bubblewrap VS apparmor

Nothing nix specific but you may be interested in https://github.com/containers/bubblewrap

Recently, I came across Chainguard and wrote the article How to build Docker Images with Melange and Apko. As a fervent supporter of Kubernetes and GitLab CI, I was eager to experiment with building images using Melange in this particular setup. GitLab's shared Runners work seamlessly with Bubblewrap, eliminating the need for additional configurations. This post is intended for enthusiasts like myself, interested in hosting their own Kubernetes Runners and leveraging the Kubernetes Runner Type of Melange.

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This is basically manually invoking what Flatpak does:

https://github.com/containers/bubblewrap

This is also useful for more than just security. E.G., you can test how your app would behave on a fresh install by masking your user configuration files. I personally also have a tool that uses it to basically bundle all dependencies from an entire Linux distribution in order to make highly portable AppImages— Been meaning to post that, will get around to it eventually maybe.

The flags above should hide your user data (`--tmpfs`), disable network access (`--unshare-all`), hide/virtualize devices and OS state (`--dev` and `--proc`), and make the rest of the root filesystem read-only (`--ro-bind`­— Including the insecure X11 socket in `/tmp`, which you might want to expose for GUI apps).

Check them against `bwrap --help`; I might have omitted one or two more things you'd need.

While trying to find out more comparison information, found this light on details issue:

https://github.com/containers/bubblewrap/issues/81

It mentions nsjail and minijail.

# /etc/systemd/system/nginx.service # Rootless Nginx service based on https://github.com/stephan13360/systemd-services/blob/master/nginx/nginx.service [Unit] # This is from the default nginx.service Description=nginx (hardened rootless) Documentation=https://nginx.org/en/docs/ Documentation=https://github.com/stephan13360/systemd-services/blob/master/nginx/README.md After=network-online.target remote-fs.target nss-lookup.target Wants=network-online.target [Service] # forking is not necessary as `daemon` is turned off in the nginx config Type=exec User=nginx Group=nginx ## can be used e.g. for accessing directory containing SSL certs #SupplementaryGroups=acme # define runtime directory /run/nginx as rootless services can't access /run RuntimeDirectory=nginx # write logs to /var/log/nginx LogsDirectory=nginx # write cache to /var/cache/nginx CacheDirectory=nginx # configuration is in /etc/nginx ConfigurationDirectory=nginx ExecStart=/usr/sbin/nginx -c /etc/nginx/nginx.conf # PID is not necessary here as the service is not forking ExecReload=/usr/sbin/nginx -s reload Restart=on-failure RestartSec=10s # Hardening # hide the entire filesystem tree from the service and also make it read only, requires systemd >=238 TemporaryFileSystem=/:ro # Remount (bind) necessary paths, based on https://gitlab.com/apparmor/apparmor/blob/master/profiles/apparmor.d/abstractions/base, # https://github.com/jelly/apparmor-profiles/blob/master/usr.bin.nginx, # https://www.freedesktop.org/software/systemd/man/systemd.exec.html#RootDirectory= # # This gives access to (probably) necessary system files, allows journald logging BindReadOnlyPaths=/lib/ /lib64/ /usr/lib/ /usr/lib64/ /etc/ld.so.cache /etc/ld.so.conf /etc/ld.so.conf.d/ /etc/bindresvport.blacklist /usr/share/zoneinfo/ /usr/share/locale/ /etc/localtime /usr/share/common-licenses/ /etc/ssl/certs/ /etc/resolv.conf BindReadOnlyPaths=/dev/log /run/systemd/journal/socket /run/systemd/journal/stdout /run/systemd/notify # Additional access to service-specific directories BindReadOnlyPaths=/usr/sbin/nginx BindReadOnlyPaths=/run/ /usr/share/nginx/ PrivateTmp=true PrivateDevices=true ProtectControlGroups=true ProtectKernelModules=true ProtectKernelTunables=true # Network access RestrictAddressFamilies=AF_UNIX AF_INET AF_INET6 # Miscellaneous SystemCallArchitectures=native # also implicit because settings like MemoryDenyWriteExecute are set NoNewPrivileges=true MemoryDenyWriteExecute=true ProtectKernelLogs=true LockPersonality=true ProtectHostname=true RemoveIPC=true RestrictSUIDSGID=true ProtectClock=true # Capabilities to bind low ports (80, 443) AmbientCapabilities=CAP_NET_BIND_SERVICE [Install] WantedBy=multi-user.target

root@hive:/usr/lib/apparmor# systemctl status apparmor ● apparmor.service - Load AppArmor profiles Loaded: loaded (/lib/systemd/system/apparmor.service; enabled; vendor preset: enabled) Active: active (exited) since Thu 2023-05-18 19:44:34 EDT; 23h ago Docs: man:apparmor(7) https://gitlab.com/apparmor/apparmor/wikis/home/ Process: 861 ExecStart=/lib/apparmor/apparmor.systemd reload (code=exited, status=0/SU> Main PID: 861 (code=exited, status=0/SUCCESS) CPU: 39ms

I know you made this comment 5 days ago, but: the last two commits were 1 and 3 day ago for me while SELinux is behind at 3 days and 2 weeks for its last two commits, and also has about half as many commits overall. So AppArmor is arguably as alive, if not more, than SELinux.

I'm working on doing what I can to secure a hobby VPS running Ubuntu. I've done some reading about apparmor (especially this document) and created a profile for nginx.

Also, I agree that the documentation doesn't seem to be exactly helpful. I'd recommend Wikipedia about what it is (for links to what these terms mean) and its documentation in the project's Wiki.

Learn how to use AppArmor: https://gitlab.com/apparmor/apparmor/-/wikis/Documentation. Enforce its profiles (at least) for internet facing apps.