Move sanity_checks into custom action plugin

This commit moves sanity_checks tasks into a custom
action plugin that is only run against a single host.

This will result in a large reduction of tasks during initialization

playbooks/init/sanity_checks.yml

@@ -1,51 +1,15 @@
 ---
 - name: Verify Requirements
-  hosts: oo_all_hosts
+  hosts: oo_first_master
+  roles:
+  - role: lib_utils
   tasks:
-  - fail:
-      msg: Flannel can not be used with openshift sdn, set openshift_use_openshift_sdn=false if you want to use flannel
-    when: openshift_use_openshift_sdn | default(true) | bool and openshift_use_flannel | default(false) | bool
-
-  - fail:
-      msg: Nuage sdn can not be used with openshift sdn, set openshift_use_openshift_sdn=false if you want to use nuage
-    when: openshift_use_openshift_sdn | default(true) | bool and openshift_use_nuage | default(false) | bool
-
-  - fail:
-      msg: Nuage sdn can not be used with flannel
-    when: openshift_use_flannel | default(false) | bool and openshift_use_nuage | default(false) | bool
-
-  - fail:
-      msg: Contiv can not be used with openshift sdn, set openshift_use_openshift_sdn=false if you want to use contiv
-    when: openshift_use_openshift_sdn | default(true) | bool and openshift_use_contiv | default(false) | bool
-
-  - fail:
-      msg: Contiv can not be used with flannel
-    when: openshift_use_flannel | default(false) | bool and openshift_use_contiv | default(false) | bool
-
-  - fail:
-      msg: Contiv can not be used with nuage
-    when: openshift_use_nuage | default(false) | bool and openshift_use_contiv | default(false) | bool
-
-  - fail:
-      msg: Calico can not be used with openshift sdn, set openshift_use_openshift_sdn=false if you want to use Calico
-    when: openshift_use_openshift_sdn | default(true) | bool and openshift_use_calico | default(false) | bool
-
-  - fail:
-      msg: The Calico playbook does not yet integrate with the Flannel playbook in Openshift. Set either openshift_use_calico or openshift_use_flannel, but not both.
-    when: openshift_use_calico | default(false) | bool and openshift_use_flannel | default(false) | bool
-
-  - fail:
-      msg: Calico can not be used with Nuage in Openshift. Set either openshift_use_calico or openshift_use_nuage, but not both
-    when: openshift_use_calico | default(false) | bool and openshift_use_nuage | default(false) | bool
-
-  - fail:
-      msg: Calico can not be used with Contiv in Openshift. Set either openshift_use_calico or openshift_use_contiv, but not both
-    when: openshift_use_calico | default(false) | bool and openshift_use_contiv | default(false) | bool
-
-  - fail:
-      msg: openshift_hostname must be 63 characters or less
-    when: openshift_hostname is defined and openshift_hostname | length > 63
-
-  - fail:
-      msg: openshift_public_hostname must be 63 characters or less
-    when: openshift_public_hostname is defined and openshift_public_hostname | length > 63
+  # sanity_checks is a custom action plugin defined in lib_utils.
+  # This module will loop through all the hostvars for each host
+  # specified in check_hosts.
+  # Since sanity_checks is an action_plugin, it executes on the control host.
+  # Thus, sanity_checks cannot gather new information about any hosts.
+  - name: Run variable sanity checks
+    sanity_checks:
+      check_hosts: "{{ groups['oo_all_hosts'] }}"
+    run_once: True

roles/lib_utils/action_plugins/sanity_checks.py

@@ -0,0 +1,96 @@
+"""
+Ansible action plugin to ensure inventory variables are set
+appropriately and no conflicting options have been provided.
+"""
+from ansible.plugins.action import ActionBase
+from ansible import errors
+
+# Tuple of variable names and default values if undefined.
+NET_PLUGIN_LIST = (('openshift_use_openshift_sdn', True),
+                   ('openshift_use_flannel', False),
+                   ('openshift_use_nuage', False),
+                   ('openshift_use_contiv', False),
+                   ('openshift_use_calico', False))
+
+
+def to_bool(var_to_check):
+    """Determine a boolean value given the multiple
+       ways bools can be specified in ansible."""
+    yes_list = (True, 1, "True", "1", "true", "Yes", "yes")
+    return var_to_check in yes_list
+
+
+class ActionModule(ActionBase):
+    """Action plugin to execute sanity checks."""
+    def template_var(self, hostvars, host, varname):
+        """Retrieve a variable from hostvars and template it.
+           If undefined, return None type."""
+        res = hostvars[host].get(varname)
+        if res is None:
+            return None
+        return self._templar.template(res)
+
+    def network_plugin_check(self, hostvars, host):
+        """Ensure only one type of network plugin is enabled"""
+        res = []
+        # Loop through each possible network plugin boolean, determine the
+        # actual boolean value, and append results into a list.
+        for plugin, default_val in NET_PLUGIN_LIST:
+            res_temp = self.template_var(hostvars, host, plugin)
+            if res_temp is None:
+                res_temp = default_val
+            res.append(to_bool(res_temp))
+
+        if sum(res) != 1:
+            plugin_str = list(zip([x[0] for x in NET_PLUGIN_LIST], res))
+
+            msg = "Host Checked: {} Only one of must be true. Found: {}".format(host, plugin_str)
+            raise errors.AnsibleModuleError(msg)
+
+    def check_hostname_vars(self, hostvars, host):
+        """Checks to ensure openshift_hostname
+           and openshift_public_hostname
+           conform to the proper length of 63 characters or less"""
+        for varname in ('openshift_public_hostname', 'openshift_hostname'):
+            var_value = self.template_var(hostvars, host, varname)
+            if var_value and len(var_value) > 63:
+                msg = '{} must be 63 characters or less'.format(varname)
+                raise errors.AnsibleModuleError(msg)
+
+    def run_checks(self, hostvars, host):
+        """Execute the hostvars validations against host"""
+        # msg = hostvars[host]['ansible_default_ipv4']
+        self.network_plugin_check(hostvars, host)
+        self.check_hostname_vars(hostvars, host)
+
+    def run(self, tmp=None, task_vars=None):
+        result = super(ActionModule, self).run(tmp, task_vars)
+
+        # self.task_vars holds all in-scope variables.
+        # Ignore settting self.task_vars outside of init.
+        # pylint: disable=W0201
+        self.task_vars = task_vars or {}
+
+        # self._task.args holds task parameters.
+        # check_hosts is a parameter to this plugin, and should provide
+        # a list of hosts.
+        check_hosts = self._task.args.get('check_hosts')
+        if not check_hosts:
+            msg = "check_hosts is required"
+            raise errors.AnsibleModuleError(msg)
+
+        # We need to access each host's variables
+        hostvars = self.task_vars.get('hostvars')
+        if not hostvars:
+            msg = hostvars
+            raise errors.AnsibleModuleError(msg)
+
+        # We loop through each host in the provided list check_hosts
+        for host in check_hosts:
+            self.run_checks(hostvars, host)
+
+        result["changed"] = False
+        result["failed"] = False
+        result["msg"] = "Sanity Checks passed"
+
+        return result