Accessing a resource created by LocalStack

If you have created a resource using LocalStack, such as an OpenSearch cluster or RDS database, you may need to access it from your application. Typically, these resources are accessible through a URL or a hostname provided by LocalStack. By default, LocalStack returns the hostname localhost.localstack.cloud, which resolves to LocalStack using DNS. For special environments (e.g., proxies), the configuration LOCALSTACK_HOST customizes the URLs returned by LocalStack. This guide will explore different scenarios and provide detailed instructions on accessing resources created by LocalStack under different scenarios.

From your host

For example, suppose you have created an OpenSearch cluster using LocalStack and want to access it from the same computer. In such a case, you can set the LOCALSTACK_HOST environment variable to specify the desired hostname and port that will be returned. Check out the service-specific documentation for more details.

From a container LocalStack created

Check out our documentation while using the endpoint URL.

For LocalStack versions before 2.3.0

The Lambda service in LocalStack also supports the HOSTNAME_FROM_LAMBDA environment variable, which can be handy if LocalStack is reachable through a specific hostname. Suppose you're running LocalStack in a user-defined network using Docker, where the LocalStack container can be accessed from other containers in the network using its service name. In that case, you can set the HOSTNAME_FROM_LAMBDA environment variable to this value to help resolve any issues with lambda functions accessing resources created by LocalStack.

From your container

Check out our documentation on using the endpoint URL.

From a separate host

LocalStack must listen to the address of the host, or 0.0.0.0.

Check out our FAQ article on accessing LocalStack from another computer.