**- 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
Calls to sonic-cfggen is CPU expensive. This PR reduces calls to
sonic-cfggen to one call during startup when starting dhcp-relay
service.
singed-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
