Protect against symlink attacks

Update embedded launch script to no longer change ownership of files
or folders that already exist.

Fixes gh-11397

spring-boot-integration-tests/spring-boot-launch-script-tests/src/test/resources/scripts/log-file-ownership.sh

@@ -0,0 +1,20 @@
+source ./test-functions.sh
+install_service
+
+chmod o+w /var/log
+
+useradd phil
+mkdir /phil-files
+chown phil /phil-files
+
+useradd andy
+chown andy /test-service/spring-boot-app.jar
+
+start_service
+stop_service
+
+su - andy -c "ln -s -f /phil-files /var/log/spring-boot-app.log"
+
+start_service
+
+ls -ld /phil-files

spring-boot-integration-tests/spring-boot-launch-script-tests/src/test/resources/scripts/pid-file-ownership.sh

@@ -0,0 +1,18 @@
+source ./test-functions.sh
+install_service
+
+useradd phil
+mkdir /phil-files
+chown phil /phil-files
+
+useradd andy
+chown andy /test-service/spring-boot-app.jar
+
+start_service
+stop_service
+
+su - andy -c "ln -s /phil-files /var/run/spring-boot-app/spring-boot-app.pid"
+
+start_service
+
+ls -ld /phil-files

spring-boot-integration-tests/spring-boot-launch-script-tests/src/test/resources/scripts/pid-folder-ownership.sh

@@ -0,0 +1,17 @@
+source ./test-functions.sh
+install_service
+
+chmod o+w /var/run
+
+useradd phil
+mkdir /phil-files
+chown phil /phil-files
+
+useradd andy
+chown andy /test-service/spring-boot-app.jar
+
+su - andy -c "ln -s -f /phil-files /var/run/spring-boot-app"
+
+start_service
+
+ls -ld /phil-files