relay.yaml

# This is the default configuration file for the relay.
#
# In addition to standard YAML syntax, you can use ${VAR} to substitute in the
# value of the environment variable VAR, and ${VAR:DEFAULT} to provide a default
# value if the variable is unset or empty. Many environment variable
# substitutions have been provided by default to make it easy to configure the
# relay for simple situations.
#
# When the value of an environment variable is substituted, it's converted to a
# YAML primitive. This is almost always what you want, but in rare situations
# where you need more control you can use $(VAR) or $(VAR:DEFAULT) to substitute
# in the original, raw values.

relay:
  # The port on which the relay service should run.
  port: ${RELAY_PORT:8990}

  # The target to which traffic should be relayed, expressed as a URL-like
  # scheme and host - e.g. "https://relay-target.example".
  target: ${TRAFFIC_RELAY_TARGET}

  # The maximum length in bytes which should be allowed for relayed response
  # bodies. The default is 2MiB.
  max-body-size: ${TRAFFIC_RELAY_MAX_BODY_SIZE:2097152}

block-content:
  # The 'body' option allows you to block content from request bodies. It
  # contains a list of objects, each of which has either an 'exclude' property
  # or a 'mask' property. The value of the property is a regular expression. For
  # 'exclude', content matching the regular expression will be completely
  # removed from the request body. For 'mask', matching content will be replaced
  # with asterisks.
  # Example:
  # body:
  #   - exclude: '\$[0-9]+(\.[0-9][0-9])?'  # Dollar quantities
  #   - exclude: 'EXCLUDE ME'
  #   - mask: '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'  # IP-like strings
  #   - mask: 'MASK ME'
  body:

  # The 'header' option works just like 'body', but it applies to header values
  # instead.
  # Example:
  # header:
  #   - exclude: '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'  # IP-like strings
  header:

  # You can also define block rules using environment variables.
  TRAFFIC_EXCLUDE_BODY_CONTENT: ${TRAFFIC_EXCLUDE_BODY_CONTENT}
  TRAFFIC_MASK_BODY_CONTENT: ${TRAFFIC_MASK_BODY_CONTENT}
  TRAFFIC_EXCLUDE_HEADER_CONTENT: ${TRAFFIC_EXCLUDE_HEADER_CONTENT}
  TRAFFIC_MASK_HEADER_CONTENT: ${TRAFFIC_MASK_HEADER_CONTENT}

cookies:
  # The relay blocks all cookies by default. This is almost always what you
  # want; otherwise, you may end up relaying cookies you don't expect, because
  # the relay normally operates in a first-party context and will receive all
  # cookies for your domain. If you need a known-safe cookie to be relayed, you
  # can use the 'allowlist' option to allowlist it by name.
  # Example:
  # allowlist:
  #   - safe_cookie
  #   - TOKEN_ID
  allowlist:

  # You can also allowlist cookies by setting the TRAFFIC_RELAY_COOKIES
  # environment variable to a space-separated list of cookie names.
  # Example:
  # TRAFFIC_RELAY_COOKIES: safe_cookie TOKEN_ID
  TRAFFIC_RELAY_COOKIES: ${TRAFFIC_RELAY_COOKIES}


headers:
  # The relay forwards the Origin header as-is by default, which is usually what
  # you want. You can use the 'override-origin' option to override the Origin
  # header if needed.
  # Example:
  # override-origin: example.com
  override-origin: ${TRAFFIC_RELAY_ORIGIN_OVERRIDE}

paths:
  # By default, the relay routes request paths to the same paths on the target,
  # but you can use the 'routes' option to override this behavior.
  #
  # This option's value is a list. Each item's 'path' is a regular expression
  # that is matched against request paths; if there's a match, the matched
  # portion of the path is replaced by the item's 'target-path'.
  #
  # It's also possible to redirect particular paths to different target hosts by
  # using 'target-url' instead of 'target-path'. When 'target-url' is used, the
  # same substitution that 'target-path' would do is performed, but the
  # result is interpreted as a complete URL instead of just a path.
  #
  # Both 'target-path' and 'target-url' can reference capture groups matched by
  # the 'path' regular expression using Go's Regexp.Expand syntax; see here for
  # more information:
  #   https://golang.org/pkg/regexp/#Regexp.Expand
  #
  # Example:
  # routes:
  #   - path: '^/foo/'
  #     target-path: '/xyz/'
  #   - path: '^/bar/'
  #     target-url: 'https://bar.target.example/api/'
  routes:

  # You can configure a simple 'target-path'-style route using environment
  # variables.
  # Example:
  # TRAFFIC_PATHS_MATCH=^/(test)/
  # TRAFFIC_PATHS_REPLACEMENT=/wow-${1}/
  TRAFFIC_PATHS_MATCH: ${TRAFFIC_PATHS_MATCH}
  TRAFFIC_PATHS_REPLACEMENT: ${TRAFFIC_PATHS_REPLACEMENT}

  # You can configure multiple 'target-url'-style routes using an environment
  # variable. The value is a space-separated list of regular expressions. The
  # regular expressions come in pairs; the first item in each pair behaves like
  # 'path' and the second behaves like 'target-url'.
  # Example:
  # TRAFFIC_RELAY_SPECIALS=^/example/(.*\.js) https://example.com/static-js/${1}
  TRAFFIC_RELAY_SPECIALS: ${TRAFFIC_RELAY_SPECIALS}