From 5ad9214c060f247acc018da981aad14db25705ab Mon Sep 17 00:00:00 2001
From: Florian Forster <octo@google.com>
Date: Tue, 1 Sep 2020 09:49:54 +0200
Subject: [PATCH] travis-ci.sh: Print an error if TRAVIS_BRANCH,
 DOCKER_PASSWORD, or DOCKER_LOGIN is undefined or empty.

---
 travis-ci.sh | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/travis-ci.sh b/travis-ci.sh
index 7c86b34..ebc5d09 100755
--- a/travis-ci.sh
+++ b/travis-ci.sh
@@ -1,18 +1,15 @@
-#!/bin/sh -e
+#!/bin/bash
 
-if [ "${TRAVIS_PULL_REQUEST}" != "false" ]; then
+set -ex
+
+if [[ "${TRAVIS_PULL_REQUEST}" != "false" ]]; then
   echo "Not building docker images out of Pull Requests"
   exit 0
 fi
 
-if [ ! -z "${TRAVIS_BRANCH}" ]; then
-  SLUG="collectd/ci:${TRAVIS_BRANCH}"
-  docker build --pull -t "${SLUG}" .
-  docker inspect "${SLUG}"
-  docker history "${SLUG}"
-  echo "${DOCKER_PASSWORD}" | docker login --username "${DOCKER_LOGIN}" --password-stdin
-  docker push "${SLUG}"
-else
-  echo 'no $TRAVIS_BRANCH defined, exiting'
-  exit 1
-fi
+declare -r SLUG="collectd/ci:${TRAVIS_BRANCH:?}"
+docker build --pull -t "${SLUG}" .
+docker inspect "${SLUG}"
+docker history "${SLUG}"
+echo "${DOCKER_PASSWORD:?}" | docker login --username "${DOCKER_LOGIN:?}" --password-stdin
+docker push "${SLUG}"