1 files changed, 49 insertions, 0 deletions
diff --git a/source/url.go b/source/url.go
new file mode 100644
index 0000000..067d48b
--- /dev/null
+++ b/source/url.go
@@ -0,0 +1,49 @@
+package source
+
+import (
+	"fmt"
+	"log/slog"
+	"net/netip"
+	nurl "net/url"
+)
+
+// a simple source that fetches an address from a url.
+// sends a http get request to url, and parses whatever it found there.
+// can be used to fetch address values from generic "my ip"
+// services which don't have direct support.
+// note that the address does have to be returned in plain-text!
+type urlSource struct {
+	log    *slog.Logger
+	url    *nurl.URL
+	family Family
+}
+
+var _ Source = (*urlSource)(nil)
+
+func newURL(log *slog.Logger, cfg Config) (*urlSource, error) {
+	log = log.With("source", "url")
+
+	url, err := nurl.ParseRequestURI(cfg.URL)
+	if err != nil {
+		return nil, fmt.Errorf("invalid url for source: %w", err)
+	}
+
+	return &urlSource{log: log, url: url, family: cfg.Family}, nil
+}
+
+func (s *urlSource) Supports(f Family) bool { return f == s.family }
+
+func (s *urlSource) Lookup(Family) (netip.Addr, error) {
+	s.log.Info(
+		"will look up address via fetching from url",
+		slog.String("url", s.url.String()),
+		slog.String("family", string(s.family)),
+	)
+
+	addr, err := fetch(s.url.String(), s.family)
+	if err != nil {
+		return netip.Addr{}, fmt.Errorf("failed to source address from url: %w", err)
+	}
+
+	return addr, nil
+}