Docs updates: fix github links, microprofile version, SE upgrade guide

docs/includes/attributes.adoc

@@ -27,7 +27,7 @@ ifndef::attributes-included[]
 :helidon-version-is-release: false
 
 ifeval::["{helidon-version-is-release}" != "true"]
-:helidon-github-tree-url: https://github.com/oracle/helidon/tree/master
+:helidon-github-tree-url: https://github.com/oracle/helidon/tree/main
 endif::[]
 
 ifeval::["{helidon-version-is-release}" == "true"]
@@ -37,7 +37,7 @@ endif::[]
 // versions
 :version-plugin-helidon: 3.0.5
 
-:version-lib-microprofile-api: 5.0
+:version-lib-microprofile-api: 6.0
 
 // microprofile specifications
 :version-lib-microprofile-lra-api: 2.0

docs/includes/security/providers/http-basic-auth.adoc

@@ -42,7 +42,7 @@ include::{rootdir}/config/io_helidon_security_providers_httpauth_HttpBasicAuthPr
 
 ==== Example code
 
-See the link:{helidon-github-tree-url}/master/examples/security/outbound-override[example] on GitHub.
+See the link:{helidon-github-tree-url}/examples/security/outbound-override[example] on GitHub.
 
 [source,yaml]
 .Configuration example

docs/includes/security/providers/http-signatures.adoc

@@ -43,7 +43,7 @@ include::{rootdir}/config/io_helidon_security_providers_httpsign_HttpSignProvide
 
 ==== Example code
 
-See the link:{helidon-github-tree-url}/master/examples/security/webserver-signatures[example] on GitHub.
+See the link:{helidon-github-tree-url}/examples/security/webserver-signatures[example] on GitHub.
 
 [source,yaml]
 .Configuration example

docs/includes/security/providers/provider-template.adoc

@@ -48,7 +48,7 @@ provider-config-key
 ----
 
 ==== Example code
-See the link:{helidon-github-tree-url}/master/examples/security/[example] on GitHub.
+See the link:{helidon-github-tree-url}/examples/security/[example] on GitHub.
 
 [source,yaml]
 .Configuration example

docs/mp/graphql.adoc

@@ -169,7 +169,7 @@ additional information on how to change the location of these resources.
 
 If you wish to use the
 link:https://github.com/graphql/graphiql[GraphQL UI] then please see the
-link:{helidon-github-tree-url}/master/examples/microprofile/graphql[GraphQL MP Example].
+link:{helidon-github-tree-url}/examples/microprofile/graphql[GraphQL MP Example].
 
 == Configuration
 
@@ -191,7 +191,7 @@ include::{rootdir}/includes/graphql.adoc[]
 == Examples
 
 For a complete example, see
-link:{helidon-github-tree-url}/master/examples/microprofile/graphql[GraphQL MP Example].
+link:{helidon-github-tree-url}/examples/microprofile/graphql[GraphQL MP Example].
 
 == Additional Information
 

docs/se/guides/upgrade_4x.adoc

@@ -21,14 +21,16 @@
 :keywords: helidon, porting, migration, upgrade, incompatibilities
 :rootdir: {docdir}/../..
 
+include::{rootdir}/includes/attributes.adoc[]
+
 In Helidon 4.x we have made some major changes to Helidon. Reactive engine has been removed. APIS and implementations are rewritten in "blocking" paradigm. This guide will help you upgrade a Helidon MP 3.x application to 4.x.
 
 
 == Java 21 Runtime
 
 Java 17 is no longer supported in Helidon 4. Java 21 or newer is required. Please follow the instructions in xref:{rootdir}/about/prerequisites.adoc[Prerequisites] for proper installation.
 
-Helidon 4 no more uses Netty. Helidon SE is now running on Helidon WebServer which is based on Virtual threads technology, available in Java 21.
+Helidon 4 no longer uses Netty. Helidon SE is now running on Helidon WebServer which is based on virtual threads technology, available in Java 21.
 
 
 == Programming paradigm
@@ -37,7 +39,7 @@ Helidon SE has changed from an asynchronous style API to an imperative/blocking
 
 == Server Initialization and Start Up
 
-In Helidon 1.x-3.x to star a server, the following actions should be done:
+In Helidon 1.x-3.x you started a server like this:
 
 [source, java]
 .Start Helidon SE 3.x Server
@@ -71,7 +73,7 @@ static Single<WebServer> startServer() {
 
 Since Helidon SE in 3.x was reactive, during the start a `Single` object is returned, the server has been started in asynchronous way. We have to use reactive methods like `thenAccept` to wait for the server to start and then to perform the desired action. The exception handling should also be done in reactive way using the corresponding method.
 
-In Helidon 4.x there are no more Reactive APIs, so the Server startup is much simpler:
+In Helidon 4.x asynchronous programming is no longer required so the server startup is much simpler:
 
 [source, java]
 .Start Helidon SE 4.x Server
@@ -96,6 +98,19 @@ public static void main(String[] args) {
 
 Just create it, configure it, and wait for it to start. If any exceptions happen, they are handled the traditional way using available language constructions.
 
+== Server Features and Media Support Discovery
+
+In previous versions of Helidon you had to explicitly register WebServer features (`register(MetricsSupport.create())`) and
+explicitly add media support (`addMediaSupport(JsonpSupport.create())`). In Helidon 4 the default behavior is
+to automatically discover these components from the classpath. So all you need to do is add the
+dependencies to your pom.xml and optionally add configuration to customize them.
+
+If you want full control using the API, you still have that option.
+
+For more information see:
+
+* xref:../observability.adoc[Observability feature support]
+* xref:../webserver.adoc#_media_types_support[Media types support]
 
 == Routing Configuration
 
@@ -133,16 +148,15 @@ In Helidon 4, the routing is configured the following way:
 .Start Helidon SE 4.x Server
 ----
 static void routing(HttpRouting.Builder routing) {
-    Config config = Config.global();
-
-    routing.register("/greet", new GreetService())  <1>
-            .addFeature(OpenApiFeature.create(config.get("openapi")))   <2>
-            .addFeature(ObserveFeature.create(config.get("observe")));
+    routing.register("/greet", new GreetService());  <1>
 }
 ----
 <1> Register Greeting service as in previous versions of Helidon.
-<2> Add `Feature` for Observability and OpenAPI.
 
+As described previously, the Metrics and Health features will be discovered automatically as long as you have
+added the dependencies for them to your project.
+
+If you wanteded to add these features to the server programatically you would do so using `WebServer.builder().addFeature()` method.
 
 `Feature` encapsulates a set of endpoints, services and/or filters. It is similar to `HttpService` but gives more freedom in setup. Main difference is that a feature can add `Filters` and it cannot be registered on a path. Features are not registered immediately—each feature can define a `Weight` or implement `Weighted` to order features according to their weight. Higher-weighted features are registered first. This is to allow ordering of features in a meaningful way (e.g. Context should be first, Tracing second, Security third etc.).
 
@@ -204,11 +218,41 @@ public class GreetService implements HttpService {  <1>
 
 Helidon 4 introduced `HttpService` that should be implemented in order to process HTTP requests. To set up routing, the method `routing(HttpRules rules)` should now be used. It receives `HttpRules` object with routes description.
 
+`ServerRequest` and `ServerResponse` are now in the `io.helidon.webserver.http` package;
+
+`Http.Status` is now `io.helidon.http.Status`
+
 WARNING: These changes make Helidon 4 incompatible with previous versions.
 
 Learn more about `HttpService` and `Routing` at xref:../webserver.adoc[Helidon SE WebServer]
 
-=== Significant Changes
+=== Other Significant Changes
+
+==== Media Support
+
+Media support has moved from the `io.helidon.media` Java package to `io.helidon.http.media` and has new dependency coordinates. For example:
+
+[source, xml]
+----
+<dependency>
+    <groupId>io.helidon.http.media</groupId>
+    <artifactId>helidon-http-media-jsonp</artifactId>
+</dependency>
+----
+
+In Helidon 4 media support is discovered by default, so you simple need to add the dependency.
+You no longer need to explicitly add media support using the `WebServer` builder.
+
+Media support no long transitively brings the Jakarta API dependencies. So you might need to add these explicitly. For example:
+
+[source, xml]
+----
+<dependency>
+    <groupId>jakarta.json</groupId>
+    <artifactId>jakarta.json-api</artifactId>
+</dependency>
+----
+
 
 ==== Testing
 
@@ -253,6 +297,19 @@ For System Metrics, please use:
 </dependency>
 ----
 
+By default Observability features are discovered automatically if you add the above dependencies.
+If you choose to add them programmatically (using `addFeature`) you will need to add the following dependency:
+
+[source, xml]
+----
+<dependency>
+    <groupId>io.helidon.webserver.observe</groupId>
+    <artifactId>helidon-webserver-observe</artifactId>
+</dependency>
+----
+
+Metrics has changed significantly in Helidon 4. See xref:../metrics/metrics.adoc[Helidon SE Metrics] for more information.
+
 ==== Security
 
 * Changed modules:
@@ -272,15 +329,41 @@ For System Metrics, please use:
 
 The global configuration represents a single instance of the `Config` class, which is implicitly employed by certain Helidon components. Furthermore, it offers a handy approach for your application to access configuration information from any part of your code.
 
-You can utilize the global configuration for easy retrieval of your application's configuration:
+It is recommended that you explicitly initialize global configuration before using any Helidon components:
+
+```
+Config config = Config.create();  // Uses default config sources
+Config.global(config);
+```
+
+You can then utilize the global configuration for easy retrieval of your application's configuration:
 
 ```
 Config config = Config.global();
 ```
 
 More information at xref:../config/introduction.adoc[Helidon SE Config].
 
+=== Logging
+
+The class `LogConfig` has moved to the `io.helidon.logging.common` Java package.
+
+The Helidon console handler has changed from `io.helidon.common.HelidonConsoleHandler` to `io.helidon.logging.jul.HelidonConsoleHandler`.
+
+If you use this handler in your `logging.properties` you will need to update it and add the following dependency:
+
+[source, xml]
+----
+<dependency>
+    <groupId>io.helidon.logging</groupId>
+    <artifactId>helidon-logging-jul</artifactId>
+    <scope>runtime</scope>
+</dependency>
+----
 
 == Conclusion
 
 Please proceed to xref:../introduction.adoc[Helidon SE Introduction] to find more information and documentation about each module.
+
+Also, the
+link:{helidon-github-tree-url}/examples/[Helidon examples] are a good resource for seeing how things are done in Helidon 4.

docs/se/observability.adoc

@@ -16,7 +16,7 @@
 
 ///////////////////////////////////////////////////////////////////////////////
 
-= Tracing
+= Observability
 :description: Helidon SE Observability
 :feature-name: Helidon Observability
 :keywords: helidon, observability