Improve volume handling and file permissions (#2)

* Use /opt/backup
* Switch back to root

Author: avvertix

Dockerfile

@@ -14,22 +14,25 @@ RUN addgroup -S backup && adduser -D -H -G backup backup
 RUN apk add --no-cache --update busybox-suid mysql-client libcap && \
     setcap cap_setgid=ep /bin/busybox
 
-COPY --chown=backup:backup *.sh /opt/
+COPY *.sh /opt/
 
 RUN rm -f /var/spool/cron/crontabs/root && \
     chmod +x /opt/entrypoint.sh && \
     chmod +x /opt/backup.sh && \
+    chown backup:backup /opt/backup.sh && \
     mkdir /var/log/cron/ && \
-    mkdir -p /home/backup/backups && \
+    mkdir -p /home/backup && \
     chown -R backup:backup /home/backup && \
     chown -R backup:backup /var/log/cron/ && \
     touch /var/spool/cron/crontabs/backup && \
     chgrp backup /var/spool/cron/crontabs/backup && \
-    chmod g+rw /var/spool/cron/crontabs/backup
+    chmod g+rw /var/spool/cron/crontabs/backup && \
+    mkdir -p /opt/backup && \
+    chown -R backup:backup /opt/backup
 
-USER backup
+VOLUME /opt/backup
 
-VOLUME /home/backup/backups
+USER root
 
 ENTRYPOINT ["/opt/entrypoint.sh"]
 

backup.sh

@@ -5,10 +5,16 @@ DB_PORT=${DB_PORT:-3306}
 
 echo "backup: starting backup script"
 
-mysqldump -u"${DB_USER}" -p"${DB_PASSWORD}" \
+/usr/bin/mysqldump -u"${DB_USER}" -p"${DB_PASSWORD}" \
   --databases "${DB_DATABASE}" \
   --host "${DB_HOST}" --port "${DB_PORT}" \
   --single-transaction --quick --skip-lock-tables \
-  --no-create-db --disable-keys --extended-insert  > "/home/backup/backups/${DB_DATABASE}.sql"
+  --no-create-db --disable-keys --extended-insert 2>>/dev/stdout > "/opt/backup/${DB_DATABASE}.sql"
+
+ret=$?
+if [ $ret -eq 0 ]; then
+    echo "backup: backup written in /opt/backup/${DB_DATABASE}.sql"
+else
+    echo "backup: backup NOT PERFORMED, mysqldump exit code ${ret}"
+fi
 
-echo "backup: backup written in /home/backup/backups/${DB_DATABASE}.sql"

docker-compose.yml

@@ -31,4 +31,4 @@ services:
     networks:
       - internal
     volumes: 
-      - "/home/backup/backups"
+      - "/opt/backup"

entrypoint.sh

@@ -6,10 +6,6 @@ CRON_LOG_LEVEL=${CRON_LOG_LEVEL:-2}
 
 # TODO: check if required variables ${DB_USER} ${DB_PASSWORD} ${DB_DATABASE} ${DB_HOST} are configured
 
-if [ ! -d "/home/backup/backups/" ]; then
-    mkdir -p "/home/backup/backups/"
-fi
-
-chown -R backup /home/backup/backups/ && \
-echo "${CRON_SCHEDULE} /opt/backup.sh >> /dev/stdout 2>&1" > /var/spool/cron/crontabs/backup && \
-crond -f -l "${CRON_LOG_LEVEL}" -L /dev/stdout
+chown -R backup /opt/backup && \
+echo "${CRON_SCHEDULE} /opt/backup.sh >> /dev/stdout 2>&1" > /var/spool/cron/crontabs/root && \
+crond -f -l "${CRON_LOG_LEVEL}" -d "${CRON_LOG_LEVEL}" -L /dev/stdout

readme.md

@@ -22,7 +22,7 @@ The best way run it is with Docker Compose:
       DB_USER: "### Replace With Database User ###"
       DB_PASSWORD: "### Replace With Database Password ###"
     volumes: 
-      - "/home/backup/backups"
+      - "/opt/backup"
 ```
 
 > Don't forget to add the database as a dependant service and place it in the 
@@ -41,8 +41,8 @@ database:
 - `DB_USER`: The user that can access the database
 - `DB_PASSWORD`: The password to access the database
 
-The database dump will be created at 11.02pm each day 
-in the `/home/backup/backups/` folder. Filename will be `{DB_DATABASE}.sql`.
+The database dump will be created at 11.02pm UTC each day 
+in the `/opt/backup/` folder. Filename will be `{DB_DATABASE}.sql`.
 
 > The backup schedule is [configurable](#backup-schedule), 11.02pm is just a default value.