Fix regex match for getting primary interface

[jayanthvn]

What type of PR is this?
bug

Which issue does this PR fix:
#1247 #1266

What does this PR do / Why do we need it:
Fixing the current regex match to pick primary interface from primary MAC which is more reliable.

If an issue # is not available please add repro steps and logs from IPAMD/CNI showing the issue:

Testing done on this change:

[root@ip-192-168-85-147 ec2-user]# PRIMARY_MAC=$(curl -H "X-aws-ec2-metadata-token: $TOKEN" http://169.254.169.254/latest/meta-data/mac)
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100    17  100    17    0     0  17000      0 --:--:-- --:--:-- --:--:-- 17000
[root@ip-192-168-85-147 ec2-user]# PRIMARY_IF=$(ip -o link show | grep -F "link/ether $PRIMARY_MAC" | awk -F'[ :]+' '{print $2}')
[root@ip-192-168-85-147 ec2-user]# echo $PRIMARY_IF
eth0

kubectl logs aws-node-88hvw -c aws-vpc-cni-init -n kube-system
+ PLUGIN_BINS='loopback portmap bandwidth aws-cni-support.sh'
+ for b in '$PLUGIN_BINS'
+ '[' '!' -f loopback ']'
+ for b in '$PLUGIN_BINS'
+ '[' '!' -f portmap ']'
+ for b in '$PLUGIN_BINS'
+ '[' '!' -f bandwidth ']'
+ for b in '$PLUGIN_BINS'
+ '[' '!' -f aws-cni-support.sh ']'
+ HOST_CNI_BIN_PATH=/host/opt/cni/bin
+ echo 'Copying CNI plugin binaries ... '
+ for b in '$PLUGIN_BINS'
+ install loopback /host/opt/cni/bin
Copying CNI plugin binaries ...
+ for b in '$PLUGIN_BINS'
+ install portmap /host/opt/cni/bin
+ for b in '$PLUGIN_BINS'
+ install bandwidth /host/opt/cni/bin
+ for b in '$PLUGIN_BINS'
+ install aws-cni-support.sh /host/opt/cni/bin
Configure rp_filter loose...
+ echo 'Configure rp_filter loose... '
++ get_metadata local-ipv4
+++ curl -X PUT http://169.254.169.254/latest/api/token -H 'X-aws-ec2-metadata-token-ttl-seconds: 60'
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100    56  100    56    0     0  56000      0 --:--:-- --:--:-- --:--:-- 56000
++ TOKEN=AQAEAHGXwoPHd-WatjsIZZX_51JLMhk73OKTbNWO-XDkiMwHgJ9UWw==
++ attempts=60
++ false
++ '[' 1 -gt 0 ']'
++ '[' 60 -eq 0 ']'
+++ curl -H 'X-aws-ec2-metadata-token: AQAEAHGXwoPHd-WatjsIZZX_51JLMhk73OKTbNWO-XDkiMwHgJ9UWw==' http://169.254.169.254/latest/meta-data/local-ipv4
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100    14  100    14    0     0  14000      0 --:--:-- --:--:-- --:--:-- 14000
++ meta=192.168.22.192
++ '[' 0 -gt 0 ']'
++ '[' 0 -gt 0 ']'
++ echo 192.168.22.192
+ HOST_IP=192.168.22.192
++ get_metadata mac
+++ curl -X PUT http://169.254.169.254/latest/api/token -H 'X-aws-ec2-metadata-token-ttl-seconds: 60'
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100    56  100    56    0     0  56000      0 --:--:-- --:--:-- --:--:-- 56000
++ TOKEN=AQAEAHGXwoP4xDK_8AY9PNKkOPBEwr-WQmbR2pDhyWKCpbR1Lqvmuw==
++ attempts=60
++ false
++ '[' 1 -gt 0 ']'
++ '[' 60 -eq 0 ']'
+++ curl -H 'X-aws-ec2-metadata-token: AQAEAHGXwoP4xDK_8AY9PNKkOPBEwr-WQmbR2pDhyWKCpbR1Lqvmuw==' http://169.254.169.254/latest/meta-data/mac
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100    17  100    17    0     0  17000      0 --:--:-- --:--:-- --:--:-- 17000
++ meta=0a:2d:8e:94:14:75
++ '[' 0 -gt 0 ']'
++ '[' 0 -gt 0 ']'
++ echo 0a:2d:8e:94:14:75
+ PRIMARY_MAC=0a:2d:8e:94:14:75
++ ip -o link show
++ grep -F 'link/ether 0a:2d:8e:94:14:75'
++ awk '-F[ :]+' '{print $2}'
+ PRIMARY_IF=eth0
+ sysctl -w net.ipv4.conf.eth0.rp_filter=2
net.ipv4.conf.eth0.rp_filter = 2
+ cat /proc/sys/net/ipv4/conf/eth0/rp_filter
2
+ '[' true == true ']'
+ sysctl -w net.ipv4.tcp_early_demux=0
net.ipv4.tcp_early_demux = 0
+ echo 'CNI init container done'
CNI init container done

Automation added to e2e:

No

Will this break upgrades or downgrades. Has updating a running cluster been tested?:
No

Does this change require updates to the CNI daemonset config files to work?:

No

Does this PR introduce any user-facing change?:

No

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[nithu0115]

👍