http/src/main/resources/reference.conf

# SPDX-License-Identifier: Apache-2.0

####################################
# pekko-http Reference Config File #
####################################

# This is the reference config file that contains all the default settings.
# Make your edits/overrides in your application.conf.

pekko.http {
  routing {
    # Enables/disables the returning of more detailed error messages to the
    # client in the error response
    # Should be disabled for browser-facing APIs due to the risk of XSS attacks
    # and (probably) enabled for internal or non-browser APIs
    # (Note that pekko-http will always produce log messages containing the full error details)
    verbose-error-messages = off

    # Enables/disables ETag and `If-Modified-Since` support for FileAndResourceDirectives
    file-get-conditional = on

    # Enables/disables the rendering of the "rendered by" footer in directory listings
    render-vanity-footer = yes

    # The maximum size between two requested ranges. Ranges with less space in between will be coalesced.
    #
    # When multiple ranges are requested, a server may coalesce any of the ranges that overlap or that are separated
    # by a gap that is smaller than the overhead of sending multiple parts, regardless of the order in which the
    # corresponding byte-range-spec appeared in the received Range header field. Since the typical overhead between
    # parts of a multipart/byteranges payload is around 80 bytes, depending on the selected representation's
    # media type and the chosen boundary parameter length, it can be less efficient to transfer many small
    # disjoint parts than it is to transfer the entire selected representation.
    range-coalescing-threshold = 80

    # The maximum number of allowed ranges per request.
    # Requests with more ranges will be rejected due to DOS suspicion.
    range-count-limit = 16

    # The maximum number of bytes per ByteString a decoding directive will produce
    # for an entity data stream.
    decode-max-bytes-per-chunk = 1m

    # Maximum content length after applying a decoding directive. When the directive
    # decompresses, for example, an entity compressed with gzip, the resulting stream can be much
    # larger than the max-content-length. Like with max-content-length, this is not necessarilly a
    # problem when consuming the entity in a streaming fashion, but does risk high memory use
    # when the entity is made strict or marshalled into an in-memory object.
    # This limit (like max-content-length) can be overridden on a case-by-case basis using the
    # withSizeLimit directive.
    decode-max-size = 8m
  }

  # server-sent events
  sse {
    # The maximum size for parsing server-sent events. Set to 0 to disable limit entirely (unlimited).
    max-event-size = 8192

    # The maximum size for parsing lines of a server-sent event. Set to 0 to disable limit entirely (unlimited).
    max-line-size = 4096

    # How to handle lines that exceed max-line-size limit.
    # Options:
    #   "fail-stream" - Fail the stream with a clear error message (default)
    #   "log-and-skip" - Log a warning and skip the oversized line, continue processing
    #   "truncate" - Log info and truncate the line to max-line-size, continue processing
    #   "dead-letter" - Send oversized line to dead letters, continue processing
    oversized-line-handling = "fail-stream"

    # How to handle events that exceed max-event-size limit.
    # Options:
    #   "fail-stream" - Fail the stream with a clear error message (default)
    #   "log-and-skip" - Log a warning and skip the oversized event, continue processing
    #   "truncate" - Log info and drop lines that would exceed max-event-size, continue processing
    #   "dead-letter" - Send oversized event to dead letters, continue processing
    oversized-event-handling = "fail-stream"

    # Empty events are used by the pekko-http SSE infrastructure for heartbeats. Received heartbeats are ignored by default
    # and not delivered in the user stream.
    #
    # This setting can be enabled to pass those empty events to the application for explicit handling.
    emit-empty-events = off
  }
}