POC: Introduce Nextcloud based on Nginx web server.

UPDATE:
 - stack.yml contains FPM & Mariadb containers, updated names and hostnames for container
TODO:
 - update config.ini for trusted proxies support

This PR introduce POC of Nextcloud based on Nginx web server with php-fpm in separated container.
Basic installation with SQLite and few operations in web gui were tested.

Nginx dockerfile is generated from Dockerfile-nginx.template
  - FROM string has hardcoded variant - apache
  - There is no upstream PHP image with Nginx, due this generate-stackbrew-library is not able to identify parent correctly

New files were introduced in image:
  - Dockerfile-nginx.template
  - nginx-foreground
    + simulates behavior of apache2-foreground cmd
  - 16.0/nginx/Dockerfile
    + generated from template Dockerfile-nginx.template
  - nextcloud.confx
    + Nginx vhost configuration
  - start_net.sh (temporary)
    + Helper script to create user-defined network for Docker
    + '--link' option for docker create is obsolete and we need communication between fpm and nginx container
  - start_container.sh (temporary)
    + Helper script to handle containers
  - Dockerfile
    + /Dockerfile for verification purposes
Updated files:
  - set -x added to all shell scripts for easier troubleshooting (temporary)
  - update.sh
    + New variant introduced
    + Number of builded variant is limited for simplified CI.
  - .travis.yml (temporary)
    + Image push to registry for testing purposes
  - docker-entrypoint.sh
    + Recognizes new argument for entrypoint - nginx-foreground

Be careful during review, github recognizes removed files for 15.0 release as renamed to 16.0/nginx variant

Motivation/Usecase:
  - I have openvz based VPS where only old Docker 1.10 is supported.
  - Apache(in nextcloud container) in combination Nginx as a reverse proxy for multiple vhosts doesn't work correctly

Image pull link:
docker pull 1john2ci/nextcloud:apache-20190509
docker pull 1john2ci/nextcloud:fpm-20190509
Travis CI test: 530329740

Deployment notes:
  - Clone source code
  - Create user-defined network for Docker
  - Start fpm container
  - Start nginx container

Signed-off-by: Malanik Jan <malanik.jan@gmail.com>

start_container.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 # ##
-# file name: start_ncd.sh
+# file name: start_container.sh_
 # Author: Malanik Jan
 # Email: malanik (_dot_) jan (_at_) gmail (_dot_) com
 # Description: 
@@ -11,54 +11,63 @@ set -x
 
 NAME=''
 NCD_VOL='/srv/nextcloud:/var/www/html:rprivate' 
-TAG='20190509'
+#20190509 stable
+TAG='16.0'
 
-read -p "Would you like to handle apache/nginx/fpm? [nginx/apache/fpm]" NAME
-read -p "Remove image? [y/n]" REMOVEIMAGE
-read -p "Start container? [y/n]" STARTCONTAINER
-if [ "${STARTCONTAINER}" == 'y' ]; then
-  read -p "Do you want to start with /bin/sleep infinity? [y/n]" STARTSLEEP
+if [[ -z "${NCD_NAME}" ]]; then
+  read -p "Would you like to handle apache/nginx/fpm? [nginx/apache/fpm]" NCD_NAME
+fi
+if [[ -z "${NCD_REMOVEIMAGE}" ]]; then
+  read -p "Remove image? [y/n]" NCD_REMOVEIMAGE
+fi
+if [[ -z "${NCD_STARTCONTAINER}" ]]; then
+  read -p "Start container? [y/n]" NCD_STARTCONTAINER
 fi
 
-IMAGE="1john2ci/nextcloud:${NAME}-ncd-${TAG}"
-NAME="${NAME}-ncd"
+if [[ "${NCD_STARTCONTAINER}" == 't' ]] && [[ -z "${NCD_STARTSLEEP}" ]]; then
+  read -p "Do you want to start with /bin/sleep infinity? [y/n]" NCD_STARTSLEEP
+fi
+
+echo "Starting script with configuration:" 
+for var in $(env | grep NCD); do
+  echo ${var} 
+done
+NCD_NAME="${TAG}-${NCD_NAME}"
+IMAGE="1john2ci/nextcloud:${NCD_NAME}"
 
 declare -A PUBLISH=(
-[nginx-ncd]=' -p 127.0.0.1:8060:80 '
+[16.0-nginx]=' -p 127.0.0.1:8060:80 '
 [fpm-ncd]=''
 )
 
 # ##
 # Cleanup
 # ##
-docker stop "${NAME}"
-docker rm "${NAME}"
-if [ "${REMOVEIMAGE}" == 'y' ]; then
+docker stop "${NCD_NAME}"
+docker rm "${NCD_NAME}"
+if [ "${NCD_REMOVEIMAGE}" == 'y' ]; then
   docker rmi "${IMAGE}" 
 fi
 
-if [ "${STARTCONTAINER}" != 'y' ] ; then
+if [ "${NCD_STARTCONTAINER}" != 'y' ] ; then
   exit 0
 fi
 # ##
 # Start Container
 # ##
-if [ "${STARTSLEEP}" == 'y' ]; then
+if [ "${NCD_STARTSLEEP}" == 'y' ]; then
   EXECCMD='/bin/sleep infinity'
 else
   EXECCMD=''
 fi
 eval "CMD='docker run -dit \
-    --hostname "${NAME}" \
-    --name "${NAME}" \
+    --hostname "${NCD_NAME}" \
+    --name "${NCD_NAME}" \
     --net 'nextcloud' \
     --volume ${NCD_VOL} \
-    "${PUBLISH[$NAME]}" \
+    "${PUBLISH[$NCD_NAME]}" \
     "${IMAGE}" \
     "${EXECCMD}" \
   '"
-export SQLITE_DATABASE='test'
-export NEXTCLOUD_ADMIN_USER='admin'
-export NEXTCLOUD_ADMIN_PASSWORD='admin'
 
 ${CMD}