docker_entrypoint.sh

#!/usr/bin/env bash
set -o pipefail -o errexit -o nounset

: "${API_ENDPOINT:?'This environment variable is required'}"
if [ -z "${PORT:-}" ]; then
  export PORT=80
fi
if [ -n "${PROXY_TIMEOUT_IN_SECS:-}" ]; then
  export PROXY_TIMEOUT_DIRECTIVES="proxy_connect_timeout ${PROXY_TIMEOUT_IN_SECS}s; proxy_send_timeout ${PROXY_TIMEOUT_IN_SECS}s; proxy_read_timeout ${PROXY_TIMEOUT_IN_SECS}s; send_timeout ${PROXY_TIMEOUT_IN_SECS}s;"
fi

# Ensure there is no default nginx configuration listening on port 80,
# as this prevents the dyno to start in Heroku:
rm /etc/nginx/conf.d/default.conf || true

# Inject env variables in hesperides.conf:
envsubst </etc/nginx/conf.d/hesperides.conf.template >/etc/nginx/conf.d/hesperides.conf

# Inject env variables in index.html:
envsubst </usr/share/nginx/html/index.html.template >/usr/share/nginx/html/index.html

# Ensure all the required JS files are present:
grep -F '<script ' /usr/share/nginx/html/index.html | sed 's/.*src="\([^"]*\)".*/\1/' | while read js_file; do
    if ! [ -s /usr/share/nginx/html/$js_file ]; then
        echo "$js_file is missing or empty"
        exit 1
    fi
done
# Ensure all the required CSS files are present:
grep -F '<link rel="stylesheet"' /usr/share/nginx/html/index.html | sed 's/.*href="\([^"]*\)".*/\1/' | while read css_file; do
    if ! [ -s /usr/share/nginx/html/$css_file ]; then
        echo "$css_file is missing or empty"
        exit 1
    fi
done

if [ $# -gt 0 ]; then
  exec "$@"
else
  exec nginx -g 'daemon off;'
fi