Some fun updates for vagrant hackers… I wanted to use the venerable clustered SSH (cssh) and screen with vagrant. I decided to expand on my vsftp script. First read:
and
to get up to speed on the background information.
Vagrant screen:
First, a simple screen hack… I often use my vssh alias to quickly ssh into a machine, but I don’t want to have to waste time with sudo-ing to root and then running screen each time. Enter vscreen:
# vagrant screen
function vscreen {
[ "$1" = '' ] || [ "$2" != '' ] && echo "Usage: vscreen <vm-name> - vagrant screen" 1>&2 && return 1
wd=`pwd` # save wd, then find the Vagrant project
while [ "`pwd`" != '/' ] && [ ! -e "`pwd`/Vagrantfile" ] && [ ! -d "`pwd`/.vagrant/" ]; do
#echo "pwd is `pwd`"
cd ..
done
pwd=`pwd`
cd $wd
if [ ! -e "$pwd/Vagrantfile" ] || [ ! -d "$pwd/.vagrant/" ]; then
echo 'Vagrant project not found!' 1>&2 && return 2
fi
d="$pwd/.ssh"
f="$d/$1.config"
h="$1"
# hostname extraction from user@host pattern
p=`expr index "$1" '@'`
if [ $p -gt 0 ]; then
let "l = ${#h} - $p"
h=${h:$p:$l}
fi
# if mtime of $f is > than 5 minutes (5 * 60 seconds), re-generate...
if [ `date -d "now - $(stat -c '%Y' "$f" 2> /dev/null) seconds" +%s` -gt 300 ]; then
mkdir -p "$d"
# we cache the lookup because this command is slow...
vagrant ssh-config "$h" > "$f" || rm "$f"
fi
[ -e "$f" ] && ssh -t -F "$f" "$1" 'screen -xRR'
}
I usually run it this way:
$ vscreen root@machine
which logs in as root, to machine and gets me (back) into screen. This is almost identical to the vsftp script which I explained in an earlier blog post.
Vagrant cssh:
First you’ll need to install cssh. On my Fedora machine it’s as easy as:
# yum install -y clusterssh
I’ve been hacking a lot on Puppet-Gluster lately, and occasionally multi-machine hacking demands multi-machine key punching. Enter vcssh:
# vagrant cssh
function vcssh {
[ "$1" = '' ] && echo "Usage: vcssh [options] [user@]<vm1>[ [user@]vm2[ [user@]vmN...]] - vagrant cssh" 1>&2 && return 1
wd=`pwd` # save wd, then find the Vagrant project
while [ "`pwd`" != '/' ] && [ ! -e "`pwd`/Vagrantfile" ] && [ ! -d "`pwd`/.vagrant/" ]; do
#echo "pwd is `pwd`"
cd ..
done
pwd=`pwd`
cd $wd
if [ ! -e "$pwd/Vagrantfile" ] || [ ! -d "$pwd/.vagrant/" ]; then
echo 'Vagrant project not found!' 1>&2 && return 2
fi
d="$pwd/.ssh"
cssh="$d/cssh"
cmd=''
cat='cat '
screen=''
options=''
multi='f'
special=''
for i in "$@"; do # loop through the list of hosts and arguments!
#echo $i
if [ "$special" = 'debug' ]; then # optional arg value...
special=''
if [ "$1" -ge 0 -o "$1" -le 4 ]; then
cmd="$cmd $i"
continue
fi
fi
if [ "$multi" = 'y' ]; then # get the value of the argument
multi='n'
cmd="$cmd '$i'"
continue
fi
if [ "${i:0:1}" = '-' ]; then # does argument start with: - ?
# build a --screen option
if [ "$i" = '--screen' ]; then
screen=' -o RequestTTY=yes'
cmd="$cmd --action 'screen -xRR'"
continue
fi
if [ "$i" = '--debug' ]; then
special='debug'
cmd="$cmd $i"
continue
fi
if [ "$i" = '--options' ]; then
options=" $i"
continue
fi
# NOTE: commented-out options are probably not useful...
# match for key => value argument pairs
if [ "$i" = '--action' -o "$i" = '-a' ] || \
[ "$i" = '--autoclose' -o "$i" = '-A' ] || \
#[ "$i" = '--cluster-file' -o "$i" = '-c' ] || \
#[ "$i" = '--config-file' -o "$i" = '-C' ] || \
#[ "$i" = '--evaluate' -o "$i" = '-e' ] || \
[ "$i" = '--font' -o "$i" = '-f' ] || \
#[ "$i" = '--master' -o "$i" = '-M' ] || \
#[ "$i" = '--port' -o "$i" = '-p' ] || \
#[ "$i" = '--tag-file' -o "$i" = '-c' ] || \
[ "$i" = '--term-args' -o "$i" = '-t' ] || \
[ "$i" = '--title' -o "$i" = '-T' ] || \
[ "$i" = '--username' -o "$i" = '-l' ] ; then
multi='y' # loop around to get second part
cmd="$cmd $i"
continue
else # match single argument flags...
cmd="$cmd $i"
continue
fi
fi
f="$d/$i.config"
h="$i"
# hostname extraction from user@host pattern
p=`expr index "$i" '@'`
if [ $p -gt 0 ]; then
let "l = ${#h} - $p"
h=${h:$p:$l}
fi
# if mtime of $f is > than 5 minutes (5 * 60 seconds), re-generate...
if [ `date -d "now - $(stat -c '%Y' "$f" 2> /dev/null) seconds" +%s` -gt 300 ]; then
mkdir -p "$d"
# we cache the lookup because this command is slow...
vagrant ssh-config "$h" > "$f" || rm "$f"
fi
if [ -e "$f" ]; then
cmd="$cmd $i"
cat="$cat $f" # append config file to list
fi
done
cat="$cat > $cssh"
#echo $cat
eval "$cat" # generate combined config file
#echo $cmd && return 1
#[ -e "$cssh" ] && cssh --options "-F ${cssh}$options" $cmd
# running: bash -c glues together --action 'foo --bar' type commands...
[ -e "$cssh" ] && bash -c "cssh --options '-F ${cssh}${screen}$options' $cmd"
}
This can be called like this:
$ vcssh annex{1..4} -l root
or like this:
$ vcssh root@hostname foo user@bar james@machine --action 'pwd'
which, as you can see, passes cssh arguments through! Can you see any other special surprises in the code? Well, you can run vcssh like this too:
$ vcssh root@foo james@bar --screen
which will perform exactly as vscreen did above, but in cssh!
You’ll see that the vagrant ssh-config lookups are cached, so this will be speedy when it’s running hot, but expect a few seconds delay when you first run it. If you want a longer cache timeout, it’s easy to change yourself in the function.
I’ve uploaded the code here, so that you don’t have to copy+paste it from my blog!
Happy hacking,
James
