3.x example removal (#8437)

Delete examples from Helidon 3
Update the examples top level README to direct users to helidon-examples
Update the examples profile to include a module called helidon-examples (instead of examples)
Add a build-examples script that clones the helidon-examples repository into the helidon-examples directory (if it doesn't already exist) and builds the examples.

.github/workflows/validate.yaml

@@ -136,8 +136,7 @@ jobs:
       - name: Maven build
         run: |
           mvn -B -e "-Dmaven.test.skip=true" $MAVEN_HTTP_ARGS -DskipTests -Ppipeline install 
-          cd examples
-          mvn -B verify
+          echo "TBD: validate examples from external repository"
   archetypes:
     timeout-minutes: 30
     strategy:

.gitignore

@@ -68,6 +68,9 @@ node/
 # Helidon CLI
 .helidon
 
+# Helidon examples repository
+helidon-examples
+
 # Other
 *~
 user.txt

etc/scripts/build-examples.sh

@@ -0,0 +1,44 @@
+#!/bin/bash -e
+#
+# Copyright (c) 2024 Oracle and/or its affiliates.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Build helidon examples, cloning the examples repository if needed
+
+# Path to this script
+[ -h "${0}" ] && readonly SCRIPT_PATH="$(readlink "${0}")" || readonly SCRIPT_PATH="${0}"
+
+# Load pipeline environment setup and define WS_DIR
+. $(dirname -- "${SCRIPT_PATH}")/includes/pipeline-env.sh "${SCRIPT_PATH}" '../..'
+
+# Setup error handling using default settings (defined in includes/error_handlers.sh)
+error_trap_setup
+
+# If needed we clone the helidon-examples repo into a subdirectory of the helidon repository
+readonly HELIDON_EXAMPLES_PATH=${WS_DIR}/helidon-examples
+if [ ! -d "${HELIDON_EXAMPLES_PATH}" ]; then
+  echo "Cloning examples repository into ${HELIDON_EXAMPLES_PATH}"
+  git clone --branch dev-3.x --single-branch [email protected]:helidon-io/helidon-examples.git "${HELIDON_EXAMPLES_PATH}"
+fi
+
+# Make sure the helidon version from the example repo aligns with this repository
+readonly HELIDON_VERSION_IN_THIS_REPO=$(mvn --non-recursive -f ${WS_DIR}/pom.xml help:evaluate -Dexpression=helidon.version | grep -v '\[INFO\]')
+readonly HELIDON_VERSION_IN_EXAMPLES=$(mvn --non-recursive -f ${HELIDON_EXAMPLES_PATH}/pom.xml help:evaluate -Dexpression=helidon.version | grep -v '\[INFO\]')
+if [ ${HELIDON_VERSION_IN_THIS_REPO} != ${HELIDON_VERSION_IN_EXAMPLES} ]; then
+  echo "The Helidon version in this repository (${HELIDON_VERSION_IN_THIS_REPO}) does not match the Helidon version in ${HELIDON_EXAMPLES_PATH} (${HELIDON_VERSION_IN_EXAMPLES})"
+  exit 78
+fi
+
+mvn ${MAVEN_ARGS} -f ${HELIDON_EXAMPLES_PATH}/pom.xml clean install

etc/scripts/checkstyle.sh

@@ -1,6 +1,6 @@
 #!/bin/bash -e
 #
-# Copyright (c) 2018, 2022 Oracle and/or its affiliates.
+# Copyright (c) 2018, 2024 Oracle and/or its affiliates.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -34,7 +34,7 @@ mvn ${MAVEN_ARGS} checkstyle:checkstyle-aggregate \
     -f ${WS_DIR}/pom.xml \
     -Dcheckstyle.output.format="plain" \
     -Dcheckstyle.output.file="${RESULT_FILE}" \
-    -Pexamples,ossrh-releases > ${LOG_FILE} 2>&1 || (cat ${LOG_FILE} ; exit 1)
+    -Possrh-releases > ${LOG_FILE} 2>&1 || (cat ${LOG_FILE} ; exit 1)
 
 grep "^\[ERROR\]" ${RESULT_FILE} \
     && die "CHECKSTYLE ERROR" || echo "CHECKSTYLE OK"

examples/README.md

@@ -4,42 +4,5 @@
 
 # Helidon Examples
 
-Welcome to the Helidon Examples! If this is your first experience with
-Helidon we recommend you start with our
-[quickstart](https://helidon.io/docs/v2/#/about/03_prerequisites)
-That will quickly get you going with your first Helidon application.
+Helidon 3 examples have been moved to the [helidon-examples](https://github.com/helidon-io/helidon-examples/tree/helidon-3.x) repository.
 
-After that you can come back here and dig into the examples. To access
-these examples we recommend checking out from a released tag. For example:
-
-```
-git clone [email protected]:oracle/helidon.git
-cd helidon
-git checkout tags/2.0.0
-```
-
-Our examples are Maven projects and can be built and run with
-Java 11 or newer -- so make sure you have those:
-
-```
-java -version
-mvn -version
-```
-
-# Building an Example
-
-Each example has a `README` that you will follow. To build most examples
-just `cd` to the directory and run `mvn package`:
-
-```
-cd examples/microprofile/hello-world-explicit
-mvn package
-```
-
-Usually the example will produce an application jar file that you can run:
-
-```
-java -jar target/example-name.jar
-```
-
-But always see the example's `README` for details.