refactor: move http api to a new transport layer

internal/roles/host/gateway.go

@@ -0,0 +1,96 @@
+package host
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+
+	"git.wzray.com/homelab/hivemind/internal/config"
+	"github.com/rs/zerolog/log"
+)
+
+type TraefikListener interface {
+	OnTraefikUpdate(traefikResponse)
+}
+
+type TraefikGateway struct {
+	client   *http.Client
+	server   *http.Server
+	listener TraefikListener
+	address  url.URL
+	domain   string
+}
+
+func NewTraefikGateway(cfg config.HostConfig, listener TraefikListener) *TraefikGateway {
+	mux := http.NewServeMux()
+	gw := &TraefikGateway{
+		client: &http.Client{},
+
+		server: &http.Server{
+			Addr:    cfg.ListenAddress,
+			Handler: mux,
+		},
+		listener: listener,
+		address: url.URL{
+			Scheme: "http",
+			Host:   cfg.LocalAddress,
+		},
+		domain: cfg.Domain,
+	}
+
+	mux.HandleFunc("/callback", gw.onCallback)
+	return gw
+}
+
+func (g *TraefikGateway) Listen() error {
+	return g.server.ListenAndServe()
+}
+
+func (g *TraefikGateway) Shutdown(ctx context.Context) error {
+	return g.server.Shutdown(ctx)
+}
+
+func (g *TraefikGateway) GetRawData() (*traefikResponse, error) {
+	var raw TraefikRawResponse
+
+	url := g.address
+	url.Path = "/api/rawdata"
+
+	req := http.Request{
+		Method: http.MethodGet,
+		URL:    &url,
+	}
+
+	req.Host = g.domain
+
+	r, err := g.client.Do(&req)
+	if err != nil {
+		return nil, fmt.Errorf("make request: %w", err)
+	}
+	defer r.Body.Close()
+
+	if err := json.NewDecoder(r.Body).Decode(&raw); err != nil {
+		return nil, fmt.Errorf("unmarshal body: %w", err)
+	}
+
+	out := parseTraefikResponse(raw)
+	return &out, nil
+}
+
+func (g *TraefikGateway) onCallback(w http.ResponseWriter, req *http.Request) {
+	var raw TraefikRawResponse
+	if err := json.NewDecoder(req.Body).Decode(&raw); err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		log.Err(err).Msg("unable to decode traefik callback data")
+		return
+	}
+
+	resp := parseTraefikResponse(raw)
+	if g.listener != nil {
+		g.listener.OnTraefikUpdate(resp)
+	}
+
+	w.Write([]byte("OK"))
+}