printing the error stream of the dhclient process before killing it (#369)

This introduces a way to log the dhclient error stream, and uses it for the Azure datasource (where we have a specific requirement for this data to be logged).

2 files changed, 11 insertions, 3 deletions

diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py
index 6d569057..41431a7a 100755
--- a/cloudinit/sources/DataSourceAzure.py
+++ b/cloudinit/sources/DataSourceAzure.py
@@ -35,7 +35,8 @@ from cloudinit.sources.helpers.azure import (
     get_system_info,
     report_diagnostic_event,
     EphemeralDHCPv4WithReporting,
-    is_byte_swapped)
+    is_byte_swapped,
+    dhcp_log_cb)
 
 LOG = logging.getLogger(__name__)
 
@@ -636,7 +637,8 @@ class DataSourceAzure(sources.DataSource):
                         name="obtain-dhcp-lease",
                         description="obtain dhcp lease",
                         parent=azure_ds_reporter):
-                    self._ephemeral_dhcp_ctx = EphemeralDHCPv4()
+                    self._ephemeral_dhcp_ctx = EphemeralDHCPv4(
+                        dhcp_log_func=dhcp_log_cb)
                     lease = self._ephemeral_dhcp_ctx.obtain_lease()
 
                 if vnet_switched:
diff --git a/cloudinit/sources/helpers/azure.py b/cloudinit/sources/helpers/azure.py
index 7bace8ca..7afa7ed8 100755
--- a/cloudinit/sources/helpers/azure.py
+++ b/cloudinit/sources/helpers/azure.py
@@ -626,10 +626,16 @@ def get_metadata_from_fabric(fallback_lease_file=None, dhcp_opts=None,
         shim.clean_up()
 
 
+def dhcp_log_cb(out, err):
+    report_diagnostic_event("dhclient output stream: %s" % out)
+    report_diagnostic_event("dhclient error stream: %s" % err)
+
+
 class EphemeralDHCPv4WithReporting(object):
     def __init__(self, reporter, nic=None):
         self.reporter = reporter
-        self.ephemeralDHCPv4 = EphemeralDHCPv4(iface=nic)
+        self.ephemeralDHCPv4 = EphemeralDHCPv4(
+            iface=nic, dhcp_log_func=dhcp_log_cb)
 
     def __enter__(self):
         with events.ReportEventStack(