Ditto

Ditto is a cli tool to mock an API or a kafka producer.

Schema

Supported fields:

• INTEGER:
  • VALUE: hardcoded value
  • INCREMENTAL: from a START value, increase by a fixed STEP
    • NOTE: An optional SIGMA can be passed to make the delta follow a normal distribution around the STEP
  • DISTRIBUTION:
    • NORMAL: returns a value for a given MU and SIGMA
    • UNIFORM: returns a value between a MIX and MAX
    • RANDOM: returns a random integer, optionally limited by a MAX value
• FLOAT:
  • VALUE: hardcoded value
  • INCREMENTAL: from a START value, increase by a fixed STEP
    • NOTE: An optional SIGMA can be passed to make the delta follow a normal distribution around the STEP
  • DISTRIBUTION:
    • NORMAL: returns a value for a given MU and SIGMA
    • UNIFORM: returns a value between a MIX and MAX
    • RANDOM: returns a random float between (0,1], optionally multiplied by a SCALE value
  • Additional Params:
    • ROUND: Number of decimal values. Defaults to 2
• STRING:
  • VALUE: hardcoded value
  • REGEX: regex template to generate a random string
  • Additional Params:
    • EMPTY: Probability ((0, 1]) of the string being empty. Defaults to 0
• TIMESTAMP:
  • VALUE: hardcoded value
  • NOW: current timestamp
  • INCREMENTAL: from a START value, increase by a fixed STEP. The start value defaults to NOW
    • NOTE: An optional SIGMA can be passed to make the delta follow a normal distribution around the STEP
    • NOTE: The step should follow the format "\d+[hms]"
  • Additional Params:
    • PRECISION: Units of the timestamp. Supported values are "s" (default), "ms", "us", "ns"
• DATETIME:
  • VALUE: hardcoded value
  • NOW: current timestamp
  • INCREMENTAL: from a START value, increase by a fixed STEP. The start value defaults to NOW
    • NOTE: STEP should follow the format "\d+[hms]"
    • NOTE: START should be a unix timestamp
    • NOTE: An optional SIGMA can be passed to make the delta follow a normal distribution around the STEP
  • Additional Params:
    • FORMAT: Format of the datetime string (using the go reference date)
• OBJECT:
  • FIELDS: Array with the nested fields

Additionally, there are certain parameters common between all types:

• NULLABLE: Probability ((0, 1]) of the value being null. Defaults to 0
• REPEATED: Whether the value is an array. It will create an array between 0 and 10 elements.

Usage

Rest

To serve message as an rest api:

ditto server rest -s schema.json -p 8080

If the schema is a folder, it will create a unique endpoint for each schema present using the name of the file as the url.

Kafka

To send messages to kafka (requires a running Kafka cluster):

ditto producer kafka -s schema.json -b localhost:9092 -S 3 [-c 2] [-d sample]

If the schema is a folder, it will send messages to a topic that matches the name of the file. If the -t flag is passed, it will send all messages to that topic.

Roadmap

• Cli command to generate schema from json
• Consume messages and verify that they follow the defined schema
• Add error support (random error codes, wrong types,...)
• Support other file formats
• Return arrays
• Tests
• Support other outputs (GraphQL,...)