lxd: general fix after testing

A few changes:
 a.) change to using '--name=value' rather than '--name' 'value'
 b.) make sure only strings are passed to command
     (useful for storage_create_loop: which is likely an integer)
 c.) document simple working example
 d.) support installing zfs if not present and storage_backedn has it.

3 files changed, 38 insertions, 13 deletions

diff --git a/cloudinit/config/cc_lxd.py b/cloudinit/config/cc_lxd.py
index aaafb643..84eec7a5 100644
--- a/cloudinit/config/cc_lxd.py
+++ b/cloudinit/config/cc_lxd.py
@@ -38,16 +38,36 @@ from cloudinit import util
 def handle(name, cfg, cloud, log, args):
     # Get config
     lxd_cfg = cfg.get('lxd')
-    if not lxd_cfg and isinstance(lxd_cfg, dict):
+    if not lxd_cfg:
         log.debug("Skipping module named %s, not present or disabled by cfg")
         return
+    if not isinstance(lxd_cfg, dict):
+        log.warn("lxd config must be a dictionary. found a '%s'",
+                 type(lxd_cfg))
+        return
+
+    init_cfg = lxd_cfg.get('init')
+    if not init_cfg:
+        init_cfg = {}
+
+    if not isinstance(init_cfg, dict):
+        log.warn("lxd/init config must be a dictionary. found a '%s'",
+                  type(init_cfg))
+        init_cfg = {}
+
+    packages = []
+    if (init_cfg.get("storage_backend") == "zfs" and not util.which('zfs')):
+       packages.append('zfs')
 
     # Ensure lxd is installed
     if not util.which("lxd"):
+        packages.append('lxd')
+    
+    if len(packages):
         try:
-            cloud.distro.install_packages(("lxd",))
+            cloud.distro.install_packages(packages)
         except util.ProcessExecutionError as e:
-            log.warn("no lxd executable and could not install lxd:", e)
+            log.warn("failed to install packages %s: %s", packages, e)
             return
 
     # Set up lxd if init config is given
@@ -55,14 +75,11 @@ def handle(name, cfg, cloud, log, args):
         'network_address', 'network_port', 'storage_backend',
         'storage_create_device', 'storage_create_loop',
         'storage_pool', 'trust_password')
-    init_cfg = lxd_cfg.get('init')
+
     if init_cfg:
-        if not isinstance(init_cfg, dict):
-            log.warn("lxd/init config must be a dictionary. found a '%s'",
-                      type(f))
-            return
         cmd = ['lxd', 'init', '--auto']
         for k in init_keys:
             if init_cfg.get(k):
-                cmd.extend(["--%s" % k.replace('_', '-'), init_cfg[k]])
+                cmd.extend(["--%s=%s" %
+                            (k.replace('_', '-'), str(init_cfg[k]))])
         util.subp(cmd)
diff --git a/doc/examples/cloud-config-lxd.txt b/doc/examples/cloud-config-lxd.txt
index f66da4c3..b9bb4aa5 100644
--- a/doc/examples/cloud-config-lxd.txt
+++ b/doc/examples/cloud-config-lxd.txt
@@ -19,3 +19,10 @@ lxd:
     network_port: 8443
     storage_backend: zfs
     storage_pool: datapool
+    storage_create_loop: 10
+
+
+# The simplist working configuration is
+# lxd:
+#  init:
+#   storage_backend: dir
diff --git a/tests/unittests/test_handler/test_handler_lxd.py b/tests/unittests/test_handler/test_handler_lxd.py
index 4d858b8f..65794a41 100644
--- a/tests/unittests/test_handler/test_handler_lxd.py
+++ b/tests/unittests/test_handler/test_handler_lxd.py
@@ -43,9 +43,10 @@ class TestLxd(t_help.TestCase):
         self.assertTrue(mock_util.which.called)
         init_call = mock_util.subp.call_args_list[0][0][0]
         self.assertEquals(init_call,
-                          ['lxd', 'init', '--auto', '--network-address',
-                           '0.0.0.0', '--storage-backend', 'zfs',
-                           '--storage-pool', 'poolname'])
+                          ['lxd', 'init', '--auto',
+                           '--network-address=0.0.0.0',
+                           '--storage-backend=zfs',
+                           '--storage-pool=poolname'])
 
     @mock.patch("cloudinit.config.cc_lxd.util")
     def test_lxd_install(self, mock_util):
@@ -55,4 +56,4 @@ class TestLxd(t_help.TestCase):
         cc_lxd.handle('cc_lxd', self.lxd_cfg, cc, LOG, [])
         self.assertTrue(cc.distro.install_packages.called)
         install_pkg = cc.distro.install_packages.call_args_list[0][0][0]
-        self.assertEquals(install_pkg, ('lxd',))
+        self.assertEquals(sorted(install_pkg), ['lxd', 'zfs'])