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- Add beautiful HTML email templates for receipts, admin notifications, and contact forms - Implement SMTP email service with Nodemailer and Handlebars templating - Add carbon equivalency calculations with EPA/DEFRA/IMO 2024 conversion factors - Add portfolio color palette system for project visualization - Integrate Wren API portfolio fetching in webhook handler - Add light mode enforcement for email client compatibility - Include Puffin logo from MinIO S3 in all templates - Add test email endpoint for template validation 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>
134 lines
3.0 KiB
Markdown
134 lines
3.0 KiB
Markdown
# DNS Troubleshooting Guide for Puffin Backend
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## Current Issue
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Backend container cannot resolve `api.wren.co` despite DNS servers (8.8.8.8, 8.8.4.4) configured in docker-compose.yml.
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## Diagnostic Steps
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### 1. Verify DNS Config in Running Container
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```bash
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docker exec puffin-backend cat /etc/resolv.conf
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```
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**Expected**: Should show `nameserver 8.8.8.8` and `nameserver 8.8.4.4`
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**If not**: Container wasn't recreated properly
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### 2. Test DNS Resolution from Container
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```bash
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# Test with nslookup (if available)
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docker exec puffin-backend nslookup api.wren.co
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# Test with getent (usually available)
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docker exec puffin-backend getent hosts api.wren.co
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# Test with wget
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docker exec puffin-backend wget -O- --timeout=5 https://api.wren.co/v1/offset_orders 2>&1 | head -20
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```
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### 3. Check if Host Can Resolve DNS
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```bash
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# On the host machine
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nslookup api.wren.co
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ping api.wren.co
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```
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**If host can't resolve**: Host DNS issue, not Docker issue
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### 4. Check Docker Daemon DNS Configuration
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```bash
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# Check Docker daemon config
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cat /etc/docker/daemon.json
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# Check Docker network DNS
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docker network inspect puffin-network | grep -A 5 "IPAM"
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```
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### 5. Test with Different DNS Servers
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Try Cloudflare DNS instead of Google:
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```yaml
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dns:
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- 1.1.1.1
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- 1.0.0.1
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```
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### 6. Check Firewall Rules
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```bash
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# Check if firewall is blocking DNS from containers
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sudo iptables -L -n | grep -i dns
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sudo ufw status verbose
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# Temporarily disable firewall to test (BE CAREFUL)
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sudo ufw disable
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# Test, then re-enable:
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sudo ufw enable
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```
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### 7. Check Docker Network Isolation
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```bash
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# Check if Docker bridge has internet access
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docker run --rm busybox ping -c 3 8.8.8.8
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docker run --rm busybox nslookup api.wren.co 8.8.8.8
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```
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## Solutions to Try
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### Solution 1: Use Host Network Mode (Testing Only)
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**WARNING**: Less secure, only for testing
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```yaml
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backend:
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network_mode: "host"
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# Remove 'networks' and 'ports' when using host mode
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```
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### Solution 2: Update Docker Daemon DNS
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Edit `/etc/docker/daemon.json`:
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```json
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{
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"dns": ["8.8.8.8", "8.8.4.4"]
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}
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```
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Then restart Docker:
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```bash
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sudo systemctl restart docker
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```
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### Solution 3: Use Host's DNS Resolver
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```yaml
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backend:
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dns:
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- 8.8.8.8
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- 8.8.4.4
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extra_hosts:
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- "api.wren.co:HOST_IP_HERE"
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```
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### Solution 4: Disable Docker's Userland Proxy
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Edit `/etc/docker/daemon.json`:
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```json
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{
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"userland-proxy": false,
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"dns": ["8.8.8.8", "8.8.4.4"]
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}
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```
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### Solution 5: Force Recreate with Network Cleanup
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```bash
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# Stop everything
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docker-compose down
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# Remove network
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docker network rm puffin-network
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# Recreate with proper DNS
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docker-compose up -d --force-recreate
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```
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## Current Status
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- ✅ DNS servers added to docker-compose.yml (8.8.8.8, 8.8.4.4)
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- ✅ Stripe webhooks working (proves network connectivity works)
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- ❌ DNS resolution failing with ENOTFOUND api.wren.co
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- ❌ Error occurs after only 26ms (DNS query not reaching nameservers)
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## Next Actions
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1. Run diagnostic commands above to identify exact failure point
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2. Check if issue is container-specific or host-wide
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3. Apply appropriate solution based on findings
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