Avoid overwriting variable values with tokens in prepareModel (#960)

* Allow for unspecified or non-existent variables file

* JIRA WDT-572 - Added specific exception type for prepare model

* JIRA WDT-572 - Revised messages for prepareModel

* Add methods to check token-only strings

* Move check for secret overwriting a property value to credential injector

* Extract ModelPreparer class from prepare_model class to allow unit tests

* Extract ModelPreparer class from prepare_model class to allow unit tests

* Corrected test messages

* Maintain variable keys for removal in credential injector

* Added config directory for use with unit tests

* Removed unused logger

* Added a unit test for prepareModel

* Moved unit test to package, disabled logging during test

* Revised test to verify unchanged variable token

* Revised test to verify variable and secret files

* Cast os.environ arguments to str to avoid IDE analysis issue

* Create unit test base class; create config in output directory; check prepared variables and secrets

* Removed unused injector configuration files

* Correct argument count for ModelPreparer

* Clear unused properties after prepare and filter, rather than during prepare

* Support multiple variable tokens in a single value

* Changed method name and added description

* Allow variable argument list in match

* Use internal method to write properties to avoid comment and escaping, and to preserve order

* Correct variable name

Author: rakillen

core/src/main/java/oracle/weblogic/deploy/prepare/PrepareException.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates.
+ * Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl.
+ */
+package oracle.weblogic.deploy.prepare;
+
+import oracle.weblogic.deploy.exception.BundleAwareException;
+import oracle.weblogic.deploy.exception.ExceptionHelper;
+
+/**
+ * The exception used by the prepare model components.
+ */
+public class PrepareException extends BundleAwareException {
+    private static final long serialVersionUID = 1L;
+
+    /**
+     * Constructs a default exception.
+     */
+    public PrepareException() {
+        // default constructor
+    }
+
+    /**
+     * Constructs a new exception with the specified message id.
+     *
+     * @param messageID the message ID
+     */
+    public PrepareException(String messageID) {
+        super(messageID);
+    }
+
+    /**
+     * Constructs a new exception with the specified message id and parameters.
+     *
+     * @param messageID the message ID
+     * @param params    the parameters to use to fill in the message tokens
+     */
+    public PrepareException(String messageID, Object... params) {
+        super(messageID, params);
+    }
+
+    /**
+     * Constructs a new exception with the specified message id and cause.
+     *
+     * @param messageID the message ID
+     * @param cause     the exception that triggered the creation of this exception
+     */
+    public PrepareException(String messageID, Throwable cause) {
+        super(messageID, cause);
+    }
+
+    /**
+     * Constructs a new exception with passed message id, cause, and parameters.
+     *
+     * @param messageID the message ID
+     * @param cause     the exception that triggered the creation of this exception
+     * @param params    the parameters to use to fill in the message tokens
+     */
+    public PrepareException(String messageID, Throwable cause, Object... params) {
+        super(messageID, cause, params);
+    }
+
+    /**
+     * Constructs a new exception with the specified cause.
+     *
+     * @param cause the exception that triggered the creation of this exception
+     */
+    public PrepareException(Throwable cause) {
+        super(cause);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public String getBundleName() {
+        return ExceptionHelper.getResourceBundleName();
+    }
+}