ansible_plugin.py: Extend ansible plugin parameters

Add the ability to optionally configure:
- The inventory group name
- The Ansible tags to be executed
- An Ansible configuration file
- An `extra_vars` dictionary to be passed to the playbook

This enables existing image-creation builds with complex Ansible
playbooks to be converted to use vmdb2.

2 files changed, 57 insertions, 14 deletions

diff --git a/vmdb/plugins/ansible.mdwn b/vmdb/plugins/ansible.mdwn
index fa014ad..3e17f99 100644
--- a/vmdb/plugins/ansible.mdwn
+++ b/vmdb/plugins/ansible.mdwn
@@ -10,9 +10,20 @@ Step keys:
 
 * `ansible` — REQUIRED; value is the tag of the root filesystem.
 
+* `config_file` — OPTIONAL; value is the filename of an Ansible
+  configuration file, relative to the .vmdb file.
+
+* `group` — OPTIONAL; the name of the Ansible inventory group. Defaults
+  to "image"
+
 * `playbook` — REQUIRED; value is the filename of the Ansible
   playbook, relative to the .vmdb file.
 
+* `tags` — OPTIONAL; a comma-separated list of Ansible tags to execute
+
+* `extra_vars` — OPTIONAL; a dictionary defining variables to pass to the
+  Ansible playbook.
+
 Example (in the .vmdb file):
 
     - apt: install
@@ -21,6 +32,12 @@ Example (in the .vmdb file):
 
     - ansible: root
       playbook: foo.yml
+      tags: bar
+      config_file: ansible.cfg
+      group: AwesomeGroup
+      extra_vars:
+        iface:
+          name: eth0
 
 Example (`foo.yml`):
 
@@ -38,9 +55,9 @@ Example (`foo.yml`):
         - name: "configure networking"
           copy:
             content: |
-              auto eth0
-              iface eth0 inet dhcp
-              iface eth0 inet6 auto
+              auto {{ iface.name }}
+              iface {{ iface.name }} inet dhcp
+              iface {{ iface.name }} inet6 auto
             dest: /etc/network/interfaces.d/wired
 
       vars:
diff --git a/vmdb/plugins/ansible_plugin.py b/vmdb/plugins/ansible_plugin.py
index d237c5b..564a321 100644
--- a/vmdb/plugins/ansible_plugin.py
+++ b/vmdb/plugins/ansible_plugin.py
@@ -15,10 +15,11 @@
 #
 # =*= License: GPL-3+ =*=
 
-
 import os
 import tempfile
 
+import yaml
+
 import vmdb
 
 
@@ -29,24 +30,43 @@ class AnsiblePlugin(vmdb.Plugin):
 
 class AnsibleStepRunner(vmdb.StepRunnerInterface):
     def get_key_spec(self):
-        return {"ansible": str, "playbook": str}
+        return {
+            "ansible": str,
+            "playbook": str,
+            "group": "image",
+            "tags": "all",
+            "config_file": "",
+            "extra_vars": {},
+        }
 
     def run(self, values, settings, state):
         tag = values["ansible"]
         playbook = values["playbook"]
+        ansible_tags = values["tags"]
+        group_name = values["group"]
+        config_file = values["config_file"]
+        extra_vars = values["extra_vars"]
         mount_point = state.tags.get_builder_mount_point(tag)
         rootfs_tarball = settings["rootfs-tarball"]
 
-        state.ansible_inventory = self.create_inventory(mount_point)
+        state.ansible_inventory = self.create_inventory(mount_point, group_name)
         vmdb.progress(
             "Created {} for Ansible inventory".format(state.ansible_inventory)
         )
 
-        vars_filename = self.create_vars(rootfs_tarball)
-        vmdb.progress("Created {} for Ansible variables".format(vars_filename))
+        extra_vars['rootfs_tarball'] = rootfs_tarball
+        state.ansible_vars_file = self.create_vars_file(extra_vars)
+        vmdb.progress(f"Created {state.ansible_vars_file} for Ansible variables")
 
         env = dict(os.environ)
         env["ANSIBLE_NOCOWS"] = "1"
+        if config_file:
+            if os.path.exists(config_file):
+                env["ANSIBLE_CONFIG"] = config_file
+                vmdb.progress(f"Using Ansible config file {config_file}")
+            else:
+                raise RuntimeError(
+                    f"Ansible config file {config_file} does not exist")
         vmdb.runcmd(
             [
                 "ansible-playbook",
@@ -54,26 +74,32 @@ class AnsibleStepRunner(vmdb.StepRunnerInterface):
                 "chroot",
                 "-i",
                 state.ansible_inventory,
+                "--tags",
+                ansible_tags,
                 "-e",
-                "@{}".format(vars_filename),
+                f"@{state.ansible_vars_file}",
                 playbook,
             ],
             env=env,
         )
 
     def teardown(self, values, settings, state):
+        if hasattr(state, "ansible_vars_file"):
+            vmdb.progress(f"Removing {state.ansible_vars_file}")
+            os.remove(state.ansible_vars_file)
+
         if hasattr(state, "ansible_inventory"):
             vmdb.progress("Removing {}".format(state.ansible_inventory))
             os.remove(state.ansible_inventory)
 
-    def create_inventory(self, chroot):
+    def create_inventory(self, chroot, group_name):
         fd, filename = tempfile.mkstemp()
-        os.write(fd, "[image]\n{}\n".format(chroot).encode())
+        os.write(fd, f"[{group_name}]\n{chroot}\n".encode())
         os.close(fd)
         return filename
 
-    def create_vars(self, tarball):
-        fd, filename = tempfile.mkstemp()
-        os.write(fd, 'rootfs_tarball: "{}"\n'.format(tarball).encode())
+    def create_vars_file(self, extra_vars):
+        fd, filename = tempfile.mkstemp(suffix=".yaml")
+        os.write(fd, yaml.dump(extra_vars).encode())
         os.close(fd)
         return filename