Environment variables

The following environment variables are supported:

Variable name	Purpose	Default	Description/example(s)
IMPOSTER_ADD_ENGINE_RESPONSE_HEADERS	Whether to add response headers for server and unique request ID.	true	false
IMPOSTER_AUTO_BASE_PATH	Whether to automatically set the base path for each configuration file, based on its relative path from the configuration root directory.	false	true
IMPOSTER_CACHE_DIR	Path to a directory in which to store cached data, such as remote specifications.	<Java temporary directory>/imposter-cache	/path/to/dir
IMPOSTER_CONFIG_DIR	The path to the configuration directory. Can be specified as a comma-separated list. See configuration location.	Empty	/path/to/config/dir - See Configuration Location.
IMPOSTER_CONFIG_SCAN_RECURSIVE	Whether to scan for configuration files recursively within the configuration directories. See recursive configuration discovery.	false	true
IMPOSTER_CONFIG_DISCOVER_ENVFILES	Whether to discover envfiles. See below.	true	false
IMPOSTER_FEATURES	Enables or disables features. See Features documentation.	Per default features.	metrics=false,stores=true
IMPOSTER_IGNORE_CONFIG_ERRORS	Whether errors encountered during configuration parsing or plugin configuration should be logged instead of thrown. Defaults to false, as skipping a configuration might also skip the security conditions it contains.	false	boolean
IMPOSTER_JS_PLUGIN	Sets the JavaScript implementation.	js-nashorn	Can be changed to js-graal plugin, if installed.
IMPOSTER_LOG_LEVEL	Sets logging level.	DEBUG	INFO, DEBUG, TRACE
IMPOSTER_LOG_REQUEST_BODY	Whether include request in structured log entries.	false	true - See Metrics, logs and telemetry.
IMPOSTER_LOG_REQUEST_HEADERS	Comma separated list of request headers to add to structured log entries.	Empty	X-Correlation-ID,User-Agent - See Metrics, logs and telemetry.
IMPOSTER_LOG_RESPONSE_BODY	Whether include response in structured log entries.	false	true - See Metrics, logs and telemetry.
IMPOSTER_LOG_RESPONSE_HEADERS	Comma separated list of response headers to add to structured log entries.	Empty	Server,Content-Type - See Metrics, logs and telemetry.
IMPOSTER_LOG_SUMMARY	Whether to log a JSON formatted summary message on each request.	false	true
IMPOSTER_LOG_SUMMARY_PRETTY	Whether to pretty print the summary log JSON.	false	true
IMPOSTER_NORMALISE_HEADER_KEYS	Forces header keys to be lowercased.	true	boolean
IMPOSTER_OPENAPI_EXPOSE_SPEC	Whether to expose the OpenAPI specification and UI. See OpenAPI plugin.	true	false
IMPOSTER_OPENAPI_REMOTE_FILE_CACHE	Whether to locally cache remote OpenAPI specifications. See OpenAPI plugin.	false	true
IMPOSTER_OPENAPI_SPEC_PATH_PREFIX	Overrides the default specification path prefix. See OpenAPI plugin.	/_spec	/openapi-spec
IMPOSTER_OPENAPI_VALIDATION_DEFAULT_BEHAVIOUR	The default behaviour for OpenAPI validation issues. See OpenAPI validation.	IGNORE	See OpenAPI validation.
IMPOSTER_PLUGIN_ARGS	Comma separated map of plugin arguments. Analogous to --pluginArg command line argument.	Empty	openapi.scheme=https,openapi.title=Mocks
IMPOSTER_PLUGIN_CLASSLOADER_STRATEGY	Sets the classloader strategy for plugins.	Parent-first	child
IMPOSTER_PLUGIN_DIR	Path to a directory containing additional plugin JAR files.	Empty	Used by Stores and Plugins.
IMPOSTER_PREFER_EXACT_MATCH_ROUTES	Whether to prefer routes with exact matches over those with path placeholders when matching requests.	true	boolean
IMPOSTER_STORE_DRIVER	Sets the store driver plugin.	store-inmem	See Stores.
IMPOSTER_STORE_KEY_PREFIX	Sets a prefix for store keys.	Empty	See Stores.
IMPOSTER_SCRIPT_CACHE_ENTRIES	The number of precompiled scripts to cache. Precompiled scripts execute faster, but the cache uses memory.	20	30
IMPOSTER_SCRIPT_PRECOMPILE	Whether to precompile scripts at startup.	true	boolean
IMPOSTER_RESPONSE_FILE_CACHE_ENTRIES	The number of response files to cache in memory. Cached response files don't require disk I/O, but the cache uses memory.	20	30
IMPOSTER_YAML_CODE_POINT_LIMIT	The maximum number of characters to parse in a YAML file. The default is 3MB. Note that the size depends on the file encoding.	3145728 (3MB)	10485760 (10MB)

Note: other features may include their own environment variables. See the feature specific documentation for more details.

Setting environment variables using a file

You can use an environment file ('envfile') to pass environment variables to Imposter. To do this, add a file named .env adjacent to your configuration files, for example:

$ ls
.env
imposter-config.yaml

$ cat .env
IMPOSTER_LOG_LEVEL=info
OTHER_ENV_VAR=example