From 0964b42e5117cce640a8ba9102a76fa54a698898 Mon Sep 17 00:00:00 2001 From: Scott Moser Date: Mon, 21 Mar 2016 21:47:24 -0400 Subject: quickly check to see if the previous instance id is still valid This adds a check in cloud-init to see if the existing (cached) datasource is still valid. It relies on support from the Datasource to implement 'check_instance_id'. That method should quickly determine (if possible) if the instance id found in the datasource is still valid. This means that we can still notice new instance ids without depending on a network datasource on every boot. I've also implemented check_instance_id for the superclass and for 3 classes: DataSourceAzure (check dmi data) DataSourceOpenstack (check dmi data) DataSourceNocloud (check the seeded data or kernel command line) LP: #1553815 --- cloudinit/stages.py | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) (limited to 'cloudinit/stages.py') diff --git a/cloudinit/stages.py b/cloudinit/stages.py index dbcf3d55..edad6450 100644 --- a/cloudinit/stages.py +++ b/cloudinit/stages.py @@ -140,7 +140,7 @@ class Init(object): ] return initial_dirs - def purge_cache(self, rm_instance_lnk=True): + def purge_cache(self, rm_instance_lnk=False): rm_list = [] rm_list.append(self.paths.boot_finished) if rm_instance_lnk: @@ -238,21 +238,29 @@ class Init(object): cfg_list = self.cfg.get('datasource_list') or [] return (cfg_list, pkg_list) - def _get_data_source(self): + def _get_data_source(self, existing): if self.datasource is not NULL_DATA_SOURCE: return self.datasource with events.ReportEventStack( name="check-cache", - description="attempting to read from cache", + description="attempting to read from cache [%s]" % existing, parent=self.reporter) as myrep: ds = self._restore_from_cache() - if ds: - LOG.debug("Restored from cache, datasource: %s", ds) - myrep.description = "restored from cache" + if ds and existing == "trust": + myrep.description = "restored from cache: %s" % ds + elif ds and existing == "check": + if hasattr(ds, 'check_instance_id') and ds.check_instance_id(): + myrep.description = "restored from checked cache: %s" % ds + else: + myrep.description = "cache invalid in datasource: %s" % ds + ds = None else: myrep.description = "no cache found" + LOG.debug(myrep.description) + if not ds: + util.del_file(self.paths.instance_link) (cfg_list, pkg_list) = self._get_datasources() # Deep copy so that user-data handlers can not modify # (which will affect user-data handlers down the line...) @@ -332,8 +340,8 @@ class Init(object): self._reset() return iid - def fetch(self): - return self._get_data_source() + def fetch(self, existing="check"): + return self._get_data_source(existing=existing) def instancify(self): return self._reflect_cur_instance() -- cgit v1.2.3