configHQ is a centralized configuration platform, which can be used as a flexible way to configure applications at runtime. Some suggested use cases: Product configurations/settings with exception handling, one/region based configurations, feature flagging, whitelisting of internal/external services, high performance key-value store, implementation of peer review process for adding, updating or removing configurations.

configHQ fits perfectly in a microservice architecture, and can be run as a microservice itself.

configHQ is a service which provides an API for applications to pull configurations. RedisJSON is used for storing the configuration queries in JSON format.

Configurations are key to the application functionality and behavior, so the speed of pulling the configuration is critical. For this purpose RedisJSON works really well, since the configurations are stored as JSON in memory.

configHQ can be managed through a user-friendly, web-based admin interface. The core of the user interface is a query builder, which is used for easy setup of configuration query rules or value storage.

The queries page will show existing queries. To create a new query, click the green button with a plus-sign above the table.

Queries	Query Builder

The query builder can be used to define a very fine grained query, with multiple groups of rules. For a successful query, either one (OR) or all (AND) groups must fulfill group rules.

Each group can have either one or more rules. A rule is a logical operation. In the example above, the rule checks if a user belongs to the bronze level of a loyalty program. The rule specifies the user's membership must be greater than 0 months and less than 12 months to be categorized as a bronze member.

Lets say the loyalty level qualifies for a specific discount, the response of the query will return a 0% discount if as default, and a 10% discount if the user's memebership lenght is up to 12 months.

The queries can now be used in an application or a service, to determine features, behavior, values and much more. Below is an example application which uses configHQ to manage the following:

• Show a discount banner if a campaign is active
• Show free delivery if the user is located in the US, otherwise generic text
• Set discount percentage based on the length of the user's membership

In this example, the query is used as a key-value store, without rules, and the default response value holds the value of the key campaign-active.	The campaign banner is enabled because campaign-active returns the value true.

In this example, the loyaly tier bronze is defined as a membership length in months between 0 and 12 months. The response value is 10(%) if the range is met, otherwise 0.	The response value returns a discount percentage based on the length of a user's membership.

In this example, the user is an international member, located outside the USA. The shipping-text query is used to return one text if the user is in the US, and another for international users.	Since the user is located outside the US, a generic text about shipping is shown.

configHQ is a project submitted to the RedisConf2021 Hackathon, and is not intended to be used in production at this point. The purpose of the code is to show an example of how Redis services can be used, and the code has not gone through testing, optimization or security audits. The project is available as-is without any warranties or guarantees, and usage is at own risk.