okami101/blog
2
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases 46 Wiki Activity

move mtu before swarm init

Browse Source
This commit is contained in:
Adrien Beaudouin
2023-07-01 13:31:39 +02:00
parent 1b71840ebc
commit 4ca499c2f5
1 changed files with 20 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files

47
content/posts/04-build-your-own-docker-swarm-cluster-part-3/index.md
View File

@ -29,37 +29,12 @@ sudo usermod -aG docker $USER
Then logout and use `docker run hello-world` and be sure all is OK. Follow [official installation](https://docs.docker.com/engine/install/ubuntu/) if not.
### Enable Docker Swarm
Finally, enable Swarm mode on `manager-01` :
```sh
docker swarm init --advertise-addr 10.0.0.2
```
{{< alert >}}
Use private network IP of manager, it' should be the same defined on `/et/hosts` on other worker servers.
{{< /alert >}}
The above command will show the command to launch to other worker nodes. Apply it on `worker-01` and `runner-01`.
When done use `docker node ls` on manager node in order to confirm the presence of the 2 workers with `Ready` status and active.
Yeah, cluster is already properly configured. Far less overwhelming than Kubernetes, I should say.
#### Hetzner & MTU
### Hetzner & MTU
{{< alert >}}
Just one last important thing before continue, specific to Hetzner. Their private network is set to **1450 MTU** by default, which is **not compatible with Docker Swarm overlay network**. You must change it to 1450 MTU in order to avoid any further dysfunctions between node swarm communication. Many thanks to [DcapCode](https://github.com/DcapCode) to reported it ❤️. [See here](https://www.reddit.com/r/portainer/comments/qt1mne/swarm_deployment_woes/) for further explanation.
{{< /alert >}}
Recreate the `ingress` network with the correct MTU :
```sh
docker network rm ingress
docker network create -d overlay --ingress --opt com.docker.network.driver.mtu=1450 ingress
```
Thankfully since version 24 of Moby, we can set a default MTU for all future networks created through next docker stacks. For this create following JSON file on `manager-01` :
{{< highlight host="manager-01" file="/etc/docker/daemon.json" >}}
@ -76,7 +51,25 @@ Thankfully since version 24 of Moby, we can set a default MTU for all future net
{{< /highlight >}}
Then restart docker daemon with `sudo service docker restart`.
Then restart docker daemon with `sudo service docker restart`. And that's it, we don't need to carry about anymore.
### Enable Docker Swarm
Finally, enable Swarm mode on `manager-01` :
```sh
docker swarm init --advertise-addr 10.0.0.2
```
{{< alert >}}
Use private network IP of manager, it' should be the same defined on `/et/hosts` on other worker servers.
{{< /alert >}}
The above command will show the command to launch to other worker nodes. Apply it on `worker-01` and `runner-01`.
When done use `docker node ls` on manager node in order to confirm the presence of the 2 workers with `Ready` status and active.
Yeah, cluster is already properly configured. Far less overwhelming than Kubernetes, I should say.
### CLI tools & environment labels