<a id="cli-aws-greengrass-create-core-definition"></a>

# create-core-definition

## Description

Creates a core definition. You may provide the initial version of the core definition now or use ‘’CreateCoreDefinitionVersion’’ at a later time. Greengrass groups must each contain exactly one Greengrass core.

See also: [AWS API Documentation](https://docs.aws.amazon.com/goto/WebAPI/greengrass-2017-06-07/CreateCoreDefinition)

## Synopsis

```
  create-core-definition
[--amzn-client-token <value>]
[--initial-version <value>]
[--name <value>]
[--tags <value>]
[--cli-input-json | --cli-input-yaml]
[--generate-cli-skeleton <value>]
[--debug]
[--endpoint-url <value>]
[--no-verify-ssl]
[--no-paginate]
[--output <value>]
[--query <value>]
[--profile <value>]
[--region <value>]
[--version <value>]
[--color <value>]
[--no-sign-request]
[--ca-bundle <value>]
[--cli-read-timeout <value>]
[--cli-connect-timeout <value>]
[--cli-binary-format <value>]
[--no-cli-pager]
[--cli-auto-prompt]
[--no-cli-auto-prompt]
[--cli-error-format <value>]
[--help]
```

## Options

`--amzn-client-token` (string)
A client token used to correlate requests and responses.

`--initial-version` (structure)
Information about the initial version of the core definition.Cores -> (list)

> A list of cores in the core definition version.

> (structure)

> > Information about a core.

> > CertificateArn -> (string) [required]

> > > The ARN of the certificate associated with the core.

> > Id -> (string) [required]

> > > A descriptive or arbitrary ID for the core. This value must be unique within the core definition version. Max length is 128 characters with pattern ‘’[a-zA-Z0-9:_-]+’’.

> > SyncShadow -> (boolean)

> > > If true, the core’s local shadow is automatically synced with the cloud.

> > ThingArn -> (string) [required]

> > > The ARN of the thing which is the core.

Shorthand Syntax:

```
Cores=[{CertificateArn=string,Id=string,SyncShadow=boolean,ThingArn=string},{CertificateArn=string,Id=string,SyncShadow=boolean,ThingArn=string}]
```

JSON Syntax:

```json
{
  "Cores": [
    {
      "CertificateArn": "string",
      "Id": "string",
      "SyncShadow": true|false,
      "ThingArn": "string"
    }
    ...
  ]
}
```

`--name` (string)
The name of the core definition.

`--tags` (map)
Tag(s) to add to the new resource.key -> (string)

> value -> (string)

Shorthand Syntax:

```
KeyName1=string,KeyName2=string
```

JSON Syntax:

```json
{"string": "string"
  ...}
```

`--cli-input-json` | `--cli-input-yaml` (string)
Reads arguments from the JSON string provided. The JSON string follows the format provided by `--generate-cli-skeleton`. If other arguments are provided on the command line, those values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally. This may not be specified along with `--cli-input-yaml`.

`--generate-cli-skeleton` (string)
Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value `input`, prints a sample input JSON that can be used as an argument for `--cli-input-json`. Similarly, if provided `yaml-input` it will print a sample input YAML that can be used with `--cli-input-yaml`. If provided with the value `output`, it validates the command inputs and returns a sample output JSON for that command. The generated JSON skeleton is not stable between versions of the AWS CLI and there are no backwards compatibility guarantees in the JSON skeleton generated.

## Global Options

`--debug` (boolean)

Turn on debug logging.

`--endpoint-url` (string)

Override command’s default URL with the given URL.

`--no-verify-ssl` (boolean)

By default, the AWS CLI uses SSL when communicating with AWS services. For each SSL connection, the AWS CLI will verify SSL certificates. This option overrides the default behavior of verifying SSL certificates.

`--no-paginate` (boolean)

Disable automatic pagination. If automatic pagination is disabled, the AWS CLI will only make one call, for the first page of results.

`--output` (string)

The formatting style for command output.

* json
* text
* table
* yaml
* yaml-stream
* off

`--query` (string)

A JMESPath query to use in filtering the response data.

`--profile` (string)

Use a specific profile from your credential file.

`--region` (string)

The region to use. Overrides config/env settings.

`--version` (string)

Display the version of this tool.

`--color` (string)

Turn on/off color output.

* on
* off
* auto

`--no-sign-request` (boolean)

Do not sign requests. Credentials will not be loaded if this argument is provided.

`--ca-bundle` (string)

The CA certificate bundle to use when verifying SSL certificates. Overrides config/env settings.

`--cli-read-timeout` (int)

The maximum socket read time in seconds. If the value is set to 0, the socket read will be blocking and not timeout. The default value is 60 seconds.

`--cli-connect-timeout` (int)

The maximum socket connect time in seconds. If the value is set to 0, the socket connect will be blocking and not timeout. The default value is 60 seconds.

`--cli-binary-format` (string)

The formatting style to be used for binary blobs. The default format is base64. The base64 format expects binary blobs to be provided as a base64 encoded string. The raw-in-base64-out format preserves compatibility with AWS CLI V1 behavior and binary values must be passed literally. When providing contents from a file that map to a binary blob `fileb://` will always be treated as binary and use the file contents directly regardless of the `cli-binary-format` setting. When using `file://` the file contents will need to properly formatted for the configured `cli-binary-format`.

* base64
* raw-in-base64-out

`--no-cli-pager` (boolean)

Disable cli pager for output.

`--cli-auto-prompt` (boolean)

Automatically prompt for CLI input parameters.

`--no-cli-auto-prompt` (boolean)

Disable automatically prompt for CLI input parameters.

`--cli-error-format` (string)

The formatting style for error output. By default, errors are displayed in enhanced format.

* legacy
* json
* yaml
* text
* table
* enhanced

`--help` (boolean)

Display help for the command/subcommand.

## Examples

#### NOTE
To use the following examples, you must have the AWS CLI installed and configured. See the [Getting started guide](https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-getting-started.html) in the *AWS CLI User Guide* for more information.

Unless otherwise stated, all examples have unix-like quotation rules. These examples will need to be adapted to your terminal’s quoting rules. See [Using quotation marks with strings](https://docs.aws.amazon.com/cli/latest/userguide/cli-usage-parameters-quoting-strings.html) in the *AWS CLI User Guide* .

**Example 1: To create an empty core definition**

The following `create-core-definition` example creates an empty (no initial version) Greengrass core definition. Before the core is usable, you must use the `create-core-definition-version` command to provide the other parameters for the core.

```bash
aws greengrass create-core-definition \
    --name cliGroup_Core
```

Output:

```json
{
    "Arn": "arn:aws:greengrass:us-west-2:123456789012:/greengrass/definition/cores/a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
    "CreationTimestamp": "2019-06-25T18:23:22.106Z",
    "Id": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
    "LastUpdatedTimestamp": "2019-06-25T18:23:22.106Z",
    "Name": "cliGroup_Core"
}
```

**Example 2: To create a core definition with an initial version**

The following `create-core-definition` example creates a core definition that contains an initial core definition version. The version can contain one core only. Before you can create a core, you must first create and provision the corresponding AWS IoT thing. This process includes the following `iot` commands, which return the `ThingArn` and `CertificateArn` required for the `create-core-definition` command.

* Create the AWS IoT thing that corresponds to the core device.
  ```bash
  aws iot create-thing \
      --thing-name "MyCoreDevice"
  ```

Output:

```json
{
    "thingArn": "arn:aws:iot:us-west-2:123456789012:thing/MyCoreDevice",
    "thingName": "MyCoreDevice",
    "thingId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE22222"
}
```

* Create public and private keys and the core device certificate for the thing. This example uses the `create-keys-and-certificate` command and requires write permissions to the current directory. Alternatively, you can use the `create-certificate-from-csr` command.
  ```bash
  aws iot create-keys-and-certificate \
      --set-as-active \
      --certificate-pem-outfile "myCore.cert.pem" \
      --public-key-outfile "myCore.public.key" \
      --private-key-outfile "myCore.private.key"
  ```

Output:

```json
{
    "certificateArn": "arn:aws:iot:us-west-2:123456789012:cert/123a15ec415668c2349a76170b64ac0878231c1e21ec83c10e92a1EXAMPLExyz",
    "certificatePem": "-----BEGIN CERTIFICATE-----\nMIIDWTCAkGgAwIBATgIUCgq6EGqou6zFqWgIZRndgQEFW+gwDQYJKoZIhvc...KdGewQS\n-----END CERTIFICATE-----\n",
    "keyPair": {
        "PublicKey": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBzrqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAqKpRgnn6yq26U3y...wIDAQAB\n-----END PUBLIC KEY-----\n",
        "PrivateKey": "-----BEGIN RSA PRIVATE KEY-----\nMIIEowIABAKCAQEAqKpRgnn6yq26U3yt5YFZquyukfRjbMXDcNOK4rMCxDR...fvY4+te\n-----END RSA PRIVATE KEY-----\n"
    },
    "certificateId": "123a15ec415668c2349a76170b64ac0878231c1e21ec83c10e92a1EXAMPLExyz"
}
```

* Create an AWS IoT policy that allows `iot` and `greengrass` actions. For simplicity, the following policy allows actions on all resources, but your policy should be more restrictive.
  ```bash
  aws iot create-policy \
      --policy-name "Core_Devices" \
      --policy-document "{\"Version\":\"2012-10-17\",\"Statement\":[{\"Effect\":\"Allow\",\"Action\":[\"iot:Publish\",\"iot:Subscribe\",\"iot:Connect\",\"iot:Receive\"],\"Resource\":[\"*\"]},{\"Effect\":\"Allow\",\"Action\":[\"iot:GetThingShadow\",\"iot:UpdateThingShadow\",\"iot:DeleteThingShadow\"],\"Resource\":[\"*\"]},{\"Effect\":\"Allow\",\"Action\":[\"greengrass:*\"],\"Resource\":[\"*\"]}]}"
  ```

Output:

```json
{
    "policyName": "Core_Devices",
    "policyArn": "arn:aws:iot:us-west-2:123456789012:policy/Core_Devices",
    "policyDocument": "{\"Version\":\"2012-10-17\",\"Statement\":[{\"Effect\":\"Allow\",\"Action\":[\"iot:Publish\",\"iot:Subscribe\",\"iot:Connect\",\"iot:Receive\"],\"Resource\":[\"*\"]},{\"Effect\":\"Allow\",\"Action\":[\"iot:GetThingShadow\",\"iot:UpdateThingShadow\",\"iot:DeleteThingShadow\"],\"Resource\":[\"*\"]},{\"Effect\":\"Allow\",\"Action\":[\"greengrass:*\"],\"Resource\":[\"*\"]}]}",
    "policyVersionId": "1"
}
```

* Attach the policy to the certificate.
  ```bash
  aws iot attach-policy \
      --policy-name "Core_Devices" \
      --target "arn:aws:iot:us-west-2:123456789012:cert/123a15ec415668c2349a76170b64ac0878231c1e21ec83c10e92a1EXAMPLExyz"
  ```

This command produces no output.

* Attach the thing to the certificate.
  ```bash
  aws iot attach-thing-principal \
      --thing-name "MyCoreDevice" \
      --principal "arn:aws:iot:us-west-2:123456789012:cert/123a15ec415668c2349a76170b64ac0878231c1e21ec83c10e92a1EXAMPLExyz"
  ```

This command produces no output.

* Create the core definition.
  ```bash
  aws greengrass create-core-definition \
      --name "MyCores" \
      --initial-version "{\"Cores\":[{\"Id\":\"MyCoreDevice\",\"ThingArn\":\"arn:aws:iot:us-west-2:123456789012:thing/MyCoreDevice\",\"CertificateArn\":\"arn:aws:iot:us-west-2:123456789012:cert/123a15ec415668c2349a76170b64ac0878231c1e21ec83c10e92a1EXAMPLExyz\",\"SyncShadow\":true}]}"
  ```

Output:

```json
{
    "LatestVersionArn": "arn:aws:greengrass:us-west-2:123456789012:/greengrass/definition/cores/a1b2c3d4-5678-90ab-cdef-EXAMPLE33333/versions/a1b2c3d4-5678-90ab-cdef-EXAMPLE44444",
    "Name": "MyCores",
    "LastUpdatedTimestamp": "2019-09-18T00:11:06.197Z",
    "LatestVersion": "a1b2c3d4-5678-90ab-cdef-EXAMPLE44444",
    "CreationTimestamp": "2019-09-18T00:11:06.197Z",
    "Id": "a1b2c3d4-5678-90ab-cdef-EXAMPLE33333",
    "Arn": "arn:aws:greengrass:us-west-2:123456789012:/greengrass/definition/cores/a1b2c3d4-5678-90ab-cdef-EXAMPLE33333"
}
```

For more information, see [Configure the AWS IoT Greengrass core](https://docs.aws.amazon.com/greengrass/v1/developerguide/gg-core.html) in the *AWS IoT Greengrass Developer Guide*.

## Output

Arn -> (string)

> The ARN of the definition.

CreationTimestamp -> (string)

> The time, in milliseconds since the epoch, when the definition was created.

Id -> (string)

> The ID of the definition.

LastUpdatedTimestamp -> (string)

> The time, in milliseconds since the epoch, when the definition was last updated.

LatestVersion -> (string)

> The ID of the latest version associated with the definition.

LatestVersionArn -> (string)

> The ARN of the latest version associated with the definition.

Name -> (string)

> The name of the definition.