Report available entropy

Change-Id: I0c37ba259d96c351e03dba1c8343fce8a84eb53e
Depends-On: https://review.opendev.org/c/openstack/kayobe-config-dev/+/777076

roles/kayobe-diagnostics/files/get_logs.sh

@@ -65,6 +65,9 @@ copy_logs() {
     # final memory usage and process list
     ps -eo user,pid,ppid,lwp,%cpu,%mem,size,rss,cmd > ${LOG_DIR}/system_logs/ps.txt
 
+    # available entropy
+    cat /proc/sys/kernel/random/entropy_avail > ${LOG_DIR}/system_logs/entropy_avail.txt
+
     # docker related information
     (docker info && docker images && docker ps -a) > ${LOG_DIR}/system_logs/docker-info.txt