pfc_gen: add the flexiblity to defer storm start and stop at Arista fanout (#1139)

* Fine control PFC storm stop at Arista fanout to allow per-queue per-port
granularity

Signed-off-by: Wenda Ni <[email protected]>

* Add the flexiblity to defer storm start and stop at fanout

Signed-off-by: Wenda Ni <[email protected]>

* Address comment: not send the command to background if stop_defer_time is not
defined

Signed-off-by: Wenda Ni <[email protected]>

Author: wendani

ansible/roles/test/templates/pfc_storm_arista.j2

@@ -1,9 +1,9 @@
 bash
 cd /mnt/flash
 {% if (pfc_asym  is defined) and (pfc_asym == True) %}
-sudo python {{pfc_gen_file}} -p {{pfc_queue_index}} -t 65535 -n {{pfc_frames_number}} -i {{pfc_fanout_interface | replace("Ethernet", "et") | replace("/", "_")}} &
+{% if pfc_storm_defer_time is defined %} sleep {{pfc_storm_defer_time}} &&{% endif %} sudo python {{pfc_gen_file}} -p {{pfc_queue_index}} -t 65535 -n {{pfc_frames_number}} -i {{pfc_fanout_interface | replace("Ethernet", "et") | replace("/", "_")}} &
 {% else %}
-sudo python {{pfc_gen_file}} -p {{(1).__lshift__(pfc_queue_index)}} -t 65535 -n {{pfc_frames_number}} -i {{pfc_fanout_interface | replace("Ethernet", "et") | replace("/", "_")}} -r {{ansible_eth0_ipv4_addr}} &
+{% if pfc_storm_defer_time is defined %} sleep {{pfc_storm_defer_time}} &&{% endif %} sudo python {{pfc_gen_file}} -p {{(1).__lshift__(pfc_queue_index)}} -t 65535 -n {{pfc_frames_number}} -i {{pfc_fanout_interface | replace("Ethernet", "et") | replace("/", "_")}} -r {{ansible_eth0_ipv4_addr}} &
 {% endif %}
 exit
 exit

ansible/roles/test/templates/pfc_storm_stop_arista.j2

@@ -1,5 +1,5 @@
 bash
 cd /mnt/flash
-sudo pkill -f "sudo python {{pfc_gen_file}} -p {{(1).__lshift__(pfc_queue_index)}} -t 65535 -n {{pfc_frames_number}} -i {{pfc_fanout_interface | replace("Ethernet", "et") | replace("/", "_")}} -r {{ansible_eth0_ipv4_addr}}"
+{% if pfc_storm_stop_defer_time is defined %} sleep {{pfc_storm_stop_defer_time}} &&{% endif %} sudo pkill -f "sudo python {{pfc_gen_file}} -p {{(1).__lshift__(pfc_queue_index)}} -t 65535 -n {{pfc_frames_number}} -i {{pfc_fanout_interface | replace("Ethernet", "et") | replace("/", "_")}} -r {{ansible_eth0_ipv4_addr}}" {% if pfc_storm_stop_defer_time is defined %}&{% endif %}
 exit
 exit