wait less for the metadata service (by default)

Waiting around for a metadata service in a given datasource means that if its
not there all the subsequent datasources have to wait, and boot is slowed down.

As it is right now, EC2 is the only one that has the right to wait.  In the
past, we had to wait around for the EC2 metadata service.  I really do not want
to extend that courtesy to other cloud platforms.  A network based metadata
service should be up as soon as networking is up.

2 files changed, 14 insertions, 15 deletions

diff --git a/cloudinit/sources/DataSourceOpenStack.py b/cloudinit/sources/DataSourceOpenStack.py
index 69807798..7fafa3f7 100644
--- a/cloudinit/sources/DataSourceOpenStack.py
+++ b/cloudinit/sources/DataSourceOpenStack.py
@@ -45,6 +45,8 @@ class DataSourceOpenStack(openstack.SourceMixin, sources.DataSource):
         self.version = None
         self.files = {}
         self.ec2_metadata = None
+        if not self.ds_cfg:
+            self.ds_cfg = {}
 
     def __str__(self):
         root = sources.DataSource.__str__(self)
@@ -54,27 +56,25 @@ class DataSourceOpenStack(openstack.SourceMixin, sources.DataSource):
     def _get_url_settings(self):
         # TODO(harlowja): this is shared with ec2 datasource, we should just
         # move it to a shared location instead...
-        ds_cfg = self.ds_cfg
-        if not ds_cfg:
-            ds_cfg = {}
-        max_wait = 120
+        # Note: the defaults here are different though.
+
+        # max_wait < 0 indicates do not wait
+        max_wait = -1
+        timeout = 10
+
         try:
-            max_wait = int(ds_cfg.get("max_wait", max_wait))
+            max_wait = int(self.ds_cfg.get("max_wait", max_wait))
         except Exception:
             util.logexc(LOG, "Failed to get max wait. using %s", max_wait)
 
-        timeout = 50
         try:
-            timeout = max(0, int(ds_cfg.get("timeout", timeout)))
+            timeout = max(0, int(self.ds_cfg.get("timeout", timeout)))
         except Exception:
             util.logexc(LOG, "Failed to get timeout, using %s", timeout)
         return (max_wait, timeout)
 
     def wait_for_metadata_service(self):
-        ds_cfg = self.ds_cfg
-        if not ds_cfg:
-            ds_cfg = {}
-        urls = ds_cfg.get("metadata_urls", [DEF_MD_URL])
+        urls = self.ds_cfg.get("metadata_urls", [DEF_MD_URL])
         filtered = [x for x in urls if util.is_resolvable_url(x)]
         if set(filtered) != set(urls):
             LOG.debug("Removed the following from metadata urls: %s",
@@ -95,8 +95,6 @@ class DataSourceOpenStack(openstack.SourceMixin, sources.DataSource):
             url2base[md_url] = url
 
         (max_wait, timeout) = self._get_url_settings()
-        if max_wait <= 0:
-            return False
         start_time = time.time()
         avail_url = url_helper.wait_for_url(urls=md_urls, max_wait=max_wait,
                                             timeout=timeout,
@@ -104,8 +102,8 @@ class DataSourceOpenStack(openstack.SourceMixin, sources.DataSource):
         if avail_url:
             LOG.debug("Using metadata source: '%s'", url2base[avail_url])
         else:
-            LOG.critical("Giving up on md from %s after %s seconds",
-                         md_urls, int(time.time() - start_time))
+            LOG.debug("Giving up on OpenStack md from %s after %s seconds",
+                      md_urls, int(time.time() - start_time))
 
         self.metadata_address = url2base.get(avail_url)
         return bool(avail_url)
diff --git a/cloudinit/url_helper.py b/cloudinit/url_helper.py
index c116a484..4a83169a 100644
--- a/cloudinit/url_helper.py
+++ b/cloudinit/url_helper.py
@@ -266,6 +266,7 @@ def wait_for_url(urls, max_wait=None, timeout=None,
     max_wait:  roughly the maximum time to wait before giving up
                The max time is *actually* len(urls)*timeout as each url will
                be tried once and given the timeout provided.
+               a number <= 0 will always result in only one try
     timeout:   the timeout provided to urlopen
     status_cb: call method with string message when a url is not available
     headers_cb: call method with single argument of url to get headers