Docker linux Security

Traefik 2 and Nextcloud

I use Traefik and Nextcloud on docker and it took me a few tries to get it to the point where nextcloud would not complain about configuration issues.

Here is the configuration I ended up with:

- "traefik.enable=true"
- ""
- "traefik.http.routers.nextcloud.middlewares=nextcloud,nextcloud_redirect"
- "traefik.http.routers.nextcloud.rule=Host(``)"
- ""
- "traefik.http.routers.nextcloud.entrypoints=websecure"
- "traefik.http.routers.nextcloud.tls.certresolver=mydnschallenge"
- "traefik.http.middlewares.nextcloud.headers.customFrameOptionsValue=ALLOW-FROM"
- "traefik.http.middlewares.nextcloud.headers.contentSecurityPolicy=frame-ancestors 'self' *"
- "traefik.http.middlewares.nextcloud.headers.stsSeconds=155520011"
- "traefik.http.middlewares.nextcloud.headers.stsIncludeSubdomains=true"
- "traefik.http.middlewares.nextcloud.headers.stsPreload=true"
- "traefik.http.middlewares.nextcloud.headers.referrerPolicy=same-origin"
- "traefik.http.middlewares.nextcloud.headers.customFrameOptionsValue=SAMEORIGIN"
- "traefik.http.middlewares.nextcloud_redirect.redirectregex.regex=/.well-known/(card|cal)dav"
- "traefik.http.middlewares.nextcloud_redirect.redirectregex.replacement=/remote.php/dav/"

This answers a question that’s been asked a few times on this post, which is “how to configure HSTS on Traefik 2”


Proftpd on CIFS share

For several of our clients, we provide an FTP server on a linux server, with the files hosted on a windows 2008r2 server and authentication being handled by active directory through proftpd-ldpap.

The windows share are automatically mounted on access with autofs in a /srv/ftp subfolder, and users are jailed in yet another level of subdirectory using proftpd.

I hit a bit of a wall recently with this setup, as everything seemed to be in order, autofs mounted the directory, proftpd allowed login with ldap auth, but for some reason I couldn’t write anything.

If I pointed proftpd at a local directory however, write was fine.


I finally found out that proftpd was trying to use “chmod” on every write, and with SMB < 3, it failed, resulting in a “permission denied” error and nothing whatsoever in the logs.


I fixed it by mounting the CIFS share with the “noperm” option:

homes -fstype=cifs,rw,credentials=/etc/cifscredentials,gid=nogroup,uid=proftpd,vers=2.1,noperm ://SERVER/SHARE\$/SFTP