Debug the manifest that would be generated by BOSH deployment scripts

debug-manifest.sh

#!/bin/sh
# == Debug Manifest ==
# This script allows to show interpolated manifests based on BOSH script files.
#
# Prerequisite: You have a script file that somewhere contains:
#   bosh -e my-bosh-env deploy my-base-manifest.yml \
#       -o operations/expose-https.yml \
#       ...
#
# Then you can simply call this script that replaces [create-env|deploy|update-cloud-config]
# with `bosh int` to show the manifest that BOSH would be deploying.
# Find out more about `bosh int`: https://bosh.io/docs/cli-v2/#interpolate
#
# Usage:
# - Basic usage:
#   debug-manifest.sh ./deploy-concourse.sh
# - Pass additional args to `bosh int`:
#   debug-manifest.sh ./deploy-concourse.sh --path /instance_groups/name=worker
#
# For safety reasons, the script removes any `bosh alias-env` commands and
# empties `BOSH_ENVIRONMENT` before calling your script to prevent accidental
# deployments.

SCRIPT_TO_DEBUG=$1
shift
BOSH_INT_ARGS="$@"

# check if script to debug exists
if [ -z ${SCRIPT_TO_DEBUG} ]; then
    echo "Please provide a script to debug as argument"
    exit 1
fi
if [ ! -f ${SCRIPT_TO_DEBUG} ]; then
    echo "The script ${SCRIPT_TO_DEBUG} is not a file!"
    exit 1
fi
# check if we find a BOSH command
if ! grep -qE "^bosh.* (deploy|update-cloud-config|create-env) " ${SCRIPT_TO_DEBUG}; then
    echo "The given script ${SCRIPT_TO_DEBUG} seems not to contain a 'bosh [create-env|deploy|update-cloud-config]' command"
    exit 1
fi


# read script and replace BOSH command with `bosh int`
SAFE_BOSH_INT_ARGS=$(echo "${BOSH_INT_ARGS}" | sed -e 's/[\/&]/\\&/g')
SED_FIND='^(bosh.*) (deploy|update-cloud-config|create-env) '
SED_REPLACE='\1 int '${SAFE_BOSH_INT_ARGS}' '
SCRIPT_CONTENTS=$(cat ${SCRIPT_TO_DEBUG} | sed -r "s/${SED_FIND}/${SED_REPLACE}/g")
# remove --no-redact option (unsupported by `bosh int`)
SCRIPT_CONTENTS=$(echo "${SCRIPT_CONTENTS}" | sed 's/--no-redact //g')

# remove `bosh alias-env` commands (not relevant for interpolation)
SCRIPT_CONTENTS=$(echo "${SCRIPT_CONTENTS}" | sed 's/^bosh.* alias-env.*$//g')


# reset BOSH environment just in case
BOSH_ENVIRONMENT=""
# run bosh int
bash -c "${SCRIPT_CONTENTS}"