ZTP infrastructure changes to support DHCP discovery provisioning data #3298

rajendra-dendukuri · 2019-08-07T02:16:42Z

Dynamically generate DHCP client configuration based on current ZTP state
Added support to request and process hostname when using DHCPv6
Do not process graphservice url dhcp option if ZTP is enabled, ZTP service
will process it
Generate /e/n/i file with all active interfaces seeking address assignment
via DHCP. Only interfaces that are created in Linux will be added to /e/n/i.
Also DHCP is started only on linked up in-band interfaces.

Signed-off-by: Rajendra Dendukuri rajendra.dendukuri@broadcom.com

- What I did
Dynamically generate contents of /e/n/i based on ZTP configuration loaded in Config DB. This allows
DHCP discovery on in-band and oob interfaces

- How I did it
Config DB is loaded with ZTP specific configuration by the config-setup service. The ZTP configuration in config DB used as input to sonic-cfggen to decide which interfaces need to running
DHCP

Also modified dhclient.conf file also modified to dynamically generate dhcp configuration when ZTP
is in progress.

- How to verify it

When ZTP is operational, contents of /etc/network/interfaces and /etc/dhcp/dhclient.conf contents need to be looked at

- Description for the changelog
Generate interfaces and dhcp client configuration for interfaces participating in Zero Touch Provisioning

- A picture of a cute animal (not mandatory but encouraged)

- Dynamically generate DHCP client configuration based on current ZTP state - Added support to request and process hostname when using DHCPv6 - Do not process graphservice url dhcp option if ZTP is enabled, ZTP service will process it - Generate /e/n/i file with all active interfaces seeking address assignment via DHCP. Only interfaces that are created in Linux will be added to /e/n/i. Also DHCP is started only on linked up in-band interfaces. Signed-off-by: Rajendra Dendukuri <rajendra.dendukuri@broadcom.com>

…o 4 space.

discovery is in progress.

rajendra-dendukuri · 2019-09-10T19:52:59Z

retest broadcom please

…ned in MGMT_INTERFACE table.

svc-acs · 2019-11-05T18:03:35Z

Build finished. No test results found.

lguohan · 2019-12-04T15:21:48Z

retest vsimage please

lguohan · 2019-12-04T15:27:08Z

src/sonic-config-engine/sonic-cfggen

@@ -281,6 +289,7 @@ def main():
        redis_bcc = RedisBytecodeCache(SonicV2Connector(host='127.0.0.1'))
        env = jinja2.Environment(loader=loader, trim_blocks=True, bytecode_cache=redis_bcc)
        env.filters['sort_by_port_index'] = sort_by_port_index
+        env.filters['is_intf_exists'] = is_intf_exists


config engine should not take current system state, it only parses the config db or minigraph. otherwise, it is making sonic-cfggen complicated.

Agreed and I will remove the newly added filter. It is not required as well.

lguohan · 2019-12-04T15:28:50Z

build_debian.sh

@@ -387,9 +387,6 @@ set /files/etc/sysctl.conf/net.ipv6.conf.default.keep_addr_on_down 1
 set /files/etc/sysctl.conf/net.ipv6.conf.all.keep_addr_on_down 1
 set /files/etc/sysctl.conf/net.ipv6.conf.eth0.keep_addr_on_down 1

-set /files/etc/sysctl.conf/net.ipv6.conf.eth0.accept_ra_defrtr 0
-set /files/etc/sysctl.conf/net.ipv6.conf.eth0.accept_ra 0


i prefer to keep it as it is. if you need dhcp, then you can enable it. I saw you have this in you interfaces.j2 file.

If we have it in /etc/sysctl.conf, there can be a case where the setting done by interface.j2 is overwritten when sysctl files are re-read by a different service. I moved setting of accept_ra to a new file "files/dhcp/90-dhcp6-systcl.conf.j2". This will decide whether accept_ra is 1/0. For DHCPv6 on eth0 to work, accept_ra must be 1.

The changes done as part of this PR enable DHCPv6 on eth0 by default just like how DHCP is enabled on eth0. This allows access to the switch using an IPv6 address. It has dual purpose to be used for ZTP over IPv6 as well as using it for management of SONiC switch using DHCPv6 assigned IPv6 address.

If we set accept_ra to 0 by default, the access to the switch using DHCPv6 is not possible.

Following are some options for us to consider:

DHCPv6 is enabled when MGMT_INTERFACE table is not defined

This is part of the proposed change.

DHCPv6 is enabled only when ZTP discovery is being performed.

This might momentarily work but user may lose connectivity to management interface if MGMT_INTRFACE configuration is not done or if accept_ra setting is not changed as part of ZTP configuration steps.

DHCPv6 is enabled only when ZTP is enabled in the build

This can be confusing as certain build combinations allows IPv6 management access out of the box and not in others.

lguohan · 2019-12-04T15:31:18Z

files/image_config/interfaces/interfaces.j2

+
+{% if ZTP['mode']['inband'] == 'true' %}
+{% for port in PORT %}
+{% set var = {'port_exists': True if port | is_intf_exists else False } %}


if you are doing inband, when do you care whether the interface exists or not. by default all interface should be created by swss. in line 58, you have hotplug meaning you can wait for the interface to appear and then start doing dhcp.

Agreed and I will remove the interface exists check.

Also, the hotplug even though mentioned in the configuration, the feature is not fully functional in ifupdown2. I checked with the ifupdown2 maintainer and it is on the ToDo list.

lguohan

sonic-cfggen should not take system state

abdosi · 2020-02-24T18:21:39Z

@lguohan @rlhui Is this needed for 201911 ?

rlhui · 2020-02-25T16:56:11Z

@lguohan @rlhui Is this needed for 201911 ?

We can take it.

#3298) * ZTP infrastructure changes to support DHCP discovery provisioning data - Dynamically generate DHCP client configuration based on current ZTP state - Added support to request and process hostname when using DHCPv6 - Do not process graphservice url dhcp option if ZTP is enabled, ZTP service will process it - Generate /e/n/i file with all active interfaces seeking address assignment via DHCP. Only interfaces that are created in Linux will be added to /e/n/i. Also DHCP is started only on linked up in-band interfaces. Signed-off-by: Rajendra Dendukuri <rajendra.dendukuri@broadcom.com>

sonic-net#3298) * ZTP infrastructure changes to support DHCP discovery provisioning data - Dynamically generate DHCP client configuration based on current ZTP state - Added support to request and process hostname when using DHCPv6 - Do not process graphservice url dhcp option if ZTP is enabled, ZTP service will process it - Generate /e/n/i file with all active interfaces seeking address assignment via DHCP. Only interfaces that are created in Linux will be added to /e/n/i. Also DHCP is started only on linked up in-band interfaces. Signed-off-by: Rajendra Dendukuri <rajendra.dendukuri@broadcom.com>

jleveque added the Enhancement ➕ label Aug 7, 2019

rajendra-dendukuri added 2 commits August 19, 2019 10:49

Added exit code check for redis-dump command. Fixed code indenation t…

421e6ce

…o 4 space.

Allow router advertisements to be accepted by eth0 when DHCPv6

364dd31

discovery is in progress.

rajendra-dendukuri and others added 2 commits September 16, 2019 22:47

Assign IPv6 address to OOB using DHCPv6 if static address is not defi…

7d7b5a4

…ned in MGMT_INTERFACE table.

Merge branch 'master' into ztp_infra

7447899

skg-net approved these changes Oct 24, 2019

View reviewed changes

Merge branch 'master' into ztp_infra

dfecb07

lguohan reviewed Dec 4, 2019

View reviewed changes

lguohan requested changes Dec 4, 2019

View reviewed changes

Remove interface exists in kernel check.

fa71ce3

lguohan approved these changes Dec 10, 2019

View reviewed changes

lguohan merged commit fec8029 into sonic-net:master Dec 10, 2019

rlhui added the Request for 201911 Branch label Feb 25, 2020

rlhui added the Included in 201911 Branch label Mar 4, 2020

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ZTP infrastructure changes to support DHCP discovery provisioning data #3298

ZTP infrastructure changes to support DHCP discovery provisioning data #3298

rajendra-dendukuri commented Aug 7, 2019

rajendra-dendukuri commented Sep 10, 2019

svc-acs commented Nov 5, 2019

lguohan commented Dec 4, 2019

lguohan Dec 4, 2019

rajendra-dendukuri Dec 6, 2019

lguohan Dec 4, 2019

rajendra-dendukuri Dec 6, 2019

lguohan Dec 4, 2019

rajendra-dendukuri Dec 6, 2019

lguohan left a comment

abdosi commented Feb 24, 2020

rlhui commented Feb 25, 2020

ZTP infrastructure changes to support DHCP discovery provisioning data #3298

ZTP infrastructure changes to support DHCP discovery provisioning data #3298

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