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:

$ DEBUG=1 localstack start

Core

VariableExample ValuesDescription
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)
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.
LEGACY_DIRECTORIES0 (default)Use legacy method of managing internal filesystem layout. See filesystem layout.
PERSISTENCE0 (default)Enable persistence. See persistence mechanism and filesystem layout.
PERSIST_ALLtrue (default)Whether to persist all resources (including user code like Lambda functions), or only “light-weight” resources (e.g., SQS queues, or Cognito users). Can be set to false to reduce storage size of DATA_DIR folders or Cloud Pods.
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.
EXTERNAL_SERVICE_PORTS_START4510 (default)Start of the external service port range (included).
EXTERNAL_SERVICE_PORTS_END4560 (default)End of the external service port range (excluded).
EAGER_SERVICE_LOADING0 (default)Boolean that toggles lazy loading of services. If eager loading is enabled, services are started at LocalStack startup rather than their first use. Eager loading significantly increases LocalStack startup time.

CLI

These variables are only relevant when using the CLI to start LocalStack.

VariableExample ValuesDescription
LOCALSTACK_VOLUME_DIR~/.cache/localstack/volume (on Linux)The location on the host of the LocalStack volume directory mount. See filesystem layout
CONFIG_PROFILEThe configuration profile to load. See Profiles
CONFIG_DIR~/.localstackThe path where LocalStack can find configuration profiles and other CLI-specific configuration

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 certain AWS services.

AppSync

VariableExample ValuesDescription
GRAPHQL_ENDPOINT_STRATEGYlegacy|domain|pathGoverns how AppSync endpoints are created to access a GraphQL API (see AppSync Endpoints)

Batch

VariableExample ValuesDescription
BATCH_DOCKER_FLAGS-e TEST_ENV=1337Additional flags provided to the batch container. Only flags for volumes, ports, environment variables and add-hosts are allowed.

Bigdata (EMR, Athena, Glue,…)

VariableExample ValuesDescription
BIGDATA_DOCKER_NETWORKNetwork the bigdata should be connected to. The LocalStack container has to be connected to that network as well. Per default, the bigdata container will be connected to a network LocalStack is also connected to.
BIGDATA_DOCKER_FLAGSAdditional flags for the bigdata container. Same restrictions as LAMBDA_DOCKER_FLAGS.

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
DYNAMODB_SHARE_DB0|1When activated, DynamodDB will use a single database instead of separate databases for each credential and region.
DYNAMODB_IN_MEMORY0 (default) |1When activated, DynamodDB will start in in-memory mode, which can have a faster throughput. If you use this options, both persistence and cloud pods will not work for DynamoDB
DYNAMODB_OPTIMIZE_DB_BEFORE_STARTUP0|1Optimize the database tables in the store before starting
DYNAMODB_DELAY_TRANSIENT_STATUSES0|1When activated, DynamoDB will introduce artificial delays in resource creation to simulate the actual cloud service more closely. Currently works only for CREATING and DELETING online index statuses.
DYNAMODB_CORS*Enable CORS support for specific allow-list list the domains separated by , use * for public access (default is *)

EKS

VariableExample ValuesDescription
EKS_LOADBALANCER_PORT8081 (default)Local port on which the Kubernetes load balancer is exposed on the host.

Elasticsearch

VariableExample ValuesDescription
ES_CUSTOM_BACKENDhttp://elasticsearch:9200Deprecated. Use OPENSEARCH_CUSTOM_BACKEND instead. URL to a custom elasticsearch backend cluster. If this is set to a valid URL, then localstack will not create elasticsearch cluster instances, but instead forward all domains to the given backend (see Custom Elasticsearch Backends).
ES_MULTI_CLUSTER0|1Deprecated. Use OPENSEARCH_MULTI_CLUSTER instead. When activated, LocalStack will spawn one Elasticsearch cluster per domain. Otherwise all domains will share a single cluster instance. This is ignored if ES_CUSTOM_BACKEND is set.
ES_ENDPOINT_STRATEGYpath|domain|port (formerly off)Deprecated. Use OPENSEARCH_ENDPOINT_STRATEGY instead. Governs how domain endpoints are created to access a cluster (see Elasticsearch Endpoints)

IAM

VariableExample ValuesDescription
ENFORCE_IAM0 (default)|1Enable IAM policy evaluation and enforcement. If this is disabled (the default), IAM policies will have no effect to your requests.
LEGACY_IAM_PROVIDER0 (default)|1(deprecated) Enable the pre-1.0 legacy IAM provider
IAM_SOFT_MODE0 (default)|1Enable IAM soft mode. This leads to policy evaluation without actually denying access. Needs ENFORCE_IAM enabled as well. For more information, see Identity and Access Management.

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 mimic 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 mimic 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_STAY_OPEN_MODE1 (default)Usage of the stay-open mode of Lambda containers. Only applicable if LAMBDA_EXECUTOR=docker-reuse. Set to 0 if you want to use Hot Swapping.
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.
LAMBDA_TRUNCATE_STDOUT2000Allows increasing the default char value for truncation of lambda logs.
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. This configuration value also applies to ECS containers. Needs to be set to the network the LocalStack container is connected to if not default bridge network.
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_CONTAINERS1 (default)Whether to remove containers after Lambdas being inactive for 10 minutes. Only applicable when using docker-reuse executor.
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.
LAMBDA_XRAY_INIT1 / 0 (default)Whether to fully initialize XRay daemon for Lambda containers (may increase Lambda startup times)
SYNCHRONOUS_KINESIS_EVENTS1 (default) / 0Whether or not to handle Kinesis Lambda event sources as synchronous invocations.

OpenSearch

VariableExample ValuesDescription
OPENSEARCH_CUSTOM_BACKENDhttp://opensearch:9200URL to a custom OpenSearch backend cluster. If this is set to a valid URL, then LocalStack will not create OpenSearch cluster instances, but instead forward all domains to the given backend (see Custom Opensearch Backends).
OPENSEARCH_MULTI_CLUSTER0|1When activated, LocalStack will spawn one OpenSearch cluster per domain. Otherwise all domains will share a single cluster instance. This is ignored if OPENSEARCH_CUSTOM_BACKEND is set.
OPENSEARCH_ENDPOINT_STRATEGYpath|domain|portGoverns how domain endpoints are created to access a cluster (see Opensearch Endpoints).

RDS

VariableExample ValuesDescription
RDS_PG_CUSTOM_VERSIONS0 / 1 (default)Whether to install and use custom Postgres versions for RDS (or alternatively, use default version 11).

S3

VariableExample ValuesDescription
S3_DIRConfigure a global parent directory that contains all buckets as sub-directories (S3_DIR=/path/to/root) or an individual directory that will get mounted as special bucket names (S3_DIR=/path/to/root/bucket1:bucket1). Only available for Localstack Pro.

StepFunctions

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.

SQS

VariableExample ValuesDescription
SQS_DELAY_PURGE_RETRY0 (default)Used to toggle PurgeQueueInProgress errors when making more than one PurgeQueue call within 60 seconds.
SQS_DELAY_RECENTLY_DELETED0 (default)Used to toggle QueueDeletedRecently errors when re-creating a queue within 60 seconds of deleting it.
SQS_ENDPOINT_STRATEGYdomain|path|offConfigures the format of Queue URLs (see SQS Queue URLs)

Security

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

VariableExample ValuesDescription
DISABLE_CORS_HEADERS0 (default)Whether to disable the returning of default CORS headers in API responses (disables access from https://app.localstack.cloud).
DISABLE_CORS_CHECKS0 (default)Whether to disable all CSRF (server-side) 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.
ENABLE_CONFIG_UPDATES0 (default)Whether to enable dynamic configuration updates at runtime.

Emails

Please check with your SMTP email service provider for the following settings.

VariableExample ValuesDescription
SMTP_HOSTlocalhostHostname of the SMTP server. The port defaults to 25.
SMTP_USERLogin username for the SMTP server if required.
SMTP_PASSLogin password for the SMTP server if required.
SMTP_EMAILsender@example.comOrigin email address. Required for Cognito only.

Provider

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

VariableValid optionsNotes
KINESIS_PROVIDERkinesis-mock (default) and kinesalite
KMS_PROVIDERmoto (default) and local-kms

Profiles

LocalStack supports configuration profiles which are stored in the ~/.localstack config directory. A configuration profile is a set of environment variables stored in an .env file in the LocalStack config directory. Here is an example of what configuration profiles might look like:

% tree ~/.localstack 
/home/username/.localstack
├── default.env
├── dev.env
└── pro.env

Here is an example of what a specific environment profile looks like

% cat ~/.localstack/pro-debug.env
LOCALSTACK_API_KEY=XXXXX
DEBUG=1
DEVELOP=1

You can load a profile by either setting the env variable CONFIG_PROFILE=<profile> or the --profile=<profile> CLI flag when using the CLI. Let’s take an example to load the dev.env profile file if it exists:

python -m localstack.cli.main --profile=dev start

If no profile is specified, the default.env profile will be loaded. While explicitly specified, the environment variables will always overwrite the profile.

To display the config environment variables, you can use the following command:

python -m localstack.cli.main --profile=dev config show

Miscellaneous

VariableExample ValuesDescription
SKIP_INFRA_DOWNLOADSWhether to skip downloading additional infrastructure components (e.g., specific Elasticsearch versions)
SKIP_SSL_CERT_DOWNLOADWhether to skip downloading the SSL certificate for localhost.localstack.cloud
CUSTOM_SSL_CERT_PATH/var/lib/localstack/custom/server.test.pemDefines the absolute path to a custom SSL certificate for localhost.localstack.cloud
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)
MOCK_UNIMPLEMENTEDWhether to return mocked success responses (instead of 501 errors) for currently unimplemented API methods
DISABLE_EVENTS1Whether to disable publishing LocalStack events
OUTBOUND_HTTP_PROXYhttp://10.10.1.3HTTP Proxy used for downloads of runtime dependencies and connections outside LocalStack itself
OUTBOUND_HTTPS_PROXYhttps://10.10.1.3HTTPS Proxy used for downloads of runtime dependencies and connections outside LocalStack itself
REQUESTS_CA_BUNDLE/var/lib/localstack/lib/ca_bundle.pemCA Bundle to be used to verify HTTPS requests made by LocalStack
DISABLE_TERM_HANDLERWhether to disable signal passing to LocalStack when running in docker. Enabling this will prevent an orderly shutdown when running inside LS in docker.

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

Additionally, the following read-only environment variables are available:

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

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.
PERSISTENCE_SINGLE_FILEtrue (default)Specify if persistence files should be combined (only relevant for legacy persistence in Community version, not relevant for advanced persistence in Pro version).
DATA_DIRblank (disabled/default), /tmp/localstack/dataLocal directory for saving persistent data. This option is deprecated since LocalStack v1 and will be ignored. Please use PERSISTENCE. Using this option will set PERSISTENCE=1 as a deprecation path. The state will be stored in your LocalStack volume in the state/ directory
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.
TMPDIR/tmp (default)Temporary folder on the host running the CLI and inside the LocalStack container .
SERVICESkinesis,lambda,sqs,serverlessOnly works with EAGER_SERVICE_LOADING=1. Comma-separated list of AWS CLI service names or shorthands to start. Per default, all services are loaded and started on the first request for that service.
<SERVICE>_BACKENDCustom endpoint URL to use for a specific service, where is the uppercase service name.
<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.