Make frontend proxy URL configurable within the react-native app

CHANGELOG.md

@@ -105,6 +105,8 @@ the release.
   ([#2503](https://github.com/open-telemetry/opentelemetry-demo/pull/2503))
 * [grafana] APM dashboard: Add host metrics per service instance
   ([#2507](https://github.com/open-telemetry/opentelemetry-demo/pull/2507))
+* [react-native-app] Make frontend proxy URL configurable through app settings
+  ([#2531](https://github.com/open-telemetry/opentelemetry-demo/pull/2531))
 
 ## 2.0.2
 

src/react-native-app/README.md

@@ -100,6 +100,13 @@ This will create a `react-native-app.apk` file in the directory where you ran
 the command. If you have an Android emulator running on your machine then you
 can drag and drop this file onto the emulator's window in order to install it.
 
+## Pointing to another demo environment
+
+By default, the app will point to `EXPO_PUBLIC_FRONTEND_PROXY_PORT` on
+localhost to interact with the demo APIs. This can be changed in the Settings
+tab when running the app to point to a demo environment running on a
+different server.
+
 ## Troubleshooting
 
 ### JS Bundle: build issues

src/react-native-app/app/(tabs)/_layout.tsx

@@ -44,6 +44,19 @@ export default function TabLayout() {
           ),
         }}
       />
+      <Tabs.Screen
+        name="settings"
+        options={{
+          title: "Settings",
+          tabBarShowLabel: false,
+          tabBarIcon: ({ color, focused }) => (
+            <TabBarIcon
+              name={focused ? "settings" : "settings-outline"}
+              color={color}
+            />
+          ),
+        }}
+      />
     </Tabs>
   );
 }

src/react-native-app/app/(tabs)/settings.tsx

@@ -0,0 +1,40 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+import { useQueryClient } from '@tanstack/react-query'
+import { ThemedView } from "@/components/ThemedView";
+import { StyleSheet } from "react-native";
+import { getFrontendProxyURL, setFrontendProxyURL } from "@/utils/Settings";
+import { setupTracerProvider } from "@/hooks/useTracer";
+import { trace } from "@opentelemetry/api";
+import { Setting } from "@/components/Setting";
+
+export default function Settings() {
+  const queryClient = useQueryClient()
+
+  const onSetFrontendProxyURL = async (value: string) => {
+    await setFrontendProxyURL(value);
+
+    // Clear any cached queries since we now have a new endpoint to hit for everything
+    await queryClient.invalidateQueries();
+
+    // Need to setup a new tracer provider since the export URL for traces has now changed
+    trace.disable();
+    const provider = setupTracerProvider(value);
+    trace.setGlobalTracerProvider(provider);
+  };
+
+  return (
+    <ThemedView style={styles.container}>
+      <Setting name="Frontend Proxy URL" get={getFrontendProxyURL} set={onSetFrontendProxyURL} />
+    </ThemedView>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    display: "flex",
+    gap: 20,
+    paddingLeft: 20,
+    height: "100%",
+  },
+});

src/react-native-app/components/ProductCard/ProductCard.tsx

@@ -6,19 +6,19 @@
 import { Product } from "@/protos/demo";
 import { ThemedView } from "@/components/ThemedView";
 import { useState, useEffect, useMemo } from "react";
-import getLocalhost from "@/utils/Localhost";
 import { Image, Pressable, StyleSheet } from "react-native";
 import { ThemedText } from "@/components/ThemedText";
 import { useThemeColor } from "@/hooks/useThemeColor";
+import getFrontendProxyURL from "@/utils/Settings";
 
 interface IProps {
   product: Product;
   onClickAdd: () => void;
 }
 
 async function getImageURL(picture: string) {
-  const localhost = await getLocalhost();
-  return `http://${localhost}:${process.env.EXPO_PUBLIC_FRONTEND_PROXY_PORT}/images/products/${picture}`;
+  const proxyURL = await getFrontendProxyURL();
+  return `${proxyURL}/images/products/${picture}`;
 }
 
 const ProductCard = ({

src/react-native-app/components/Setting.tsx

@@ -0,0 +1,76 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+import {Pressable, StyleSheet, TextInput, type TextInputProps} from "react-native";
+import { ThemedView } from "@/components/ThemedView";
+import { ThemedText } from "@/components/ThemedText";
+import { useThemeColor } from "@/hooks/useThemeColor";
+import {useCallback, useEffect, useState} from "react";
+import Toast from "react-native-toast-message";
+
+export type SettingProps = TextInputProps & {
+  name: string;
+  get: () => Promise<string>;
+  set: (value: string) => Promise<void>;
+};
+
+export function Setting({ name, get, set, ...otherProps }: SettingProps) {
+  const color = useThemeColor({}, "text");
+  const [loading, setLoading] = useState(false);
+  const [text, setText] = useState('');
+
+  useEffect(() => {
+    get().then(existingValue => {
+      setText(existingValue);
+      setLoading(false);
+    });
+  }, []);
+
+  const onApply = useCallback(async () => {
+    await set(text);
+
+    Toast.show({
+      type: "success",
+      position: "bottom",
+      text1: `${name} applied`,
+    });
+  }, [text]);
+
+  return (
+    <ThemedView style={styles.container}>
+      <ThemedText>{name}:</ThemedText>
+      {loading ? (
+        <ThemedText>Fetching current value...</ThemedText>
+      ) : (
+        <>
+          <TextInput
+            style={{ color }}
+            onChangeText={setText}
+            value={text}
+             {...otherProps}
+          />
+          <Pressable style={styles.apply} onPress={onApply}>
+            <ThemedText style={styles.applyText}>Apply</ThemedText>
+          </Pressable>
+        </>
+      )}
+    </ThemedView>
+  );
+}
+
+
+const styles = StyleSheet.create({
+  container: {
+    display: "flex",
+    gap: 5,
+  },
+  apply: {
+    borderRadius: 4,
+    backgroundColor: "green",
+    alignItems: "center",
+    width: 100,
+    position: "relative",
+  },
+  applyText: {
+    color: "white",
+  },
+});

src/react-native-app/hooks/useTracer.ts

@@ -21,7 +21,6 @@ import {
   ATTR_SERVICE_VERSION,
 } from "@opentelemetry/semantic-conventions/incubating";
 import { OTLPTraceExporter } from "@opentelemetry/exporter-trace-otlp-http";
-import getLocalhost from "@/utils/Localhost";
 import { useEffect, useState } from "react";
 import {
   getDeviceId,
@@ -30,10 +29,9 @@ import {
 } from "react-native-device-info";
 import { Platform } from "react-native";
 import { SessionIdProcessor } from "@/utils/SessionIdProcessor";
+import getFrontendProxyURL from "@/utils/Settings";
 
-const Tracer = async () => {
-  const localhost = await getLocalhost();
-
+export const setupTracerProvider = (proxyURL: string) => {
   // TODO Should add a resource detector for React Native that provides this automatically
   const resource = resourceFromAttributes({
     [ATTR_SERVICE_NAME]: "react-native-app",
@@ -49,23 +47,27 @@ const Tracer = async () => {
   //  for React Native.
   //  Alternatively could offer a TracerProvider that exposed a JS interface on top of the OTEL Android and Swift SDKS,
   //  giving developers the option of collecting telemetry at the native mobile layer
-  const provider = new WebTracerProvider({
+  return new WebTracerProvider({
     resource,
     spanProcessors: [
       new BatchSpanProcessor(
         new OTLPTraceExporter({
-          url: `http://${localhost}:${process.env.EXPO_PUBLIC_FRONTEND_PROXY_PORT}/otlp-http/v1/traces`,
+          url: `${proxyURL}/otlp-http/v1/traces`,
         }),
         {
           scheduledDelayMillis: 500,
         },
       ),
-
       // TODO introduce a React Native session processor package that could be used here, taking into account mobile
       // specific considerations for the session such as putting the app into the background
       new SessionIdProcessor(),
     ],
   });
+}
+
+const Tracer = async () => {
+  const proxyURL = await getFrontendProxyURL();
+  const provider = setupTracerProvider(proxyURL);
 
   provider.register({
     propagator: new CompositePropagator({

src/react-native-app/utils/Request.ts

@@ -3,7 +3,7 @@
 /**
  * Copied with modification from src/frontend/utils/Request.ts
  */
-import getLocalhost from "@/utils/Localhost";
+import getFrontendProxyURL from "@/utils/Settings";
 
 interface IRequestParams {
   url: string;
@@ -22,9 +22,8 @@ const request = async <T>({
     "content-type": "application/json",
   },
 }: IRequestParams): Promise<T> => {
-  const localhost = await getLocalhost();
-  const API_URL = `http://${localhost}:${process.env.EXPO_PUBLIC_FRONTEND_PROXY_PORT}`;
-  const requestURL = `${API_URL}${url}?${new URLSearchParams(queryParams).toString()}`;
+  const proxyURL = await getFrontendProxyURL();
+  const requestURL = `${proxyURL}${url}?${new URLSearchParams(queryParams).toString()}`;
   const requestBody = body ? JSON.stringify(body) : undefined;
   const response = await fetch(requestURL, {
     method,

src/react-native-app/utils/Settings.ts

@@ -0,0 +1,22 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+import AsyncStorage from "@react-native-async-storage/async-storage";
+import getLocalhost from "@/utils/Localhost";
+
+const FRONTEND_PROXY_URL_SETTING = 'frontend_proxy_url';
+
+export const getFrontendProxyURL = async (): Promise<string> => {
+  const proxyURL = await AsyncStorage.getItem(FRONTEND_PROXY_URL_SETTING);
+  if (proxyURL) {
+    return proxyURL
+  } else {
+    const localhost = await getLocalhost();
+    return `http://${localhost}:${process.env.EXPO_PUBLIC_FRONTEND_PROXY_PORT}`;
+  }
+};
+
+export const setFrontendProxyURL = async (url: string) => {
+  await AsyncStorage.setItem(FRONTEND_PROXY_URL_SETTING, url);
+}
+
+export default getFrontendProxyURL;