# EnvVar Configuration

> Configure applications using environment variables from ConfigMaps and Secrets

- **Category**: Cloud
- **Subcategory**: Configuration
- **Canonical URL**: https://designpattern.fyi/patterns/k8s_env_var_configuration/

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## Description
The EnvVar Configuration pattern uses environment variables to configure applications, with values sourced from ConfigMaps and Secrets. This enables externalized configuration without rebuilding container images. Environment variables can contain literal values or entire configuration files, providing flexibility for different deployment environments.


## Use Cases
Use when you need to externalize application configuration or when you want to configure applications differently for different environments.





## Trade-offs


### Advantages

- Externalized configuration

- No image rebuilds for config changes

- Support for sensitive data with Secrets

- Simple and widely understood




### Considerations & Drawbacks

- Limited to string values

- Requires pod restart for changes

- Not suitable for large configurations







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**Reference**: [Original Source](https://github.com/k8spatterns/examples/tree/master/configuration/EnvVarConfiguration)