---
title: "Setup a Docker Swarm cluster - Part III"
date: 2022-02-20
description: "Build an opinionated containerized platform for developer..."
tags: ["docker", "swarm"]
slug: build-your-own-docker-swarm-cluster-part-3
draft: true
---

{{< lead >}}
Build your own cheap while powerful self-hosted complete CI/CD solution by following this opinionated guide 🎉
{{< /lead >}}

This is the **Part III** of more global topic tutorial. [Back to first part]({{< ref "/posts/2022-02-13-build-your-own-docker-swarm-cluster" >}}) to start from beginning.

## Keep the containers image up-to-date

It's finally time to test our new cluster environment by testing some images through the Portainer GUI. We'll start by installing [`Diun`](https://crazymax.dev/diun/), a nice tool for keeping our images up-to-date.

Create a new `diun` stack through Portainer and set following content :

```yml
version: "3.2"

services:
  diun:
    image: crazymax/diun:latest
    command: serve
    volumes:
      - /mnt/storage-pool/diun:/data
      - /var/run/docker.sock:/var/run/docker.sock
    environment:
      TZ: Europe/Paris
      DIUN_WATCH_SCHEDULE: 0 */6 * * *
      DIUN_PROVIDERS_SWARM: 'true'
      DIUN_PROVIDERS_SWARM_WATCHBYDEFAULT: 'true'
      DIUN_NOTIF_MAIL_HOST:
      DIUN_NOTIF_MAIL_PORT:
      DIUN_NOTIF_MAIL_USERNAME:
      DIUN_NOTIF_MAIL_PASSWORD:
      DIUN_NOTIF_MAIL_FROM:
      DIUN_NOTIF_MAIL_TO:
    deploy:
      placement:
        constraints:
          - node.role == manager
```

{{< tabs >}}
{{< tab tabName="volumes" >}}

| name                     | description                                                                                                                                                                                                                                                 |
| ------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `/mnt/storage-pool/diun` | It will be used for storage of Diun db location, Diun need it for storing detection of new images version and avoid notification spams. **Don't forget** to create a new dedicated folder in the GlusterFS volume with `sudo mkdir /mnt/storage-pool/diun`. |
| `/var/run/docker.sock`   | For proper current docker images used detection through Docker API                                                                                                                                                                                          |

{{< /tab >}}
{{< tab tabName="environment" >}}

| name                                  | description                                                                           |
| ------------------------------------- | ------------------------------------------------------------------------------------- |
| `TZ`                                  | Required for proper timezone schedule                                                 |
| `DIUN_WATCH_SCHEDULE`                 | The standard linux cron schedule                                                      |
| `DIUN_PROVIDERS_SWARM`                | Required for detecting all containers on all nodes                                    |
| `DIUN_PROVIDERS_SWARM_WATCHBYDEFAULT` | If `true`, no need of explicit docker label everywhere                                |
| `DIUN_NOTIF_MAIL_*`                   | Set all according to your own mail provider, or use any other supported notification. |

{{< alert >}}
Use below section of Portainer for setting all personal environment variable. In all cases, all used environment variables must be declared inside YML.
{{< /alert >}}

{{< /tab >}}
{{< /tabs >}}

![Diun Stack](diun-stack.png)

## Installation of databases

### MySQL

### PostgreSQL