I have a setup which behaves in a way i cannot get my head around. So I have a local bash script generateTrafficOnHosts.sh which reads IP addresses from a file. It then calls a bash script getTraffic.sh on each remote host, i.e. each IP address it calls. However, after the first remote execution via ssh, it just finishes. Here's my local generateTrafficOnHosts.sh script:
#!/bin/bash # Connects to a series of hosts and runs the get-traffic.sh script on them. # The hosts are taken from a file with a list of randomly generated IDs, # while their IDs are taken from a connectfile. # ... # some convenience functions here # ... ####################################### # runs the traffic generation script on # a host. # Globals: # # Arguments: # <IP of the remote host> # Returns: # None ####################################### function run_on_host() { local RESULTS RESULTS=$(ssh -i key.pem user@"$1" '/home/user/get-traffic.sh 2>&1 >/dev/null') } ####################################### # Runs the load on the hosts # Globals: # HOSTSFILE # Arguments: # None # Returns: # None ####################################### function run_load_on_hosts() { while read line do local ip=$(get_ip_for_key ${line}) echo "getting IP for key in line ${line}" if [[ $ip != "" ]]; then echo "running on host $line($ip)" run_on_host "${ip}" else echo "error: LINE'$line', IP'$ip'" fi done < "$HOSTSFILE" } function main() { check "$@" run_load_on_hosts } main "$@" The remote script get-traffic.sh looks like this:
#!/bin/bash PORT=47111 # Time limit in seconds TIME_LIMIT=10 # Blocksize of the dd command: how much data shall be downloaded per chunk? BS=1M while [[ "$SECONDS" -le "$TIME_LIMIT" ]]; do # $SECONDS is a shell variable nc "${HOST}" "${PORT}" | dd count=1 bs="${BS}" iflag=fullblock > /dev/null done Now for the odd behaviour: the script only runs for the first host in the hosts file. If I replace the line ssh -i ... with, say, sleep 1; echo "running...", everything runs smoothly. The same applies if I replace the remote command /home/user/get-traffic.sh with e.g. ls /home/user - everything is good. However, the script also returns after the first iteration if I replace the remote command with ls.
I have been tracking this bug for hours now, and I have run out of ideas hours ago. Anyone, please?!? :|
