# Cosmium

Cosmium is a lightweight Cosmos DB emulator designed to facilitate local development and testing. While it aims to provide developers with a solution for running a local database during development, it's important to note that it's not 100% compatible with Cosmos DB. However, it serves as a convenient tool for E2E or integration tests during the CI/CD pipeline.

One of Cosmium's notable features is its ability to save and load state to a single JSON file. This feature makes it easy to load different test cases or share state with other developers, enhancing collaboration and efficiency in development workflows.

# Getting Started
### Downloading Cosmium

You can download the latest version of Cosmium from the [GitHub Releases page](https://github.com/pikami/cosmium/releases). Choose the appropriate release for your operating system and architecture.

### Supported Platforms

Cosmium is available for the following platforms:

* **Linux**: cosmium-linux-amd64
* **macOS**: cosmium-darwin-amd64
* **macOS on Apple Silicon**: cosmium-darwin-arm64
* **Windows**: cosmium-windows-amd64.exe

### Running Cosmium

Once downloaded, you can launch Cosmium using the following command:

```sh
./cosmium-linux-amd64 \
  -Cert "cert.crt" \
  -CertKey "cert.key" \
  -Persist "./save.json" \
  -InitialData "./save.json"
```

Connection String Example:
```
AccountEndpoint=https://localhost:8081/;AccountKey=C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==;
```

###  Running Cosmos DB Explorer

If you want to run Cosmos DB Explorer alongside Cosmium, you'll need to build it yourself and point the `-ExplorerDir` argument to the dist directory. Please refer to the [Cosmos DB Explorer repository](https://github.com/Azure/cosmos-explorer) for instructions on building the application.

Once running, the explorer can be reached by navigating following URL: `https://127.0.0.1:8081/_explorer/` (might be different depending on your configuration).

### SSL Certificate

By default, Cosmium runs on HTTP. However, if you provide an SSL certificate, it will use HTTPS. Most applications will require HTTPS, so you can specify paths to the SSL certificate and key (PEM format) using the `-Cert` and `-CertKey` arguments, respectively.

### Other Available Arguments

* **-AccountKey**: Account key for authentication (default "C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==")
* **-DisableAuth**: Disable authentication
* **-Host**: Hostname (default "localhost")
* **-InitialData**: Path to JSON containing initial state
* **-Persist**: Saves data to the given path on application exit
* **-Port**: Listen port (default 8081)

These arguments allow you to configure various aspects of Cosmium's behavior according to your requirements.

# License
This project is [MIT licensed](./LICENSE).