<!--
title: Serverless Framework - Apache OpenWhisk Guide - Functions
menuText: Functions
menuOrder: 5
description: How to configure Apache OpenWhisk functions in the Serverless Framework
layout: Doc
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### [Read this on the main serverless docs site](https://www.serverless.com/framework/docs/providers/openwhisk/guide/functions)

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# OpenWhisk - Functions

If you are using OpenWhisk as a provider, all _functions_ inside the service are OpenWhisk Actions.

## Configuration

All of the OpenWhisk Actions in your serverless service can be found in `serverless.yml` under the `functions` property.

```yml
# serverless.yml
service: myService

provider:
  name: openwhisk
  runtime: nodejs:6 # optional, default is nodejs:default
  memory: 512 # optional, default is 256
  timeout: 30 # optional, default is 60

functions:
  hello:
    handler: handler.hello # required, handler set in Apache OpenWhisk
    name: some_custom_name # optional, default is ${service}_${function}
    runtime: nodejs # optional overwrite, default is provider runtime
    memory: 512 # optional overwrite, default is 256
    timeout: 10 # optional overwrite, default is 60
    parameters:
      foo: bar // default parameters
```

The `handler` property points to the file and module containing the code you want to run in your function.

```javascript
// handler.js
exports.handler = function (params) {};
```

You can add as many functions as you want within this property.

```yml
# serverless.yml

service: myService

provider:
  name: openwhisk

functions:
  functionOne:
    handler: handler.functionOne
    description: optional description for your Action
  functionTwo:
    handler: handler.functionTwo
  functionThree:
    handler: handler.functionThree
```

Your functions can either inherit their settings from the `provider` property.

```yml
# serverless.yml
service: myService

provider:
  name: openwhisk
  runtime: nodejs:6
  memory: 512 # will be inherited by all functions

functions:
  functionOne:
    handler: handler.functionOne
```

Or you can specify properties at the function level.

```yml
# serverless.yml
service: myService

provider:
  name: openwhisk
  runtime: nodejs:6

functions:
  functionOne:
    handler: handler.functionOne
    memory: 512 # function specific
    parameters:
      foo: bar // default parameters
```

You can specify an array of functions, which is useful if you separate your functions in to different files:

```yml
# serverless.yml
---
functions:
  - ${file(./foo-functions.yml)}
  - ${file(./bar-functions.yml)}
```

```yml
# foo-functions.yml
getFoo:
  handler: handler.foo
deleteFoo:
  handler: handler.foo
```

## Packages

OpenWhisk provides a concept called "packages" to manage related actions. Packages can contain multiple actions under a common identifier in a namespace. Configuration values needed by all actions in a package can be set as default properties on the package, rather than individually on each action.

_Packages are identified using the following format:_ `/namespaceName/packageName/actionName`.

### Implicit Packages

Functions can be assigned to packages by setting the function `name` with a package reference.

```yaml
functions:
  foo:
    handler: handler.foo
    name: 'myPackage/foo'
  bar:
    handler: handler.bar
    name: 'myPackage/bar'
```

In this example, two new actions (`foo` & `bar`) will be created using the `myPackage` package.

Packages which do not exist will be automatically created during deployments. When using the `remove` command, any packages referenced in the `serverless.yml` will be deleted.

### Explicit Packages

Packages can also be defined explicitly to set shared configuration parameters. Default package parameters are merged into event parameters for each invocation.

```yaml
functions:
  foo:
    handler: handler.foo
    name: 'myPackage/foo'

resources:
  packages:
    myPackage:
      name: optionalCustomName
      parameters:
        hello: world
```

_Explicit packages support the following properties: `name`, `parameters`, `annotations` and `shared`._

## Binding Services (IBM Cloud Functions)

**_This feature requires the [IBM Cloud CLI](https://console.bluemix.net/docs/cli/reference/bluemix_cli/download_cli.html#download_install) and [IBM Cloud Functions plugin](https://console.bluemix.net/openwhisk/learn/cli) to be installed._**

IBM Cloud Functions supports [automatic binding of service credentials](https://console.bluemix.net/docs/openwhisk/binding_services.html#binding_services) to actions using the CLI.

Bound service credentials will be passed as the `__bx_creds` parameter in the invocation parameters.

This feature is also available through the `serverless.yaml` file using the `bind` property for each function.

```yaml
functions:
  my_function:
    handler: file_name.handler
    bind:
      - service:
          name: cloud-object-storage
          instance: my-cos-storage
```

The `service` configuration supports the following properties.

- `name`: identifier for the cloud service
- `instance`: instance name for service (_optional_)
- `key`: key name for instance and service (_optional_)

_If the `instance` or `key` properties are missing, the first available instance and key found will be used._

Binding services removes the need to manually create default parameters for service keys from platform services.

More details on binding service credentials to actions can be found in the [official documentation](https://console.bluemix.net/docs/openwhisk/binding_services.html#binding_services) and [this blog post](http://jamesthom.as/blog/2018/06/05/binding-iam-services-to-ibm-cloud-functions/).

Packages defined in the `resources` section can bind services using the same configuration properties.

```yaml
resources:
  packages:
    myPackage:
      bind:
        - service:
            name: cloud-object-storage
            instance: my-cos-storage
```

## Runtimes

The OpenWhisk provider plugin supports the following runtimes.

- Node.js
- Python
- Java
- Php
- Ruby
- Swift
- Binary
- Docker

Please see the following repository for sample projects using those runtimes.

[https://github.com/serverless/examples/](https://github.com/serverless/examples/)