Use environment variables properly.

app/pkg/logsviewer/client.go

@@ -3,9 +3,18 @@ package logsviewer
 import (
 	"context"
 	"encoding/json"
+	"github.com/go-logr/zapr"
 	"github.com/jlewi/foyle/app/api"
+	"github.com/maxence-charriere/go-app/v9/pkg/app"
+	"github.com/pkg/errors"
+	"go.uber.org/zap"
 	"io"
 	"net/http"
+	"strings"
+)
+
+var (
+	defaultClient *LogsClient
 )
 
 // LogsClient client for the logs service.
@@ -31,3 +40,24 @@ func (c *LogsClient) GetBlockLog(ctx context.Context, blockID string) (*api.Bloc
 	}
 	return block, nil
 }
+
+func GetClient() *LogsClient {
+	if defaultClient == nil {
+		log := zapr.NewLogger(zap.L())
+		// N.B. I think using EndpointEnvVar is better using Window().Location().Href because of how we would deal with
+		// Reverse proxies. If we're behind some sort of reverse proxy we'd probably want the server to set the
+		// appropriate baseURL
+		endpoint := app.Getenv(EndpointEnvVar)
+		if endpoint == "" {
+			log.Error(errors.New("EndpointEnvVar is not set"), "Failed to create logsclient")
+		}
+		if !strings.HasSuffix(endpoint, "/") {
+			endpoint = endpoint + "/"
+		}
+		log.Info("Creating logs client", "endpoint", endpoint)
+		defaultClient = &LogsClient{
+			Endpoint: endpoint,
+		}
+	}
+	return defaultClient
+}

app/pkg/logsviewer/selector.go

@@ -1,9 +1,7 @@
 package logsviewer
 
 import (
-	"github.com/go-logr/zapr"
 	"github.com/maxence-charriere/go-app/v9/pkg/app"
-	"go.uber.org/zap"
 	"strings"
 )
 
@@ -30,23 +28,14 @@ func (h *blockSelector) Render() app.UI {
 		app.Button().
 			Text("Display").
 			OnClick(func(ctx app.Context, e app.Event) {
-				// Handle button click event here
-				// TODO(jeremy): Using os.Getenv is not working as a way of passing values from the server to the
-				// client.
-				// endpoint := os.Getenv(EndpointEnvVar)
-				endpoint := "http://localhost:8080/"
-				client := LogsClient{
-					Endpoint: endpoint,
-				}
+				client := GetClient()
 				blockID := app.Window().GetElementByID(blockInputID).Get("value").String()
 				blockID = strings.TrimSpace(blockID)
 				if blockID == "" {
 					h.traceValue = "No Block ID provided"
 					h.Update()
 					return
 				}
-				log := zapr.NewLogger(zap.L())
-				log.Info("Fetching block log", "blockID", blockID, "endpoint", endpoint)
 				blockLog, err := client.GetBlockLog(ctx, blockID)
 				if err != nil {
 					ctx.SetState(getErrorState, err.Error())