docs: detailed docs with links

Author: csviri

core/src/main/java/io/javaoperatorsdk/jenvtest/KubeAPIServerConfigBuilder.java

@@ -6,7 +6,8 @@
 
 public final class KubeAPIServerConfigBuilder {
 
-  public static final String JENVTEST_DOWNLOAD_BINARIES = "JENVTEST_DOWNLOAD_BINARIES";
+  // environment variables
+  public static final String JENVTEST_DOWNLOAD_BINARIES = "JENVTEST_OFFLINE_MODE";
   public static final String JENVTEST_DIR_ENV_VAR = "JENVTEST_DIR";
   public static final String JENVTEST_API_SERVER_VERSION_ENV_VAR = "JENVTEST_API_SERVER_VERSION";
 

docs/README.md

@@ -1,17 +1,29 @@
+# User Documentation
 
+jenvtest is a relatively simple test that support integration testing with Kubernetes API Server.
+The whole concept and implementation is relatively simple, this doc describes some high level concepts
+and provides some more detailed information.
 
 ## Configuration Options
 
+See available configuration options documented in [KubeAPIServerConfig](https://github.com/java-operator-sdk/jenvtest/blob/main/core/src/main/java/io/javaoperatorsdk/jenvtest/KubeAPIServerConfig.java#L6-L6)
 
+Not all those properties can be overridden using [`@EnableKubeAPIServer`](https://github.com/java-operator-sdk/jenvtest/blob/main/core/src/main/java/io/javaoperatorsdk/jenvtest/junit/EnableKubeAPIServer.java)
+annotation, since might not make sense to do it for an individual test case. However, those can be passed to
+[`KubeApiServer`](https://github.com/java-operator-sdk/jenvtest/blob/main/core/src/main/java/io/javaoperatorsdk/jenvtest/junit/EnableKubeAPIServer.java)
+and also configured globally using environment variables, see [KubeAPIServerConfigBuilder](https://github.com/java-operator-sdk/jenvtest/blob/main/core/src/main/java/io/javaoperatorsdk/jenvtest/KubeAPIServerConfigBuilder.java)
 
+### Updating kube config file
 
+In general, it is not advised but if instructed kube config file (~/kube/config) is updated by the framework.
+See related property in [`@EnableKubeAPIServer`](https://github.com/java-operator-sdk/jenvtest/blob/main/core/src/main/java/io/javaoperatorsdk/jenvtest/junit/EnableKubeAPIServer.java#L27-L27)
+annotation. The config file is automatically cleaned up on stop.   
 
 ## How does it work
 
 In the background Kubernetes and etcd (and kubectl) binaries are downloaded if not found locally.
-
-All the certificates for the Kube API Server and for the client is generated. The client config file
-(`~/kube/config`) file is updated, to any client can be used to talk to the API Server.
+All the certificates for the Kube API Server and for the client is generated. 
+The client certificates are generated with group `system:masters`; 
 
 ## Downloading binaries
 
@@ -20,4 +32,4 @@ If there are multiple binaries found, the latest if selected (unless a target ve
 
 Also [`setup-envtest`](https://pkg.go.dev/sigs.k8s.io/controller-runtime/tools/setup-envtest#section-readme) can be used
 to download binaries manually. By executing `setup-envtest use --bin-dir ~/.jenvtest` will download the latest required
-binaries to the default directory. This is useful if always running the tests in offline mode.
+binaries to the default directory. This is useful if always running the tests in offline mode.