**- Why I did it**
To introduce dynamic support of BBR functionality into bgpcfgd.
BBR is adding `neighbor PEER_GROUP allowas-in 1' for all BGP peer-groups which points to T0
Now we can add and remove this configuration based on CONFIG_DB entry
**- How I did it**
I introduced a new CONFIG_DB entry:
- table name: "BGP_BBR"
- key value: "all". Currently only "all" is supported, which means that all peer-groups which points to T0s will be updated
- data value: a dictionary: {"status": "status_value"}, where status_value could be either "enabled" or "disabled"
Initially, when bgpcfgd starts, it reads initial BBR status values from the [constants.yml](https://github.com/Azure/sonic-buildimage/pull/5626/files#diff-e6f2fe13a6c276dc2f3b27a5bef79886f9c103194be4fcb28ce57375edf2c23cR34). Then you can control BBR status by changing "BGP_BBR" table in the CONFIG_DB (see examples below).
bgpcfgd knows what peer-groups to change fron [constants.yml](https://github.com/Azure/sonic-buildimage/pull/5626/files#diff-e6f2fe13a6c276dc2f3b27a5bef79886f9c103194be4fcb28ce57375edf2c23cR39). The dictionary contains peer-group names as keys, and a list of address-families as values. So when bgpcfgd got a request to change the BBR state, it changes the state only for peer-groups listed in the constants.yml dictionary (and only for address families from the peer-group value).
**- How to verify it**
Initially, when we start SONiC FRR has BBR enabled for PEER_V4 and PEER_V6:
```
admin@str-s6100-acs-1:~$ vtysh -c 'show run' | egrep 'PEER_V.? allowas'
neighbor PEER_V4 allowas-in 1
neighbor PEER_V6 allowas-in 1
```
Then we apply following configuration to the db:
```
admin@str-s6100-acs-1:~$ cat disable.json
{
"BGP_BBR": {
"all": {
"status": "disabled"
}
}
}
admin@str-s6100-acs-1:~$ sonic-cfggen -j disable.json -w
```
The log output are:
```
Oct 14 18:40:22.450322 str-s6100-acs-1 DEBUG bgp#bgpcfgd: Received message : '('all', 'SET', (('status', 'disabled'),))'
Oct 14 18:40:22.450620 str-s6100-acs-1 DEBUG bgp#bgpcfgd: execute command '['vtysh', '-f', '/tmp/tmpmWTiuq']'.
Oct 14 18:40:22.681084 str-s6100-acs-1 DEBUG bgp#bgpcfgd: execute command '['vtysh', '-c', 'clear bgp peer-group PEER_V4 soft in']'.
Oct 14 18:40:22.904626 str-s6100-acs-1 DEBUG bgp#bgpcfgd: execute command '['vtysh', '-c', 'clear bgp peer-group PEER_V6 soft in']'.
```
Check FRR configuraiton and see that no allowas parameters are there:
```
admin@str-s6100-acs-1:~$ vtysh -c 'show run' | egrep 'PEER_V.? allowas'
admin@str-s6100-acs-1:~$
```
Then we apply enabling configuration back:
```
admin@str-s6100-acs-1:~$ cat enable.json
{
"BGP_BBR": {
"all": {
"status": "enabled"
}
}
}
admin@str-s6100-acs-1:~$ sonic-cfggen -j enable.json -w
```
The log output:
```
Oct 14 18:40:41.074720 str-s6100-acs-1 DEBUG bgp#bgpcfgd: Received message : '('all', 'SET', (('status', 'enabled'),))'
Oct 14 18:40:41.074720 str-s6100-acs-1 DEBUG bgp#bgpcfgd: execute command '['vtysh', '-f', '/tmp/tmpDD6SKv']'.
Oct 14 18:40:41.587257 str-s6100-acs-1 DEBUG bgp#bgpcfgd: execute command '['vtysh', '-c', 'clear bgp peer-group PEER_V4 soft in']'.
Oct 14 18:40:42.042967 str-s6100-acs-1 DEBUG bgp#bgpcfgd: execute command '['vtysh', '-c', 'clear bgp peer-group PEER_V6 soft in']'.
```
Check FRR configuraiton and see that the BBR configuration is back:
```
admin@str-s6100-acs-1:~$ vtysh -c 'show run' | egrep 'PEER_V.? allowas'
neighbor PEER_V4 allowas-in 1
neighbor PEER_V6 allowas-in 1
```
*** The test coverage ***
Below is the test coverage
```
---------- coverage: platform linux2, python 2.7.12-final-0 ----------
Name Stmts Miss Cover
----------------------------------------------------
bgpcfgd/__init__.py 0 0 100%
bgpcfgd/__main__.py 3 3 0%
bgpcfgd/config.py 78 41 47%
bgpcfgd/directory.py 63 34 46%
bgpcfgd/log.py 15 3 80%
bgpcfgd/main.py 51 51 0%
bgpcfgd/manager.py 41 23 44%
bgpcfgd/managers_allow_list.py 385 21 95%
bgpcfgd/managers_bbr.py 76 0 100%
bgpcfgd/managers_bgp.py 193 193 0%
bgpcfgd/managers_db.py 9 9 0%
bgpcfgd/managers_intf.py 33 33 0%
bgpcfgd/managers_setsrc.py 45 45 0%
bgpcfgd/runner.py 39 39 0%
bgpcfgd/template.py 64 11 83%
bgpcfgd/utils.py 32 24 25%
bgpcfgd/vars.py 1 0 100%
----------------------------------------------------
TOTAL 1128 530 53%
```
**- Which release branch to backport (provide reason below if selected)**
- [ ] 201811
- [x] 201911
- [x] 202006
**- Why I did it**
I was asked to change "Allow list" prefix-list generation rule.
Previously we generated the rules using following method:
```
For each {prefix}/{masklen} we would generate the prefix-rule
permit {prefix}/{masklen} ge {masklen}+1
Example:
Prefix 1.2.3.4/24 would have following prefix-list entry generated
permit 1.2.3.4/24 ge 23
```
But we discovered the old rule doesn't work for all cases we have.
So we introduced the new rule:
```
For ipv4 entry,
For mask < 32 , we will add ‘le 32’ to cover all prefix masks to be sent by T0
For mask =32 , we will not add any ‘le mask’
For ipv6 entry, we will add le 128 to cover all the prefix mask to be sent by T0
For mask < 128 , we will add ‘le 128’ to cover all prefix masks to be sent by T0
For mask = 128 , we will not add any ‘le mask’
```
**- How I did it**
I change prefix-list entry generation function. Also I introduced a test for the changed function.
**- How to verify it**
1. Build an image and put it on your dut.
2. Create a file test_schema.conf with the test configuration
```
{
"BGP_ALLOWED_PREFIXES": {
"DEPLOYMENT_ID|0|1010:1010": {
"prefixes_v4": [
"10.20.0.0/16",
"10.50.1.0/29"
],
"prefixes_v6": [
"fc01:10::/64",
"fc02:20::/64"
]
},
"DEPLOYMENT_ID|0": {
"prefixes_v4": [
"10.20.0.0/16",
"10.50.1.0/29"
],
"prefixes_v6": [
"fc01:10::/64",
"fc02:20::/64"
]
}
}
}
```
3. Apply the configuration by command
```
sonic-cfggen -j test_schema.conf --write-to-db
```
4. Check that your bgp configuration has following prefix-list entries:
```
admin@str-s6100-acs-1:~$ show runningconfiguration bgp | grep PL_ALLOW
ip prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_1010:1010_V4 seq 10 deny 0.0.0.0/0 le 17
ip prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_1010:1010_V4 seq 20 permit 127.0.0.1/32
ip prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_1010:1010_V4 seq 30 permit 10.20.0.0/16 le 32
ip prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_1010:1010_V4 seq 40 permit 10.50.1.0/29 le 32
ip prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_empty_V4 seq 10 deny 0.0.0.0/0 le 17
ip prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_empty_V4 seq 20 permit 127.0.0.1/32
ip prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_empty_V4 seq 30 permit 10.20.0.0/16 le 32
ip prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_empty_V4 seq 40 permit 10.50.1.0/29 le 32
ipv6 prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_1010:1010_V6 seq 10 deny ::/0 le 59
ipv6 prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_1010:1010_V6 seq 20 deny ::/0 ge 65
ipv6 prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_1010:1010_V6 seq 30 permit fc01:10::/64 le 128
ipv6 prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_1010:1010_V6 seq 40 permit fc02:20::/64 le 128
ipv6 prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_empty_V6 seq 10 deny ::/0 le 59
ipv6 prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_empty_V6 seq 20 deny ::/0 ge 65
ipv6 prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_empty_V6 seq 30 permit fc01:10::/64 le 128
ipv6 prefix-list PL_ALLOW_LIST_DEPLOYMENT_ID_0_COMMUNITY_empty_V6 seq 40 permit fc02:20::/64 le 128
```
Co-authored-by: Pavel Shirshov <pavel.contrib@gmail.com>
implements a new feature: "BGP Allow list."
This feature allows us to control which IP prefixes are going to be advertised via ebgp from the routes received from EBGP neighbors.
implements a new feature: "BGP Allow list."
This feature allows us to control which IP prefixes are going to be advertised via ebgp from the routes received from EBGP neighbors.
The one big bgp configuration template was splitted into chunks.
Currently we have three types of bgp neighbor peers:
general bgp peers. They are represented by CONFIG_DB::BGP_NEIGHBOR table entries
dynamic bgp peers. They are represented by CONFIG_DB::BGP_PEER_RANGE table entries
monitors bgp peers. They are represented by CONFIG_DB::BGP_MONITORS table entries
This PR introduces three templates for each peer type:
bgp policies: represent policieas that will be applied to the bgp peer-group (ip prefix-lists, route-maps, etc)
bgp peer-group: represent bgp peer group which has common configuration for the bgp peer type and uses bgp routing policy from the previous item
bgp peer-group instance: represent bgp configuration, which will be used to instatiate a bgp peer-group for the bgp peer-type. Usually this one is simple, consist of the referral to the bgp peer-group, bgp peer description and bgp peer ip address.
This PR redefined constant.yml file. Now this file has a setting for to use or don't use bgp_neighbor metadata. This file has more parameters for now, which are not used. They will be used in the next iteration of bgpcfgd.
Currently all tests have been disabled. I'm going to create next PR with the tests right after this PR is merged.
I'm going to introduce better bgpcfgd in a short time. It will include support of dynamic changes for the templates.
FIX:: #4231
* Rename asn/deployment_id_asn_map.yaml to constants/constants.yaml
* Fix bgp templates
* Add community for loopback when bgpd is isolated
* Use correct community value
