CacheBehavior

A complex type that describes how CloudFront processes requests.

You must create at least as many cache behaviors (including the default cache behavior) as you have origins if you want CloudFront to serve objects from all of the origins. Each cache behavior specifies the one origin from which you want CloudFront to get objects. If you have two origins and only the default cache behavior, the default cache behavior will cause CloudFront to get objects from one of the origins, but the other origin is never used.

For the current quota (formerly known as limit) on the number of cache behaviors that you can add to a distribution, see Quotas in the Amazon CloudFront Developer Guide.

If you don't want to specify any cache behaviors, include only an empty CacheBehaviors element. Don't specify an empty individual CacheBehavior element, because this is invalid. For more information, see CacheBehaviors.

To delete all cache behaviors in an existing distribution, update the distribution configuration and include only an empty CacheBehaviors element.

To add, change, or remove one or more cache behaviors, update the distribution configuration and specify all of the cache behaviors that you want to include in the updated distribution.

For more information about cache behaviors, see Cache Behavior Settings in the Amazon CloudFront Developer Guide.

PathPattern

The pattern (for example, images/*.jpg) that specifies which requests to apply the behavior to. When CloudFront receives a viewer request, the requested path is compared with path patterns in the order in which cache behaviors are listed in the distribution.

Note

You can optionally include a slash (/) at the beginning of the path pattern. For example, /images/*.jpg. CloudFront behavior is the same with or without the leading /.

The path pattern for the default cache behavior is * and cannot be changed. If the request for an object does not match the path pattern for any cache behaviors, CloudFront applies the behavior in the default cache behavior.

For more information, see Path Pattern in the Amazon CloudFront Developer Guide.

Type: String

Required: Yes

TargetOriginId

The value of ID for the origin that you want CloudFront to route requests to when they match this cache behavior.

Type: String

Required: Yes

ViewerProtocolPolicy

The protocol that viewers can use to access the files in the origin specified by TargetOriginId when a request matches the path pattern in PathPattern. You can specify the following options:

allow-all: Viewers can use HTTP or HTTPS.
redirect-to-https: If a viewer submits an HTTP request, CloudFront returns an HTTP status code of 301 (Moved Permanently) to the viewer along with the HTTPS URL. The viewer then resubmits the request using the new URL.
https-only: If a viewer sends an HTTP request, CloudFront returns an HTTP status code of 403 (Forbidden).

For more information about requiring the HTTPS protocol, see Requiring HTTPS Between Viewers and CloudFront in the Amazon CloudFront Developer Guide.

Note

The only way to guarantee that viewers retrieve an object that was fetched from the origin using HTTPS is never to use any other protocol to fetch the object. If you have recently changed from HTTP to HTTPS, we recommend that you clear your objects' cache because cached objects are protocol agnostic. That means that an edge location will return an object from the cache regardless of whether the current request protocol matches the protocol used previously. For more information, see Managing Cache Expiration in the Amazon CloudFront Developer Guide.

Type: String

Valid Values: allow-all | https-only | redirect-to-https

Required: Yes

AllowedMethods

A complex type that controls which HTTP methods CloudFront processes and forwards to your Amazon S3 bucket or your custom origin. There are three choices:

CloudFront forwards only GET and HEAD requests.
CloudFront forwards only GET, HEAD, and OPTIONS requests.
CloudFront forwards GET, HEAD, OPTIONS, PUT, PATCH, POST, and DELETE requests.

If you pick the third choice, you may need to restrict access to your Amazon S3 bucket or to your custom origin so users can't perform operations that you don't want them to. For example, you might not want users to have permissions to delete objects from your origin.

Type: AllowedMethods object

Required: No

CachePolicyId

The unique identifier of the cache policy that is attached to this cache behavior. For more information, see Creating cache policies or Using the managed cache policies in the Amazon CloudFront Developer Guide.

A CacheBehavior must include either a CachePolicyId or ForwardedValues. We recommend that you use a CachePolicyId.

Type: String

Required: No

Compress

Whether you want CloudFront to automatically compress certain files for this cache behavior. If so, specify true; if not, specify false. For more information, see Serving Compressed Files in the Amazon CloudFront Developer Guide.

Type: Boolean

Required: No

DefaultTTL

This field is deprecated. We recommend that you use the DefaultTTL field in a cache policy instead of this field. For more information, see Creating cache policies or Using the managed cache policies in the Amazon CloudFront Developer Guide.

The default amount of time that you want objects to stay in CloudFront caches before CloudFront forwards another request to your origin to determine whether the object has been updated. The value that you specify applies only when your origin does not add HTTP headers such as Cache-Control max-age, Cache-Control s-maxage, and Expires to objects. For more information, see Managing How Long Content Stays in an Edge Cache (Expiration) in the Amazon CloudFront Developer Guide.

Type: Long

Required: No

FieldLevelEncryptionId

The value of ID for the field-level encryption configuration that you want CloudFront to use for encrypting specific fields of data for this cache behavior.

Type: String

Required: No

ForwardedValues

This field is deprecated. We recommend that you use a cache policy or an origin request policy instead of this field. For more information, see Working with policies in the Amazon CloudFront Developer Guide.

If you want to include values in the cache key, use a cache policy. For more information, see Creating cache policies or Using the managed cache policies in the Amazon CloudFront Developer Guide.

If you want to send values to the origin but not include them in the cache key, use an origin request policy. For more information, see Creating origin request policies or Using the managed origin request policies in the Amazon CloudFront Developer Guide.

A CacheBehavior must include either a CachePolicyId or ForwardedValues. We recommend that you use a CachePolicyId.

A complex type that specifies how CloudFront handles query strings, cookies, and HTTP headers.

Type: ForwardedValues object

Required: No

FunctionAssociations

A list of CloudFront functions that are associated with this cache behavior. CloudFront functions must be published to the LIVE stage to associate them with a cache behavior.

Type: FunctionAssociations object

Required: No

LambdaFunctionAssociations

A complex type that contains zero or more Lambda@Edge function associations for a cache behavior.

Type: LambdaFunctionAssociations object

Required: No

MaxTTL

This field is deprecated. We recommend that you use the MaxTTL field in a cache policy instead of this field. For more information, see Creating cache policies or Using the managed cache policies in the Amazon CloudFront Developer Guide.

The maximum amount of time that you want objects to stay in CloudFront caches before CloudFront forwards another request to your origin to determine whether the object has been updated. The value that you specify applies only when your origin adds HTTP headers such as Cache-Control max-age, Cache-Control s-maxage, and Expires to objects. For more information, see Managing How Long Content Stays in an Edge Cache (Expiration) in the Amazon CloudFront Developer Guide.

Type: Long

Required: No

MinTTL

This field is deprecated. We recommend that you use the MinTTL field in a cache policy instead of this field. For more information, see Creating cache policies or Using the managed cache policies in the Amazon CloudFront Developer Guide.

The minimum amount of time that you want objects to stay in CloudFront caches before CloudFront forwards another request to your origin to determine whether the object has been updated. For more information, see Managing How Long Content Stays in an Edge Cache (Expiration) in the Amazon CloudFront Developer Guide.

You must specify 0 for MinTTL if you configure CloudFront to forward all headers to your origin (under Headers, if you specify 1 for Quantity and * for Name).

Type: Long

Required: No

OriginRequestPolicyId

The unique identifier of the origin request policy that is attached to this cache behavior. For more information, see Creating origin request policies or Using the managed origin request policies in the Amazon CloudFront Developer Guide.

Type: String

Required: No

RealtimeLogConfigArn

The Amazon Resource Name (ARN) of the real-time log configuration that is attached to this cache behavior. For more information, see Real-time logs in the Amazon CloudFront Developer Guide.

Type: String

Required: No

ResponseHeadersPolicyId

The identifier for a response headers policy.

Type: String

Required: No

SmoothStreaming

Indicates whether you want to distribute media files in the Microsoft Smooth Streaming format using the origin that is associated with this cache behavior. If so, specify true; if not, specify false. If you specify true for SmoothStreaming, you can still distribute other content using this cache behavior if the content matches the value of PathPattern.

Type: Boolean

Required: No

TrustedKeyGroups

A list of key groups that CloudFront can use to validate signed URLs or signed cookies.

When a cache behavior contains trusted key groups, CloudFront requires signed URLs or signed cookies for all requests that match the cache behavior. The URLs or cookies must be signed with a private key whose corresponding public key is in the key group. The signed URL or cookie contains information about which public key CloudFront should use to verify the signature. For more information, see Serving private content in the Amazon CloudFront Developer Guide.

Type: TrustedKeyGroups object

Required: No

TrustedSigners

Important

We recommend using TrustedKeyGroups instead of TrustedSigners.

A list of AWS account IDs whose public keys CloudFront can use to validate signed URLs or signed cookies.

When a cache behavior contains trusted signers, CloudFront requires signed URLs or signed cookies for all requests that match the cache behavior. The URLs or cookies must be signed with the private key of a CloudFront key pair in the trusted signer's AWS account. The signed URL or cookie contains information about which public key CloudFront should use to verify the signature. For more information, see Serving private content in the Amazon CloudFront Developer Guide.

Type: TrustedSigners object

Required: No

CacheBehavior

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