diff --git a/Dockerfile b/Dockerfile
index 91a7641..360d90d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -19,7 +19,7 @@
 RUN mkdir -p /usr/share/jenkins/ref/init.groovy.d
 
 
-COPY init.groovy /usr/share/jenkins/ref/init.groovy.d/tcp-slave-angent-port.groovy
+COPY init.groovy /usr/share/jenkins/ref/init.groovy.d/tcp-slave-agent-port.groovy
 
 ENV JENKINS_VERSION 1.596.2
 
@@ -36,6 +36,9 @@
 # will be used by attached slave agents:
 EXPOSE 50000
 
+ENV COPY_REFERENCE_FILE_LOG /var/log/copy_reference_file.log
+RUN touch $COPY_REFERENCE_FILE_LOG && chown jenkins.jenkins $COPY_REFERENCE_FILE_LOG
+
 USER jenkins
 
 COPY jenkins.sh /usr/local/bin/jenkins.sh
diff --git a/README.md b/README.md
index 9d9a956..9846eab 100644
--- a/README.md
+++ b/README.md
@@ -98,8 +98,9 @@
 
 ```
 FROM jenkins
-COPY plugins /usr/share/jenkins/ref/plugins
+COPY plugins.txt /usr/share/jenkins/ref/
 COPY custom.groovy /usr/share/jenkins/ref/init.groovy.d/custom.groovy
+RUN /usr/local/bin/plugins.sh /usr/share/jenkins/ref/plugins.txt
 ```
 
 When jenkins container starts, it will check JENKINS_HOME has this reference content, and copy them there if required. It will not override such files, so if you upgraded some plugins from UI they won't be reverted on next start.
diff --git a/jenkins.sh b/jenkins.sh
index 1bd0f85..da0dd65 100755
--- a/jenkins.sh
+++ b/jenkins.sh
@@ -6,18 +6,19 @@
 # can then change this, upgrade plugins, etc.
 copy_reference_file() {
 	f=${1%/} 
-	echo "$f"
+	echo "$f" >> $COPY_REFERENCE_FILE_LOG
     rel=${f:23}
     dir=$(dirname ${f})
-    echo " $f -> $rel"    
+    echo " $f -> $rel" >> $COPY_REFERENCE_FILE_LOG
 	if [[ ! -e /var/jenkins_home/${rel} ]] 
 	then
-		echo "copy $rel to JENKINS_HOME"
+		echo "copy $rel to JENKINS_HOME" >> $COPY_REFERENCE_FILE_LOG
 		mkdir -p /var/jenkins_home/${dir:23}
 		cp -r /usr/share/jenkins/ref/${rel} /var/jenkins_home/${rel}; 
 	fi; 
 }
 export -f copy_reference_file
+echo "--- Copying files at $(date)" >> $COPY_REFERENCE_FILE_LOG
 find /usr/share/jenkins/ref/ -type f -exec bash -c 'copy_reference_file {}' \;
 
 # if `docker run` first argument start with `--` the user is passing jenkins launcher arguments