Proxy Hosts#

Proxy hosts are the core resource in PosternProxy. Each one tells Caddy to accept traffic for one or more domain names and forward it to an upstream service.

What a proxy host does#

When you create a proxy host, PosternProxy:

  1. Adds a Caddy route that matches the specified domain names
  2. Optionally enforces HTTPS and HSTS
  3. Forwards matching requests to the configured upstream (or load-balances across multiple upstreams)
  4. Optionally applies an access list, rate limit, custom headers, or custom error pages
  5. Manages TLS automatically via Let’s Encrypt (unless you supply a custom certificate)

The form tabs#

The Add / Edit Proxy Host modal has the following tabs:

TabPurpose
DetailsDomain names, primary upstream, basic options
UpstreamsExtra backends for load balancing
SSLCertificate selection, HTTPS enforcement, HSTS
LocationsSub-path routing overrides
HealthActive and passive health check settings
SecurityAccess list, rate limiting
ErrorsCustom HTML for 404/502/503 responses
HeadersRequest and response header injection
AdvancedRaw Caddy JSON merged into the route

Quick reference#

SettingDescription
Domain NamesOne or more hostnames (press Enter after each)
Forward Schemehttp or https — protocol used to reach your upstream
Forward Hostname / IPInternal address of the service to proxy
PortUpstream port number
Websocket SupportEnables Upgrade header pass-through
Block ExploitsAdds Caddy request-blocking rules for common exploit patterns
Cache Assets(UI label) — sets Cache-Control on static asset responses

Enable / disable#

Each proxy host can be toggled on or off without deleting it. When disabled, Caddy removes the route immediately; traffic returns a 404 until re-enabled.

Sub-pages#