mjhjmtu

With this loop we sequential update on all servers (server list = consul members | grep awk 'print $2' | cut -d ":" -f1) the package consul.

for i in $(consul members | grep awk 'print $2' | cut -d ":" -f1) ; do sshpass -p $PASSWORD ssh -oStrictHostKeyChecking=no -q root@$i "hostname && yum clean all && yum -y update consul && systemctl restart consul.service" ; done

We have over 1000 servers, so we wish to run the sshpass in parallel on 10 servers. I found GNU Parallel for this task.

Howo use it with sshpass and make sure no server (server list) is done twice?

Indeed, pssh sounds like the better solution. If you must use parallel it should be fairly simple: pipe the hostnames one per line into a single command that uses as a placehold. Eg:

consul members | ... awk 'print $2' | cut -d ":" -f1 |
parallel -j 10 sshpass -p "$PASSWORD" ssh -oStrictHostKeyChecking=no -q root@ "hostname && yum clean all && yum -y update consul && systemctl restart consul.service"

Using sshpass should not make any difference. Test it first with a simple command such as just hostname.

Use pssh with ssh host key authentication it's better

first, on the local box, as the user to connect with, do ssh-keygen to create a public key

then use ssh-copy-id to copy that public key to all the remote servers. then do sometinhg like:

pssh -h <(consul members | grep awk 'print $2' | cut -d ":" -f1) -o /tmp/update-consul-servers -i "yum clean all && yum -y update consul && systemctl restart consul.service"

All, this is the working shell that prompt password in the script, do the require command and list which server is not authenticated.

for i in cat /root/fahmi/up.list ;

do
if ! sshpass -p 'password' ssh -n -T -o StrictHostKeyChecking=no user@"$i";
then
echo "Server $i not accessible";
fi
sshpass -p 'password' ssh -T -o StrictHostKeyChecking=no user@"$i" <./command.sh

done