---
sidebar_position: 2
title: Deployment in sealos
---

`Sealos` is an open-source Kubernetes deployment system that allows us to quickly create an on-demand, pay-as-you-go application cluster.

## First, enter Sealos and open "Application Management"

![](/img/kubernetes/sealos/1.png)

## Create a new application

![](/img/kubernetes/sealos/2.png)

### Create dependencies

As an enterprise-level application, `tailchat` has the minimum dependencies of `mongodb`, `redis`, and `minio`. Let's create them one by one.

#### MongoDB

For convenience, we will fix one instance and bind it to local storage. The image used is `mongo:4`. Note that because we did not set a password for the database, do not provide network services to the public network. The container exposes port 27017, which is the default database service port. The content is as follows:

![](/img/kubernetes/sealos/3.png)

Click "Deploy Application" to submit the deployment. Wait patiently for a while, and you can see that the application has started up.

![](/img/kubernetes/sealos/4.png)

> Note: that the initial allocation of 64m is too small for MongoDB, so I changed it to 128m by modifying the application. Resource allocation can be changed at any time, which is also a convenient feature of Sealos/Kubernetes.

#### Minio

Next, we will create Minio, an open-source object storage service. We can also quickly create it through Sealos's UI. The image used is `minio/minio`. Note that we need to make some adjustments:

- Expose port: 9000
- Change the run command to: `minio server /data`
- Set environment variables:
- MINIO_ROOT_USER: tailchat
- MINIO_ROOT_PASSWORD: com.msgbyte.tailchat
- Local storage: `/data`

The final result is as follows:

![](/img/kubernetes/sealos/5.png)

Click the "Deploy" button and you can see that the service has started up normally.

#### Redis

Finally, we need to deploy Redis as a content cache and message forwarding. The image used is `redis:alpine`, and the exposed port is `6379`. The final result is as follows:

![](/img/kubernetes/sealos/6.png)

### Create Tailchat itself

At this point, all the dependencies required by Tailchat have been deployed, as shown below:

![](/img/kubernetes/sealos/7.png)

Now we can deploy the Tailchat itself. The Tailchat itself will be relatively complex, but because Sealos is purely UI-based, it will not be too complicated.

- Use image: `moonrailgun/tailchat`
- Expose port: `11000` (remember to open external access)
- Configure environment variables as follows:
  ```
  SERVICEDIR=services,plugins
  TRANSPORTER=redis://redis:6379
  REDIS_URL=redis://redis:6379
  MONGO_URL=mongodb://mongo/tailchat
  MINIO_URL=minio:9000
  MINIO_USER=tailchat
  MINIO_PASS=com.msgbyte.tailchat
  ```

The final effect is as follows:

![](/img/kubernetes/sealos/8.png)

After waiting patiently for a while, you can see that the Tailchat service has started up.

![](/img/kubernetes/sealos/9.png)

## Preview service

First, we can check the availability of the Tailchat service by adding `/health` to the external address provided by the service, such as `https://<xxxxxxxxxx>.cloud.sealos.io/health`. When it starts up, the Tailchat service will return content like this:

![](/img/kubernetes/sealos/10.png)

This JSON string contains the image version used, node name, system usage, and microservice loading status. Here we can see that my common services, such as `user`/`chat.message`, and some services with plugin prefixes such as `plugin.registry`, have all started up normally, indicating that our server is running normally. Now we can directly access our external address and see that after a short loading time, the page opens normally and automatically jumps to the login page.

![](/img/kubernetes/sealos/11.png)

Register an account casually, and you can see that we can enter the main interface of Tailchat normally, as shown in the following figure:

![](/img/kubernetes/sealos/12.png)

At this point, our service has successfully landed in Sealos.

## Scaling service

Of course, as a distributed architecture system, Tailchat naturally supports horizontal scaling. In Sealos, scaling is also very simple. Just modify the number of instances through the change operation:

![](/img/kubernetes/sealos/13.png)

![](/img/kubernetes/sealos/14.png)

![](/img/kubernetes/sealos/15.png)

At this point, when we access `https://<xxxxxxxxxx>.cloud.sealos.io/health`, we can see that we can access different nodes.

![](/img/kubernetes/sealos/16.png)