only collect noschedule once

As part of the existing json file, there is a 'kubectl get nodes'
json dump. Instead of collecting this information each pod launch,
use the data already gathered. This data is immutable during the
test runs. This greatly improves the overall runtime of the test
script by preventing expensive kubectl execs per node per iteration.

Signed-off-by: David Lyle <dklyle0@gmail.com>

Author: dklyle

metrics/collectd/collectd.bash

@@ -34,6 +34,7 @@ cleanup_stats() {
 	while read -u 3 name node; do
 		kubectl exec -ti $name -- sh -c "cd /opt/collectd; tar -czvf localhost.tar.gz localhost"
 		# make a backup on the host in-case collection fail
+		kubectl exec -ti $name -- sh -c "mkdir -p /mnt/opt/collectd"
 		kubectl exec -ti $name -- sh -c "cp /opt/collectd/localhost.tar.gz /mnt/opt/collectd/localhost.tar.gz"
 		kubectl cp $name:/opt/collectd/localhost.tar.gz ${RESULT_DIR}/${node}.tar.gz
 	done 3< <(kubectl get pods --selector name=collectd-pods -o json | jq -r '.items[] | "\(.metadata.name) \(.spec.nodeName)"')