Step 3: Load a Simple Docker Project

Table of Contents

• Step 3: Load a Simple Docker Project

  • Installing NextCloud on Docker

  • Create a Reverse Proxy for NextCloud

Snap applications are easy to install because they take care of all of the dependencies and run them in a semi-isolated environment.

• One drawback is that the application is tightly integrated. Configuring it or modifying it to use a different component is hard to do.

• It’s not practical to use snaps to run part of the application on one box and then have the database on another server. Or, you might not be able to use MariaDB instead of the pre-configured MySQL instance.

Docker containers address these problems. Like snaps, Docker containers run in isolation, meaning they will not conflict with services running on the host machine.

1. For this step, we will run the Docker-based application in a similar fashion to how snaps operate.

2. We still have the problem of one application per box, but this moves us closer to distributed computing because Docker lets developers spread or distribute the components across different containers.

This Docker project works in isolation. It is a single container that contains the webserver, database, and all of the data.

Installing NextCloud on Docker

Nextcloud is an open-source tool for cloud storage. It has web, desktop, and mobile applications.

• This installation is for demonstration purposes only.

• We will do a production-ready install later so you can use to store your data in the cloud

We’ll use the instruction from https://github.com/nextcloud/docker Nextcloud to run NextCloud in Docker.

1. Run the Docker container

   • The command has these arguments:

     run -d

     Runs the container in daemon mode, which means running it in the background

     -p 20850:80

     The port pairs.

     • The first port (20850) is the external port, which is accessible to the VPS.

     • The second port (80) is internal to the Docker container.

     nextcloud

     Name of the container to run. This container is pulled from Docker Hub.

   docker run -d -p 20850:80 nextcloud
   

   Output

   root@vps298933:~# docker run -d -p 20850:80 nextcloud
   Unable to find image 'nextcloud:latest' locally
   latest: Pulling from library/nextcloud
   f7e2b70d04ae: Pull complete
   744aedb7995c: Pull complete
   07afe22f8a58: Pull complete
   c7bf4f31c4a4: Pull complete
   b528e75732cc: Pull complete
   27e7d214ded2: Pull complete
   894549c23c16: Pull complete
   9aa6d55932b2: Pull complete
   1b27fd7479e6: Pull complete
   eacdac7d65c9: Pull complete
   66f1bd2ad7cf: Pull complete
   ee6444380c18: Pull complete
   1500f6dd9b69: Pull complete
   18560f19c8c4: Pull complete
   bddc5d1da8e7: Pull complete
   6e33450d197c: Pull complete
   6f195f51537c: Pull complete
   a8c28fabf19a: Pull complete
   ad044e6f6c56: Pull complete
   20144f3a754f: Pull complete
   Digest: sha256:4c3a690b1771ba414c0a347514baae52dae3ec34feb747d5db0c4188d8462562
   Status: Downloaded newer image for nextcloud:latest
   0b3091ea59c416ce8c2dc1fbdbce960ce3c1164e53d2c6fc440222c059abc10a
   root@vps298933:~#
   

2. Let’s verify that it is running using docker ps

   docker ps

   List all running containers

   docker ps -a

   List all running and stopped containers

   Output

   root@vps298933:~# docker ps
   CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                  NAMES
   f09da32f5217        nextcloud           "/entrypoint.sh apac…"   9 minutes ago       Up 9 minutes        0.0.0.0:20850->80/tcp   hardcore_bhaskara
   root@vps298933:~#
   

   If you do not see it, then run docker ps -a to see if it tried to start, but then failed. If it did not start correctly, then stop and remove it.

   • Steps to stopping and removing a running container:

     1. docker stop <Container ID>

     2. docker rm <Container ID>

3. Let’s verify that the application will respond to a web request using curl.

   curl http://localhost:20850
   

   Output

   root@vps298933:~# curl http://localhost:20850
   <!DOCTYPE html>
   <html class="ng-csp" data-placeholder-focus="false" lang="en" data-locale="en" >
           <head data-requesttoken="utvzF1Gkzv92ZJIBFqsjSLd3adMzlGsTqkDz1IHAs2c=:y5GmUDz1/ok0CaBDW8wIcY4lC6Bf5iNg8g6crbeu9VI=">
                   <meta charset="utf-8">
                   <title>
                   Nextcloud               </title>
                   <meta http-equiv="X-UA-Compatible" content="IE=edge">
                   <meta name="referrer" content="no-referrer">
                   <meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0">
                   <meta name="apple-itunes-app" content="app-id=1125420102">
                   <meta name="theme-color" content="#0082c9">
                   <link rel="icon" href="/core/img/favicon.ico">
                   <link rel="apple-touch-icon-precomposed" href="/core/img/favicon-touch.png">
                   <link rel="mask-icon" sizes="any" href="/core/img/favicon-mask.svg" color="#0082c9">
   .
   .
   .
   

Create a Reverse Proxy for NextCloud

Repeat the steps that you used for Rocket.Chat to create reverse proxy.

1. Create sub-domain cloud.example.com

2. Create your Reverse Proxy using these settings

   • server_name cloud.example.com;

   • proxy_pass http://localhost:20850;

3. Enable the Nginx Site

4. Restart Nginx