update vsftpd

vsftpd/Dockerfile

@@ -5,9 +5,21 @@
 FROM alpine
 MAINTAINER kev <noreply@datageek.info>
 
-RUN apk add -U vsftpd \
-    && rm -rf /var/cache/apk/* \
-    && echo "seccomp_sandbox=NO" >> /etc/vsftpd/vsftpd.conf
+RUN set -xe \
+    && apk add -U vsftpd \
+    && rm -rf /var/cache/apk/*
+
+RUN { \
+        echo "ftpd_banner=Welcome to VSFTPD service."; \
+        echo "write_enable=YES"; \
+        echo "local_enable=YES"; \
+        echo "chroot_local_user=YES"; \
+        echo "allow_writeable_chroot=YES"; \
+        echo "seccomp_sandbox=NO"; \
+    } >> /etc/vsftpd/vsftpd.conf
+
+VOLUME /var/lib/ftp
+WORKDIR /var/lib/ftp
 
 EXPOSE 21