The dependency tree is built when a gateway’s resources are imported into AAGM. There are three kinds of dependencies in AAGM (while there are only two in the gateway itself).

Regular Dependencies

Regular dependencies are so most basic form of a dependency. One resource requires another resource to be present to work correctly. This might be a service referencing a JDBC connection, a policy fragment or a certificate.

Dynamic Dependencies

Dynamic dependencies are resolved during runtime. Instead of referencing the dependency directly a cluster property is referenced that holds the name of the dependency. This way it is possible for library authors to write policies that can be configured in the customer’s environment.

It is possible to reference either cluster properties (${gateway.NAME}) or varaibles within the policy itself (${NAME}).

Missing Dependencies

Missing dependencies are either regular or dynamic ones. The target of the dependency is not available at the gateway. While migrating a service or policy with a missing dependency might work, running it however will fail during runtime.