Google Cloud Storage Service Registry

Google Cloud Storage is a managed service for storing unstructured data. CAS takes advantage of Google Cloud Storage to store service and application definitions. Applications are grouped based on type and are stored in their own bucket, which are managed and/or created automatically.

Support is enabled by including the following dependency in the overlay:

<dependency>
    <groupId>org.apereo.cas</groupId>
    <artifactId>cas-server-support-gcp-storage-service-registry</artifactId>
    <version>${cas.version}</version>
</dependency>

implementation "org.apereo.cas:cas-server-support-gcp-storage-service-registry:${project.'cas.version'}"

dependencyManagement {
    imports {
        mavenBom "org.apereo.cas:cas-server-support-bom:${project.'cas.version'}"
    }
}

dependencies {
    implementation "org.apereo.cas:cas-server-support-gcp-storage-service-registry"
}

dependencies {
    /*
        The following platform references should be included automatically and are listed here for reference only.

        implementation enforcedPlatform("org.apereo.cas:cas-server-support-bom:${project.'cas.version'}")
        implementation platform(org.springframework.boot.gradle.plugin.SpringBootPlugin.BOM_COORDINATES)
        
    */
    implementation "org.apereo.cas:cas-server-support-gcp-storage-service-registry"
}

Integration support is backed by the Spring Cloud GCP project. Their reference documentation provides detailed information on how to integrate Google Cloud APIs with CAS.

To understand how to set up application default credentials, please review this page.

CAS Configuration

The following settings and properties are available from the CAS configuration catalog:

_{The configuration settings listed below are tagged as Required in the CAS configuration metadata. This flag indicates that the presence of the setting may be needed to activate or affect the behavior of the CAS feature and generally should be reviewed, possibly owned and adjusted. If the setting is assigned a default value, you do not need to strictly put the setting in your copy of the configuration, but should review it nonetheless to make sure it matches your deployment expectations.}

_{The configuration settings listed below are tagged as Optional in the CAS configuration metadata. This
flag indicates that the presence of the setting
is not immediately necessary in the end-user CAS configuration, because a default value is assigned or
the activation of the feature is not conditionally controlled by the setting value. In other words, you should only include this field in your
configuration if you need to modify the default value or if you need to turn on the feature controlled by the setting.}

_{The configuration settings listed below are tagged as Third Party in the CAS configuration metadata. This flag indicates that the configuration setting is not controlled, owned or managed by the CAS ecosystem, and affects functionality that is offered by a third-party library, such as Spring Boot or Spring Cloud to CAS. For additional info, you might have to visit the third-party source to find more details.}

spring.cloud.gcp.storage.auto-create-files=

com.google.cloud.spring.autoconfigure.storage.GcpStorageProperties.

_{Copy Configuration Property

Copied!} _{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

Note

When possible, properties should be stored in lower-case kebab format, such as cas.property-name=value. The only possible exception to this rule is when naming actuator endpoints; The name of the actuator endpoints (i.e. ssoSessions) MUST remain in camelCase mode.

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

spring.cloud.gcp.storage.auto-create-files=...

This is the most common form of property configuration that is recognized by CAS, regardless of the actual property source, which might in fact be managed separately outside the CAS environment, by another system or cloud framework.

CAS properties can be specified using the YAML syntax:

spring: 
  cloud: 
    gcp: 
      storage: 
        auto-create-files: "..."

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dspring.cloud.gcp.storage.auto-create-files="..." -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory. Note the placement of the system property which must be specified before the CAS web application is launched.

CAS properties can specified as system environment variables before the CAS web application is launched:

export SPRING_CLOUD_GCP_STORAGE_AUTO_CREATE_FILES="..."

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --spring.cloud.gcp.storage.auto-create-files="..."

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

spring.cloud.gcp.storage.credentials.default-scopes=

com.google.cloud.spring.core.Credentials.

_{Copy Configuration Property

Copied!} _{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

Note

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

spring.cloud.gcp.storage.credentials.default-scopes=...

CAS properties can be specified using the YAML syntax:

spring: 
  cloud: 
    gcp: 
      storage: 
        credentials: 
          default-scopes: "..."

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dspring.cloud.gcp.storage.credentials.default-scopes="..." -jar build/libs/cas.war

CAS properties can specified as system environment variables before the CAS web application is launched:

export SPRING_CLOUD_GCP_STORAGE_CREDENTIALS_DEFAULT_SCOPES="..."

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --spring.cloud.gcp.storage.credentials.default-scopes="..."

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

spring.cloud.gcp.storage.enabled=true

Auto-configure Google Cloud Storage components.

_{Copy Configuration Property

Copied!} _{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

Note

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

spring.cloud.gcp.storage.enabled=true

CAS properties can be specified using the YAML syntax:

spring: 
  cloud: 
    gcp: 
      storage: 
        enabled: "true"

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dspring.cloud.gcp.storage.enabled="true" -jar build/libs/cas.war

CAS properties can specified as system environment variables before the CAS web application is launched:

export SPRING_CLOUD_GCP_STORAGE_ENABLED="true"

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --spring.cloud.gcp.storage.enabled="true"

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

spring.cloud.gcp.storage.host=

Host of the Storage client that is formatted as `https://${service}.${universeDomain}/`.

com.google.cloud.spring.autoconfigure.storage.GcpStorageProperties.

_{Copy Configuration Property

Copied!} _{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

Note

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

spring.cloud.gcp.storage.host=...

CAS properties can be specified using the YAML syntax:

spring: 
  cloud: 
    gcp: 
      storage: 
        host: "..."

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dspring.cloud.gcp.storage.host="..." -jar build/libs/cas.war

CAS properties can specified as system environment variables before the CAS web application is launched:

export SPRING_CLOUD_GCP_STORAGE_HOST="..."

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --spring.cloud.gcp.storage.host="..."

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

spring.cloud.gcp.storage.project-id=

com.google.cloud.spring.autoconfigure.storage.GcpStorageProperties.

_{Copy Configuration Property

Copied!} _{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

Note

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

spring.cloud.gcp.storage.project-id=...

CAS properties can be specified using the YAML syntax:

spring: 
  cloud: 
    gcp: 
      storage: 
        project-id: "..."

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dspring.cloud.gcp.storage.project-id="..." -jar build/libs/cas.war

CAS properties can specified as system environment variables before the CAS web application is launched:

export SPRING_CLOUD_GCP_STORAGE_PROJECT_ID="..."

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --spring.cloud.gcp.storage.project-id="..."

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

spring.cloud.gcp.storage.universe-domain=

Universe domain of the client which is part of the host that is formatted as `https://${service}.${universeDomain}/`.

com.google.cloud.spring.autoconfigure.storage.GcpStorageProperties.

_{Copy Configuration Property

Copied!} _{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

Note

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

spring.cloud.gcp.storage.universe-domain=...

CAS properties can be specified using the YAML syntax:

spring: 
  cloud: 
    gcp: 
      storage: 
        universe-domain: "..."

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dspring.cloud.gcp.storage.universe-domain="..." -jar build/libs/cas.war

CAS properties can specified as system environment variables before the CAS web application is launched:

export SPRING_CLOUD_GCP_STORAGE_UNIVERSE_DOMAIN="..."

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --spring.cloud.gcp.storage.universe-domain="..."

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

Configuration Metadata

The collection of configuration properties listed in this section are automatically generated from the CAS source and components that contain the actual field definitions, types, descriptions, modules, etc. This metadata may not always be 100% accurate, or could be lacking details and sufficient explanations.

Be Selective

This section is meant as a guide only. Do NOT copy/paste the entire collection of settings into your CAS configuration; rather pick only the properties that you need. Do NOT enable settings unless you are certain of their purpose and do NOT copy settings into your configuration only to keep them as reference. All these ideas lead to upgrade headaches, maintenance nightmares and premature aging.

YAGNI

Note that for nearly ALL use cases, declaring and configuring properties listed here is sufficient. You should NOT have to explicitly massage a CAS XML/Java/etc configuration file to design an authentication handler, create attribute release policies, etc. CAS at runtime will auto-configure all required changes for you. If you are unsure about the meaning of a given CAS setting, do NOT turn it on without hesitation. Review the codebase or better yet, ask questions to clarify the intended behavior.

Naming Convention

Property names can be specified in very relaxed terms. For instance cas.someProperty, cas.some-property, cas.some_property are all valid names. While all forms are accepted by CAS, there are certain components (in CAS and other frameworks used) whose activation at runtime is conditional on a property value, where this property is required to have been specified in CAS configuration using kebab case. This is both true for properties that are owned by CAS as well as those that might be presented to the system via an external library or framework such as Spring Boot, etc.

Note

Settings and properties that are controlled by the CAS platform directly always begin with the prefix cas. All other settings are controlled and provided to CAS via other underlying frameworks and may have their own schemas and syntax. BE CAREFUL with the distinction. Unrecognized properties are rejected by CAS and/or frameworks upon which CAS depends. This means if you somehow misspell a property definition or fail to adhere to the dot-notation syntax and such, your setting is entirely refused by CAS and likely the feature it controls will never be activated in the way you intend.

Validation

Configuration properties are automatically validated on CAS startup to report issues with configuration binding, especially if defined CAS settings cannot be recognized or validated by the configuration schema. Additional validation processes are also handled via Configuration Metadata and property migrations applied automatically on startup by Spring Boot and family.

Indexed Settings

CAS settings able to accept multiple values are typically documented with an index, such as cas.some.setting[0]=value. The index [0] is meant to be incremented by the adopter to allow for distinct multiple configuration blocks.

Google Cloud Storage with Pub/Sub Listener

CAS allows the Google Cloud Storage-backed service registry to listen for object-change events published through Google Pub/Sub. When a service definition or related registry object is created, updated, or deleted in the configured GCS bucket, the listener receives the notification and can refresh or invalidate the local registry state accordingly.

This is useful in clustered or cloud-native deployments where multiple CAS nodes may rely on the same GCS bucket as the source of truth. Instead of requiring restarts, polling, or manual refreshes, registry changes can be propagated to running nodes as events occur, helping keep service definitions synchronized across the deployment with lower latency and less operational overhead.

The subscription/topic name is set to be cas-service-regisry-gcp-storage. For the CAS listener to operate, the required Pub/Sub infrastructure must exist ahead of time. The Cloud Storage service account for the project must also have permission to publish messages to the topic. CAS only consumes messages from the configured subscription; it does not automatically create the topic, subscription, bucket notification, or IAM bindings.

You may configure the bucket to emit supported events such as OBJECT_FINALIZE and OBJECT_DELETE.

Feature Activation

To activate this feature, the following feature toggle(s) must be turned on:

CasFeatureModule.ServiceRegistry.gcp-storage-pubsub.enabled=true

To learn more about configuration feature toggles, please see this page.

Event payloads are expected to match the following structure:

{
  "eventType": "OBJECT_FINALIZE",
  "bucketId": "...",
  "objectId": "...",
  "objectGeneration": "1710000000000000",
  "eventTime": "2025-06-13T17:22:30.000Z",
  "payloadFormat": "JSON_API_V1",
  "notificationConfig": "..."
}

Troubleshooting

To enable additional logging, configure the log4j configuration file to add the following levels:

...
<Logger name="com.google.cloud" level="debug" additivity="false">
    <AppenderRef ref="casConsole"/>
    <AppenderRef ref="casFile"/>
</Logger>
...

Auto Initialization

Upon startup and configuration permitting, the registry is able to auto initialize itself from default JSON service definitions available to CAS. See this guide for more info.