start.sh

#!/bin/bash
# Copyright 2015 Google Inc. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
#you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and

# Env says we're using SSL
if [ -n "${ENABLE_SSL+1}" ] && [ "${ENABLE_SSL,,}" = "true" ]; then
  echo "Enabling SSL..."
  # If 301 redirect env var is enabled use those confs instead
  if [ -n "${ENABLE_REDIRECT_CONFS}" ] && [ "${ENABLE_REDIRECT_CONFS,,}" = "true" ]; then
    cp /usr/src/301-redirect_ssl.conf /etc/nginx/extra-conf.d/301-redirect.conf
    sed -i "s;{{REDIRECT_URL}};${REDIRECT_URL};g;" /etc/nginx/extra-conf.d/301-redirect.conf
    sed -i "s;{{BASE_URL}};${BASE_URL};g;" /etc/nginx/extra-conf.d/301-redirect.conf
    sed -i "s/.*proxy.conf;//g" /etc/nginx/nginx.conf
    cp /usr/src/proxy_ssl.conf /etc/nginx/conf.d/proxy.conf
  else
    cp /usr/src/proxy_ssl.conf /etc/nginx/conf.d/proxy.conf
  fi
else
  # No SSL
  if [ -n "${ENABLE_REDIRECT_CONFS}" ] && [ "${ENABLE_REDIRECT_CONFS,,}" = "true" ]; then
    cp /usr/src/301-redirect_nossl.conf /etc/nginx/extra-conf.d/301-redirect.conf
    sed -i "s;{{REDIRECT_URL}};${REDIRECT_URL};g;" /etc/nginx/extra-conf.d/301-redirect.conf
    sed -i "s;{{BASE_URL}};${BASE_URL};g;" /etc/nginx/extra-conf.d/301-redirect.conf
    sed -i "s/.*proxy.conf;//g" /etc/nginx/nginx.conf
    cp /usr/src/proxy_nossl.conf /etc/nginx/conf.d/proxy.conf
  else
    cp /usr/src/proxy_nossl.conf /etc/nginx/conf.d/proxy.conf
  fi
fi

# If an htpasswd file is provided, download and configure nginx
if [ -n "${ENABLE_BASIC_AUTH+1}" ] && [ "${ENABLE_BASIC_AUTH,,}" = "true" ]; then
  echo "Enabling basic auth..."
  sed -i "s;#auth_basic;auth_basic;g;" /etc/nginx/conf.d/proxy.conf
fi

# If the SERVICE_HOST_ENV_NAME and SERVICE_PORT_ENV_NAME vars are provided,
# there are two options:
#  - Option 1:
# they point to the env vars set by Kubernetes that contain the actual
# target address and port. Override the default with them.
#  - Option 2:
# they point to a host and port accessible from the container, respectively,
# as in a multi-container pod scenario in Kubernetes.
# E.g.
#    - SERVICE_HOST_ENV_NAME=localhost
#    - SERVICE_PORT_ENV_NAME=8080
if [ -n "${SERVICE_HOST_ENV_NAME+1}" ]; then
  # get value of the env variable in SERVICE_HOST_ENV_NAME as host, if that's not set,
  # SERVICE_HOST_ENV_NAME has the host value
  TARGET_SERVICE=${!SERVICE_HOST_ENV_NAME:=$SERVICE_HOST_ENV_NAME}
fi
if [ -n "${SERVICE_PORT_ENV_NAME+1}" ]; then
  # get value of the env variable in SERVICE_PORT_ENV_NAME as port, if that's not set,
  # SERVICE_PORT_ENV_NAME has the port value
  TARGET_SERVICE="$TARGET_SERVICE:${!SERVICE_PORT_ENV_NAME:=$SERVICE_PORT_ENV_NAME}"
fi

# Tell nginx the address and port of the service to proxy to
sed -i "s;{{TARGET_SERVICE}};${TARGET_SERVICE};g;" /etc/nginx/conf.d/proxy.conf

# Tell nginx if you want to block or allow iframing of pages and what domain name is allowed to iframe your content
if [ -n "${XFRAME_OPTION+1}" ]; then
  echo "Applying iframe option..."
  sed -i "s;{{XFRAME_VALUE}};${XFRAME_OPTION};g;" /etc/nginx/conf.d/proxy.conf
else
  echo "Denying iframes..."
  sed -i "s;{{XFRAME_VALUE}};DENY;g;" /etc/nginx/conf.d/proxy.conf
fi

if [ -n "${ENABLE_REDIRECT_CONFS}" ] && [ "${ENABLE_REDIRECT_CONFS,,}" = "true" ]; then
  rm -f /etc/nginx/conf.d/proxy.conf
fi

echo "Starting nginx..."
nginx -g 'daemon off;'