forked from codegangsta/caddy-nats
/
publish.go
79 lines (63 loc) · 1.93 KB
/
publish.go
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package publish
import (
"fmt"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
"github.com/caddyserver/caddy/v2/modules/caddyhttp"
"github.com/sandstorm/caddy-nats-bridge/common"
"github.com/sandstorm/caddy-nats-bridge/natsbridge"
"go.uber.org/zap"
"net/http"
)
type Publish struct {
Subject string `json:"subject,omitempty"`
ServerAlias string `json:"serverAlias,omitempty"`
logger *zap.Logger
app *natsbridge.NatsBridgeApp
}
func (Publish) CaddyModule() caddy.ModuleInfo {
return caddy.ModuleInfo{
ID: "http.handlers.nats_publish",
New: func() caddy.Module {
// Default values
return &Publish{
ServerAlias: "default",
}
},
}
}
func (p *Publish) Provision(ctx caddy.Context) error {
p.logger = ctx.Logger(p)
natsAppIface, err := ctx.App("nats")
if err != nil {
return fmt.Errorf("getting NATS app: %v. Make sure NATS is configured in nats options", err)
}
p.app = natsAppIface.(*natsbridge.NatsBridgeApp)
return nil
}
func (p Publish) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
repl := r.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
common.AddNATSPublishVarsToReplacer(repl, r)
//TODO: What method is best here? ReplaceAll vs ReplaceWithErr?
subj := repl.ReplaceAll(p.Subject, "")
p.logger.Debug("publishing NATS message", zap.String("subject", subj))
server, ok := p.app.Servers[p.ServerAlias]
if !ok {
return fmt.Errorf("NATS server alias %s not found", p.ServerAlias)
}
msg, err := common.NatsMsgForHttpRequest(r, subj)
if err != nil {
return err
}
err = server.Conn.PublishMsg(msg)
if err != nil {
return fmt.Errorf("could not publish NATS message: %w", err)
}
// TODO: wiretap mode :) -> Response to NATS.
return next.ServeHTTP(w, r)
}
var (
_ caddyhttp.MiddlewareHandler = (*Publish)(nil)
_ caddy.Provisioner = (*Publish)(nil)
_ caddyfile.Unmarshaler = (*Publish)(nil)
)