Modify j2 template files in docker-dhcp-relay. Add dhcprelayd to group dhcp-relay instead of isc-dhcp-relay-VlanXXX, which would make dhcprelayd to become critical process.
In dhcprelayd, subscribe FEATURE table to check whether dhcp_server feature is enabled.
2.1 If dhcp_server feature is disabled, means we need original dhcp_relay functionality, dhcprelayd would do nothing. Because dhcrelay/dhcpmon configuration is generated in supervisord configuration, they will automatically run.
2.2 If dhcp_server feature is enabled, dhcprelayd will stop dhcpmon/dhcrelay processes started by supervisord and subscribe dhcp_server related tables in config_db to start dhcpmon/dhcrelay processes.
2.3 While dhcprelayd running, it will regularly check feature status (by default per 5s) and would encounter below 4 state change about dhcp_server feature:
A) disabled -> enabled
In this scenario, dhcprelayd will subscribe dhcp_server related tables and stop dhcpmon/dhcrelay processes started by supervisord and start new pair of dhcpmon/dhcrelay processes. After this, dhcpmon/dhcrelay processes are totally managed by dhcprelayd.
B) enabled -> enabled
In this scenaro, dhcprelayd will monitor db changes in dhcp_server related tables to determine whether to restart dhcpmon/dhrelay processes.
C) enabled -> disabled
In this scenario, dhcprelayd would unsubscribe dhcp_server related tables and kill dhcpmon/dhcrelay processes started by itself. And then dhcprelayd will start dhcpmon/dhcrelay processes via supervisorctl.
D) disabled -> disabled
dhcprelayd will check whether dhcrelay processes running status consistent with supervisord configuration file. If they are not consistent, dhcprelayd will kill itself, then dhcp_relay container will stop because dhcprelayd is critical process.
Why I did it
Currently SONiC use the 'isc-dhcp-relay' package to allow DHCP relay functionality on IPv4 networks only.
This will allow the IPv6 functionality along the IPv4 type.
How I did it
Edit supervisord template to start DHCPv6 instances when configured to do so on Config DB.
Align cfg unit test to the new change.
Add DHCPv6 relay minigraph parsing support and a suitable t0 topology xml file for UT.
How to verify it
Configure DHCPv6 agents as described on the feature HLD: Azure/SONiC#765
Test it with real client/server with IPv6 or use the dedicated automatic test: Azure/sonic-mgmt#3565
Signed-off-by: Shlomi Bitton <shlomibi@nvidia.com>
* Split docker-dhcp-relay.supervisord.conf.j2 template into several files for easier code maintenance
#### Why I did it
It is possible to have DHCP relay configuration with no servers/
helpers which result in DHCP container to crash. This PR fixes this
issue by not starting DHCP relay for vlans with no DHCP helpers.
resolves: #6931closes: #6931
#### How I did it
Do not add program group for dhcp relay with not dhcp helpers
#### How to verify it
Unit test
Recent changes brought l2 vlan concept which do not have DHCP
clients behind them and so DHCP relay is not required. Also,
dhcpmon fails to launch on those vlans as their interfaces
lack IP addresses. This PR limit launch of both DHCP relay
and dhcpmon to L3 vlans only.
singed-off-by: Tamer Ahmed <tamer.ahmed@microsoft.com>
- Why I did it
Initially, we used Monit to monitor critical processes in each container. If one of critical processes was not running
or crashed due to some reasons, then Monit will write an alerting message into syslog periodically. If we add a new process
in a container, the corresponding Monti configuration file will also need to update. It is a little hard for maintenance.
Currently we employed event listener of Supervisod to do this monitoring. Since processes in each container are managed by
Supervisord, we can only focus on the logic of monitoring.
- How I did it
We borrowed the event listener of Supervisord to monitor critical processes in containers. The event listener will take
following steps if it was notified one of critical processes exited unexpectedly:
The event listener will first check whether the auto-restart mechanism was enabled for this container or not. If auto-restart mechanism was enabled, event listener will kill the Supervisord process, which should cause the container to exit and subsequently get restarted.
If auto-restart mechanism was not enabled for this contianer, the event listener will enter a loop which will first sleep 1 minute and then check whether the process is running. If yes, the event listener exits. If no, an alerting message will be written into syslog.
- How to verify it
First, we need checked whether the auto-restart mechanism of a container was enabled or not by running the command show feature status. If enabled, one critical process should be selected and killed manually, then we need check whether the container will be restarted or not.
Second, we can disable the auto-restart mechanism if it was enabled at step 1 by running the commnad sudo config feature autorestart <container_name> disabled. Then one critical process should be selected and killed. After that, we will see the alerting message which will appear in the syslog every 1 minute.
- Which release branch to backport (provide reason below if selected)
201811
201911
[x ] 202006
**- Why I did it**
We were building a custom version of Supervisor because I had added patches to prevent hangs and crashes if the system clock ever rolled backward. Those changes were merged into the upstream Supervisor repo as of version 3.4.0 (http://supervisord.org/changes.html#id9), therefore, we should be able to simply install the vanilla package via pip. This will also allow us to easily move to Python 3, as Python 3 support was added in version 4.0.0.
**- How I did it**
- Remove Makefiles and patches for building supervisor package from source
- Install Python 3 supervisor package version 4.2.1 in Buster base container
- Also install Python 3 version of supervisord-dependent-startup in Buster base container
- Debian package installed binary in `/usr/bin/`, but pip package installs in `/usr/local/bin/`, so rather than update all absolute paths, I changed all references to simply call `supervisord` and let the system PATH find the executable to prevent future need for changes just in case we ever need to switch back to build a Debian package, then we won't need to modify these again.
- Install Python 2 supervisor package >= 3.4.0 in Stretch and Jessie base containers
Printing both snapshot and current counter sets will make it easier to pinpoint
which message type(s) is/are not being relayed. This PR prints both counter sets.
Also, this PR defines gnu11 as a C standard to compile with in order to avoid
making changes when porting to 201811 branch.
singed-off-by: Tamer Ahmed <tamer.ahmed@microsoft.com>
When BGP routes are missing, DHCP packets get relayed over mgmt
interface. This results in dhcpmon alerting that DHCP packets are
not being relayed. This is PR include mgmt interface as uplink
device, and so, if DHCP packet gets relayed over mgmt interface,
regular dhcpmon alert will not be issues. Instead, dhcpmon will
check the mgmt interface counts and issue a separate alert regarding
packets travelling through mgmt network.
In addition, this PR includes the following enhancements:
1. Add SIGUSR1 handler that prints out current packet counts
2. Increase alert grace window to 3 minutes from currently 2 minutes
3. Time is now computed more accurately
4. Print vlan name before counters
signed-off-by: Tamer Ahmed <tamer.ahmed@microsoft.com>
When stopping the swss, pmon or bgp containers, log messages like the following can be seen:
```
Aug 23 22:50:43.789760 sonic-dut INFO swss#supervisord 2020-08-23 22:50:10,061 ERRO pool dependent-startup event buffer overflowed, discarding event 34
Aug 23 22:50:43.789760 sonic-dut INFO swss#supervisord 2020-08-23 22:50:10,063 ERRO pool dependent-startup event buffer overflowed, discarding event 35
Aug 23 22:50:43.789760 sonic-dut INFO swss#supervisord 2020-08-23 22:50:10,064 ERRO pool dependent-startup event buffer overflowed, discarding event 36
Aug 23 22:50:43.789760 sonic-dut INFO swss#supervisord 2020-08-23 22:50:10,066 ERRO pool dependent-startup event buffer overflowed, discarding event 37
```
This is due to the number of programs in the container managed by supervisor, all generating events at the same time. The default event queue buffer size in supervisor is 10. This patch increases that value in all containers in order to eliminate these errors. As more programs are added to the containers, we may need to further adjust these values. I increased all buffer sizes to 25 except for containers with more programs or templated supervisor.conf files which allow for a variable number of programs. In these cases I increased the buffer size to 50. One final exception is the swss container, where the buffer fills up to ~50, so I increased this buffer to 100.
Resolves https://github.com/Azure/sonic-buildimage/issues/5241
DHCP relay MONitor (dhcpmon) keeps track of DORA messages. If DHCP Relay
is detected to be not forwarding DORA message, dhcpmon will log such event
to syslog. Under the hood dhcpmon keeps counts of clients DR messages,
forwarded DR messages, DHCP server OA messages, and forwarded OA messages.
dhcpmon will check every 12 sec (configurable) if counts are monotonically
increasing and record snapshot of those counters. dhcpmon will report
discrepancies when detected between current counters and snapshot counters.
pull-request: https://github.com/Azure/sonic-buildimage/pull/3886
signed-off-by: Tamer Ahmed <tamer.ahmed@microsoft.com>
* [DHCP Relay]: Support new <DhcpRelays> minigraph tag; support multiple VLANs
* Don't start dhcrelay in quiet mode so as to get startup output in syslog
* Update sonic-cfggen tests to support new '<DhcpRelays>' tag
* <DhcpRelays> tag is only present for VLANs which require a DHCP relay agent -- only parse if present
* Don't attempt to configure a DHCP relay agent for VLANs without specified DHCP servers
* Modify to work with Taoyu's minigraph/DB changes (#942)
* Reduce number of DHCP servers in sonic-cfggen unit tests from 4 to 2
* Remove isc-dhcp-relay sample output file from sonic-cfggen test, as we no longer generate that file
* Update Option 82 isc-dhcp-relay patch to load all interface name-alias maps into memory once at start instead of calling sonic-cfggen on each packet we relay
* Remove executable permission from Jinja2 template
* Set max hop count to 1 so that DHCP relay will only relay packets with a hop count of zero
* Replace tabs with spaces
* Modify overlooked sonic-cfggen call, use Config DB instead of minigraph
* Also ensure > 1 VLAN requires a DHCP relay agent before outputting to template
* Generate port name-alias map file using sonic-cfggen and parse that in lieu of parsing port_config.ini directly
* No longer drop packets with hop count > 0; Instead, drop packets which already contain agent info
