nginx-proxy docker container crashes with exit code 2

Question

Introduction

Hello folks! It is great to have helpful and skillful members like you. I am stuck after reproducing the step-by-step instructions from various blogs to create a whole suite of Docker-powered apps from a small hosted VPS. Mainly to create a blog with ghost, nginx and ssl.

Problem

While executing docker-compose.yml the nginx container stops:

• nginx-gen | 2018/04/09 07:52:03 Generated '/etc/nginx/conf.d/default.conf' from 5 containers
• nginx-gen | 2018/04/09 07:52:03 Sending container 'nginx' signal '1'
• nginx-gen | 2018/04/09 07:52:03 Watching docker events
• nginx | nginx-gen | 2018/04/09 07:52:03 Contents of /etc/nginx/conf.d/default.conf did not change. Skipping notification ''
• nginx-gen | 2018/04/09 07:52:03 Received event die for container 789c0544cf96
• nginx-gen | 2018/04/09 07:52:03 Debounce minTimer fired
• nginx exited with code 2

Setup

• GCP CE g1-small (1 vCPU, 1,7 GB Memory)
• Ubuntu 16.04.4 LTS
• Docker version 18.03.0-ce, build 0520e24
• docker-compose version 1.20.1, build 5d8c71b

Docker Images

• jwilder/nginx-proxy
• jwilder/docker-gen
• jrcs/letsencrypt-nginx-proxy-companion

Files #

• nginx.tmpl (Source: https://github.com/jwilder/nginx-proxy/blob/master/nginx.tmpl)
• docker-compose.yml

Notes

• All files are in the same folder.
• Used already docker network create nginx-proxy

docker-compose.yml

version: '2'

services:

  nginx:
    image: jwilder/nginx-proxy
    container_name: nginx
    ports:
      - '80:80'
      - '443:443'
    volumes:
      - /var/run/docker.sock:/tmp/docker.sock:ro
      - /etc/nginx/conf.d
      - /etc/nginx/vhost.d # to update vhost configuration
      - /usr/share/nginx/html # to write challenge files
      - "../../../volumes/proxy/certs:/etc/nginx/certs:ro"
    networks:
     - default

  nginx-gen:
    image: jwilder/docker-gen
    container_name: nginx-gen
    volumes:
     - "/var/run/docker.sock:/tmp/docker.sock:ro"
     - "./:/etc/docker-gen/templates/:ro"
    volumes_from:
     - nginx
    entrypoint: /usr/local/bin/docker-gen -notify-sighup nginx -watch -wait -5s:30s /etc/docker-gen/templates/nginx.tmpl /etc/nginx/conf.d/default.conf

  ssl-companion:
    image: jrcs/letsencrypt-nginx-proxy-companion
    container_name: ssl-companion
    volumes_from:
     - nginx
    volumes:
     - "/var/run/docker.sock:/var/run/docker.sock:ro"
     - "../../../volumes/proxy/certs:/etc/nginx/certs:rw"

  mariadb:
    image: 'bitnami/mariadb:latest'
    volumes:
      - '/mariadb_data:/bitnami:z'
    environment:
      - ALLOW_EMPTY_PASSWORD=yes
      - MARIADB_USER=<USER_NAME> # change <USER_NAME>
      - MARIADB_DATABASE=<DB_NAME> # change <DB_NAME>

  blog:
    image: 'bitnami/ghost:latest'
    expose:
      - '2368'
    depends_on:
      - mariadb
    environment:
      - VIRTUAL_HOST=<YOUR_VR_HOST> # change <YOUR_VR_HOST> 
      - LETSENCRYPT_HOST=<YOUR_LC_HOST> # change <YOUR_LC_HOST>
      - LETSENCRYPT_EMAIL=<YOUR_EMAIL> # change <YOUR_EMAIL>
      - GHOST_DATABASE_USER=<USER_NAME> # change <USER_NAME>
      - GHOST_DATABASE_NAME=<DB_NAME> # change <DB_NAME>
      - GHOST_HOST=localhost
      - MARIADB_HOST=mariadb
      - MARIADB_PORT_NUMBER=3306
      - ALLOW_EMPTY_PASSWORD=yes
    volumes:
      - '/ghost_data:/bitnami:z'
    restart: unless-stopped
    networks:
     - default

networks:
  default:
    external:
      name: nginx-proxy