cloud-init-dev team mailing list archive

[Scott Moser <ssmoser2+ubuntu@xxxxxxxxx>]

Scott Moser has proposed merging ~smoser/cloud-init:bug/1732964-kill-dhclient-on-ec2 into cloud-init:master.

Commit message:
EC2: Kill dhclient process used in sandbox dhclient.

dhclient runs, obtains a address and then backgrounds itself.
cloud-init did not take care to kill it after it was done with it.
After it has run and created the leases, we can kill it.

LP: #1732964

Requested reviews:
  cloud-init commiters (cloud-init-dev)
Related bugs:
  Bug #1732964 in cloud-init: "dhclient process started by cloud-init-local.service still running afterwards"
  https://bugs.launchpad.net/cloud-init/+bug/1732964

For more details, see:
https://code.launchpad.net/~smoser/cloud-init/+git/cloud-init/+merge/333905
-- 
Your team cloud-init commiters is requested to review the proposed merge of ~smoser/cloud-init:bug/1732964-kill-dhclient-on-ec2 into cloud-init:master.

diff --git a/cloudinit/net/dhcp.py b/cloudinit/net/dhcp.py
index 0cba703..f3a412a 100644
--- a/cloudinit/net/dhcp.py
+++ b/cloudinit/net/dhcp.py
@@ -8,6 +8,7 @@ import configobj
 import logging
 import os
 import re
+import signal
 
 from cloudinit.net import find_fallback_nic, get_devicelist
 from cloudinit import temp_utils
@@ -119,7 +120,13 @@ def dhcp_discovery(dhclient_cmd_path, interface, cleandir):
     cmd = [sandbox_dhclient_cmd, '-1', '-v', '-lf', lease_file,
            '-pf', pid_file, interface, '-sf', '/bin/true']
     util.subp(cmd, capture=True)
-    return parse_dhcp_lease_file(lease_file)
+    pid = None
+    try:
+        pid = int(util.load_file(pid_file).strip())
+        return parse_dhcp_lease_file(lease_file)
+    finally:
+        if pid:
+            os.kill(pid, signal.SIGKILL)
 
 
 def networkd_parse_lease(content):