Shell script to be used to simplify opening a shell in a container within a pod in a Kubernetes cluster.

kshell.sh

#!/bin/sh

# Using this script you simply have to specify the first letters of a pod 
# to open a shell, the default shell is bash, but you can specify an
# alternative as second parameter.
#
# For example, if you have the two following pods:
# - caching-service-blablabla-123123-abcdef
# - creditcard-frontend-blabla-3213213-fghijk
#
# And you want to get a bash shell into the second, you would do:
# `kshell.sh cr`
# ...and that should do the trick.
# 
# And if you happend to have a pod with a container without bash, you
# could do:
# `kshell.sh cr sh`
# and that will open sh instead of the default bash.
#
# If multiple pods match, the first one is selected. For exaple:
# `kshell.sh c`
# will probably give you a bash in the `caching-service...`
# 
# This script doesn't support pods with multiple containers yet, if you 
# try to use it on these, you will get the familliar kubectl error about
# you having to specify a container.


if [ "$1" = "" ]; then
  echo "Usage: kshell [Pod] {shell (defaults to bash)}"
  exit 1
fi

NEEDLE=$1
SHELL=$2
SHELL="${SHELL:-bash}"

COLUMNS=`tput cols`
LINES=`tput lines`
TERM=xterm

for name in `kubectl get pods -o json | jq '.items[].metadata.name' -r`; do
  if [[ $name == $NEEDLE* ]]; then
    kubectl exec -i -t $name env COLUMNS=$COLUMNS LINES=$LINES TERM=$TERM $SHELL
    exit 0
  fi
done

echo "No Pod begining by $NEEDLE was found"
exit 1