Lint Dockerfiles for CI/CD

lint-dockerfile.sh

#!/usr/bin/env bash

# usage: ./lint-dockerfile.sh <path-to-dockerfile>
# purpose: lints dockerfile for common errors
# requires: docker to be installed

DOCKERFILE_PATH=$1

echo "Linting dockerfile : DOCKERFILE_PATH"
docker run -it --rm --privileged -v `pwd`:/root/ projectatomic/dockerfile-lint dockerfile_lint -f ${DOCKERFILE_PATH} | grep ERRORS > dockerfile-lint.out

# isolate lint warnings
awk '/WARNINGS/,/INFO/' dockerfile-lint.out | sed '$d' | tail +3 > dockerfile-lint-warnings.out
testok = "true"
if [ $? -eq 0 ]; then
  echo "Linting dockerfile : WARNINGS found"
  # Print warnings
  cat dockerfile-lint-warnings.out
fi
# isolate lint info
awk '/ERRORS/,/WARNINGS/' dockerfile-lint.out | sed '$d' | tail +3 > dockerfile-lint-info.out
grep '--------INFO---------'  dockerfile-lint.out
if [ $? -eq 0 ]; then
  echo "Linting dockerfile : INFORMATION output generated"
  # Print up to 25 lines of info notices
  grep -A25 "INFO" dockerfile-lint.out | tail +3
fi
# isolate lint errors
awk '/ERRORS/,/WARNINGS/' dockerfile-lint.out | sed '$d' | tail +3 > dockerfile-lint-errors.out
if [ $? -eq 0 ]; then
  testok = "false"
  echo "Linting dockerfile : ERRORS found"
  # Print errors
  cat dockerfile-lint-errors.out
fi
if [ "$testok" != "true" ]; then
  echo "Linting dockerfile : Tests failed, check job output"
  exit 1
fi