tests: Send more ICMP packets to determime external connectivity

We use ping to determine if the container has external connectivity.
We also use the management IP in Ansible to connect to the container
which is in a different interface than the external one. The management
interface has a static IP so it's available much earlier than the
external one which obtains the IP via DHCP. As such, in some cases,
the external interface may not be configured early enough and the ping
fails. We can improve this situation by sending more ICMP packets less
frequently to give the interface sometime to be configured properly.
This patch effectively allows 30 seconds for interface to reach a working
state to determine if there is external connectivity or not which should
be more than enough.

This fixes some random CI failures where one container has external
connectivity and another one doesn't even though they are configured
exactly the same.

For example:

2017-05-04 19:30:44.264567 | changed: [container1] => {
2017-05-04 19:30:44.264610 |     "changed": true,
2017-05-04 19:30:44.264627 |     "cmd": "ping -c 3 8.8.8.8",
...
2017-05-04 19:30:44.264900 |     "stdout": "PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.\n\n--- 8.8.8.8 ping statistics ---\n3 packets transmitted, 0 received, 100% packet loss, time 1998ms",
2017-05-04 19:30:44.264911 |     "stdout_lines": [
2017-05-04 19:30:44.264929 |         "PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.",
2017-05-04 19:30:44.264937 |         "",
2017-05-04 19:30:44.264952 |         "--- 8.8.8.8 ping statistics ---",
2017-05-04 19:30:44.264974 |         "3 packets transmitted, 0 received, 100% packet loss, time 1998ms"
2017-05-04 19:30:44.264981 |     ]

but

2017-05-04 19:30:34.299060 | changed: [container2] => {
2017-05-04 19:30:34.299112 |     "changed": true,
2017-05-04 19:30:34.299128 |     "cmd": "ping -c 3 8.8.8.8",
...
2017-05-04 19:30:34.299683 |     "stdout": "PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.\n64 bytes from 8.8.8.8: icmp_seq=1 ttl=56 time=3.67 ms\n64 bytes from 8.8.8.8: icmp_seq=2 ttl=56 time=3.65 ms\n64 bytes from 8.8.8.8: icmp_seq=3 ttl=56 time=3.66 ms\n\n--- 8.8.8.8 ping statistics ---\n3 packets transmitted, 3 received, 0% packet loss, time 2003ms\nrtt min/avg/max/mdev = 3.656/3.664/3.678/0.070 ms",
2017-05-04 19:30:34.299697 |     "stdout_lines": [
2017-05-04 19:30:34.299715 |         "PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.",
2017-05-04 19:30:34.299735 |         "64 bytes from 8.8.8.8: icmp_seq=1 ttl=56 time=3.67 ms",
2017-05-04 19:30:34.299755 |         "64 bytes from 8.8.8.8: icmp_seq=2 ttl=56 time=3.65 ms",
2017-05-04 19:30:34.299775 |         "64 bytes from 8.8.8.8: icmp_seq=3 ttl=56 time=3.66 ms",
2017-05-04 19:30:34.299783 |         "",
2017-05-04 19:30:34.299798 |         "--- 8.8.8.8 ping statistics ---",
2017-05-04 19:30:34.299820 |         "3 packets transmitted, 3 received, 0% packet loss, time 2003ms",
2017-05-04 19:30:34.299839 |         "rtt min/avg/max/mdev = 3.656/3.664/3.678/0.070 ms"
2017-05-04 19:30:34.299845 |     ]

Change-Id: I77eb168d6c3abc5e679c7dd60c52353dc44f8afb

tests/test-containers-functional.yml

@@ -83,7 +83,7 @@
         that:
           - "'foo=bar' in environment_content"
     - name: Test connectivity to external address
-      shell: ping -c 3 8.8.8.8
+      shell: ping -i 5 -c 6 8.8.8.8
       register: ping_external_address
       failed_when: false
     - name: Verify connectivity to external address