Add env var parameters to launch.script

Some of the features of the launch.script were not exposed for users
to be able to control at runtime. It now accepts things like
PID_FOLDER and LOG_FOLDER as environment variables, and also adopts
a clear naming convention where only the inputs are UPPER_CASE.

spring-boot-docs/src/main/asciidoc/deployment.adoc

@@ -321,13 +321,13 @@ or `systemd`.
 
 
 
-==== Installation as a init.d (system v) service
+==== Installation as a init.d (System V) service
 The default executable script that is embedded into Spring Boot executable jars will act
 as an `init.d` script when it is symlinked to `/etc/init.d`. The standard `start`, `stop`,
 `restart` and `status` commands can be used. The script supports the following features:
 
 * Starts the services as the user that owns the jar file
-* Tracks application PIDs using `/var/run/<appname>.pid`
+* Tracks application PIDs using `/var/run/<appname>/<appname>.pid`
 * Writes console logs to `/var/log/<appname>.log`
 
 Assuming that you have a Spring Boot application installed in `/var/myapp`, to install a
@@ -350,6 +350,33 @@ if you use Debian:
 	$ update-rc.d myapp defaults <priority>
 ----
 
+=== Running a JAR as a regular (not service) script
+
+The script accepts the following parameters as environment variables, so you can change the
+default behaviour in a script or on the command line:
+
+* `MODE` - the "mode" of operation. The default depends on the way the jar was built, but
+will usually be "auto" (meaning it tries to guess if it is an init script by checking if
+it is a symlink in a directory called "init.d"). You can explicitly set it to "service"
+so that the "stop|start|status|restart" commands work, or to "run" if you just want to
+run the script and not in the background.
+
+* `PID_FOLDER` - the root name of the pid folder (`/var/run` by default).
+
+* `LOG_FOLDER` - the name of the folder to put log files in (`/var/log` by default).
+
+* `APP_NAME` - the name of the app. If the jar is run from a symlink the script guesses the 
+app name, but if it is not a symlink, or you want to explicitly set the app name this can be
+useful.
+
+* `JAVA_HOME` - the location of the `java` executable is discovered by using the `PATH` by 
+default, but you can set it explicitly if there is an executable file at `$JAVA_HOME/bin/java`.
+
+* `JARFILE` - the explicit location of the jar file, in case the script is being used to launch
+a jar that it is not actually embedded in.
+
+* `DEBUG` - if not empty will set the `-x` flag on the shell process, making it easy to
+see the logic in the script.
 
 
 ==== Installation as a systemd service

spring-boot-tools/spring-boot-loader-tools/src/main/resources/org/springframework/boot/loader/tools/launch.script

@@ -9,20 +9,34 @@
 #   :: Spring Boot Startup Script ::
 #
 
+[[ -n "$DEBUG" ]] && set -x
+
 WORKING_DIR="$(pwd)"
-PID_FOLDER="/var/run"
-USER_PID_FOLDER="/tmp"
-LOG_FOLDER="/var/log"
-USER_LOG_FOLDER="/tmp"
+[[ -n "$JARFILE" ]] && jarfile="$JARFILE"
+[[ -n "$APP_NAME" ]] && identity="$APP_NAME"
+[[ -z "$PID_FOLDER" ]] && PID_FOLDER="/var/run"
+[[ -z "$LOG_FOLDER" ]] && LOG_FOLDER="/var/log"
+! [[ -x "$PID_FOLDER" ]] && PID_FOLDER="/tmp"
+! [[ -x "$LOG_FOLDER" ]] && LOG_FOLDER="/tmp"
 
 # Setup defaults
-[[ -z "$mode" ]] && mode="{{mode:auto}}" # modes are "auto", "service" or "run"
+[[ -z "$MODE" ]] && MODE="{{mode:auto}}" # modes are "auto", "service" or "run"
 
 # ANSI Colors
 echoRed() { echo $'\e[0;31m'$1$'\e[0m'; }
 echoGreen() { echo $'\e[0;32m'$1$'\e[0m'; }
 echoYellow() { echo $'\e[0;33m'$1$'\e[0m'; }
 
+# Utility functions
+checkPermissions() {
+  touch "$pid_file" &> /dev/null || { echoRed "Operation not permitted (cannot access pid file)"; exit 1; }
+  touch "$log_file" &> /dev/null || { echoRed "Operation not permitted (cannot access log file)"; exit 1; }
+}
+
+isRunning() {
+  ps -p $1 &> /dev/null
+}
+
 # Follow symlinks to find the real jar and detect init.d script
 cd $(dirname "$0")
 [[ -z "$jarfile" ]] && jarfile=$(pwd)/$(basename "$0")
@@ -36,36 +50,36 @@ cd "$WORKING_DIR"
 
 # Determine the script mode
 action="run"
-if [[ "$mode" == "auto" && -n "$init_script" ]] || [[ "$mode" == "service" ]]; then
+if [[ "$MODE" == "auto" && -n "$init_script" ]] || [[ "$MODE" == "service" ]]; then
   action="$1"
   shift
 fi
 
 # Create an identity for log/pid files
-if [[ -n "$init_script" ]]; then
-  identity="${init_script}"
-else
-  jar_folder=$(dirname "$jarfile")
-  identity=$(basename "${jarfile%.*}")_${jar_folder//\//}
+if [[ -z "$identity" ]]; then
+  if [[ -n "$init_script" ]]; then
+    identity="${init_script}"
+  else
+    jar_folder=$(dirname "$jarfile")
+    identity=$(basename "${jarfile%.*}")_${jar_folder//\//}
+  fi
 fi
 
 # Build the pid and log filenames
-if [[ -n "$init_script" ]]; then
-  pid_file="$PID_FOLDER/${identity}/${identity}.pid"
-  log_file="$LOG_FOLDER/${identity}.log"
-else
-  pid_file="$USER_PID_FOLDER/${identity}.pid"
-  log_file="$USER_LOG_FOLDER/${identity}.log"
+if [[ "$identity" == "$init_script" ]] || [[ "$identity" == "$APP_NAME" ]]; then
+  PID_FOLDER="$PID_FOLDER/${identity}"
 fi
+pid_file="$PID_FOLDER/${identity}.pid"
+log_file="$LOG_FOLDER/${identity}.log"
 
-# Determine the user to run as
+# Determine the user to run as if we are root
 [[ $(id -u) == "0" ]] && run_user=$(ls -ld "$jarfile" | awk '{print $3}')
 
 # Find Java
-if type -p java 2>&1> /dev/null; then
-    javaexe=java
-elif [[ -n "$JAVA_HOME" ]] && [[ -x "$JAVA_HOME/bin/java" ]]; then
+if [[ -n "$JAVA_HOME" ]] && [[ -x "$JAVA_HOME/bin/java" ]]; then
     javaexe="$JAVA_HOME/bin/java"
+elif type -p java 2>&1> /dev/null; then
+    javaexe=java
 elif [[ -x "/usr/bin/java" ]];  then
     javaexe="/usr/bin/java"
 else
@@ -76,16 +90,6 @@ fi
 # Build actual command to execute
 command="$javaexe -jar -Dsun.misc.URLClassPath.disableJarChecking=true $jarfile $@"
 
-# Utility functions
-checkPermissions() {
-  touch "$pid_file" &> /dev/null || { echoRed "Operation not permitted (cannot access pid file)"; exit 1; }
-  touch "$log_file" &> /dev/null || { echoRed "Operation not permitted (cannot access log file)"; exit 1; }
-}
-
-isRunning() {
-  ps -p $1 &> /dev/null
-}
-
 # Action functions
 start() {
   if [[ -f "$pid_file" ]]; then
@@ -94,9 +98,9 @@ start() {
   fi
   pushd $(dirname "$jarfile") > /dev/null
   if [[ -n "$run_user" ]]; then
-    mkdir "$PID_FOLDER/${identity}" &> /dev/null
+    mkdir "$PID_FOLDER" &> /dev/null
     checkPermissions
-    chown "$run_user" "$PID_FOLDER/${identity}"
+    chown "$run_user" "$PID_FOLDER"
     chown "$run_user" "$pid_file"
     chown "$run_user" "$log_file"
     su -c "$command &> \"$log_file\" & echo \$!" $run_user > "$pid_file"
@@ -115,6 +119,7 @@ start() {
 stop() {
   [[ -f $pid_file ]] || { echoRed "Not running (pidfile not found)"; exit 1; }
   pid=$(cat "$pid_file")
+  rm -f "$pid_file"
   isRunning $pid || { echoRed "Not running (process ${pid} not found)"; exit 1; }
   kill -HUP $pid &> /dev/null || { echoRed "Unable to kill process ${pid}"; exit 1; }
   for i in $(seq 1 20); do