Actions

Subsections

The Action entity schema contains the necessary information to deploy an OpenWhisk function and define its deployment configurations, inputs and outputs.

Fields

Key NameRequiredValue TypeDefaultDescription
versionnoversionN/AThe optional user-controlled version for the Action.
functionyesstringN/ARequired source location (path inclusive) of the Action code either:Relative to the Package manifest file.Relative to the specified Repository.
codenostringN/AThis optional field is now replaced by the “function” field.
runtimemaybestringN/Ahe required runtime name (and optional version) that the Action code requires for an execution environment.Note: May be optional if tooling is allowed to make assumptions about file extensions or infer from functional code.
inputsnolist of parameterN/AThe optional ordered list inputs to the Action.
outputsnolist of parameterN/AThe optional outputs from the Action.
limitsnomap of limit keys and valuesN/AOptional map of limit keys and their values.See section “Valid limit keys” (below) for a listing of recognized keys and values.
feednobooleanfalseOptional indicator that the Action supports the required parameters (and operations) to be run as a Feed Action.
webnostringtrue | false | yes | no | rawThe optional flag that makes the action accessible to REST calls without authentication.For details on all types of Web Actions, see: Web Actions.
raw-httpnobooleanfalseThe optional flag (annotation) to indicate if a Web Action is able to consume the raw contents within the body of an HTTP request.Note: this option is ONLY valid if “web” or “web-export” is set to ‘true’.
dockernostringN/AThe optional key that references a Docker image (e.g., openwhisk/skeleton).
nativenobooleanfalseThe optional key (flag) that indicates the Action is should use the Docker skeleton image for OpenWhisk (i.e., short-form for docker: openwhisk/skeleton).
finalnobooleanfalseThe optional flag (annotation) which makes all of the action parameters that are already defined immutable.Note: this option is ONLY valid if “web” or “web-export” is set to ‘true’.
mainnostringN/AThe optional name of the function to be aliased as a function named “main”.Note: by convention, Action functions are required to be called “main”; this field allows existing functions not named “main” to be aliased and accessed as if they were named “main”.
annotationsnoN/AThe optional map of annotation key-values. See below for Action annotations on actions.

Action Annotations

The following annotations have special meanings for Actions:

Key NameRequiredValue TypeDefaultDescription
finalnobooleannot set (false)Parameters are protected and treated as immutable. This is required for web actions (i.e., web or web-export set to true.
web-exportnoboolean | yes | no | rawnot set (false)The optional annotation used to export an action as a web action which is accessible through an API REST interface (url).
web-custom-optionsnobooleannot set (false)The optional annotation that enables a web action to respond to OPTIONS requests with customized headers, otherwise a default CORS response applies.
require-whisk-authnostring | integer | booleannot set (false)The optional annotation that can secure a web action so that it is only accessible to an authenticated subject.See Securing web actions

Requirements

  • The Action entity schema SHALL include all general Entity Schema fields in addition to any fields declared above.
  • The Action name (i.e., <actionName> MUST be less than or equal to 256 characters.
  • Supplying a runtime name without a version indicates that OpenWhisk SHOULD use the current default version.
  • Supplying a runtime major version without a minor version (et al.) indicates OpenWhisk SHOULD use the most current minor version.
  • Unrecognized limit keys (and their values) SHALL be ignored.
  • Invalid values for known limit keys SHALL result in an error.
  • If the Feed is a Feed Action (i.e., the feed key's value is set to true), it MUST support the following parameters:
    • lifecycleEvent: one of CREATE, DELETE, PAUSE,or UNPAUSE. These operation names MAY be supplied in lowercase (i.e., create, delete, pause, etc.).
    • triggerName: the fully-qualified name of the trigger which contains events produced from this feed.
    • authKey: the Basic auth. credentials of the OpenWhisk user who owns the trigger.
  • The keyname kind is currently supported as a synonym for the key named ‘runtime’; in the future it MAY be deprecated.
  • When the code key-value is specified, the runtime SHALL be a required field.

Annotation requirements

  • The annotation require-whisk-auth SHALL only be valid for web actions (i.e., if the web key or web-export annotation is set to true).
  • If the value of the require-whisk-auth annotation is an integer its value MUST be a positive integer less than or equal to the MAX_INT value of 9007199254740991.
  • When the web or web-export key is present and set to true the web action's MUST also be marked final. This happens automatically when the web or web-export keys are present and set to true.

Notes

  • Input and output parameters are implemented as JSON Objects within the CLI client framework.
  • The maximum code size for an Action currently must be less than 48 MB.
  • The maximum payload size for an Action (i.e., POST content length or size) currently must be less than 1 MB.
  • The maximum parameter size for an Action currently must be less than 1 MB.
  • if no value for runtime is supplied, the value language:default will be assumed.

Grammar

<actionName>[.<type>]:
  <Entity schema>
  version: <version>
  function: <string>
  code: <string>
  runtime: <name>[@<[range of ]version>]
  inputs:
    <list of parameter>
  outputs:
    <list of parameter>
  limits:
    <list of limit key-values>
  feed: <boolean> # default: false
  web: <boolean> | yes | no | raw
  raw-http: <boolean>
  docker: <string>
  native: <boolean>
  final: <boolean>
  main: <string>
  annotations:
    <map of annotation key-values>
    web-export: <boolean> | yes | no | raw # optional
    web-custom-options: <boolean> # optional, only valid when `web-export` enabled
    require-whisk-auth: <boolean> | <string> | <positive integer> # optional, only valid when `web-export` enabled

Note: the optional [.] grammar is used for naming Web Actions.

Example

my_awesome_action:
  version: 1.0
  description: An awesome action written for node.js
  function: src/js/action.js
  runtime: nodejs@>0.12<6.0
  web: true
  inputs:
    not_awesome_input_value:
      description: Some input string that is boring
      type: string
  outputs:
    awesome_output_value:
      description: Impressive output string
      type: string
  limits:
    memorySize: 512 kB
    logSize: 5 MB
  annotations:
    require-whisk-auth: "my-auth-token"

Valid Runtime names

The following runtime values are currently supported by the OpenWhisk platform “out-of-box” at around the time of the Openwhisk platform release 1.0.

Runtime valueOpenWhisk kindDocker imageTagDescription
go | go:1.15 (default)go:1.15openwhisk/action-golang-v1.15nightlyGo 1.15 runtime
go | go:1.11 (default)go:1.11openwhisk/action-golang-v1.11nightlyGo 1.11 runtime
nodejs@12nodejs:12openwhisk/nodejs12actionnightlyNodeJS 12 runtime
nodejs | nodejs@10 (default)nodejs:10openwhisk/action-nodejs-v10nightlyNodeJS 10 runtime
nodejs@8nodejs:8openwhisk/action-nodejs-v8nightlyNodeJS 8 runtime
nodejs@6 (deprecated)nodejs:6openwhisk/nodejs6actionnightlyNodeJS 6 runtime
java | java8 (default)java:8openwhisk/java8actionnightlyJava (8) language runtime
php | php@7.4 (default)php:7.4openwhisk/action-php-v7.4nightlyPHP (7.3) language runtime
php@7.3php:7.3openwhisk/action-php-v7.3nightlyPHP (7.3) language runtime
php@7.2 (deprecated)php:7.2openwhisk/action-php-v7.2nightlyPHP (7.2) language runtime
php@7.1 (deprecated)php:7.1openwhisk/action-php-v7.1nightlyPHP (7.1) language runtime
python | python@3 (default)python:3openwhisk/python3actionnightlyPython 3 (3.6) language runtime
python@2python:2openwhisk/python2action1.13.0-incubatingPython 2 (2.7) language runtime
ruby | (default)ruby:2.5openwhisk/action-ruby-v2.5nightlyRuby 2.5 language runtime
swift | swift@5.4 (default)swift:5.4openwhisk/action-swift-v5.4nightlySwift 4.2 language runtime
swift | swift@4.2 (default)swift:4.2openwhisk/action-swift-v4.2nightlySwift 4.2 language runtime
swift@4.1swift:4.1openwhisk/action-swift-v4.1nightlySwift 4.1 language runtime
swift@3.1.1 (deprecated)swift:3.1.1openwhisk/action-swift-v3.1.1nightlySwift 3.1.1 language runtime
dotnet | dotnet@2.2 (default)dotnet:2.2openwhisk/action-dotnet-v2.2nightly.NET Core 2.2 runtime
dotnet@3.1dotnet:3.1openwhisk/action-dotnet-v3.1nightly.NET Core 3.1 runtime
rust@1.34rust:1.34openwhisk/actionloop-rust-v1.34:latestLatest Rust 1.34 language runtime
language:defaultN/AN/AN/APermit the OpenWhisk platform to select the correct default language runtime.

See the file runtimes.json in the main apache/openwhisk repository for the latest supported runtimes nad versions.

Notes

  • WARNING: For OpenWhisk project builds, the Docker image used is tagged nightly in Docker Hub (e.g, for GitHub pull requests). Production uses of OpenWhisk code may use different images and tagged (released) image versions.
  • If no value for runtime is supplied, the value language:default will be assumed.
  • OpenWhisk runtimes may also include additional built-in packages (or libraries) that have been determined be useful for Actions surveyed and tested by the OpenWhisk platform.

Recognized File extensions

Although it is best practice to provide a runtime value when declaring an Action, it is not required. In those cases, that a runtime is not provided, the package tooling will attempt to derive the correct runtime based upon the the file extension for the Action's function (source code file). The following file extensions are recognized and will be run on the version of corresponding Runtime listed below:

Valid Limit keys

Limit Notes

  1. The default values and ranges for limit configurations reflect the defaults for the OpenWhisk platform (open source code).  These values may be changed over time to reflect the open source community consensus.
  2. Serverless providers that use Apache OpenWhisk MAY choose to enforce different defaults and value ranges for limits.
  3. This limit is not currently user configurable.
  4. The parameter size limit also applies to Triggers and Packages.

Web Actions

OpenWhisk can turn any Action into a ‘web action’ causing it to return HTTP content without use of an API Gateway. Simply supply a supported ‘type’ extension to indicate which content type is to be returned and identified in the HTTP header (e.g., .json, .html, .text or .http).

Return values from the Action's function are used to construct the HTTP response. The following response parameters are supported in the response object.

  • headers: a JSON object where the keys are header-names and the values are string values for those headers (default is no headers).
  • code: a valid HTTP status code (default is 200 OK).
  • body: a string which is either plain text or a base64 encoded string (for binary data).