How to use bash $(awk) in single ssh-command?

Try this

ssh myServer "uname -a | awk '{print \$2}' "

Use the double quotes " in order to group the commands you will execute remotely.

You also need to escape the $ in the $2 argument, so that it is not calculated locally, but passed on to awk remotely.

Edit:

If you want to include the $( ), you again have to escape the $ symbol, like this:

ssh myServer "echo \$(uname -a | awk '{print \$2}') "

You can also escape the backtick `, like this:

ssh myServer "echo \`uname -a | awk '{print \$2}'\` "

It is better to use a heredoc with ssh to avoid escaping quotes everywhere in a more complex command:

ssh -T myServer <<-'EOF'
uname -a | awk '{print $2}'
exit
EOF

Just some additional note:

In my case, the escape of the $ doesn't help:

ts1350:> ssh sysadm@node "grep feature features.txt| awk '{print $6}' "
Password: 
A  feature   -name  ue_trace_mme    | off
ts1350:> ssh sysadm@node "grep feature features.txt| awk '{print \$6}' "
Password: 
awk: cmd. line:1: {print \}
awk: cmd. line:1:        ^ backslash not last character on line
awk: cmd. line:1: {print \}
awk: cmd. line:1:        ^ syntax error
ts1350:> ssh sysadm@node "grep feature features.txt| awk '{print \\$6}' "
Password: 
awk: cmd. line:1: {print \\}
awk: cmd. line:1:        ^ backslash not last character on line
awk: cmd. line:1: {print \\}
awk: cmd. line:1:        ^ syntax error

While add a space between $ and the number works:

Fri Oct  4 14:49:28 CEST 2019
ts1350:> ssh sysadm@node "grep feature features.txt| awk '{print $ 6}' "
Password: 
off

Hope this secodnary way help someone like me.

Thanks to @dave in his answer: How to print a specific column with awk on a remote ssh session?

What about piping the output of the command and run awk locally?

ssh yourhost uname -a | awk '{ print $2 } '