traffic_script.md

Traffic script

Hermes sends traffic based on the definition of a json file. By default, it is loaded from /etc/scripts/traffic.json, and needs to be compliant with its schema definition. The schema can be accessed by executing: ./hermes -s. It is also thrown to the console if the validation fails.

In brief, what you need is (maybe better to look at example or the schema, an API definition is coming):

• dns: string - your server address
• port: string - your server port
• secure: bool - Optional: used to indicate if the connection shall be established using TLS. (Defaults to false if not present).
• timeout: integer - the number of ms to wait until non answered requests are considered to be a timeout error
• flow: array of strings – the name or id of the messages, in order, that define your traffic. For example: [“request1”, “request2”].
• messages: json object – the definition of each one of the messages defined in your flow. Every element mentioned under flow, must be defined as an object inside this field, named after its id, with the following content:
  • method: string – Http method for this message (“POST”, “GET”…)
  • url: string – The url for your request. Do not start with “/”!
  • body: json object – The body of your request
  • response: json object – must contain:
    • code: integer – the http response code used to consider that the request was successful, once answered
  • save_from_answer – json object, Optional: used to pass information from an answer to a subsequent request containing:
    • name: string – an id you want to give to the chunk of the response you want to save
    • path: string – the path where lies the chunk of the answer you want to save from the response
    • value_type: string – The type of the chunk of answer you want to save (only string, int or object supported right now)
  • add_from_saved_to_body – json object, Optional: used to construct a request based on a previously stored json fragment from a save_from_answer object:
    • name: string – the id you gave to a previous save_from_answer
    • path: string – the path where you want to add the json fragment into the new request
    • value_type: string – The type of the fragment (only string, int or object supported right now)
• ranges: json object – Optional: Use this feature if you want the scripts to iterate over certain values. Each property you add here with a name (e.g. "my_prop”) will be expanded when such name is found under angle braces (e.g. blabla<my_prop>blabla) in both url and body of each message. Each of those defined names must contain:
  • min: integer – minimum value of the iteration
  • max: integer – maximum value of the iteration

For a given script, “request2” will be never sent before “request1” has been answered. If a new request is needed to be sent before that happens, a new script is initialized. When ranges are defined, a new value of the range is taken for every initialized script.