feat(chart): add hostAliases support to main, worker, and webhook-processor pods

[Vishesh-Gupta]

Summary

Adds an optional hostAliases values.yaml key that's templated into /etc/hosts on all three pod types (main, worker, webhook-processor), following the same {{- with .Values.X }} pattern already used for nodeSelector/tolerations/affinity.

Motivation

When self-hosting n8n behind a tunnel/reverse-proxy setup (e.g. Cloudflare Tunnel, or a private-network SaaS connector), n8n's own outbound requests to its own public hostname (N8N_HOST/WEBHOOK_URL) — for example the MCP OAuth server's discovery/token endpoints, which n8n's own OAuth client and third-party MCP clients hit at that public FQDN — have to leave the cluster/VPC and hairpin back in through the external ingress path. This can break in setups where:

• The tunnel/proxy actively disallows loopback ("hairpin") traffic, or
• The client hitting WEBHOOK_URL needs a same-Host-header request served entirely inside the private network for latency/security reasons.

hostAliases lets operators pin the pod's own public hostname directly to an internal ClusterIP/private IP so this traffic never leaves the cluster, without needing external DNS changes.

Changes

• charts/n8n/templates/deployment-main.yaml, deployment-worker.yaml, deployment-webhook-processor.yaml: render spec.hostAliases from .Values.hostAliases when set (no-op otherwise).
• charts/n8n/values.yaml: new hostAliases: [] default with documentation comment and example.
• charts/n8n/values.schema.json: schema for the new key.

Test plan

• helm lint charts/n8n passes.
• helm template with hostAliases set renders correctly on main, worker (queue mode), and webhook-processor pods.
• helm template with default values (no hostAliases) produces no hostAliases key in any pod spec — fully backward compatible.

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Summary by cubic

Adds optional hostAliases to the Helm chart to inject /etc/hosts entries for the main, worker, and webhook-processor pods. This lets pods resolve n8n’s public hostname to an internal IP to avoid hairpinning through external ingress or tunnels.

• New Features
  • Adds .Values.hostAliases (default [], schema-validated) with docs in values.yaml.
  • Renders spec.hostAliases in all three deployments when set; no-op when unset.

^{Written for commit c3ef66d. Summary will update on new commits.}

[Vishesh-Gupta]

@krider2010 can someone review this? I believe this would be a good addition