Allow LOG_FOLDER and PID_FOLDER defaults to be set at build time

This commit enhances the default launch script to allow the default
values for LOG_FOLDER and PID_FOLDER to be set at build time. They
can now be set using the logFolder and pidFolder properties
respectively.

Closes gh-4787

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

@@ -629,6 +629,12 @@ for Gradle and to `${project.name}` for Maven.
 |`initInfoChkconfig`
 |The `chkconfig` section of "`INIT INFO`". Defaults to `2345 99 01`.
 
+|`logFolder`
+|The default value for `LOG_FOLDER`. Only valid for an `init.d` service.
+
+|`pidFolder`
+|The default value for `PID_FOLDER`. Only valid for an `init.d` service.
+
 |`useStartStopDaemon`
 |If the `start-stop-daemon` command, when it's available, should be used to control the
  process. Defaults to `true`.

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

@@ -46,8 +46,8 @@ configfile="$(basename "${jarfile%.*}.conf")"
 [[ -r "${jarfolder}/${configfile}" ]] && source "${jarfolder}/${configfile}"
 
 # Initialize PID/LOG locations if they weren't provided by the config file
-[[ -z "$PID_FOLDER" ]] && PID_FOLDER="/var/run"
-[[ -z "$LOG_FOLDER" ]] && LOG_FOLDER="/var/log"
+[[ -z "$PID_FOLDER" ]] && PID_FOLDER="{{pidFolder:/var/run}}"
+[[ -z "$LOG_FOLDER" ]] && LOG_FOLDER="{{logFolder:/var/log}}"
 ! [[ -x "$PID_FOLDER" ]] && PID_FOLDER="/tmp"
 ! [[ -x "$LOG_FOLDER" ]] && LOG_FOLDER="/tmp"
 

spring-boot-tools/spring-boot-loader-tools/src/test/java/org/springframework/boot/loader/tools/DefaultLaunchScriptTests.java

@@ -76,6 +76,16 @@ public class DefaultLaunchScriptTests {
 		assertThatPlaceholderCanBeReplaced("useStartStopDaemon");
 	}
 
+	@Test
+	public void logFolderCanBeReplaced() throws Exception {
+		assertThatPlaceholderCanBeReplaced("logFolder");
+	}
+
+	@Test
+	public void pidFolderCanBeReplaced() throws Exception {
+		assertThatPlaceholderCanBeReplaced("pidFolder");
+	}
+
 	@Test
 	public void defaultForUseStartStopDaemonIsTrue() throws Exception {
 		DefaultLaunchScript script = new DefaultLaunchScript(null, null);