JSON Service Registry

This registry reads services definitions from JSON configuration files at the application context initialization time. JSON files are expected to be found inside a configured directory location and this registry will recursively look through the directory structure to find relevant JSON files.

Support is enabled by adding the following module into the overlay:

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<dependency>
  <groupId>org.apereo.cas</groupId>
  <artifactId>cas-server-support-json-service-registry</artifactId>
  <version>${cas.version}</version>
</dependency>
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implementation "org.apereo.cas:cas-server-support-json-service-registry:${project.'cas.version'}"
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dependencyManagement {
  imports {
    mavenBom "org.apereo.cas:cas-server-support-bom:${project.'cas.version'}"
  }
}

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

A sample JSON file follows:

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{
  "@class" : "org.apereo.cas.services.RegexRegisteredService",
  "serviceId" : "testId",
  "name" : "testJsonFile",
  "id" : 103935657744185,
  "evaluationOrder" : 10
}

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.

  • cas.service-registry.json.location=
  • The location of the resource. Resources can be URLS, or files found either on the classpath or outside somewhere in the file system.

    org.apereo.cas.configuration.model.support.services.json.JsonServiceRegistryProperties.

    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.

  • cas.service-registry.json.watcher-enabled=true
  • Flag indicating whether a background watcher thread is enabled for the purposes of live reloading of service registry data changes from persistent data store.

    org.apereo.cas.configuration.model.support.services.json.JsonServiceRegistryProperties.

    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. When possible, properties should be stored in lower-case kebab format, such as cas.property-name=value.S ettings 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, specially if defined CAS settings cannot be recognized or validated by the configuration schema. The validation process is on by default and can be skipped on startup using a special system property SKIP_CONFIG_VALIDATION that should be set to true. 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.

    Clustering Services

    You MUST consider that if your CAS server deployment is clustered, each CAS node in the cluster must have access to the same set of JSON configuration files as the other, or you may have to devise a strategy to keep changes synchronized from one node to the next.

    The JSON service registry is also able to auto detect changes to the specified directory. It will monitor changes to recognize file additions, removals and updates and will auto-refresh CAS so changes do happen instantly.

    Escaping Characters

    Please make sure all field values in the JSON blob are correctly escaped, specially for the service id. If the service is defined as a regular expression, certain regex constructs such as "." and "\d" need to be doubly escaped.

    The naming convention for new JSON files is recommended to be the following:

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    JSON fileName = serviceName + "-" + serviceNumericId + ".json"
    

    Based on the above formula, for example the above JSON snippet shall be named: testJsonFile-103935657744185.json. Remember that because files are created based on the serviceName, you will need to make sure characters considered invalid for file names are not used as part of the name. Furthermore, note that CAS MUST be given full read/write permissions on directory which contains service definition files.

    Duplicate Services

    As you add more files to the directory, you need to be absolutely sure that no two service definitions will have the same id. If this happens, loading one definition will stop loading the other. While service ids can be chosen arbitrarily, make sure all service numeric identifiers are unique. CAS will also output warnings if duplicate data is found.

    JSON Syntax

    CAS uses a version of the JSON syntax that provides a much more relaxed syntax with the ability to specify comments.

    A given JSON file for instance could be formatted as such in CAS:

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    {
      /*
        Generic service definition that applies to https/imaps urls
        that wish to register with CAS for authentication.
      */
      "@class" : "org.apereo.cas.services.RegexRegisteredService",
      "serviceId" : "^(https|imaps)://.*",
      "name" : "HTTPS and IMAPS",
      "id" : 10000001,
    }
    

    Note the trailing comma at the end. See the above link for more info on the alternative syntax.

    Replication

    If CAS is deployed in a cluster, the service definition files must be kept in sync for all CAS nodes. Please review this guide to learn more about available options.

    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.