diff --git a/Dockerfile b/Dockerfile
index ab583f3..28be26c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,14 @@
 FROM alpine:latest
 
 RUN  \
-    apk -U add proftpd proftpd-mod_tls proftpd-mod_ifsession proftpd-utils openssl perl acme.sh && \
+    apk -U add proftpd proftpd-mod_tls proftpd-mod_ifsession \
+      proftpd-mod_deflate proftpd-mod_geoip proftpd-mod_sql_sqlite \
+      proftpd-utils openssl perl acme.sh lftp sqlite && \
     mkdir -p /var/run/proftpd /etc/proftpd/custom.conf.d/
 
 COPY rootfs /
 
+HEALTHCHECK  --interval=2m --timeout=3s \
+  CMD /app/healthcheck.sh || exit 1
+
 ENTRYPOINT ["/app/entrypoint.sh"]
diff --git a/README.md b/README.md
index 3501f63..86e4e50 100644
--- a/README.md
+++ b/README.md
@@ -144,3 +144,55 @@ docker exec -ti my-ftps ftpasswd --passwd --name=paolo --uid=1000 --home=/home/p
 ```
 
 You also have to create and chown the user's home folder.
+
+## sql db for user authentication
+
+It is possible to use a sqlite db for user authentication, just add `SQLITE_AUTH=1` to the environment:
+
+```yaml
+version: "3"
+services:
+  ftps-server:
+    image: docker.asperti.com/paspo/ftps
+    restart: always
+    ports:
+      - "21:21"
+      - "20:20"
+      - "21210-21220:21210-21220"
+    volumes:
+      - "/srv/ftps/auth:/auth"
+      - "/srv/ftps/conf:/etc/proftpd/custom.conf.d:ro"
+      - "/srv/ftps/data:/home"
+      - "/etc/letsencrypt:/certs:ro"
+    environment:
+      - SQLITE_AUTH=1
+      - MASQUERADE=ftp.mydomain.com
+      - PASSIVEPORTS_START=21210
+      - PASSIVEPORTS_END=21220
+      - MAXCLIENTS=500
+      - MAXCLIENTSPERHOST=100
+      - TLS_CERT=/certs/live/ftp.mydomain.com/cert.pem
+      - TLS_KEY=/certs/live/ftp.mydomain.com/privkey.pem
+      - TLS_CHAIN=/certs/live/ftp.mydomain.com/chain.pem
+```
+
+Now, instead of using `/auth/passwd`, proftpd is using `/auth/ftpd.db`.
+To create a new user, you must now update this db.
+
+To create a new user:
+
+```bash
+docker exec -ti my-ftps sqlite3 sqlite3 /auth/ftpd.db <<EOF
+INSERT OR IGNORE INTO users (userid,passwd,uid,gid,homedir,shell) VALUES ('new_user','',1000,1000,'/home/new_user','/bin/false');
+INSERT OR IGNORE INTO groups (groupname,gid,members) VALUES ('new_user',1000,'new_user');
+EOF
+```
+
+To update a password:
+
+```bash
+PASSWD_SHA=$(echo -n ChangeThisPass | mkpasswd -m sha512)
+docker exec -ti my-ftps sqlite3 sqlite3 /auth/ftpd.db <<EOF
+UPDATE users SET passwd='$PASSWD_SHA' WHERE userid='new_user';
+EOF
+```
diff --git a/rootfs/app/entrypoint.sh b/rootfs/app/entrypoint.sh
index d32ac7a..fef740f 100755
--- a/rootfs/app/entrypoint.sh
+++ b/rootfs/app/entrypoint.sh
@@ -29,6 +29,42 @@ else
   /app/cert-init.sh
 fi
 
+############ INIT DB if needed
+SQLITE_AUTH=${SQLITE_AUTH:-no}
+if [ "$SQLITE_AUTH" = "1" ] ; then
+  if [ ! -f /auth/ftpd.db ] ; then
+    sqlite3 /auth/ftpd.db < /app/init.sql
+  fi
+fi
+
+############ GENERATE RANDOM PASSWORD FOR HEALTHCHECK
+head /dev/urandom | tr -dc A-Za-z0-9 | head -c 20  > /app/healthcheck.pwd
+chmod 600 /app/healthcheck.pwd
+
+############ UPDATE HEALTHCHECK CREDS
+HEALTHCHECK_UID=1999
+mkdir -p /home/healthcheck
+chown ${HEALTHCHECK_UID}:${HEALTHCHECK_UID} /home/healthcheck
+if [ "$SQLITE_AUTH" = "1" ] ; then
+  PASSWD_SHA=$(cat /app/healthcheck.pwd | mkpasswd -m sha512)
+  sqlite3 /auth/ftpd.db <<EOF
+INSERT OR IGNORE INTO users (userid,passwd,uid,gid,homedir,shell) VALUES ('healthcheck','',${HEALTHCHECK_UID},${HEALTHCHECK_UID},'/home/healthcheck','/bin/false');
+INSERT OR IGNORE INTO groups (groupname,gid,members) VALUES ('healthcheck',${HEALTHCHECK_UID},'healthcheck');
+UPDATE users SET passwd='$PASSWD_SHA' WHERE userid='healthcheck';
+EOF
+else
+  cat /app/healthcheck.pwd | ftpasswd --stdin --passwd --name=healthcheck \
+    --uid=${HEALTHCHECK_UID} \
+    --home=/home/healthcheck --sha512 --shell=/bin/false --file=/auth/passwd
+fi
+
+############ CONFIGURE AUTH
+if [ "$SQLITE_AUTH" = "1" ] ; then
+  echo "AuthOrder mod_sql.c" > /etc/prodtpd/conf.d/auth.conf
+else
+  echo "AuthOrder mod_auth_file.c" > /etc/prodtpd/conf.d/auth.conf
+fi
+
 ############ START CRON
 crond -b
 
diff --git a/rootfs/app/healthcheck.sh b/rootfs/app/healthcheck.sh
new file mode 100755
index 0000000..4bc244a
--- /dev/null
+++ b/rootfs/app/healthcheck.sh
@@ -0,0 +1,7 @@
+#!/bin/sh
+
+USER=healthcheck
+LFTP_PASSWORD=$(cat /app/healthcheck.pwd)
+
+lftp -e "set ssl-allow true; set ftp:ssl-force true; set ftp:passive-mode true;set ssl:verify-certificate false;open -u ${USER},${LFTP_PASSWORD} ftp://127.0.0.1; ls ; bye" > /dev/null
+echo $?
diff --git a/rootfs/app/init.sql b/rootfs/app/init.sql
new file mode 100644
index 0000000..67611d2
--- /dev/null
+++ b/rootfs/app/init.sql
@@ -0,0 +1,14 @@
+CREATE TABLE `users` (
+  userid VARCHAR(30) NOT NULL UNIQUE,
+  passwd VARCHAR(80) NOT NULL,
+  uid INTEGER UNIQUE,
+  gid INTEGER,
+  homedir VARCHAR(255),
+  shell VARCHAR(255), 
+  last_accessed DATETIME
+);
+CREATE TABLE `groups` (
+  groupname VARCHAR(30) NOT NULL UNIQUE,
+  gid INTEGER NOT NULL,
+  members VARCHAR(255)
+);
diff --git a/rootfs/etc/proftpd/conf.d/custom.conf b/rootfs/etc/proftpd/conf.d/custom.conf
index 5556c65..57af025 100644
--- a/rootfs/etc/proftpd/conf.d/custom.conf
+++ b/rootfs/etc/proftpd/conf.d/custom.conf
@@ -1,4 +1,3 @@
-AuthOrder mod_auth_file.c
 AuthUserFile /auth/passwd
 RequireValidShell off
 ScoreBoardFile /run/proftpd/scoreboard
@@ -23,4 +22,28 @@ DefaultRoot ~
   DelayTable /run/proftpd/proftpd.delay
 </IfModule>
 
+<IfModule mod_deflate.c>
+  DeflateEngine on
+</IfModule>
+
+<IfModule mod_sql.c>
+<IfModule mod_sql_sqlite.c>
+  SQLBackend sqlite3
+  SQLConnectInfo /auth/ftpd.db
+  SQLEngine On
+  SQLAuthenticate users
+  SQLAuthTypes OpenSSL Crypt
+  SQLUserInfo  users userid passwd uid gid homedir shell
+  SQLGroupInfo groups groupname gid members
+
+  SQLNamedQuery last_accessed UPDATE "last_accessed = DATETIME('now') WHERE userid='%u'" users
+  SQLLog PASS last_accessed
+  SQLMinId 33
+  SQLDefaultUID 33
+  SQLDefaultGID 33
+
+  RequireValidShell off
+</IfModule>
+</IfModule>
+
 Include /etc/proftpd/custom.conf.d/