Improve handling of JDK 8 install for container-features (#1066)

Author: Chuxel

script-library/container-features/src/features.json

@@ -188,7 +188,7 @@
 			"type": "option",
 			"default": false,
 			"init": true,
-			"buildArg": "_VSC_INSTALL_GIT",			
+			"buildArg": "_VSC_INSTALL_GIT",
 			"include": [
 				"azure-cli",
 				"cpp",
@@ -605,7 +605,8 @@
 				"PATH": "${SDKMAN_DIR}/bin:${SDKMAN_DIR}/candidates/java/current/bin:${PATH}"
 			},
 			"settings": {
-				"java.home": "/usr/local/sdkman/candidates/java/current"
+				"java.home": "/extension-java-home",
+				"java.import.gradle.java.home": "/usr/local/sdkman/candidates/java/current"
 			},
 			"include": [
 				"azure-cli",

script-library/container-features/src/java-wrapper.sh

@@ -9,9 +9,41 @@ USERNAME=${3:-"automatic"}
 UPDATE_RC=${4:-"true"}
 ADDITIONAL_JAVA_VERSION=11
 
-/tmp/build-features/java-debian.sh "${JAVA_VERSION}" "${SDKMAN_DIR}" "${USERNAME}" "${UPDATE_RC}"
-
-# If the user selected JDK 8, install the JDK 11 as well
+is_jdk_8="false"
 if echo "${JAVA_VERSION}" | grep -E '^8([\s\.]|$)' > /dev/null 2>&1; then
+    is_jdk_8="true"
+fi
+
+# If the user selected JDK 8, install the JDK 11 as well since this is needed by the Java extension
+if [ "${is_jdk_8}" = "true" ]; then
+    echo "(*) Installing JDK ${ADDITIONAL_JAVA_VERSION} as Java VS Code extension requires a recent JDK..."
     /tmp/build-features/java-debian.sh "${ADDITIONAL_JAVA_VERSION}" "${SDKMAN_DIR}" "${USERNAME}" "${UPDATE_RC}"
+    jdk_11_folder="$(ls --format=single-column ${SDKMAN_DIR}/candidates/java | grep -oE -m 1 '11\..+')"
+    ln -s "${SDKMAN_DIR}/candidates/java/${jdk_11_folder}" /extension-java-home
+
+    # Determine the appropriate non-root user
+    username=""
+    possible_users=("vscode" "node" "codespace" "$(awk -v val=1000 -F ":" '$3==val{print $1}' /etc/passwd)")
+    for current_user in ${possible_users[@]}; do
+        if id -u ${current_user} > /dev/null 2>&1; then
+            username=${current_user}
+            break
+        fi
+    done
+    if [ "${username}" = "" ]; then
+        username=root
+    fi
+else
+    ln -s ${SDKMAN_DIR}/candidates/java/current /extension-java-home
 fi
+
+echo "(*) Installing JDK ${JAVA_VERSION}..."
+/tmp/build-features/java-debian.sh "${JAVA_VERSION}" "${SDKMAN_DIR}" "${USERNAME}" "${UPDATE_RC}"
+if [ "${is_jdk_8}" = "true" ]; then
+    # Set current and default version to last SDK installed
+    jdk_full_version="$(ls --format=single-column "${SDKMAN_DIR}/candidates/java" | sort -rV | grep -oE -m 1 "${JAVA_VERSION}\\..+" )"
+    echo "(*) Setting default JDK to ${jdk_full_version}..."
+    . ${SDKMAN_DIR}/bin/sdkman-init.sh 
+    sdk use java "${jdk_full_version}"
+    sdk default java "${jdk_full_version}"
+fi