snappy: disable by default

this does 2 things actually
a.) disables snappy by default, and adds checks to filesystem to enable it
    this way it runs on snappy systems, but not on others.
b.) removes the 'render2env' that was mostly spike code.

LP: #1428495

1 files changed, 31 insertions, 51 deletions

diff --git a/cloudinit/config/cc_snappy.py b/cloudinit/config/cc_snappy.py
index 1588443f..133336d4 100644
--- a/cloudinit/config/cc_snappy.py
+++ b/cloudinit/config/cc_snappy.py
@@ -14,15 +14,16 @@ LOG = logging.getLogger(__name__)
 frequency = PER_INSTANCE
 SNAPPY_ENV_PATH = "/writable/system-data/etc/snappy.env"
 
-CI_SNAPPY_CFG = {
-    'env_file_path': SNAPPY_ENV_PATH,
+BUILTIN_CFG = {
     'packages': [],
     'packages_dir': '/writable/user-data/cloud-init/click_packages',
-    'ssh_enabled': False
+    'ssh_enabled': False,
+    'system_snappy': "auto"
 }
 
 """
 snappy:
+  system_snappy: auto
   ssh_enabled: True
   packages:
     - etcd
@@ -30,25 +31,6 @@ snappy:
 """
 
 
-def flatten(data, fill=None, tok="_", prefix='', recurse=True):
-    if fill is None:
-        fill = {}
-    for key, val in data.items():
-        key = key.replace("-", "_")
-        if isinstance(val, dict) and recurse:
-            flatten(val, fill, tok=tok, prefix=prefix + key + tok,
-                    recurse=recurse)
-        elif isinstance(key, str):
-            fill[prefix + key] = val
-    return fill
-
-
-def render2env(data, tok="_", prefix=''):
-    flat = flatten(data, tok=tok, prefix=prefix)
-    ret = ["%s='%s'" % (key, val) for key, val in flat.items()]
-    return '\n'.join(ret) + '\n'
-
-
 def install_package(pkg_name, config=None):
     cmd = ["snappy", "install"]
     if config:
@@ -98,36 +80,34 @@ def disable_enable_ssh(enabled):
         util.write_file(not_to_be_run, "cloud-init\n")
 
 
+def system_is_snappy():
+    # channel.ini is configparser loadable.
+    # snappy will move to using /etc/system-image/config.d/*.ini
+    # this is certainly not a perfect test, but good enough for now.
+    content = util.load_file("/etc/system-image/channel.ini", quiet=True)
+    if 'ubuntu-core' in content.lower():
+        return True
+    if os.path.isdir("/etc/system-image/config.d/"):
+        return True
+    return False
+
+
 def handle(name, cfg, cloud, log, args):
-    mycfg = cfg.get('snappy', {'ssh_enabled': False})
+    cfgin = cfg.get('snappy')
+    if not cfgin:
+        cfgin = {}
+    mycfg = util.mergemanydict([cfgin, BUILTIN_CFG])
+
+    sys_snappy = str(mycfg.get("system_snappy", "auto"))
+    if util.is_false(sys_snappy):
+        LOG.debug("%s: System is not snappy. disabling", name)
+        return
 
-    if not mycfg:
-        LOG.debug("%s: no top level found", name)
+    if sys_snappy.lower() == "auto" and not(system_is_snappy()):
+        LOG.debug("%s: 'auto' mode, and system not snappy", name)
         return
 
-    # take out of 'cfg' the cfg keys that cloud-init uses, so
-    # mycfg has only content external to cloud-init.
-    ci_cfg = CI_SNAPPY_CFG.copy()
-    for i in ci_cfg:
-        if i in mycfg:
-            ci_cfg[i] = mycfg[i]
-            del mycfg[i]
-
-    # render the flattened environment variable style file to a path
-    # this was useful for systemd config environment files.  given:
-    # snappy:
-    #   foo:
-    #     bar: wark
-    #     cfg1:
-    #       key1: value
-    # you get the following in env_file_path.
-    #   foo_bar=wark
-    #   foo_cfg1_key1=value
-    contents = render2env(mycfg)
-    header = '# for internal use only, not a guaranteed interface\n'
-    util.write_file(ci_cfg['env_file_path'], header + render2env(mycfg))
-
-    install_packages(ci_cfg['packages_dir'],
-                     ci_cfg['packages'])
-
-    disable_enable_ssh(ci_cfg.get('ssh_enabled', False))
+    install_packages(mycfg['packages_dir'],
+                     mycfg['packages'])
+
+    disable_enable_ssh(mycfg.get('ssh_enabled', False))