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Configuration
1
Environment variables which affect LocalStack.
/localstack/configuration/

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

{{< command >}} $ DEBUG=1 localstack start {{< / command >}}

Core

Variable Example Values Description
EDGE_BIND_HOST 127.0.0.1 (default), 0.0.0.0 (docker) Address the edge service binds to.
EDGE_PORT 4566 (default) Port number for the edge service, the main entry point for all API invocations.
HOSTNAME localhost (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_EXTERNAL localhost (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.
DEBUG 0|1 Flag to increase log level and print more verbose logs (useful for troubleshooting issues)
IMAGE_NAME localstack/localstack (default), localstack/localstack:0.11.0 Specific name and tag of LocalStack Docker image to use.
USE_LIGHT_IMAGE 1 (default) Deprecated. Whether to use the light-weight Docker image. Overwritten by IMAGE_NAME.
LEGACY_DIRECTORIES 0 (default) Use legacy method of managing internal filesystem layout. See [filesystem layout]({{< ref "filesystem" >}}).
PERSISTENCE 0 (default) Enable persistence. See [persistence mechanism]({{< ref "persistence-mechanism" >}}) and [filesystem layout]({{< ref "filesystem" >}}).
PERSIST_ALL true (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_NAME localstack_main (default) Specify the main docker container name
INIT_SCRIPTS_PATH /some/path Deprecated. Specify the path to the initializing files with extensions .sh that are found default in /docker-entrypoint-initaws.d.
LS_LOG trace, trace-internal, debug, info, warn, error, warning Specify the log level. Currently overrides the DEBUG configuration. trace for detailed request/response, trace-internal for internal calls, too.
EXTERNAL_SERVICE_PORTS_START 4510 (default) Start of [the external service port range]({{< ref "external-ports" >}}) (included).
EXTERNAL_SERVICE_PORTS_END 4560 (default) End of [the external service port range]({{< ref "external-ports" >}}) (excluded).
EAGER_SERVICE_LOADING 0 (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.

Variable Example Values Description
LOCALSTACK_VOLUME_DIR ~/.cache/localstack/volume (on Linux) The location on the host of the LocalStack volume directory mount. See [filesystem layout]({{< ref "filesystem#using-the-cli" >}})
CONFIG_PROFILE The configuration profile to load. See [Profiles]({{< ref "#profiles" >}})
CONFIG_DIR ~/.localstack The 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.

Variable Example Values Description
DOCKER_FLAGS Allows to pass custom flags (e.g., volume mounts) to "docker run" when running LocalStack in Docker.
DOCKER_SOCK /var/run/docker.sock Path to local Docker UNIX domain socket
DOCKER_BRIDGE_IP 172.17.0.1 IP of the docker bridge used to enable access between containers
LEGACY_DOCKER_CLIENT 0|1 Whether LocalStack should use the command-line Docker client and subprocess execution to run Docker commands, rather than the Docker SDK.
DOCKER_CMD docker (default), sudo docker Shell command used to run Docker containers (only used in combination with LEGACY_DOCKER_CLIENT)
FORCE_NONINTERACTIVE When 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]({{< ref "#appsync" >}})
  • [Batch]({{< ref "#batch" >}})
  • [DynamoDB]({{< ref "#dynamodb" >}})
  • [Elastic Kubernetes Service (EKS)]({{< ref "#eks" >}})
  • [Elasticsearch]({{< ref "#elasticsearch" >}})
  • [Kinesis]({{< ref "#kinesis" >}})
  • [Lambda]({{< ref "#lambda" >}})
  • [Stepfunctions]({{< ref "#stepfunctions" >}})

AppSync

Variable Example Values Description
GRAPHQL_ENDPOINT_STRATEGY legacy|domain|path Governs how AppSync endpoints are created to access a GraphQL API (see [AppSync Endpoints]({{< ref "appsync#endpoints" >}}))

Batch

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

BigData (EMR, Athena, Glue)

Variable Example Values Description
BIGDATA_DOCKER_NETWORK Network 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_FLAGS Additional flags for the bigdata container. Same restrictions as LAMBDA_DOCKER_FLAGS.

DynamoDB

Variable Example Values Description
DYNAMODB_ERROR_PROBABILITY Decimal value between 0.0(default) and 1.0 Randomly inject ProvisionedThroughputExceededException errors into DynamoDB API responses.
DYNAMODB_HEAP_SIZE 256m (default), 1G Sets the JAVA EE maximum memory size for DynamoDB; full table scans require more memory
DYNAMODB_SHARE_DB 0|1 When activated, DynamodDB will use a single database instead of separate databases for each credential and region.
DYNAMODB_IN_MEMORY 0 (default) |1 When 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_STARTUP 0|1 Optimize the database tables in the store before starting
DYNAMODB_DELAY_TRANSIENT_STATUSES 0|1 When 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

Variable Example Values Description
EKS_LOADBALANCER_PORT 8081 (default) Local port on which the Kubernetes load balancer is exposed on the host.

Elasticsearch

{{% alert title="Deprecated" color="warning" %}} While the ElasticSearch API is actively maintained, the configuration variables for ElasticSearch have been deprecated. Please use the OpenSearch configuration variables instead. The OpenSearch configuration variables are used to manage both, OpenSearch and ElasticSearch clusters. {{% /alert %}}

Variable Example Values Description
ES_CUSTOM_BACKEND http://elasticsearch:9200 Deprecated. 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]({{< ref "elasticsearch#custom-elasticsearch-backends" >}})).
ES_MULTI_CLUSTER 0|1 Deprecated. 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_STRATEGY path|domain|port (formerly off) Deprecated. Use OPENSEARCH_ENDPOINT_STRATEGY instead. Governs how domain endpoints are created to access a cluster (see [Elasticsearch Endpoints]({{< ref "elasticsearch#endpoints" >}}))

IAM

Variable Example Values Description
ENFORCE_IAM 0 (default)|1 Enable IAM policy evaluation and enforcement. If this is disabled (the default), IAM policies will have no effect to your requests.
LEGACY_IAM_PROVIDER 0 (default)|1 (deprecated) Enable the pre-1.0 legacy IAM provider
IAM_SOFT_MODE 0 (default)|1 Enable 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]({{< ref "iam" >}}).

Kinesis

Variable Example Values Description
KINESIS_ERROR_PROBABILITY Decimal value between 0.0(default) and 1.0 Randomly inject ProvisionedThroughputExceededException errors into Kinesis API responses.
KINESIS_SHARD_LIMIT 100 (default), Infinity (to disable) Integer value , causing the Kinesis API to start throwing exceptions to mimic the default shard limit.
KINESIS_ON_DEMAND_STREAM_COUNT_LIMIT 10 (default), Infinity (to disable) Integer value , causing the Kinesis API to start throwing exceptions to mimic the default on demand stream count limit.
KINESIS_LATENCY 500 (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 (New / asf)

Variable Example Values Description
LAMBDA_TRUNCATE_STDOUT 2000 (default) Allows increasing the default char limit for truncation of lambda log lines when printed in the console.
BUCKET_MARKER_LOCAL hot-reload (default) Optional bucket name for running lambdas locally.
LAMBDA_DOCKER_NETWORK Optional 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_FLAGS -e KEY=VALUE, -v host:container, -p host:container, --add-host domain:ip Additional 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_REMOVE_CONTAINERS 1 (default) Whether to remove containers after Lambdas being inactive for 10 minutes. Only applicable when using docker-reuse executor.
LAMBDA_RUNTIME_EXECUTOR docker (default) Where Lambdas will be executed
kubernetes PRO-only. Execute lambdas in a Kubernetes cluster
LAMBDA_RUNTIME_ENVIRONMENT_TIMEOUT 10 (default) How many seconds Lambda will wait for the runtime environment to start up
LAMBDA_RUNTIME_IMAGE_MAPPING Allows two options to customize the resolution of Lambda runtime:
1. pattern with <runtime> placeholder, e.g. custom-repo/lambda-<runtime>:2022
2. json dict mapping the to an image, e.g. {"python3.9": "custom-repo/lambda-py:thon3.9"}
LAMBDA_K8S_IMAGE_PREFIX amazon/aws-lambda- (default) Prefix for images that will be used to execute Lambda functions in kubernetes.

Lambda (Legacy)

Variable Example Values Description
LAMBDA_EXECUTOR Method 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]({{< ref "lambda-executors" >}}).
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-reuse Create one Docker container per function and reuse it across invocations.
LAMBDA_STAY_OPEN_MODE 1 (default) Usage of the [stay-open mode]({{< ref "lambda-executors#stay-open-mode" >}}) of Lambda containers. Only applicable if LAMBDA_EXECUTOR=docker-reuse. Set to 0 if you want to use [Hot Swapping]({{< ref "hot-swapping" >}}).
LAMBDA_REMOTE_DOCKER determines 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.
false your 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_STDOUT 2000 Allows increasing the default char value for truncation of lambda logs.
BUCKET_MARKER_LOCAL Optional bucket name for running lambdas locally.
LAMBDA_CODE_EXTRACT_TIME 25 Time 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_NETWORK Optional 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_DNS Optional DNS server for the container running your lambda function.
LAMBDA_DOCKER_FLAGS -e KEY=VALUE, -v host:container, -p host:container, --add-host domain:ip Additional 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_REGISTRY lambci/lambda (default) An alternative docker registry from where to pull lambda execution containers.
LAMBDA_REMOVE_CONTAINERS 1 (default) Whether to remove containers after Lambdas being inactive for 10 minutes. Only applicable when using docker-reuse executor.
LAMBDA_FALLBACK_URL Fallback 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_URL URL used to forward all Lambda invocations (useful to run Lambdas via an external service).
LAMBDA_JAVA_OPTS -Xmx512M Allow 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_LAMBDA localstack Endpoint 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_INIT 1 / 0 (default) Whether to fully initialize XRay daemon for Lambda containers (may increase Lambda startup times)
SYNCHRONOUS_KINESIS_EVENTS 1 (default) / 0 Whether or not to handle Kinesis Lambda event sources as synchronous invocations.

OpenSearch

Variable Example Values Description
OPENSEARCH_CUSTOM_BACKEND http://opensearch:9200 URL 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]({{< ref "opensearch#custom-opensearch-backends" >}})).
OPENSEARCH_MULTI_CLUSTER 0|1 When 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_STRATEGY path|domain|port Governs how domain endpoints are created to access a cluster (see [Opensearch Endpoints]({{< ref "opensearch#endpoints" >}})).

RDS

Variable Example Values Description
RDS_PG_CUSTOM_VERSIONS 0 / 1 (default) Whether to install and use custom Postgres versions for RDS (or alternatively, use default version 11).

S3

Variable Example Values Description
S3_DIR Configure 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

Variable Example Values Description
STEPFUNCTIONS_LAMBDA_ENDPOINT default URL 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

Variable Example Values Description
SQS_DELAY_PURGE_RETRY 0 (default) Used to toggle PurgeQueueInProgress errors when making more than one PurgeQueue call within 60 seconds.
SQS_DELAY_RECENTLY_DELETED 0 (default) Used to toggle QueueDeletedRecently errors when re-creating a queue within 60 seconds of deleting it.
SQS_ENDPOINT_STRATEGY domain|path|off Configures the format of Queue URLs (see [SQS Queue URLs]({{< ref "sqs#queue-urls" >}}))

Security

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

Variable Example Values Description
DISABLE_CORS_HEADERS 0 (default) Whether to disable the returning of default CORS headers in API responses (disables access from https://app.localstack.cloud).
DISABLE_CORS_CHECKS 0 (default) Whether to disable all CSRF (server-side) mitigations.
DISABLE_CUSTOM_CORS_S3 0 (default) Whether to disable CORS override by S3.
DISABLE_CUSTOM_CORS_APIGATEWAY 0 (default) Whether to disable CORS override by apigateway.
EXTRA_CORS_ALLOWED_ORIGINS Comma-separated list of origins that are allowed to communicate with localstack.
EXTRA_CORS_ALLOWED_HEADERS Comma-separated list of header names to be be added to Access-Control-Allow-Headers CORS header.
EXTRA_CORS_EXPOSE_HEADERS Comma-separated list of header names to be be added to Access-Control-Expose-Headers CORS header.
ENABLE_CONFIG_UPDATES 0 (default) Whether to enable dynamic configuration updates at runtime.

Emails

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

Variable Example Values Description
SMTP_HOST localhost:1025 Hostname (and optionally the port) of the SMTP server. The port defaults to 25.
SMTP_USER Login username for the SMTP server if required.
SMTP_PASS Login password for the SMTP server if required.
SMTP_EMAIL sender@example.com Origin email address. Required for Cognito only.

Provider

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

Variable Valid options Notes
KINESIS_PROVIDER Deprecated. kinesis-mock (default) and kinesalite
KMS_PROVIDER moto (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:

{{< command >}} python -m localstack.cli.main --profile=dev start {{< / command >}}

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:

{{< command >}} python -m localstack.cli.main --profile=dev config show {{< / command >}}

Miscellaneous

Variable Example Values Description
SKIP_INFRA_DOWNLOADS Deprecated. Whether to skip downloading additional infrastructure components (e.g., specific Elasticsearch versions)
SKIP_SSL_CERT_DOWNLOAD Whether to skip downloading the SSL certificate for localhost.localstack.cloud
CUSTOM_SSL_CERT_PATH /var/lib/localstack/custom/server.test.pem Defines the absolute path to a custom SSL certificate for localhost.localstack.cloud
IGNORE_ES_DOWNLOAD_ERRORS Whether to ignore errors (e.g., network/SSL) when downloading Elasticsearch plugins
OVERRIDE_IN_DOCKER Overrides 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_URL Optional target URL to forward all edge requests to (e.g., for distributed deployments)
MOCK_UNIMPLEMENTED Deprecated. Whether to return mocked success responses (instead of 501 errors) for currently unimplemented API methods
DISABLE_EVENTS 1 Whether to disable publishing LocalStack events
OUTBOUND_HTTP_PROXY http://10.10.1.3 HTTP Proxy used for downloads of runtime dependencies and connections outside LocalStack itself
OUTBOUND_HTTPS_PROXY https://10.10.1.3 HTTPS Proxy used for downloads of runtime dependencies and connections outside LocalStack itself
REQUESTS_CA_BUNDLE /var/lib/localstack/lib/ca_bundle.pem CA Bundle to be used to verify HTTPS requests made by LocalStack
DISABLE_TERM_HANDLER Whether to disable signal passing to LocalStack when running in docker. Enabling this will prevent an orderly shutdown when running inside LS in docker.

Debugging

Variable Example Values Description
DEVELOP Starts a debugpy server before starting LocalStack services
DEVELOP_PORT Port number for debugpy server
WAIT_FOR_DEBUGGER Forces 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]({{< ref "dns-server" >}}).

Variable Example Values Description
DNS_ADDRESS 0.0.0.0 (default) Address the LocalStack should bind the DNS server on (port 53 tcp/udp). Value 0 to disable.
DNS_SERVER 8.8.8.8 (default) Fallback DNS server for non-modified queries.
DNS_RESOLVE_IP 127.0.0.1 IP address the DNS integration should return as A record for modified queries. This will override any automatic detection of the proper response IP.
DNS_LOCAL_NAME_PATTERNS Names which should be resolved to the LocalStack IP, as python-compatible regex.

LocalStack Pro

Variable Example Values Description
LOCALSTACK_API_KEY API key to activate LocalStack Pro.
LOG_LICENSE_ISSUES 1 (default) Whether to log issues with the license activation to the console.
REQUIRE_PRO 0 (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

Variable Usage Example Description
LOCALSTACK_HOSTNAME http://${LOCALSTACK_HOSTNAME}:4566 Name 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

Variable Example Values Description
USE_SSL false (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_REGION Deprecated. AWS region to use when talking to the API (needs to be activated via USE_SINGLE_REGION=1). LocalStack now has full multi-region support.
USE_SINGLE_REGION Deprecated. Whether to use the legacy single-region mode, defined via DEFAULT_REGION.
PERSISTENCE_SINGLE_FILE true (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_DIR blank (disabled/default), /tmp/localstack/data Local 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/path Temporary 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 .
SERVICES kinesis,lambda,sqs,serverless Only 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>_BACKEND Custom endpoint URL to use for a specific service, where is the uppercase service name.
<SERVICE>_PORT_EXTERNAL 4567 Port 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.