app.json/lib/schema.js

Create, validate, and render Heroku app.json manifests

"use strict"
var schema = {
  "properties": {
    "name": {
      "description": "A clean and simple name to identify the template (30 characters max).",
      "type": "string",
      "minLength": 3,
      "maxLength": 30,
      "allowEmpty": false,
      "example": "Small Sharp Tool"
    },
    "description": {
      "description": "A brief summary of the app: what it does, who it's for, why it exists, etc.",
      "type": "string",
      "example": "This app does one little thing, and does it well.",
      "maxLength": 140
    },
    "keywords": {
      "description": "An array of strings describing the app.",
      "type": "array",
      "example": ["productivity", "HTML5", "scalpel"]
    },
    "website": {
      "description": "The project's website.",
      "type": "string",
      "format": "url",
      "allowEmpty": false,
      "example": "https://small-sharp-tool.com/"
    },
    "repository": {
      "description": "The location of the application's source code, such as a Git URL, GitHub URL, Subversion URL, or Mercurial URL.",
      "type": "string",
      "format": "url",
      "allowEmpty": false,
      "example": "https://github.com/jane-doe/small-sharp-tool"
    },
    "logo": {
      "description": "The URL of the application's logo image. Dimensions should be square. Format can be SVG, PNG, or JPG.",
      "type": "string",
      "format": "url",
      "allowEmpty": false,
      "example": "https://small-sharp-tool.com/logo.svg"
    },
    "success_url": {
      "description": "A URL specifying where to redirect the user once their new app is deployed. If value is a fully-qualified URL, the user should be redirected to that URL. If value begins with a slash `/`, the user should be redirected to that path in their newly deployed app.",
      "type": "string",
      "allowEmpty": false,
      "example": "/welcome"
    },
    "scripts": {
      "description": "A key-value object specifying scripts or shell commands to execute at different stages in the build/release process. Currently, `postdeploy` is the only supported script.",
      "type": "object",
      "example": {"postdeploy": "bundle exec rake bootstrap"}
    },
    "env": {
      "description": "A key-value object for environment variables, or [config vars](https://devcenter.heroku.com/articles/config-vars) in Heroku parlance. Keys are the names of the environment variables. Values can be strings or objects. If the value is a string, it will be used. If the value is an object, it defines specific requirements for that variable:\n\n- `description`: a human-friendly blurb about what the value is for and how to determine what it should be\n- `value`: a default value to use. This should always be a string.\n- `required`: A boolean indicating whether the given value is required for the app to function (default: `true`).\n- `generator`: a string representing a function to call to generate the value. Currently the only supported generator is `secret`, which generates a pseudo-random string of characters.",
      "type": "object",
      "example": {
        "BUILDPACK_URL": "https://github.com/stomita/heroku-buildpack-phantomjs",
        "SECRET_TOKEN": {
          "description": "A secret key for verifying the integrity of signed cookies.",
          "generator": "secret"
        },
        "WEB_CONCURRENCY": {
          "description": "The number of processes to run.",
          "value": "5"
        }
      }
    },
    "addons": {
      "description": "An array of strings specifying Heroku addons to provision on the app before deploying. Each addon should be in the format `addon:plan` or `addon`. If plan is omitted, that addon's default plan will be provisioned.",
      "type": "array",
      "example": [
        "openredis",
        "mongolab:shared-single-small"
      ]
    },
    "formation": {
      "description": "An array of objects specifying dynos to scale on the app before deploying.",
      "type": "array",
      "example": [
        { "process": "web",    "quantity": 1, "size": "standard-2X" },
        { "process": "worker", "quantity": 1, "size": "standard-2X" }
      ]
    }
  }
}

// Assemble an example schema
schema.example = {}
Object.keys(schema.properties).map(function(key){
  schema.example[key] = schema.properties[key].example
})

// Assemble a template-ready stringified version of the schema
schema.exampleJSON = JSON.stringify(schema.example, null, 2)

// Coerce schema properties into a template-friendly format
schema.propertiesArray = Object.keys(schema.properties).map(function(name) {
  var prop = schema.properties[name]
  prop.name = name
  prop.requiredOrOptional = prop.required ? "required" : "optional"

  var jsonDoc = {}
  jsonDoc[prop.name] = prop.example
  prop.exampleJSON = JSON.stringify(jsonDoc, null, 2)
  return prop
})

module.exports = schema