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add cronjob case

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Adrien Beaudouin
2022-05-15 11:12:05 +02:00
parent fe89abcb4e
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content/posts/04-build-your-own-docker-swarm-cluster-part-3/index.md
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@ -407,13 +407,17 @@ Note as this primary endpoint was automatically created by the above `tcp://task
If you go to the stacks menu, you will note that both `traefik` and `portainer` are *Limited* control, because these stacks were done outside Portainer. From now, we'll create and deploy stacks directly from Portainer GUI.
{{< /alert >}}
## Keep the containers image up-to-date ⬆️
## Some maintenance cluster tools 🐕‍🦺
It's finally time to test our new cluster environment by testing some stacks through the Portainer GUI. We'll start by installing [`Diun`](https://crazymax.dev/diun/), a very useful tool which notify us when used docker images has available update in its Docker registry.
It's finally time to test our new cluster environment by testing some stacks through the Portainer GUI !
### Keep the containers image up-to-date ⬆️
We'll start by installing [`Diun`](https://crazymax.dev/diun/), a very useful tool which notify us when used docker images has available update in its Docker registry.
Create the next stack through Portainer :
{{< highlight host="stack" file="diun" >}}
{{< highlight host="stack" file="maintenance" >}}
```yml
version: '3'
@ -455,13 +459,13 @@ services:
{{< /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. |
| 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.
@ -484,6 +488,53 @@ You can check the service logs which consist of all tasks logs aggregate.
[![Diun Logs](diun-logs.png)](diun-logs.png)
### Distributed cron jobs 🕰️
It's frequent to have some crontab jobs for long-running maintenance tasks as database dumping, backups, exports and so on. But can we achieve that on this cluster environment ? Actually **crazy-max** has developed [Cron](https://github.com/crazy-max/swarm-cronjob) precisely for this purpose ! Let's add this service into same above maintenance stack.
{{< highlight host="stack" file="maintenance" >}}
```yml
#...
cronjob:
image: crazymax/swarm-cronjob
volumes:
- /var/run/docker.sock:/var/run/docker.sock
environment:
TZ: Europe/Paris
LOG_LEVEL: info
LOG_JSON: 'false'
deploy:
placement:
constraints:
- node.role == manager
```
{{< /highlight >}}
This service will now search for any crontab related docker service labels across all Swarm cluster, and launch it accordingly `schedule` settings which uses standard crontab format. All you have to do is to use following structure for any service you want to run periodically :
```yml
#...
deploy:
labels:
- swarm.cronjob.enable=true
- swarm.cronjob.schedule=5 * * * *
- swarm.cronjob.skip-running=true
replicas: 0
restart_policy:
condition: none
#...
```
| name | description |
| ---------------------------- | ------------------------------------------------------------------- |
| `swarm.cronjob.enable` | Enable cron launch |
| `swarm.cronjob.schedule` | The standard linux cron schedule |
| `swarm.cronjob.skip-running` | Prevent overlapping |
| `replicas` | Set to 0 in order to prevent launching service after stack creation |
| `restart_policy.condition` | Set none to prevent infinite restart after completion of job |
## Get your own S3 💽
Let's try with a tool with a web UI. Here is how get your own S3 bucket and be free from any external S3 provider. We'll use our GlusterFS volume as a real storage.