @@ module VagrantPlugins
       module Guest
         module Pip
 
-          def self.pip_install(machine, package, version = "", upgrade = true)
+          def self.pip_install(machine, package, version = "", pip_args = "", upgrade = true)
             upgrade_arg = "--upgrade " if upgrade
             version_arg = ""
 
@@ -13,7 +13,7 @@ module VagrantPlugins
               version_arg = "==#{version}"
             end
 
-            machine.communicate.sudo "pip install #{upgrade_arg}#{package}#{version_arg}"
+            machine.communicate.sudo "pip install #{pip_args} #{upgrade_arg}#{package}#{version_arg}"
           end
 
           def self.get_pip(machine)

plugins/provisioners/ansible/cap/guest/redhat/ansible_install.rb

@@ -8,10 +8,10 @@ module VagrantPlugins
         module RedHat
           module AnsibleInstall
 
-            def self.ansible_install(machine, install_mode, ansible_version)
+            def self.ansible_install(machine, install_mode, ansible_version, pip_args)
               if install_mode == :pip
                 pip_setup machine
-                Pip::pip_install machine, "ansible", ansible_version
+                Pip::pip_install machine, "ansible", ansible_version, pip_args
               else
                 ansible_rpm_install machine
               end

plugins/provisioners/ansible/cap/guest/ubuntu/ansible_install.rb

@@ -7,9 +7,9 @@ module VagrantPlugins
         module Ubuntu
           module AnsibleInstall
 
-            def self.ansible_install(machine, install_mode, ansible_version)
+            def self.ansible_install(machine, install_mode, ansible_version, pip_args)
               if install_mode == :pip
-                Debian::AnsibleInstall::ansible_pip_install machine, ansible_version
+                Debian::AnsibleInstall::ansible_pip_install machine, ansible_version, pip_args
               else
                 ansible_apt_install machine
               end

plugins/provisioners/ansible/config/guest.rb

@@ -10,6 +10,7 @@ module VagrantPlugins
         attr_accessor :tmp_path
         attr_accessor :install
         attr_accessor :install_mode
+        attr_accessor :pip_args
         attr_accessor :version
 
         def initialize
@@ -17,6 +18,7 @@ module VagrantPlugins
 
           @install           = UNSET_VALUE
           @install_mode      = UNSET_VALUE
+          @pip_args          = UNSET_VALUE
           @provisioning_path = UNSET_VALUE
           @tmp_path          = UNSET_VALUE
           @version           = UNSET_VALUE
@@ -27,6 +29,7 @@ module VagrantPlugins
 
           @install           = true                   if @install           == UNSET_VALUE
           @install_mode      = :default               if @install_mode      == UNSET_VALUE
+          @pip_args          = ""                     if @pip_args          == UNSET_VALUE
           @provisioning_path = "/vagrant"             if provisioning_path  == UNSET_VALUE
           @tmp_path          = "/tmp/vagrant-ansible" if tmp_path           == UNSET_VALUE
           @version           = ""                     if @version           == UNSET_VALUE

plugins/provisioners/ansible/provisioner/guest.rb

@@ -49,7 +49,7 @@ module VagrantPlugins
              (config.version.to_s.to_sym == :latest ||
               !@machine.guest.capability(:ansible_installed, config.version))
             @machine.ui.detail I18n.t("vagrant.provisioners.ansible.installing")
-            @machine.guest.capability(:ansible_install, config.install_mode, config.version)
+            @machine.guest.capability(:ansible_install, config.install_mode, config.version, config.pip_args)
           end
 
           # Check that Ansible Playbook command is available on the guest

test/unit/plugins/provisioners/ansible/config/guest_test.rb

@@ -27,6 +27,7 @@ describe VagrantPlugins::Ansible::Config::Guest do
                             install_mode
                             inventory_path
                             limit
+                            pip_args
                             playbook
                             playbook_command
                             provisioning_path

website/source/docs/provisioning/ansible_local.html.md

@@ -79,6 +79,9 @@ This section lists the _specific_ options for the Ansible Local provisioner. In
 
     The default value is `:default`, and any invalid value for this option will silently fall back to the default value.
 
+- `pip_args` (string) - When Ansible is installed via pip this option allows the defition of additional pip arguments to be passed along on the
+command line (for example, [--index-url](https://pip.pypa.io/en/stable/reference/pip_install/#cmdoption-i)).
+
 - `provisioning_path` (string) - An absolute path on the guest machine where the Ansible files are stored. The `ansible-galaxy` and `ansible-playbook` commands are executed from this directory. This is the location to place an [ansible.cfg](http://docs.ansible.com/ansible/intro_configuration.html) file, in case you need it.
 
     The default value is `/vagrant`.