Implement security hardening across frontend, backend, and infrastructure

- nginx: add X-Content-Type-Options, X-Frame-Options, X-XSS-Protection,
  and Referrer-Policy headers on all responses; rate limit /api/auth/login
  to 5 req/min per IP (burst 3) to prevent brute force
- frontend: add escHtml() utility to api.js; use it on all notes fields
  across dashboard, log, history, flock, and budget pages to prevent XSS
- log.js: fix broken loadRecent() call referencing removed #recent-body
  element; replaced with loadHistory() from history.js
- schemas.py: raise minimum password length from 6 to 10 characters
- admin.py: add audit logging for password reset, disable, delete, and
  impersonate actions; fix impersonate to use named admin param for logging
- main.py: add startup env validation — exits with clear error if any
  required env var is missing; configure structured logging to stdout
- docker-compose.yml: add log rotation (10 MB / 3 files) to all services

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

backend/main.py

@@ -1,5 +1,6 @@
 import os
 import logging
+import sys
 from contextlib import asynccontextmanager
 
 from fastapi import FastAPI
@@ -12,8 +13,21 @@ from auth import hash_password
 from routers import eggs, flock, feed, stats, other
 from routers import auth_router, admin
 
+logging.basicConfig(
+    level=logging.INFO,
+    format="%(asctime)s %(levelname)s %(name)s: %(message)s",
+    stream=sys.stdout,
+)
 logger = logging.getLogger("yolkbook")
 
+_REQUIRED_ENV = ["ADMIN_USERNAME", "ADMIN_PASSWORD", "JWT_SECRET", "DATABASE_URL"]
+
+def _validate_env():
+    missing = [k for k in _REQUIRED_ENV if not os.environ.get(k)]
+    if missing:
+        logger.critical("Missing required environment variables: %s", ", ".join(missing))
+        sys.exit(1)
+
 
 def _seed_admin():
     """Create or update the admin user from environment variables.
@@ -68,6 +82,7 @@ def _run_migrations():
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
+    _validate_env()
     Base.metadata.create_all(bind=engine)
     _run_migrations()
     _seed_admin()

backend/routers/admin.py

@@ -1,3 +1,5 @@
+import logging
+
 from fastapi import APIRouter, Depends, HTTPException
 from sqlalchemy import select
 from sqlalchemy.orm import Session
@@ -8,6 +10,7 @@ from schemas import UserCreate, UserOut, ResetPasswordRequest, TokenResponse
 from auth import hash_password, create_access_token, get_current_admin, get_current_user
 
 router = APIRouter(prefix="/api/admin", tags=["admin"])
+logger = logging.getLogger("yolkbook")
 
 
 @router.get("/users", response_model=list[UserOut])
@@ -50,6 +53,7 @@ def reset_password(
         raise HTTPException(status_code=404, detail="User not found")
     user.hashed_password = hash_password(body.new_password)
     db.commit()
+    logger.warning("Admin '%s' reset password for user '%s' (id=%d).", current_admin.username, user.username, user.id)
     return {"detail": f"Password reset for {user.username}"}
 
 
@@ -66,6 +70,7 @@ def disable_user(
         raise HTTPException(status_code=400, detail="Cannot disable your own account")
     user.is_disabled = True
     db.commit()
+    logger.warning("Admin '%s' disabled user '%s' (id=%d).", current_admin.username, user.username, user.id)
     return {"detail": f"User {user.username} disabled"}
 
 
@@ -94,6 +99,7 @@ def delete_user(
         raise HTTPException(status_code=404, detail="User not found")
     if user.id == current_admin.id:
         raise HTTPException(status_code=400, detail="Cannot delete your own account")
+    logger.warning("Admin '%s' deleted user '%s' (id=%d).", current_admin.username, user.username, user.id)
     db.delete(user)
     db.commit()
 
@@ -101,11 +107,12 @@ def delete_user(
 @router.post("/users/{user_id}/impersonate", response_model=TokenResponse)
 def impersonate_user(
     user_id: int,
-    _: User = Depends(get_current_admin),
+    current_admin: User = Depends(get_current_admin),
     db: Session = Depends(get_db),
 ):
     user = db.get(User, user_id)
     if not user:
         raise HTTPException(status_code=404, detail="User not found")
     token = create_access_token(user.id, user.username, user.is_admin, user.timezone)
+    logger.warning("Admin '%s' (id=%d) is impersonating user '%s' (id=%d).", current_admin.username, current_admin.id, user.username, user.id)
     return TokenResponse(access_token=token)

backend/schemas.py

@@ -16,10 +16,10 @@ class TokenResponse(BaseModel):
 
 class ChangePasswordRequest(BaseModel):
     current_password: str
-    new_password: str = Field(min_length=6)
+    new_password: str = Field(min_length=10)
 
 class ResetPasswordRequest(BaseModel):
-    new_password: str = Field(min_length=6)
+    new_password: str = Field(min_length=10)
 
 class TimezoneUpdate(BaseModel):
     timezone: str = Field(min_length=1, max_length=64)
@@ -29,7 +29,7 @@ class TimezoneUpdate(BaseModel):
 
 class UserCreate(BaseModel):
     username: str = Field(min_length=2, max_length=64)
-    password: str = Field(min_length=6)
+    password: str = Field(min_length=10)
 
 class UserOut(BaseModel):
     id:          int

docker-compose.yml

@@ -5,6 +5,11 @@ services:
     image: mysql:8.0
     restart: unless-stopped
     env_file: .env
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
     environment:
       MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
       MYSQL_DATABASE:      ${MYSQL_DATABASE}
@@ -27,6 +32,11 @@ services:
     build: ./backend
     restart: unless-stopped
     env_file: .env
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
     environment:
       DATABASE_URL:     mysql+pymysql://${MYSQL_USER}:${MYSQL_PASSWORD}@db/${MYSQL_DATABASE}
       ADMIN_USERNAME:   ${ADMIN_USERNAME}
@@ -42,6 +52,11 @@ services:
   nginx:
     image: nginx:alpine
     restart: unless-stopped
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
     ports:
       - "8056:80"
     volumes:

nginx/html/js/api.js

@@ -66,6 +66,17 @@ function fmtMoneyFull(val) {
     return '$' + Number(val).toFixed(4);
 }
 
+// Escape HTML special characters to prevent XSS when rendering user content
+function escHtml(str) {
+    if (!str) return '';
+    return str
+        .replace(/&/g, '&')
+        .replace(/</g, '&lt;')
+        .replace(/>/g, '&gt;')
+        .replace(/"/g, '&quot;')
+        .replace(/'/g, '&#39;');
+}
+
 // Highlight the nav link that matches the current page
 function highlightNav() {
     const path = window.location.pathname.replace(/\.html$/, '').replace(/\/$/, '') || '/';

nginx/html/js/budget.js

@@ -59,7 +59,7 @@ function renderTable() {
                     <td>Feed</td>
                     <td>${parseFloat(e.bags)} bags @ ${fmtMoney(e.price_per_bag)}/bag</td>
                     <td>${fmtMoney(total)}</td>
-                    <td class="notes">${e.notes || ''}</td>
+                    <td class="notes">${escHtml(e.notes)}</td>
                     <td class="actions">
                         <button class="btn btn-ghost btn-sm" onclick="startEditFeed(${e.id})">Edit</button>
                         <button class="btn btn-danger btn-sm" onclick="deleteFeed(${e.id})">Delete</button>
@@ -73,7 +73,7 @@ function renderTable() {
                     <td>Other</td>
                     <td>—</td>
                     <td>${fmtMoney(e.total)}</td>
-                    <td class="notes">${e.notes || ''}</td>
+                    <td class="notes">${escHtml(e.notes)}</td>
                     <td class="actions">
                         <button class="btn btn-ghost btn-sm" onclick="startEditOther(${e.id})">Edit</button>
                         <button class="btn btn-danger btn-sm" onclick="deleteOther(${e.id})">Delete</button>
@@ -111,7 +111,7 @@ function startEditFeed(id) {
             <input type="number" min="0.01" step="0.01" value="${parseFloat(entry.price_per_bag)}" placeholder="price" style="width:80px;">/bag
         </td>
         <td>—</td>
-        <td><input type="text" value="${entry.notes || ''}" placeholder="Notes"></td>
+        <td><input type="text" value="${escHtml(entry.notes)}" placeholder="Notes"></td>
         <td class="actions">
             <button class="btn btn-primary btn-sm" onclick="saveEditFeed(${id})">Save</button>
             <button class="btn btn-ghost btn-sm"   onclick="renderTable()">Cancel</button>
@@ -165,7 +165,7 @@ function startEditOther(id) {
         <td>Other</td>
         <td>—</td>
         <td><input type="number" min="0.01" step="0.01" value="${parseFloat(entry.total)}" style="width:100px;"></td>
-        <td><input type="text" value="${entry.notes || ''}" placeholder="Notes"></td>
+        <td><input type="text" value="${escHtml(entry.notes)}" placeholder="Notes"></td>
         <td class="actions">
             <button class="btn btn-primary btn-sm" onclick="saveEditOther(${id})">Save</button>
             <button class="btn btn-ghost btn-sm"   onclick="renderTable()">Cancel</button>

nginx/html/js/dashboard.js

@@ -115,7 +115,7 @@ async function loadDashboard() {
             <tr>
                 <td>${fmtDate(e.date)}</td>
                 <td>${e.eggs}</td>
-                <td class="notes">${e.notes || ''}</td>
+                <td class="notes">${escHtml(e.notes)}</td>
             </tr>
         `).join('');
 

nginx/html/js/flock.js

@@ -30,7 +30,7 @@ function renderTable() {
         <tr data-id="${e.id}">
             <td>${fmtDate(e.date)}</td>
             <td>${e.chicken_count}</td>
-            <td class="notes">${e.notes || ''}</td>
+            <td class="notes">${escHtml(e.notes)}</td>
             <td class="actions">
                 <button class="btn btn-ghost btn-sm" onclick="startEdit(${e.id})">Edit</button>
                 <button class="btn btn-danger btn-sm" onclick="deleteEntry(${e.id})">Delete</button>
@@ -46,7 +46,7 @@ function startEdit(id) {
     row.innerHTML = `
         <td><input type="date" value="${entry.date}"></td>
         <td><input type="number" min="0" value="${entry.chicken_count}" style="width:80px;"></td>
-        <td><input type="text" value="${entry.notes || ''}" placeholder="Notes"></td>
+        <td><input type="text" value="${escHtml(entry.notes)}" placeholder="Notes"></td>
         <td class="actions">
             <button class="btn btn-primary btn-sm" onclick="saveEdit(${id})">Save</button>
             <button class="btn btn-ghost btn-sm"   onclick="renderTable()">Cancel</button>

nginx/html/js/history.js

@@ -42,7 +42,7 @@ function renderTable() {
         <tr data-id="${e.id}">
             <td>${fmtDate(e.date)}</td>
             <td>${e.eggs}</td>
-            <td class="notes">${e.notes || ''}</td>
+            <td class="notes">${escHtml(e.notes)}</td>
             <td class="actions">
                 <button class="btn btn-ghost btn-sm" onclick="startEdit(${e.id})">Edit</button>
                 <button class="btn btn-danger btn-sm" onclick="deleteEntry(${e.id})">Delete</button>
@@ -67,7 +67,7 @@ function startEdit(id) {
     row.innerHTML = `
         <td><input type="date" value="${entry.date}"></td>
         <td><input type="number" min="0" value="${entry.eggs}" style="width:80px;"></td>
-        <td><input type="text" value="${entry.notes || ''}" placeholder="Notes"></td>
+        <td><input type="text" value="${escHtml(entry.notes)}" placeholder="Notes"></td>
         <td class="actions">
             <button class="btn btn-primary btn-sm" onclick="saveEdit(${id})">Save</button>
             <button class="btn btn-ghost btn-sm"   onclick="renderTable()">Cancel</button>

nginx/html/js/log.js

@@ -1,26 +1,3 @@
-async function loadRecent() {
-    const tbody = document.getElementById('recent-body');
-    try {
-        const eggs = await API.get('/api/eggs');
-        const recent = eggs.slice(0, 7);
-
-        if (recent.length === 0) {
-            tbody.innerHTML = '<tr class="empty-row"><td colspan="3">No entries yet.</td></tr>';
-            return;
-        }
-
-        tbody.innerHTML = recent.map(e => `
-            <tr>
-                <td>${fmtDate(e.date)}</td>
-                <td>${e.eggs}</td>
-                <td class="notes">${e.notes || ''}</td>
-            </tr>
-        `).join('');
-    } catch (err) {
-        tbody.innerHTML = '<tr class="empty-row"><td colspan="3">Could not load recent entries.</td></tr>';
-    }
-}
-
 document.addEventListener('DOMContentLoaded', () => {
     const form = document.getElementById('log-form');
     const msg  = document.getElementById('msg');
@@ -42,11 +19,9 @@ document.addEventListener('DOMContentLoaded', () => {
             showMessage(msg, 'Entry saved!');
             form.reset();
             setToday(document.getElementById('date'));
-            loadRecent();
+            loadHistory();
         } catch (err) {
             showMessage(msg, `Error: ${err.message}`, 'error');
         }
     });
-
-    loadRecent();
 });

nginx/nginx.conf

@@ -13,6 +13,9 @@ http {
     gzip_types      text/plain text/css application/javascript application/json;
     gzip_min_length 1000;
 
+    # ── Rate limiting — login endpoint ────────────────────────────────────────
+    limit_req_zone $binary_remote_addr zone=login:10m rate=5r/m;
+
     server {
         listen 80;
         server_name _;
@@ -20,6 +23,12 @@ http {
         root  /usr/share/nginx/html;
         index index.html;
 
+        # ── Security headers ──────────────────────────────────────────────────
+        add_header X-Content-Type-Options  "nosniff"                       always;
+        add_header X-Frame-Options         "SAMEORIGIN"                    always;
+        add_header X-XSS-Protection        "1; mode=block"                 always;
+        add_header Referrer-Policy         "strict-origin-when-cross-origin" always;
+
         # ── Static files ──────────────────────────────────────────────────────
         location / {
             try_files $uri $uri.html $uri/ =404;
@@ -28,10 +37,33 @@ http {
         # Cache static assets aggressively and suppress access log noise
         location ~* \.(css|js|svg|ico|png|jpg|webp|woff2?)$ {
             expires 7d;
-            add_header Cache-Control "public, immutable";
+            add_header Cache-Control          "public, immutable";
+            add_header X-Content-Type-Options "nosniff"                       always;
+            add_header X-Frame-Options        "SAMEORIGIN"                    always;
+            add_header X-XSS-Protection       "1; mode=block"                 always;
+            add_header Referrer-Policy        "strict-origin-when-cross-origin" always;
             access_log off;
         }
 
+        # ── Login rate limiting ───────────────────────────────────────────────
+        location = /api/auth/login {
+            limit_req zone=login burst=3 nodelay;
+
+            proxy_pass         http://api:8000;
+            proxy_http_version 1.1;
+
+            proxy_set_header   Host              $host;
+            proxy_set_header   X-Real-IP         $remote_addr;
+            proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
+            proxy_set_header   X-Forwarded-Proto $scheme;
+
+            add_header Cache-Control          "no-store"                      always;
+            add_header X-Content-Type-Options "nosniff"                       always;
+            add_header X-Frame-Options        "SAMEORIGIN"                    always;
+            add_header X-XSS-Protection       "1; mode=block"                 always;
+            add_header Referrer-Policy        "strict-origin-when-cross-origin" always;
+        }
+
         # ── API reverse proxy ─────────────────────────────────────────────────
         # All /api/* requests are forwarded to the FastAPI container.
         # The container is reachable by its service name on the Docker network.
@@ -44,8 +76,11 @@ http {
             proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
             proxy_set_header   X-Forwarded-Proto $scheme;
 
-            # Don't cache API responses
+            add_header Cache-Control          "no-store"                      always;
-            add_header Cache-Control "no-store";
+            add_header X-Content-Type-Options "nosniff"                       always;
+            add_header X-Frame-Options        "SAMEORIGIN"                    always;
+            add_header X-XSS-Protection       "1; mode=block"                 always;
+            add_header Referrer-Policy        "strict-origin-when-cross-origin" always;
         }
 
         # ── Custom error pages ────────────────────────────────────────────────