feedkit: split the former maximumdirect.net/weatherd project in two.

feedkit now contains a reusable core, while weatherfeeder is a concrete implementation that includes weather-specific functions.

sinks/builtins.go

@@ -0,0 +1,55 @@
+package sinks
+
+import (
+	"fmt"
+	"strings"
+
+	"gitea.maximumdirect.net/ejr/feedkit/config"
+)
+
+// RegisterBuiltins registers sink drivers included in this binary.
+//
+// In feedkit, these are "infrastructure primitives" — they are not domain-specific.
+// Individual daemons can choose to call this (or register their own custom sinks).
+func RegisterBuiltins(r *Registry) {
+	// Stdout sink: great for debugging, piping to jq, etc.
+	r.Register("stdout", func(cfg config.SinkConfig) (Sink, error) {
+		return NewStdoutSink(cfg.Name), nil
+	})
+
+	// File sink: writes/archives events somewhere on disk.
+	r.Register("file", func(cfg config.SinkConfig) (Sink, error) {
+		return NewFileSinkFromConfig(cfg)
+	})
+
+	// Postgres sink: persists events durably.
+	r.Register("postgres", func(cfg config.SinkConfig) (Sink, error) {
+		return NewPostgresSinkFromConfig(cfg)
+	})
+
+	// RabbitMQ sink: publishes events to a broker for downstream consumers.
+	r.Register("rabbitmq", func(cfg config.SinkConfig) (Sink, error) {
+		return NewRabbitMQSinkFromConfig(cfg)
+	})
+}
+
+// ---- helpers for validating sink params ----
+//
+// These helpers live in sinks (not config) on purpose:
+// - config is domain-agnostic and should not embed driver-specific validation helpers.
+// - sinks are adapters; validating their own params here keeps the logic near the driver.
+
+func requireStringParam(cfg config.SinkConfig, key string) (string, error) {
+	v, ok := cfg.Params[key]
+	if !ok {
+		return "", fmt.Errorf("sink %q: params.%s is required", cfg.Name, key)
+	}
+	s, ok := v.(string)
+	if !ok {
+		return "", fmt.Errorf("sink %q: params.%s must be a string", cfg.Name, key)
+	}
+	if strings.TrimSpace(s) == "" {
+		return "", fmt.Errorf("sink %q: params.%s cannot be empty", cfg.Name, key)
+	}
+	return s, nil
+}