Harden build reproducibility and input sanitization

Address PR review feedback:
- Add TODO comments for image digest pinning in compose files
- Use literal domains in multi-domain compose example (avoid env var injection)
- Sanitize ROUTING_MAP domain/target values against haproxy config injection
- Replace single-threaded http.server with ThreadingTCPServer for evidence serving

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: h4x3rotab

custom-domain/dstack-ingress/README.md

@@ -112,11 +112,11 @@ services:
       GATEWAY_DOMAIN: _.dstack-prod5.phala.network
       SET_CAA: true
       DOMAINS: |
-        ${APP_DOMAIN}
-        ${API_DOMAIN}
+        app.example.com
+        api.example.com
       ROUTING_MAP: |
-        ${APP_DOMAIN}=app-main:80
-        ${API_DOMAIN}=app-api:8080
+        app.example.com=app-main:80
+        api.example.com=app-api:8080
     volumes:
       - /var/run/tappd.sock:/var/run/tappd.sock
       - letsencrypt:/etc/letsencrypt

custom-domain/dstack-ingress/docker-compose.multi.yaml

@@ -1,5 +1,6 @@
 services:
   ingress:
+    # TODO: pin by digest for production (dstacktee/dstack-ingress@sha256:...)
     image: dstacktee/dstack-ingress:latest
     ports:
       - "443:443"
@@ -10,11 +11,11 @@ services:
       GATEWAY_DOMAIN: _.dstack-prod5.phala.network
       SET_CAA: true
       DOMAINS: |
-        ${APP_DOMAIN}
-        ${API_DOMAIN}
+        app.example.com
+        api.example.com
       ROUTING_MAP: |
-        ${APP_DOMAIN}=app-main:80
-        ${API_DOMAIN}=app-api:80
+        app.example.com=app-main:80
+        api.example.com=app-api:8080
 
     volumes:
       - /var/run/tappd.sock:/var/run/tappd.sock

custom-domain/dstack-ingress/docker-compose.yaml

@@ -1,5 +1,6 @@
 services:
   dstack-ingress:
+    # TODO: pin by digest for production (dstacktee/dstack-ingress@sha256:...)
     image: dstacktee/dstack-ingress:latest
     ports:
       - "443:443"

custom-domain/dstack-ingress/scripts/entrypoint.sh

@@ -219,6 +219,16 @@ setup_haproxy_cfg_multi() {
         target=$(echo "$target" | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')
         [[ -n "$domain" && -n "$target" ]] || continue
 
+        # Validate domain and target to prevent config injection
+        if ! domain=$(sanitize_domain "$domain"); then
+            echo "Error: Invalid domain in ROUTING_MAP: ${line}" >&2
+            exit 1
+        fi
+        if ! target=$(sanitize_target_endpoint "$target"); then
+            echo "Error: Invalid target in ROUTING_MAP: ${line}" >&2
+            exit 1
+        fi
+
         # Strip protocol prefix from target if present
         target=$(parse_target_endpoint "$target")
 
@@ -394,9 +404,15 @@ elif [ -n "$DOMAIN" ] && [ -n "$TARGET_ENDPOINT" ]; then
     setup_haproxy_cfg
 fi
 
-# Start evidence HTTP server if enabled
+# Start evidence HTTP server if enabled (threaded to avoid blocking on slow clients)
 if [ "$EVIDENCE_SERVER" = "true" ]; then
-    python3 -m http.server "$EVIDENCE_PORT" --directory /evidences &
+    python3 -c "
+import http.server, socketserver, os
+os.chdir('/evidences')
+handler = http.server.SimpleHTTPRequestHandler
+with socketserver.ThreadingTCPServer(('', ${EVIDENCE_PORT}), handler) as s:
+    s.serve_forever()
+" &
     echo "Evidence server started on port ${EVIDENCE_PORT}"
 fi