jensvog / basic-chat-app

Serverless chat application with multiple channels

basic-chat-app

Serverless chat application with multiple channels

Functions

• Create channel: Creates a new communication channel
• Get channels: Receives all available channel
• Create Entry: Creates a new chat entry in a channel
• Update Entry: Updates a chat entry
• Delete Entry: Deletes a chat entry
• Get Entries: Receives all chat entries of a channel

All Post requests are validated with JSON schema files. They are located under src/models/*.json.

Create channel

Path: /createChannel

Method: POST

Input:

{
    name: string
}

Output:

{
    channelId: string
    name: string
}

Get channels

Path: /channels

Method: GET

Output:

[
    {
        channelId: string
        name: string
    },
    ...
]

Create entry

Path: /createEntry

Method: POST

Input:

{
    channelId: string
    message: string
}

Output:

{
    channelId: string,
    entryId: string,
    userId: string,
    userName: string,
    message: string,
    createdAt: string
}

Update entry

Path: update/{channelId}/entry/{entryId}

Method: PATCH

Input:

{
    message: string
}

Delete entry

Path: delete/{channelId}/entry/{entryId}

Method: DELETE

Get entries

Path: chats/{channelId}

Method: GET

Output:

[
    {
        channelId: string,
        entryId: string,
        userId: string,
        message: string,
        createdAt: string
    },
    ...
]

CORS

Project handles CORS with middy middleware

CI / CD environment

The project uses GitHub actions to build and deploy the application to AWS. The npm packages are automatically installed and the application is deployed with serverless.

Postman

The application can be tested with Postman. A collections is appended in the repository under postman_collection.json. Before it can be used authenthifcation has to be set up with a Bearer token.

Branch Setup

Project has dev and master branch. dev-branch is used for development, while the master-branch is used for production use.

Authentification

In order to post and edit messages it is needed to login. Auth0 is used as a login mechanism.

Source Code

The source code is located under the src/ directory.

lambda/http/ contains lambda heads for the functions

businessLogic/ contains the business login

dataLayers/ contains the AWS interface to DynamoDB

Logging

Logging is realized using the winston logger.

Databases

The project uses DynanoDB for storing the data. There are two tables created.

Channel Table

{
    channelId: string
    message: string
}

Entry Table

{
    channelId: string,
    entryId: string,
    userId: string,
    userName: string,
    message: string,
    createdAt: string
}