dit-digital-service-manual/docs/Software Development/06-Environment Variables.md

Environment Variables for Micro-Service Applications

This document provides a brief description of the environment variables that are used by the micro-service applications developed and maintained by the Department of Information & Technology (DIT). These variables are used to configure various aspects of the applications, such as database connections, cloud storage access, message queue settings, etc. The environment variables follow a standard naming convention that consists of two parts: the prefix and the suffix. The prefix indicates the component or service that the variable belongs to, and the suffix indicates the specific parameter or attribute that the variable represents. For example, DATABASE__HOST is an environment variable that specifies the host name of the database server for the application.

The following table lists the environment variables that are common to all DIT micro-service applications, along with their descriptions.

Environment Variable	Description
CAS__URL	The URI format for the connection string of database server
CAS__M2M_CLIENT_ID	The URI format for the connection string of database server
CAS__M2M_CLIENT_SECRET	The URI format for the connection string of database server
DATABASE__URL	The URI format for the connection string of database server
DATABASE__HOST	The host name or IP address of the database server
DATABASE__USERNAME	The username for accessing the database
DATABASE__PASSWORD	The password for accessing the database
DATABASE__NAME	The name of the database
DATABASE__PORT	The port number of the database server
S3__REGION	The AWS region of the S3 bucket
S3__ENDPOINT	The endpoint URL of the S3 bucket
S3__ACCESS_KEY_ID	The access key ID for accessing the S3 bucket
S3__SECRET_ACCESS_KEY	The secret access key for accessing the S3 bucket
S3__SELF_BUCKET	The name of the S3 bucket used for storing self-related files
S3__UPLOADS_API_BUCKET	The name of the S3 bucket used for storing uploaded files via Uploads API
SIDEKIQ__USERNAME	The username for accessing the Sidekiq web interface
SIDEKIQ__PASSWORD	The password for accessing the Sidekiq web interface
REDIS_SENTINEL__HOST	The host name or IP address of the Redis Sentinel server
REDIS_SENTINEL__PORT	The port number of the Redis Sentinel server
REDIS_SENTINEL__PASSWORD	The password for accessing the Redis Sentinel server
REDIS_SENTINEL__MASTER	The name of the Redis Sentinel master
REDIS__PASSWORD	The password for accessing the Redis server
REDIS__DB	The number of the Redis database
SIDEKIQ__REDIS_DB	The number of the Redis database for Sidekiq
SENTRY__DSN	The data source name (DSN) for Sentry error tracking
SENTRY__TRACE_RATE	The sampling rate for Sentry performance tracing
SENTRY__ENVIRONMENT	The environment name for Sentry error tracking
GATEWAY__CERTIFICATE	The certificate file for accessing the gateway service
RABBITMQ__URL	The URL the RabbitMQ server
RABBITMQ__HOST	The host name or IP address of the RabbitMQ server
RABBITMQ__PORT	The port number of the RabbitMQ server
RABBITMQ__VHOST	The virtual host name of the RabbitMQ server
RABBITMQ__USERNAME	The username for accessing the RabbitMQ server
RABBITMQ__PASSWORD	The password for accessing the RabbitMQ server
RABBITMQ__EXCHANGE_NAME	The name of the exchange for RabbitMQ server

In addition to these common environment variables, some applications may have specific environment variables that are related to their functionality or dependencies. These variables are prefixed with the name of the application or service that they belong to, such as TAX_CORPORATE_REGISTRATION_PORTAL_URL. These variables are documented in their respective application repositories or README files.

Environment Variables for Micro-Service Applications

1. Use double underscores (__) to separate words in the variable name.
2. Use all uppercase letters for the variable name.
3. Use descriptive names for the variable that indicate their purpose or usage.
4. Use consistent naming across all microservice applications developed by DIT.
5. Store environment variables securely, using an encrypted secrets store, such as HashiCorp Vault or Amazon Secrets Manager.
6. Avoid hard-coding sensitive information, such as passwords or API keys, in the code.

Conclusion

The standard naming convention for environment variables used by microservice applications developed and maintained by the Department of Information & Technology (DIT) has been outlined in this document. Following these guidelines will ensure consistency and clarity across all microservice applications developed by DIT.