Configuration

Environment variables which affect LocalStack.

LocalStack allows for many different configuration options. You can pass these via environment variables, e.g., like the following:

$ SERVICES=kinesis,lambda,sqs,dynamodb DEBUG=1 localstack start

Core

VariableExample ValuesDescription
SERVICESkinesis,lambda,sqs,serverlessComma-separated list of AWS CLI service names or shorthands to start up.
EDGE_BIND_HOST127.0.0.1 (default), 0.0.0.0 (docker)Address the edge service binds to.
EDGE_PORT4566 (default)Port number for the edge service, the main entry point for all API invocations.
HOSTNAMElocalhost (default)Name of the host to expose the services internally. For framework-internal communication, e.g., services are started in different containers using docker-compose.
HOSTNAME_EXTERNALlocalhost (default)Name of the host to expose the services externally. This host is used, e.g., when returning queue URLs from the SQS service to the client.
DEBUG0|1Flag to increase log level and print more verbose logs (useful for troubleshooting issues)
<SERVICE>_PORT_EXTERNAL4567Port number to expose a specific service externally . SQS_PORT_EXTERNAL, e.g. , is used when returning queue URLs from the SQS service to the client.
IMAGE_NAMElocalstack/localstack (default), localstack/localstack:0.11.0Specific name and tag of LocalStack Docker image to use.
USE_LIGHT_IMAGE1 (default)Whether to use the light-weight Docker image. Overwritten by IMAGE_NAME.
TMPDIR/tmp (default)Temporary folder on the host running the CLI and inside the LocalStack container .
HOST_TMP_FOLDER/some/pathTemporary folder on the host that gets mounted as $TMPDIR/localstack into the LocalStack container. Required only for Lambda volume mounts when using LAMBDA_REMOTE_DOCKER=false.
DATA_DIRblank (disabled/default), /tmp/localstack/dataLocal directory for saving persistent data (see: TODO)
PERSISTENCE_SINGLE_FILEtrue (default)Specify if persistence files should be combined.
<SERVICE>_BACKENDCustom endpoint URL to use for a specific service, where is the uppercase service name. See (TODO) for supported services and (TODO) for examples for third-party integration
MAIN_CONTAINER_NAMElocalstack_main (default)Specify the main docker container name
INIT_SCRIPTS_PATH/some/pathSpecify the path to the initializing files with extensions .sh that are found default in /docker-entrypoint-initaws.d.
LS_LOGtrace, trace-internal, debug, info, warn, error, warningSpecify the log level. Currently overrides the DEBUG configuration. trace for detailed request/response, trace-internal for internal calls, too.

Docker

Docker is used extensively by LocalStack, and there are several configuration parameters for how LocalStack interacts with Docker.

VariableExample ValuesDescription
DOCKER_FLAGSAllows to pass custom flags (e.g., volume mounts) to “docker run” when running LocalStack in Docker.
DOCKER_SOCK/var/run/docker.sockPath to local Docker UNIX domain socket
DOCKER_BRIDGE_IP172.17.0.1IP of the docker bridge used to enable access between containers
LEGACY_DOCKER_CLIENT0|1Whether LocalStack should use the command-line Docker client and subprocess execution to run Docker commands, rather than the Docker SDK.
DOCKER_CMDdocker (default), sudo dockerShell command used to run Docker containers (only used in combination with LEGACY_DOCKER_CLIENT)
FORCE_NONINTERACTIVEWhen running with Docker, disables the --interactive and --tty flags. Useful when running headless.

Local AWS Services

This section covers configuration values that are specific to AWS services.

DynamoDB

VariableExample ValuesDescription
DYNAMODB_ERROR_PROBABILITYDecimal value between 0.0(default) and 1.0Randomly inject ProvisionedThroughputExceededException errors into DynamoDB API responses.
DYNAMODB_HEAP_SIZE256m (default), 1GSets the JAVA EE maximum memory size for DynamoDB; full table scans require more memory

Kinesis

VariableExample ValuesDescription
KINESIS_ERROR_PROBABILITYDecimal value between 0.0(default) and 1.0Randomly inject ProvisionedThroughputExceededException errors into Kinesis API responses.
KINESIS_SHARD_LIMIT100 (default), Infinity (to disable)Integer value , causing the Kinesis API to start throwing exceptions to mimick the default shard limit.
KINESIS_LATENCY500 (default), 0 (to disable)Integer value of milliseconds, causing the Kinesis API to delay returning a response in order to mimick latency from a live AWS call.
KINESIS_INITIALIZE_STREAMS"my-first-stream:1,my-other-stream:2:us-west-2,my-last-stream:1"A comma-delimited string of stream names, its corresponding shard count and an optional region to initialize during startup. If the region is not provided, the default region is used. Only works with the kinesis-mock KINESIS_PROVIDER.

Lambda

VariableExample ValuesDescription
LAMBDA_EXECUTORMethod to use for executing Lambda functions. For docker and docker-reuse, if LocalStack itself is started inside Docker, then the docker command needs to be available inside the container (usually requires to run the container in privileged mode). More information in Lambda Executor Modes.
docker (default)Run each function invocation in a separate Docker container.
local (fallback)Run Lambda functions in a temporary directory on the local machine.
docker-reuseCreate one Docker container per function and reuse it across invocations.
LAMBDA_REMOTE_DOCKERdetermines whether Lambda code is copied or mounted into containers
true (default)your Lambda function definitions will be passed to the container by copying the zip file (potentially slower). It allows for remote execution, where the host and the client are not on the same machine.
falseyour Lambda function definitions will be passed to the container by mounting a volume (potentially faster). This requires to have the Docker client and the Docker host on the same machine. Also, HOST_TMP_FOLDER must be set properly, and a volume mount like ${HOST_TMP_FOLDER}:/tmp/localstack needs to be configured if you’re using docker-compose.
BUCKET_MARKER_LOCALOptional bucket name for running lambdas locally.
LAMBDA_CODE_EXTRACT_TIME25Time in seconds to wait at max while extracting Lambda code. By default it is 25 seconds for limiting the execution time to avoid client/network timeout issues.
LAMBDA_DOCKER_NETWORKOptional Docker network for the container running your lambda function.
LAMBDA_DOCKER_DNSOptional DNS server for the container running your lambda function.
LAMBDA_DOCKER_FLAGS-e KEY=VALUE, -v host:container, -p host:container, --add-host domain:ipAdditional flags passed to Lambda Docker run|create commands (e.g., useful for specifying custom volume mounts). Does only support environment, volume, port and add-host flags
LAMBDA_CONTAINER_REGISTRYlambci/lambda (default)An alternative docker registry from where to pull lambda execution containers.
LAMBDA_REMOVE_CONTAINERStrue (default)Whether to remove containers after Lambdas finished executing.
LAMBDA_FALLBACK_URLFallback URL to use when a non-existing Lambda is invoked. Either records invocations in DynamoDB (value dynamodb://<table_name>) or forwards invocations as a POST request (value http(s)://...).
LAMBDA_FORWARD_URLURL used to forward all Lambda invocations (useful to run Lambdas via an external service).
LAMBDA_JAVA_OPTS-Xmx512MAllow passing custom JVM options to Java Lambdas executed in Docker. Use _debug_port_ placeholder to configure the debug port, e.g., -agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=_debug_port_.
HOSTNAME_FROM_LAMBDAlocalstackEndpoint host under which APIs are accessible from Lambda containers (optional). This can be useful in docker-compose stacks to use the local container hostname if neither IP address nor container name of the main container are available (e.g., in CI). Often used in combination with LAMBDA_DOCKER_NETWORK.

Stepfunction

VariableExample ValuesDescription
STEPFUNCTIONS_LAMBDA_ENDPOINTdefaultURL to use as the Lambda service endpoint in Step Functions. By default this is the LocalStack Lambda endpoint. Use default to select the original AWS Lambda endpoint.

Security

Please be aware that the following configurations may have severe security implications!

VariableExample ValuesDescription
DISABLE_CORS_CHECKS0 (default)Whether to disable all CSRF mitigations.
DISABLE_CUSTOM_CORS_S30 (default)Whether to disable CORS override by S3.
DISABLE_CUSTOM_CORS_APIGATEWAY0 (default)Whether to disable CORS override by apigateway.
EXTRA_CORS_ALLOWED_ORIGINSComma-separated list of origins that are allowed to communicate with localstack.
EXTRA_CORS_ALLOWED_HEADERSComma-separated list of header names to be be added to Access-Control-Allow-Headers CORS header.
EXTRA_CORS_EXPOSE_HEADERSComma-separated list of header names to be be added to Access-Control-Expose-Headers CORS header.

Provider

Some of the services can be configured to switch to a particular provider:

VariableValid options
KINESIS_PROVIDERkinesis-mock (default) and kinesalite
KMS_PROVIDERmoto (default) and local-kms
SQS_PROVIDERmoto (default) and elasticmq

Miscellaneous

VariableExample ValuesDescription
SKIP_INFRA_DOWNLOADSWhether to skip downloading additional infrastructure components (e.g., specific Elasticsearch versions).
IGNORE_ES_DOWNLOAD_ERRORSWhether to ignore errors (e.g., network/SSL) when downloading Elasticsearch plugins.
OVERRIDE_IN_DOCKEROverrides the check whether LocalStack is executed within a docker container. If set to true, LocalStack assumes it runs in a docker container. Should not be set unless necessary.
EDGE_FORWARD_URLOptional target URL to forward all edge requests to (e.g., for distributed deployments).
DISABLE_EVENTS1Whether to disable publishing LocalStack events

Debugging

VariableExample ValuesDescription
DEVELOPStarts a debugpy server before starting LocalStack services
DEVELOP_PORTPort number for debugpy server
WAIT_FOR_DEBUGGERForces LocalStack to wait for a debugger to start the services

DNS

More information here.

VariableExample ValuesDescription
DNS_ADDRESS0.0.0.0 (default)Address the LocalStack should bind the DNS server on (port 53 tcp/udp). Value 0 to disable.
DNS_SERVER8.8.8.8 (default)Fallback DNS server for non-modified queries.
DNS_LOCAL_NAME_PATTERNSNames which should be resolved to the LocalStack IP, as python-compatible regex.

LocalStack Pro

More information here.

VariableExample ValuesDescription
LOCALSTACK_API_KEYAPI key to activate LocalStack Pro.
LOG_LICENSE_ISSUES1 (default)Whether to log issues with the license activation to the console.
REQUIRE_PRO0 (default)Whether to require license activation to succeed to start LocalStack. If set to 0 (default) LocalStack will start as community version if the license cannot be activated.

Read-only

VariableUsage ExampleDescription
LOCALSTACK_HOSTNAMEhttp://${LOCALSTACK_HOSTNAME}:4566Name of the host where LocalStack services are available. Use this hostname as endpoint in order to access the services from within your Lambda functions (e.g., to store an item to DynamoDB or S3 from a Lambda).

Deprecated

VariableExample ValuesDescription
USE_SSLfalse (default)Whether to use https://… URLs with SSL encryption. Deprecated as of version 0.11.3 - each service endpoint now supports multiplexing HTTP/HTTPS traffic over the same port.
DEFAULT_REGIONAWS region to use when talking to the API (needs to be activated via USE_SINGLE_REGION=1). Deprecated and inactive as of version 0.12.17 - LocalStack now has full multi-region support.
USE_SINGLE_REGIONWhether to use the legacy single-region mode, defined via DEFAULT_REGION.