Model in Image is an alternative to the operator’s Domain in Image and Domain in PV domain types. See Choose a domain home source type for a comparison of operator domain types.
Unlike Domain in PV and Domain in Image, Model in Image eliminates the need to pre-create your WebLogic domain home prior to deploying your Domain YAML file.
This feature is supported for standard WLS domains, Restricted JRF domains, and JRF domains.
For JRF domains, Model in Image provides additional support for initializing the infrastructure database for a domain when a domain is started for the first time, supplying an database password, and obtaining an database wallet for re-use in subsequent restarts of the same domain. See Requirements for JRF domain types.
WDT models are a convenient and simple alternative to WebLogic Scripting Tool (WLST) configuration scripts and templates. They compactly define a WebLogic domain using YAML files and support including application archives in a ZIP file. For a description of the model format and its integration with Model in Image, see Usage and Model files. The WDT model format is fully described in the open source, WebLogic Deploy Tool GitHub project.
When you deploy a Model in Image domain resource YAML file:
The operator will run a Kubernetes Job called the ‘introspector job’ that:
After the introspector job completes:
DOMAIN_UID-weblogic-domain-introspect-cm(possibly with some additional maps distinguished by serial names) and puts the packaged domain home in it.
Model updates can be applied at runtime by changing an image, secrets, a domain resource, or a WDT model ConfigMap after initial deployment.
Some updates may be applied to a running domain without requiring any WebLogic pod restarts (an online update), but others may require rolling the pods to propagate the update’s changes (an offline update), and still others may require shutting down the entire domain before applying the update (a full domain restart update). It is the administrator’s responsibility to make the necessary changes to a domain resource to initiate the correct type of update.
See Runtime updates.
To understand how Model in Image works with CI/CD, see CI/CD considerations.