integrate sops-nix for secret management

.sops.yaml

@@ -0,0 +1,25 @@
+# To set up sops-nix:
+# 1. Generate an age key on each host:
+#      mkdir -p ~/.config/sops/age
+#      age-keygen -o ~/.config/sops/age/keys.txt
+#    Or derive from the host SSH key:
+#      nix-shell -p ssh-to-age --run 'cat /etc/ssh/ssh_host_ed25519_key.pub | ssh-to-age'
+#
+# 2. Replace the placeholder age keys below with the actual public keys.
+#
+# 3. Encrypt secret files:
+#      sops secrets/homelab.yaml
+#
+# 4. To re-key after changing keys:
+#      sops updatekeys secrets/homelab.yaml
+
+keys:
+  - &homelab age1XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX # replace with: ssh-to-age < /etc/ssh/ssh_host_ed25519_key.pub
+  - &admin   age1XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX # replace with: age-keygen output from your admin machine
+
+creation_rules:
+  - path_regex: secrets/homelab\.yaml$
+    key_groups:
+      - age:
+          - *homelab
+          - *admin

modules/system/homelab/auth.nix

@@ -1,7 +1,7 @@
-{ homelab, ... }: {
+{ config, homelab, ... }: {
   services.pocket-id = {
     enable = true;
-    credentials.ENCRYPTION_KEY = "/mnt/data/pocketid/encryption-key";
+    credentials.ENCRYPTION_KEY = config.sops.secrets.pocketid_encryption_key.path;
     dataDir = "/mnt/data/pocketid/data";
     settings = {
       PORT = "1411";

modules/system/homelab/dash.nix

@@ -1,4 +1,4 @@
-{ timezone, homelab, ... }: let 
+{ config, timezone, homelab, ... }: let 
   rss = [
     "https://www.raspberrypi.com/news/feed/"
     "https://www.jeffgeerling.com/blog.xml"
@@ -96,7 +96,7 @@ in {
   };
   services.glance = {
     enable = true;
-    environmentFile = "/var/lib/glance/.env";
+    environmentFile = config.sops.secrets.glance_env.path;
     settings = {
       server = {
         host = "127.0.0.1";

modules/system/homelab/pass.nix

@@ -1,9 +1,9 @@
-{ homelab, ... }: {
+{ config, homelab, ... }: {
   services.vaultwarden = {
     enable = true;
     domain = "pass.proxy.${homelab.domain}";
     backupDir = "/mnt/data/vaultwarden/backups";
-    environmentFile = "/mnt/data/vaultwarden/.env";
+    environmentFile = config.sops.secrets.vaultwarden_env.path;
     config = {
       ROCKET_PORT = 8060;
       ROCKET_ADDRESS = "127.0.0.1";

modules/system/homelab/proxy.nix

@@ -1,4 +1,4 @@
-{ homelab, lib, ... }: let
+{ config, homelab, lib, ... }: let
   base = "proxy.${homelab.domain}";
   hosts = {
     "server"     = { dest = "https://server.dns.${homelab.domain}:8006"; auth = false; };
@@ -45,8 +45,7 @@ in {
       domain = "*.${base}";
       extraDomainNames = [ base ];
       dnsProvider = "cloudflare";
-      environmentFile = "/var/lib/acme/cloudflare.env";
-      # ^^^contents: CLOUDFLARE_DNS_API_TOKEN=XXXXX
+      environmentFile = config.sops.templates."cloudflare.env".path;
     };
   };
   
@@ -81,7 +80,7 @@ in {
         locations."/" = {
           proxyPass = cfg.dest;
           proxyWebsockets = true;
-          basicAuthFile = if cfg.auth then "/var/lib/nginx/.htpasswd" else null;
+          basicAuthFile = if cfg.auth then config.sops.secrets.nginx_htpasswd.path else null;
           extraConfig = exta-conf;
         };
       }) hosts;

modules/system/homelab/sops.nix

@@ -0,0 +1,59 @@
+{ config, ... }: {
+  sops = {
+    defaultSopsFile = ../../../secrets/homelab.yaml;
+    age.sshKeyPaths = [ "/etc/ssh/ssh_host_ed25519_key" ];
+
+    secrets = {
+      cloudflare_dns_api_token = {
+        owner = "acme";
+        group = "acme";
+      };
+
+      cloudflared_tunnel_credentials = {
+        owner = "cloudflared";
+        group = "cloudflared";
+      };
+
+      cloudflared_cert = {
+        owner = "cloudflared";
+        group = "cloudflared";
+      };
+
+      vaultwarden_env = {
+        owner = "vaultwarden";
+        group = "vaultwarden";
+        restartUnits = [ "vaultwarden.service" ];
+      };
+
+      glance_env = {
+        owner = "glance";
+        group = "glance";
+        restartUnits = [ "glance.service" ];
+      };
+
+      pocketid_encryption_key = {
+        owner = "root";
+        group = "root";
+        restartUnits = [ "pocket-id.service" ];
+      };
+
+      tailscale_authkey = {
+        owner = "root";
+        group = "root";
+        restartUnits = [ "tailscaled.service" ];
+      };
+
+      nginx_htpasswd = {
+        owner = "nginx";
+        group = "nginx";
+        restartUnits = [ "nginx.service" ];
+      };
+    };
+
+    templates."cloudflare.env" = {
+      owner = "acme";
+      group = "acme";
+      content = "CLOUDFLARE_DNS_API_TOKEN=${config.sops.placeholder.cloudflare_dns_api_token}";
+    };
+  };
+}

modules/system/homelab/tunnels.nix

@@ -1,4 +1,4 @@
-{ pkgs, lib, homelab, ... }: let
+{ config, pkgs, lib, homelab, ... }: let
   routes = {
     "git.${homelab.domain}"     = "http://localhost:5080";
     "auth.${homelab.domain}"    = "http://localhost:1411";
@@ -10,8 +10,8 @@ in {
   services.cloudflared = {
     enable = true;
     tunnels.homelab = {
-      credentialsFile = "/mnt/data/cloudflared/homelab.json";
-      certificateFile = "/mnt/data/cloudflared/cert.pem";
+      credentialsFile = config.sops.secrets.cloudflared_tunnel_credentials.path;
+      certificateFile = config.sops.secrets.cloudflared_cert.path;
       default = "http_status:404";
       ingress = routes;
     };
@@ -31,7 +31,7 @@ in {
 
     script = lib.concatMapStringsSep "\n" (domain: ''
       echo "Ensuring DNS route for ${domain}..."
-      ${pkgs.cloudflared}/bin/cloudflared tunnel --origincert /mnt/data/cloudflared/cert.pem route dns ${homelab.cf-tunnel-id} ${domain} || true
+      ${pkgs.cloudflared}/bin/cloudflared tunnel --origincert ${config.sops.secrets.cloudflared_cert.path} route dns ${homelab.cf-tunnel-id} ${domain} || true
     '') (builtins.attrNames routes);
   };
 }

modules/system/server.nix

@@ -1,4 +1,4 @@
-{ lib, homelab, ... }: let
+{ config, lib, homelab, ... }: let
   ts-flags = [
     "--advertise-exit-node"
     "--advertise-routes=10.3.14.0/24,192.168.1.0/24"
@@ -20,6 +20,7 @@ in {
     ./homelab/dns.nix
     ./homelab/git.nix
     ./homelab/ai.nix
+    ./homelab/sops.nix
     
     ./core/swapfile.nix
     ./core/oom.nix
@@ -29,7 +30,7 @@ in {
 
   services.tailscale = {
     enable = true;
-    authKeyFile = "/mnt/data/tailscale/authkey";
+    authKeyFile = config.sops.secrets.tailscale_authkey.path;
     useRoutingFeatures = "server";
     extraUpFlags = ts-flags;
     extraSetFlags = ts-flags;

scripts/check-sops.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+# Pre-commit hook: block commits containing unencrypted sops secret files.
+# Install with: ln -sf ../../scripts/check-sops.sh .git/hooks/pre-commit
+
+set -euo pipefail
+
+staged_secrets=$(git diff --cached --name-only --diff-filter=ACM -- 'secrets/*.yaml' 'secrets/*.yml' 'secrets/*.json')
+
+if [ -z "$staged_secrets" ]; then
+    exit 0
+fi
+
+failed=0
+
+for file in $staged_secrets; do
+    # sops-encrypted YAML/JSON files always contain a top-level "sops" key with metadata
+    if ! git show ":$file" | grep -q '"sops"\|sops:'; then
+        echo "ERROR: $file is not encrypted with sops! Encrypt it first:"
+        echo "       sops $file"
+        echo
+        echo "hint: bypass with: git commit --no-verify"
+        failed=1
+    fi
+done
+
+if [ "$failed" -ne 0 ]; then
+    echo ""
+    echo "Commit aborted. Encrypt secret files before committing."
+    exit 1
+fi

secrets/homelab.yaml

@@ -0,0 +1,11 @@
+# This file should be encrypted with sops before committing.
+# Run: sops secrets/homelab.yaml
+# All values below are placeholders. Replace them with actual values.
+cloudflare_dns_api_token: REPLACE_ME
+cloudflared_tunnel_credentials: REPLACE_ME
+cloudflared_cert: REPLACE_ME
+vaultwarden_env: REPLACE_ME
+glance_env: REPLACE_ME
+pocketid_encryption_key: REPLACE_ME
+tailscale_authkey: REPLACE_ME
+nginx_htpasswd: REPLACE_ME