Couldn't the attacker just drop a dangerous binary into the data volume then?

Sure thing, I'll edit this reply when I get back to my computer. Just note that I also have a tailscale and nginx container in the pod which are not necessary.

You'll see my nginx config which reverse proxies to the port the service is running on. On public servers I have another nginx running with SSL that proxies to the port I map the pod's port 80 to.

I usually run my pods as an unpriviledged user with loginctl enable-linger which starts the enabled systemctl --user services on boot.

All that being said I haven't publically exposed linkwarden yet, mainly because it's the second most resource intensive service I run and I have all my public stuff on a shitty vps.

Edit: My opsec is so bad hahaha

Edit2: I just realized the caps I gave were to the tailscale container, not the linkwarden container. Linkwarden can run with no caps :)

I added the tailscale stuff back

files:

linkwarden-pod.kube:

[Install]
WantedBy=default.target

[Kube]
# Point to the yaml in the same directory
Yaml=linkwarden-pod.yml
PublishPort=127.0.0.1:7777:80
AutoUpdate=registry

[Service]
Restart=always

linkwarden-pod.yml:

***
apiVersion: v1
kind: Pod
metadata:
  name: linkwarden
spec:
  containers:
    - name: ts-linkwarden
      image: docker.io/tailscale/tailscale:latest
      env:
        - name: TS_HOSTNAME
          value: "link"
        - name: TS_STATE_DIR
          value: /var/lib/tailscale
        - name: TS_AUTHKEY
          valueFrom:
            secretKeyRef:
              name: ts-auth-kube
              key: ts-auth
      volumeMounts:
        - name: linkwarden-ts-storage
          mountPath: /var/lib/tailscale
      securityContext:
        capabilities:
          add:
            - NET_ADMIN
            - SYS_MODULE

    - name: linkwarden
      image: ghcr.io/linkwarden/linkwarden:latest
      env:
        - name: INSTANCE_NAME
          value: link.mydomain.com
        - name: AUTH_URL
          value: http://linkwarden:3000/api/v1/auth
        - name: NEXTAUTH_SECRET
          value: LOL_I_JUST_PUBLISHED_THIS_I_CHANGED_IT
        - name: DATABASE_URL
          value: postgresql://postgres:password@linkwarden-postgres:5432/postgres
        - name: NEXT_PUBLIC_DISABLE_REGISTRATION
          value: "true"

    - name: linkwarden-nginx
      image: docker.io/library/nginx:alpine
      volumeMounts:
        - name: linkwarden-nginx-conf
          subPath: nginx.conf
          mountPath: /etc/nginx/nginx.conf
          readOnly: true

    - name: linkwarden-postgres
      image: docker.io/library/postgres:latest
      env:
        - name: POSTGRES_PASSWORD
          value: "password"
      volumeMounts:
        - name: linkwarden-postgres-db
          mountPath: /var/lib/postgresql/data

  volumes:
    - name: linkwarden-nginx-conf
      configMap:
        name: linkwarden-nginx-conf
        items:
          - key: nginx.conf
            path: nginx.conf
    - name: linkwarden-postgres-db
      persistentVolumeClaim:
        claimName: linkwarden-postgres-db-claim
    - name: linkwarden-ts-storage
      persistentVolumeClaim:
        claimName: linkwarden-ts-pv-claim

***
apiVersion: v1
kind: ConfigMap
metadata:
  name: linkwarden-nginx-conf
data:
  nginx.conf: |
    #user  nobody;
    worker_processes  1;
     #pid        logs/nginx.pid;


    events {
        worker_connections  1024;
    }


    http {
        include       mime.types;
        default_type  application/octet-stream;


        sendfile        on;

        #keepalive_timeout  0;
        keepalive_timeout  65;

        gzip  off;

        # set_real_ip_from cw.55.55.1;
        real_ip_header X-Forwarded-For;
        real_ip_recursive on;

        server {
            listen       80;
            server_name  _;

            location / {
                    proxy_pass http://localhost:3000/;

                    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                    proxy_set_header X-Forwarded-Port $server_port;
                    proxy_set_header X-Forwarded-Scheme $scheme;
                    proxy_set_header X-Forwarded-Proto  $scheme;
                    proxy_set_header X-Real-IP $remote_addr;
                    proxy_set_header Accept-Encoding "";
                    proxy_set_header Host $host;
            }
        }
    }

I also have a little helper script you might like

copy.sh:

#!/bin/bash

SYSTEMD_DIRECTORY="${HOME}/.config/containers/systemd"
POD_NAME="linkwarden-pod"

mkdir -p "$SYSTEMD_DIRECTORY"
cp "${POD_NAME}".{kube,yml} "${SYSTEMD_DIRECTORY}"/

systemctl --user daemon-reload