Create Cloud Storage subscriptions

This document describes how to create a Cloud Storage subscription. You can use the Google Cloud console, the Google Cloud CLI, the client library, or the Pub/Sub API to create a Cloud Storage subscription.

Before you begin

Before reading this document, ensure that you're familiar with the following:

How a Cloud Storage subscription works.
How Cloud Storage works and how to create and manage Cloud Storage buckets .
How to configure a dead letter topic to handle message failures.

Required roles and permissions

To get the permissions that you need to create a Cloud Storage subscription, ask your administrator to grant you the Pub/Sub Editor ( roles/pubsub.editor ) IAM role on the project. For more information about granting roles, see Manage access to projects, folders, and organizations .

This predefined role contains the permissions required to create a Cloud Storage subscription. To see the exact permissions that are required, expand the Required permissionssection:

Required permissions

The following permissions are required to create a Cloud Storage subscription:

pubsub.subscriptions.create on the project
pubsub.topics.attachSubscription on the topic

You might also be able to get these permissions with custom roles or other predefined roles .

Cross-project subscriptions

If you create a subscription in one project for a topic in another project, you must have pubsub.subscriptions.create permission on the project in which you are creating the subscription, and pubsub.topics.attachSubscription permission on the topic.

Grant IAM roles to the service account

Pub/Sub uses an Identity and Access Management (IAM) service account to access Google Cloud resources. By default, it uses the Pub/Sub service agent ( service- PROJECT_NUMBER @gcp-sa-pubsub.iam.gserviceaccount.com ).

To enable Pub/Sub to write to Cloud Storage, the service account requires the following roles:

Storage Object Creator( roles/storage.objectCreator )
Storage Legacy Bucket Reader( roles/storage.legacyBucketReader )

You can give the service account permissions either for the project or the Cloud Storage bucket, as follows:

Project

In the Google Cloud console, go to the Bucketspage.

Go to Buckets
Select Include Google-provided role grants.
Find the row for the Cloud Pub/Subservice account and click Edit principal.
Click Add another roleand select the Storage Object Creatorrole. Repeat this step for the Storage Legacy Bucket Readerrole.

For more information, see Grant an IAM role by using the console .

Cloud Storage bucket

In the Google Cloud console, go to Buckets.

Go to Buckets
Click the name of the Cloud Storage bucket to which you want to grant permission.
In the Bucket detailspage, click the Permissionstab.
In the Permissionspane, click the View by principalstab.
Click Grant access.
In the New principalsfield, enter the service account identifier, in the following format:

service- PROJECT_NUMBER @gcp-sa-pubsub.iam.gserviceaccount.com .
In the Assign roleslist, select Storage Object Creator.
Click Add another roleand select Storage Legacy Bucket Reader.
Click Save. The principal is granted the roles on the resource.

Use a custom service account

By granting the Storage Object Creatorand Storage Legacy Bucket Readerroles to the Cloud Pub/Subservice account, any user who has permission to create a subscription in your project can write to the Cloud Storage bucket. If you want to provide more granular permissions, configure a user-managed service account instead.

The following permissions are required to configure a user-managed service account to write to Cloud Storage:

The user-managed service account must have the Storage Object Creatorand Storage Legacy Bucket Readerroles.
The Cloud Pub/Subservice account must have the iam.serviceAccounts.getAccessToken permission on the user-managed service account.
The user creating the subscription must have the iam.serviceAccounts.actAs permission on the user-managed service account.

When you create the subscription, specify the user-managed service account as the subscription service account .

Cloud Storage subscription properties

Cloud Storage subscriptions support all of the common subscription properties . The following sections describe properties that are specific to Cloud Storage subscriptions.

Bucket name

A Cloud Storage bucket must already exist before you create a Cloud Storage subscription.

The messages are sent as batches and stored in the Cloud Storage bucket. A single batch or file is stored as an object in the bucket.

The Cloud Storage bucket must have Requester Pays disabled.

To create a Cloud Storage bucket, see Create buckets .

Filename prefix, suffix, and datetime

The output Cloud Storage files generated by the Cloud Storage subscription are stored as objects in the Cloud Storage bucket. The name of the object stored in the Cloud Storage bucket is of the following format: <file-prefix><UTC-date-time>_<uuid><file-suffix> .

The following list includes details of the file format and the fields that you can customize:

<file-prefix> is the custom filename prefix. This is an optional field.
<UTC-date-time> is a customizable auto-generated string based on the time the object is created.
<uuid> is an auto-generated random string for the object.
<file-suffix> is the custom filename suffix. This is an optional field. The filename suffix cannot end in "/".
You can change the filename prefix and suffix:
- For example, if the value of the filename prefix is prod_ and the value of the filename suffix is _archive , a sample object name is prod_2023-09-25T04:10:00+00:00_uN1QuE_archive .
- If you don't specify the filename prefix and suffix, the object name stored in the Cloud Storage bucket is of the format: <UTC-date-time>_<uuid> .
- Cloud Storage object naming requirements also apply to the filename prefix and suffix. For more information, see About Cloud Storage objects .
You can change how the date and time are displayed in the filename:
- Required datetime matchers that you can use only once: year ( YYYY or YY ), month ( MM ), day ( DD ), hour ( hh ), minute ( mm ), second ( ss ). For example, YY-YYYY or MMM is invalid.
- Optional matchers that you can use only once: datetime separator ( T ) and and timezone offset ( Z or +00:00 ).
- Optional elements that you can use multiple times: hyphen ( - ), underscore ( _ ), colon ( : ), and forward slash ( / ).
- For example, if the value of the filename datetime format is YYYY-MM-DD/hh_mm_ssZ , a sample object name is prod_2023-09-25/04_10_00Z_uNiQuE_archive .
- If the filename datetime format ends in a character which is not a matcher, that character will replace the separator between <UTC-date-time> and <uuid> . For example, if the value of the filename datetime format is YYYY-MM-DDThh_mm_ss- , a sample object name is prod_2023-09-25T04_10_00-uNiQuE_archive .

File batching

Cloud Storage subscriptions let you decide when you want to create a new output file that is stored as an object in the Cloud Storage bucket. Pub/Sub writes an output file when one of the specified batching conditions are met. The following are the Cloud Storage batching conditions:

Storage batch max duration.This is a required setting. Pub/Sub writes a new output file if the specified value for max duration is exceeded. The duration is measured from when Pub/Sub begins writing to a new file to the time the file is finalized. For example, if you set the max duration to 5 minutes, Pub/Sub finalizes the file at most 5 minutes after Pub/Sub began writing to the file. A new file can be created before the max duration has passed. If you don't specify the value, a default value of 5 minutes is applied. The following are the applicable values for max duration:
- Minimum value = 1 minute
- Default value = 5 minutes
- Maximum value = 10 minutes
Storage batch max bytes.This is an optional setting. The Cloud Storage subscription writes a new output file if the specified value of max bytes is exceeded. The following are the applicable values for max bytes:
- Minimum value = 1 KB
- Maximum value = 10 GiB
Storage batch max messages.This is an optional setting. The Cloud Storage subscription writes a new output file if the specified number of max messages is exceeded. The following are the applicable values for max messages:
- Minimum value = 1000

For example, you can configure max duration as 6 minutes and max bytes as 2 GB. If at the 4th minute, the output file reaches a file size of 2 GB, Pub/Sub finalizes the previous file and starts writing to a new file.

A Cloud Storage subscription might write to multiple files in a Cloud Storage bucket simultaneously. If you have configured your subscription to create a new file every 6th minute, you might observe multiple Cloud Storage files being created every 6 minutes.

In some situations, Pub/Sub might start writing to a new file earlier than the time configured by the file batching conditions. A file might also exceed the Max bytes value if the subscription receives messages larger than the Max bytes value.

File format

When you create a Cloud Storage subscription, you can specify the format of the output files that are to be stored in a Cloud Storage bucket as Textor Avro.

Text: The messages are stored as plain text. A newline character separates a message from the previous message in the file. Only message payloads are stored, not attributes or other metadata.

Avro: The messages are stored in Apache Avro binary format. When you select Avro, you can enable the following additional properties:

Write metadata: This option lets you store the message metadata along with the message. Metadata such as subscription_name , message_id , publish_time , and attributes fields are written to top-level fields in the output Avro object while all other message properties other than data (for example, an ordering_key, if present) are added as entries in the attributes map.

If write metadatais disabled, only the message payload is written to the output Avro object. Here is the Avro schema for the output messages with write metadatadisabled:

  { 
  
 "type" 
 : 
  
 "record" 
 , 
  
 "namespace" 
 : 
  
 "com.google.pubsub" 
 , 
  
 "name" 
 : 
  
 "PubsubMessage" 
 , 
  
 "fields" 
 : 
  
 [ 
  
 { 
  
 "name" 
 : 
  
 "data" 
 , 
  
 "type" 
 : 
  
 "bytes" 
  
 } 
  
 ] 
 }

Here is the Avro schema for the output messages with write metadataenabled:

  { 
  
 "type" 
 : 
  
 "record" 
 , 
  
 "namespace" 
 : 
  
 "com.google.pubsub" 
 , 
  
 "name" 
 : 
  
 "PubsubMessageWithMetadata" 
 , 
  
 "fields" 
 : 
  
 [ 
  
 { 
  
 "name" 
 : 
  
 "subscription_name" 
 , 
  
 "type" 
 : 
  
 "string" 
  
 }, 
  
 { 
  
 "name" 
 : 
  
 "message_id" 
 , 
  
 "type" 
 : 
  
 "string" 
  
 }, 
  
 { 
  
 "name" 
 : 
  
 "publish_time" 
 , 
  
 "type" 
 : 
  
 { 
  
 "type" 
 : 
  
 "long" 
 , 
  
 "logicalType" 
 : 
  
 "timestamp-micros" 
  
 } 
  
 }, 
  
 { 
  
 "name" 
 : 
  
 "attributes" 
 , 
  
 "type" 
 : 
  
 { 
  
 "type" 
 : 
  
 "map" 
 , 
  
 "values" 
 : 
  
 "string" 
  
 } 
  
 }, 
  
 { 
  
 "name" 
 : 
  
 "data" 
 , 
  
 "type" 
 : 
  
 "bytes" 
  
 } 
  
 ] 
 }

Use topic schema: This option lets Pub/Sub use the schema of the Pub/Sub topic to which the subscription is attached when writing Avro files.

When you use this option, remember to check the following additional requirements:
- The topic schema must be in Apache Avro format .
- If both use topic schemaand write metadataare enabled, the topic schema must have a Record object at its root. Pub/Sub will expand the Record's list of fields to include the metadata fields. As a result, the Record cannot contain any fields with the same name as the metadata fields ( subscription_name , message_id , publish_time , or attributes ).

Service account

You have the following options to write messages to a Cloud Storage bucket:

Configure a custom service account so that only users who have the iam.serviceAccounts.actAs permission on the service account can create a subscription that writes to the bucket. An example role that includes the iam.serviceAccounts.actAs permission is the Service Account User( roles/iam.serviceAccountUser ) role.
Use the default Pub/Sub service agent that lets any user with the ability to create subscriptions in the project to create a subscription that writes to the bucket. The Pub/Sub service agent is the default setting when you don't specify a custom service account.

Create a Cloud Storage subscription

Console

In the Google Cloud console, go to the Subscriptionspage.

Go to Subscriptions
Click Create subscription.
For the Subscription IDfield, enter a name.

For information about how to name a subscription, see Guidelines to name a topic or a subscription .
Choose or create a topic from the drop-down menu.

The subscription receives messages from the topic.

For information about how to create a topic, see Create and manage topics .
Select Delivery typeas Write to Cloud Storage.
For the Cloud Storage bucket, click Browse.
- You can select an existing bucket from any appropriate project.
- You can also click the create icon and follow the instructions on the screen to create a new bucket.
  
  After you create the bucket, select the bucket for the Cloud Storage subscription.
  
  For more information about how to create a bucket, see Create buckets .
When you specify the bucket, Pub/Sub checks for the appropriate permissions on the bucket for the Pub/Sub service agent. If there are permissions issues, you see a message similar to the following: Unable to verify if the Pub/Sub service agent has write permissions on this bucket. You may be lacking permissions to view or set permissions .
If you get permission issues, click Set Permissionand follow the on-screen instructions.

Alternatively, follow the instructions in Assign Cloud Storage roles to the Pub/Sub service agent .
For File format, select Textor Avro.

If you select Avro, you can also optionally specify if you want to store the message metadata in the output.

For more information about the two options including the message metadata option for the Avro format, see File format .
Optional: You can specify the File name prefix, suffix, and datetimefor all your files that are to be written to the Cloud Storage bucket. A file is stored as an object in the bucket.

For more information about how to set the file prefix, suffix, and datetime, see Filename prefix, suffix, and datetime .
For File batching, specify a maximum time to elapse before creating a new file.

You can also optionally set the maximum file size or maximum number of messages for the files.

For more information about both file batching options, see File batching .
We strongly recommend that you enable Dead letteringto handle message failures.

For more information, see Dead letter topic .
You can keep the other settings as their defaults and click Create.

gcloud

In the Google Cloud console, activate Cloud Shell.

Activate Cloud Shell

At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.
To create a Cloud Storage subscription, run the gcloud pubsub subscriptions create command .
```
gcloud  
pubsub  
subscriptions  
create  
 SUBSCRIPTION_ID 
  
 \ 
  
--topic = 
 TOPIC_ID 
  
 \ 
  
--cloud-storage-bucket = 
 BUCKET_NAME 
  
 \ 
  
--cloud-storage-file-prefix = 
 CLOUD_STORAGE_FILE_PREFIX 
  
 \ 
  
--cloud-storage-file-suffix = 
 CLOUD_STORAGE_FILE_SUFFIX 
  
 \ 
  
--cloud-storage-file-datetime-format = 
 CLOUD_STORAGE_FILE_DATETIME_FORMAT 
  
 \ 
  
--cloud-storage-max-duration = 
 CLOUD_STORAGE_MAX_DURATION 
  
 \ 
  
--cloud-storage-max-bytes = 
 CLOUD_STORAGE_MAX_BYTES 
  
 \ 
  
--cloud-storage-max-messages = 
 CLOUD_STORAGE_MAX_MESSAGES 
  
 \ 
  
--cloud-storage-output-format = 
 CLOUD_STORAGE_OUTPUT_FORMAT 
  
 \ 
  
--cloud-storage-write-metadata  
--cloud-storage-use-topic-schema
```
If you want to use a custom service account, provide it as an additional argument:
```
gcloud  
pubsub  
subscriptions  
create  
 SUBSCRIPTION_ID 
  
 \ 
  
--topic = 
 TOPIC_ID 
  
 \ 
  
--cloud-storage-bucket = 
 BUCKET_NAME 
  
 \ 
  
--cloud-storage-file-prefix = 
 CLOUD_STORAGE_FILE_PREFIX 
  
 \ 
  
--cloud-storage-file-suffix = 
 CLOUD_STORAGE_FILE_SUFFIX 
  
 \ 
  
--cloud-storage-file-datetime-format = 
 CLOUD_STORAGE_FILE_DATETIME_FORMAT 
  
 \ 
  
--cloud-storage-max-duration = 
 CLOUD_STORAGE_MAX_DURATION 
  
 \ 
  
--cloud-storage-max-bytes = 
 CLOUD_STORAGE_MAX_BYTES 
  
 \ 
  
--cloud-storage-max-messages = 
 CLOUD_STORAGE_MAX_MESSAGES 
  
 \ 
  
--cloud-storage-output-format = 
 CLOUD_STORAGE_OUTPUT_FORMAT 
  
 \ 
  
--cloud-storage-write-metadata  
--cloud-storage-use-topic-schema  
--cloud-storage-service-account-email = 
 SERVICE_ACCOUNT_NAME 
  
```
In the command, only SUBSCRIPTION_ID , the --topic flag, and the --cloud-storage-bucket flag are required. The remaining flags are optional and can be omitted.

Replace the following:
- SUBSCRIPTION_ID : The name or ID of your new Cloud Storage subscription.
- TOPIC_ID : The name or ID of your topic.
- BUCKET_NAME : Specifies the name of an existing bucket. For example, prod_bucket . The bucket name must not include the project ID. To create a bucket, see Create buckets .
- CLOUD_STORAGE_FILE_PREFIX : Specifies the prefix for the Cloud Storage filename. For example, log_events_ .
- CLOUD_STORAGE_FILE_SUFFIX : Specifies the suffix for the Cloud Storage filename. For example, .txt .
- CLOUD_STORAGE_FILE_DATETIME_FORMAT : Specifies the datetime format for the Cloud Storage filename. For example, YYYY-MM-DD/hh_mm_ssZ .
- CLOUD_STORAGE_MAX_DURATION : The maximum duration that can elapse before a new Cloud Storage file is created. The value must be between 1m and 10m. For example, 5m .
- CLOUD_STORAGE_MAX_BYTES : The maximum bytes that can be written to a Cloud Storage file before a new file is created. The value must be between 1KB to 10GB. For example, 20MB .
- CLOUD_STORAGE_MAX_MESSAGES : The maximum number of messages that can be written to a Cloud Storage file before a new file is created. The value must be greater than or equal to 1000. For example, 100000 .
- CLOUD_STORAGE_OUTPUT_FORMAT : The output format for data written to Cloud Storage. Values are as follows:
  - text : Messages are written as raw text, separated by a newline.
  - avro : Messages are written as an Avro binary. --cloud-storage-write-metadata and --cloud-storage-use-topic-schema only affect subscriptions with output format avro .
- SERVICE_ACCOUNT_NAME : Specifies the name of the service account to use to write to Cloud Storage.

C++

Before trying this sample, follow the C++ setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub C++ API reference documentation .

To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for client libraries .

  namespace 
  
 pubsub 
  
 = 
  
 :: 
 google 
 :: 
 cloud 
 :: 
 pubsub 
 ; 
 namespace 
  
 pubsub_admin 
  
 = 
  
 :: 
 google 
 :: 
 cloud 
 :: 
 pubsub_admin 
 ; 
 []( 
 pubsub_admin 
 :: 
 SubscriptionAdminClient 
  
 client 
 , 
  
 std 
 :: 
 string 
  
 const 
&  
 project_id 
 , 
  
 std 
 :: 
 string 
  
 const 
&  
 topic_id 
 , 
  
 std 
 :: 
 string 
  
 const 
&  
 subscription_id 
 , 
  
 std 
 :: 
 string 
  
 const 
&  
 bucket 
 ) 
  
 { 
  
 google 
 :: 
 pubsub 
 :: 
 v1 
 :: 
 Subscription 
  
 request 
 ; 
  
 request 
 . 
 set_name 
 ( 
  
 pubsub 
 :: 
 Subscription 
 ( 
 project_id 
 , 
  
 subscription_id 
 ). 
 FullName 
 ()); 
  
 request 
 . 
 set_topic 
 ( 
 pubsub 
 :: 
 Topic 
 ( 
 project_id 
 , 
  
 topic_id 
 ). 
 FullName 
 ()); 
  
 request 
 . 
 mutable_cloud_storage_config 
 () 
 - 
> set_bucket 
 ( 
 bucket 
 ); 
  
 auto 
  
 sub 
  
 = 
  
 client 
 . 
 CreateSubscription 
 ( 
 request 
 ); 
  
 if 
  
 ( 
 ! 
 sub 
 ) 
  
 { 
  
 if 
  
 ( 
 sub 
 . 
 status 
 (). 
 code 
 () 
  
 == 
  
 google 
 :: 
 cloud 
 :: 
 StatusCode 
 :: 
 kAlreadyExists 
 ) 
  
 { 
  
 std 
 :: 
 cout 
 << 
 "The subscription already exists 
 \n 
 " 
 ; 
  
 return 
 ; 
  
 } 
  
 throw 
  
 std 
 :: 
 move 
 ( 
 sub 
 ). 
 status 
 (); 
  
 } 
  
 std 
 :: 
 cout 
 << 
 "The subscription was successfully created: " 
 << 
 sub 
 - 
> DebugString 
 () 
 << 
 " 
 \n 
 " 
 ; 
 }

C#

Before trying this sample, follow the C# setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub C# API reference documentation .

To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for client libraries .

  using 
  
  Google.Cloud.PubSub.V1 
 
 ; 
 using 
  
  Google.Protobuf.WellKnownTypes 
 
 ; 
 using 
  
 System 
 ; 
 public 
  
 class 
  
 CreateCloudStorageSubscriptionSample 
 { 
  
 public 
  
 Subscription 
  
 CreateCloudStorageSubscription 
 ( 
 string 
  
 projectId 
 , 
  
 string 
  
 topicId 
 , 
  
 string 
  
 subscriptionId 
 , 
  
 string 
  
 bucket 
 , 
  
 string 
  
 filenamePrefix 
 , 
  
 string 
  
 filenameSuffix 
 , 
  
 TimeSpan 
  
 maxDuration 
 ) 
  
 { 
  
  SubscriberServiceApiClient 
 
  
 subscriber 
  
 = 
  
  SubscriberServiceApiClient 
 
 . 
  Create 
 
 (); 
  
  TopicName 
 
  
 topicName 
  
 = 
  
  TopicName 
 
 . 
  FromProjectTopic 
 
 ( 
 projectId 
 , 
  
 topicId 
 ); 
  
  SubscriptionName 
 
  
 subscriptionName 
  
 = 
  
  SubscriptionName 
 
 . 
  FromProjectSubscription 
 
 ( 
 projectId 
 , 
  
 subscriptionId 
 ); 
  
 var 
  
 subscriptionRequest 
  
 = 
  
 new 
  
  Subscription 
 
  
 { 
  
 SubscriptionName 
  
 = 
  
 subscriptionName 
 , 
  
 TopicAsTopicName 
  
 = 
  
 topicName 
 , 
  
 CloudStorageConfig 
  
 = 
  
 new 
  
  CloudStorageConfig 
 
  
 { 
  
 Bucket 
  
 = 
  
 bucket 
 , 
  
 FilenamePrefix 
  
 = 
  
 filenamePrefix 
 , 
  
 FilenameSuffix 
  
 = 
  
 filenameSuffix 
 , 
  
 MaxDuration 
  
 = 
  
  Duration 
 
 . 
  FromTimeSpan 
 
 ( 
 maxDuration 
 ) 
  
 } 
  
 }; 
  
 var 
  
 subscription 
  
 = 
  
 subscriber 
 . 
  CreateSubscription 
 
 ( 
 subscriptionRequest 
 ); 
  
 return 
  
 subscription 
 ; 
  
 } 
 }

Go

Before trying this sample, follow the Go setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub Go API reference documentation .

To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for client libraries .

  import 
  
 ( 
  
 "context" 
  
 "fmt" 
  
 "io" 
  
 "time" 
  
 "cloud.google.com/go/pubsub/v2" 
  
 "cloud.google.com/go/pubsub/v2/apiv1/pubsubpb" 
  
 "google.golang.org/protobuf/types/known/durationpb" 
 ) 
 // createCloudStorageSubscription creates a Pub/Sub subscription that exports messages to Cloud Storage. 
 func 
  
 createCloudStorageSubscription 
 ( 
 w 
  
 io 
 . 
 Writer 
 , 
  
 projectID 
 , 
  
 topic 
 , 
  
 subscription 
 , 
  
 bucket 
  
 string 
 ) 
  
 error 
  
 { 
  
 // projectID := "my-project-id" 
  
 // topic := "projects/my-project-id/topics/my-topic" 
  
 // subscription := "projects/my-project/subscriptions/my-sub" 
  
 // bucket := "my-bucket" // bucket must not have the gs:// prefix 
  
 ctx 
  
 := 
  
 context 
 . 
 Background 
 () 
  
 client 
 , 
  
 err 
  
 := 
  
 pubsub 
 . 
 NewClient 
 ( 
 ctx 
 , 
  
 projectID 
 ) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 fmt 
 . 
 Errorf 
 ( 
 "pubsub.NewClient: %w" 
 , 
  
 err 
 ) 
  
 } 
  
 defer 
  
 client 
 . 
 Close 
 () 
  
 sub 
 , 
  
 err 
  
 := 
  
 client 
 . 
 SubscriptionAdminClient 
 . 
 CreateSubscription 
 ( 
 ctx 
 , 
  
& pubsubpb 
 . 
 Subscription 
 { 
  
 Name 
 : 
  
 subscription 
 , 
  
 Topic 
 : 
  
 topic 
 , 
  
 CloudStorageConfig 
 : 
  
& pubsubpb 
 . 
 CloudStorageConfig 
 { 
  
 Bucket 
 : 
  
 bucket 
 , 
  
 FilenamePrefix 
 : 
  
 "log_events_" 
 , 
  
 FilenameSuffix 
 : 
  
 ".avro" 
 , 
  
 OutputFormat 
 : 
  
& pubsubpb 
 . 
 CloudStorageConfig_AvroConfig_ 
 { 
  
 AvroConfig 
 : 
  
& pubsubpb 
 . 
 CloudStorageConfig_AvroConfig 
 { 
  
 WriteMetadata 
 : 
  
 true 
 , 
  
 }, 
  
 }, 
  
 MaxDuration 
 : 
  
 durationpb 
 . 
 New 
 ( 
 1 
  
 * 
  
 time 
 . 
 Minute 
 ), 
  
 MaxBytes 
 : 
  
 1e8 
 , 
  
 }, 
  
 }) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 fmt 
 . 
 Errorf 
 ( 
 "failed to create cloud storage sub: %w" 
 , 
  
 err 
 ) 
  
 } 
  
 fmt 
 . 
 Fprintf 
 ( 
 w 
 , 
  
 "Created Cloud Storage subscription: %v\n" 
 , 
  
 sub 
 ) 
  
 return 
  
 nil 
 }

Java

Before trying this sample, follow the Java setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub Java API reference documentation .

To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for client libraries .

  import 
  
 com.google.cloud.pubsub.v1. SubscriptionAdminClient 
 
 ; 
 import 
  
 com.google.protobuf. Duration 
 
 ; 
 import 
  
 com.google.pubsub.v1. CloudStorageConfig 
 
 ; 
 import 
  
 com.google.pubsub.v1. ProjectSubscriptionName 
 
 ; 
 import 
  
 com.google.pubsub.v1. ProjectTopicName 
 
 ; 
 import 
  
 com.google.pubsub.v1. Subscription 
 
 ; 
 import 
  
 java.io.IOException 
 ; 
 public 
  
 class 
 CreateCloudStorageSubscriptionExample 
  
 { 
  
 public 
  
 static 
  
 void 
  
 main 
 ( 
 String 
 ... 
  
 args 
 ) 
  
 throws 
  
 Exception 
  
 { 
  
 // TODO(developer): Replace these variables before running the sample. 
  
 String 
  
 projectId 
  
 = 
  
 "your-project-id" 
 ; 
  
 String 
  
 topicId 
  
 = 
  
 "your-topic-id" 
 ; 
  
 String 
  
 subscriptionId 
  
 = 
  
 "your-subscription-id" 
 ; 
  
 String 
  
 bucket 
  
 = 
  
 "your-bucket" 
 ; 
  
 String 
  
 filenamePrefix 
  
 = 
  
 "log_events_" 
 ; 
  
 String 
  
 filenameSuffix 
  
 = 
  
 ".text" 
 ; 
  
  Duration 
 
  
 maxDuration 
  
 = 
  
  Duration 
 
 . 
 newBuilder 
 (). 
 setSeconds 
 ( 
 300 
 ). 
 build 
 (); 
  
 createCloudStorageSubscription 
 ( 
  
 projectId 
 , 
  
 topicId 
 , 
  
 subscriptionId 
 , 
  
 bucket 
 , 
  
 filenamePrefix 
 , 
  
 filenameSuffix 
 , 
  
 maxDuration 
 ); 
  
 } 
  
 public 
  
 static 
  
 void 
  
 createCloudStorageSubscription 
 ( 
  
 String 
  
 projectId 
 , 
  
 String 
  
 topicId 
 , 
  
 String 
  
 subscriptionId 
 , 
  
 String 
  
 bucket 
 , 
  
 String 
  
 filenamePrefix 
 , 
  
 String 
  
 filenameSuffix 
 , 
  
  Duration 
 
  
 maxDuration 
 ) 
  
 throws 
  
 IOException 
  
 { 
  
 try 
  
 ( 
  SubscriptionAdminClient 
 
  
 subscriptionAdminClient 
  
 = 
  
  SubscriptionAdminClient 
 
 . 
 create 
 ()) 
  
 { 
  
  ProjectTopicName 
 
  
 topicName 
  
 = 
  
  ProjectTopicName 
 
 . 
 of 
 ( 
 projectId 
 , 
  
 topicId 
 ); 
  
  ProjectSubscriptionName 
 
  
 subscriptionName 
  
 = 
  
  ProjectSubscriptionName 
 
 . 
 of 
 ( 
 projectId 
 , 
  
 subscriptionId 
 ); 
  
  CloudStorageConfig 
 
  
 cloudStorageConfig 
  
 = 
  
  CloudStorageConfig 
 
 . 
 newBuilder 
 () 
  
 . 
 setBucket 
 ( 
 bucket 
 ) 
  
 . 
  setFilenamePrefix 
 
 ( 
 filenamePrefix 
 ) 
  
 . 
  setFilenameSuffix 
 
 ( 
 filenameSuffix 
 ) 
  
 . 
  setMaxDuration 
 
 ( 
 maxDuration 
 ) 
  
 . 
 build 
 (); 
  
  Subscription 
 
  
 subscription 
  
 = 
  
 subscriptionAdminClient 
 . 
 createSubscription 
 ( 
  
  Subscription 
 
 . 
 newBuilder 
 () 
  
 . 
 setName 
 ( 
 subscriptionName 
 . 
  toString 
 
 ()) 
  
 . 
 setTopic 
 ( 
 topicName 
 . 
  toString 
 
 ()) 
  
 . 
  setCloudStorageConfig 
 
 ( 
 cloudStorageConfig 
 ) 
  
 . 
 build 
 ()); 
  
 System 
 . 
 out 
 . 
 println 
 ( 
 "Created a CloudStorage subscription: " 
  
 + 
  
 subscription 
 . 
 getAllFields 
 ()); 
  
 } 
  
 } 
 }

Node.js

Before trying this sample, follow the Node.js setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub Node.js API reference documentation .

To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for client libraries .

  /** 
  
 * 
  
 TODO 
 ( 
 developer 
 ): 
  
 Uncomment 
  
 these 
  
 variables 
  
 before 
  
 running 
  
 the 
  
 sample 
 . 
  
 */ 
 // 
  
 const 
  
 topicName 
  
 = 
  
 'YOUR_TOPIC_NAME' 
 ; 
 // 
  
 const 
  
 subscriptionName 
  
 = 
  
 'YOUR_SUBSCRIPTION_NAME' 
 ; 
 // 
  
 const 
  
 bucket 
  
 = 
  
 'YOUR_BUCKET_ID' 
 ; 
 // 
  
 const 
  
 filenamePrefix 
  
 = 
  
 'YOUR_FILENAME_PREFIX' 
 ; 
 // 
  
 const 
  
 filenameSuffix 
  
 = 
  
 'YOUR_FILENAME_SUFFIX' 
 ; 
 // 
  
 const 
  
 maxDuration 
  
 = 
  
 60 
 ; 
 // 
  
 Imports 
  
 the 
  
 Google 
  
 Cloud 
  
 client 
  
 library 
 const 
  
 { 
 PubSub 
 } 
  
 = 
  
 require 
 ( 
 '@google-cloud/pubsub' 
 ); 
 // 
  
 Creates 
  
 a 
  
 client 
 ; 
  
 cache 
  
 this 
  
 for 
  
 further 
  
 use 
 const 
  
 pubSubClient 
  
 = 
  
 new 
  
 PubSub 
 (); 
 async 
  
 function 
  
 createCloudStorageSubscription 
 ( 
  
 topicName 
 , 
  
 subscriptionName 
 , 
  
 bucket 
 , 
  
 filenamePrefix 
 , 
  
 filenameSuffix 
 , 
  
 maxDuration 
 , 
 ) 
  
 { 
  
 const 
  
 options 
  
 = 
  
 { 
  
 cloudStorageConfig 
 : 
  
 { 
  
 bucket 
 , 
  
 filenamePrefix 
 , 
  
 filenameSuffix 
 , 
  
 maxDuration 
 : 
  
 { 
  
 seconds 
 : 
  
 maxDuration 
 , 
  
 }, 
  
 }, 
  
 }; 
  
 await 
  
 pubSubClient 
  
 . 
 topic 
 ( 
 topicName 
 ) 
  
 . 
 createSubscription 
 ( 
 subscriptionName 
 , 
  
 options 
 ); 
  
 console 
 . 
 log 
 ( 
  
 ` 
 Created 
  
 subscription 
  
 $ 
 { 
 subscriptionName 
 } 
  
 with 
  
 a 
  
 cloud 
  
 storage 
  
 configuration 
 . 
 ` 
 , 
  
 ); 
 }

Node.js

Before trying this sample, follow the Node.js setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub Node.js API reference documentation .

To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for client libraries .

  /** 
 * 
 TODO 
 ( 
 developer 
 ): 
 Uncomment 
 these 
 variables 
 before 
 running 
 the 
 sample 
 . 
 */ 
 // 
 const 
 topicName 
 = 
 'YOUR_TOPIC_NAME' 
 ; 
 // 
 const 
 subscriptionName 
 = 
 'YOUR_SUBSCRIPTION_NAME' 
 ; 
 // 
 const 
 bucket 
 = 
 'YOUR_BUCKET_ID' 
 ; 
 // 
 const 
 filenamePrefix 
 = 
 'YOUR_FILENAME_PREFIX' 
 ; 
 // 
 const 
 filenameSuffix 
 = 
 'YOUR_FILENAME_SUFFIX' 
 ; 
 // 
 const 
 maxDuration 
 = 
 60 
 ; 
 // 
 Imports 
 the 
 Google 
 Cloud 
 client 
 library 
 import 
  
 { 
 CreateSubscriptionOptions 
 , 
 PubSub 
 } 
 from 
  
 '@google-cloud/pubsub' 
 ; 
 // 
 Creates 
 a 
 client 
 ; 
 cache 
 this 
 for 
 further 
 use 
 const 
 pubSubClient 
 = 
 new 
 PubSub 
 (); 
 async 
 function 
 createCloudStorageSubscription 
 ( 
 topicName 
 : 
 string 
 , 
 subscriptionName 
 : 
 string 
 , 
 bucket 
 : 
 string 
 , 
 filenamePrefix 
 : 
 string 
 , 
 filenameSuffix 
 : 
 string 
 , 
 maxDuration 
 : 
 number 
 , 
 ) 
 { 
 const 
 options 
 : 
 CreateSubscriptionOptions 
 = 
 { 
 cloudStorageConfig 
 : 
 { 
 bucket 
 , 
 filenamePrefix 
 , 
 filenameSuffix 
 , 
 maxDuration 
 : 
 { 
 seconds 
 : 
 maxDuration 
 , 
 }, 
 }, 
 }; 
 await 
 pubSubClient 
 . 
 topic 
 ( 
 topicName 
 ) 
 . 
 createSubscription 
 ( 
 subscriptionName 
 , 
 options 
 ); 
 console 
 . 
 log 
 ( 
 ` 
 Created 
 subscription 
 $ 
 { 
 subscriptionName 
 } 
 with 
 a 
 cloud 
 storage 
 configuration 
 . 
 ` 
 , 
 ); 
 }

PHP

Before trying this sample, follow the PHP setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub PHP API reference documentation .

To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for client libraries .

  use Google\Cloud\PubSub\PubSubClient; 
 /** 
 * Creates a Pub/Sub GCS subscription. 
 * 
 * @param string $projectId  The Google project ID. 
 * @param string $topicName  The Pub/Sub topic name. 
 * @param string $subscriptionName  The Pub/Sub subscription name. 
 * @param string $bucket The Cloud Storage bucket name without any prefix like "gs://". 
 */ 
 function create_cloud_storage_subscription($projectId, $topicName, $subscriptionName, $bucket) 
 { 
 $pubsub = new PubSubClient([ 
 'projectId' => $projectId, 
 ]); 
 $topic = $pubsub->topic($topicName); 
 $subscription = $topic->subscription($subscriptionName); 
 $config = ['bucket' => $bucket]; 
 $subscription->create([ 
 'cloudStorageConfig' => $config 
 ]); 
 printf('Subscription created: %s' . PHP_EOL, $subscription->name()); 
 }

Python

Before trying this sample, follow the Python setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub Python API reference documentation .

To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for client libraries .

  from 
  
 google.cloud 
  
 import 
 pubsub_v1 
 from 
  
 google.protobuf 
  
 import 
 duration_pb2 
 # TODO(developer) 
 # project_id = "your-project-id" 
 # topic_id = "your-topic-id" 
 # subscription_id = "your-subscription-id" 
 # bucket = "my-bucket" 
 filename_prefix 
 = 
 "log_events_" 
 filename_suffix 
 = 
 ".avro" 
 # Either CloudStorageConfig.AvroConfig or CloudStorageConfig.TextConfig 
 # defaults to TextConfig 
 avro_config 
 = 
 pubsub_v1 
 . 
 types 
 . 
  CloudStorageConfig 
 
 . 
  AvroConfig 
 
 ( 
 write_metadata 
 = 
 True 
 ) 
 publisher 
 = 
 pubsub_v1 
 . 
  PublisherClient 
 
 () 
 subscriber 
 = 
 pubsub_v1 
 . 
  SubscriberClient 
 
 () 
 topic_path 
 = 
 publisher 
 . 
 topic_path 
 ( 
 project_id 
 , 
 topic_id 
 ) 
 subscription_path 
 = 
 subscriber 
 . 
 subscription_path 
 ( 
 project_id 
 , 
 subscription_id 
 ) 
 max_duration 
 = 
 duration_pb2 
 . 
  Duration 
 
 () 
 max_duration 
 . 
 FromSeconds 
 ( 
 300 
 ) 
 cloudstorage_config 
 = 
 pubsub_v1 
 . 
 types 
 . 
  CloudStorageConfig 
 
 ( 
 bucket 
 = 
 bucket 
 , 
 filename_prefix 
 = 
 filename_prefix 
 , 
 filename_suffix 
 = 
 filename_suffix 
 , 
 avro_config 
 = 
 avro_config 
 , 
 # Min 1 minutes, max 10 minutes 
 max_duration 
 = 
 max_duration 
 , 
 # Min 1 KB, max 10 GiB 
 max_bytes 
 = 
 10000000 
 , 
 ) 
 # Wrap the subscriber in a 'with' block to automatically call close() to 
 # close the underlying gRPC channel when done. 
 with 
 subscriber 
 : 
 subscription 
 = 
 subscriber 
 . 
 create_subscription 
 ( 
 request 
 = 
 { 
 "name" 
 : 
 subscription_path 
 , 
 "topic" 
 : 
 topic_path 
 , 
 "cloud_storage_config" 
 : 
 cloudstorage_config 
 , 
 } 
 ) 
 print 
 ( 
 f 
 "CloudStorage subscription created: 
 { 
 subscription 
 } 
 ." 
 ) 
 print 
 ( 
 f 
 "Bucket for subscription is: 
 { 
 bucket 
 } 
 " 
 ) 
 print 
 ( 
 f 
 "Prefix is: 
 { 
 filename_prefix 
 } 
 " 
 ) 
 print 
 ( 
 f 
 "Suffix is: 
 { 
 filename_suffix 
 } 
 " 
 )

Monitor a Cloud Storage subscription

Cloud Monitoring provides a number of metrics to monitor subscriptions .

For a list of all the available metrics related to Pub/Sub and their descriptions, see the Monitoring documentation for Pub/Sub .

You can also monitor subscriptions from within Pub/Sub .

What's next

Troubleshoot a Cloud Storage subscription .
Read about Cloud Storage .
Review pricing for Pub/Sub, including Cloud Storage subscription .

Create Cloud Storage subscriptions Stay organized with collections Save and categorize content based on your preferences.

Before you begin

Required roles and permissions

Required permissions

Cross-project subscriptions

Grant IAM roles to the service account

Project

Cloud Storage bucket

Use a custom service account

Cloud Storage subscription properties

Bucket name

Filename prefix, suffix, and datetime

File batching

File format

Service account

Create a Cloud Storage subscription

Console

gcloud

C++

C#

Go

Java

Node.js

Node.js

PHP

Python

Monitor a Cloud Storage subscription

What's next

Create Cloud Storage subscriptions