https://github.com/alexdlaird/java-ngrok-example-spring

Spring example for java-ngrok
https://github.com/alexdlaird/java-ngrok-example-spring

education java java-ngrok localhost localtunnel ngrok reverse-proxy spring spring-boot spring-web tunnel tunneling webhook

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Spring example for java-ngrok

• Host: GitHub
• URL: https://github.com/alexdlaird/java-ngrok-example-spring
• Owner: alexdlaird
• License: mit
• Created: 2021-08-23T17:42:51.000Z (about 3 years ago)
• Default Branch: main
• Last Pushed: 2024-04-22T13:01:17.000Z (7 months ago)
• Last Synced: 2024-05-02T05:50:25.700Z (7 months ago)
• Topics: education, java, java-ngrok, localhost, localtunnel, ngrok, reverse-proxy, spring, spring-boot, spring-web, tunnel, tunneling, webhook
• Language: Java
• Homepage: https://github.com/alexdlaird/java-ngrok
• Size: 146 KB
• Stars: 5
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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# java-ngrok Example - Spring

This is an example project that shows how to easily integrate [`java-ngrok`](https://github.com/alexdlaird/java-ngrok)

with [Spring](https://spring.io/guides/gs/spring-boot/).

## Configuration

Create a [`NgrokConfiguration`](https://github.com/alexdlaird/java-ngrok-example-spring/blob/main/src/main/java/com/github/alexdlaird/ngrok/example/spring/conf/NgrokConfiguration.java)

class that lets us use the config to enable `ngrok` and pass it some useful parameters.

```java

@Component

@Getter

@Setter

@ConfigurationProperties(prefix = "ngrok")

public class NgrokConfiguration {

    private boolean enabled;

    private String region;

    public boolean isEnabled() {

        return enabled;

    }

    public void setEnabled(boolean enabled) {

        this.enabled = enabled;

    }

}

```

And pass parameters to our Spring application through

[our config file](https://github.com/alexdlaird/java-ngrok-example-spring/blob/main/src/main/resources/application.properties):

```yaml

spring.profiles.active=dev

ngrok.enabled=true

```

## Application Integration

If `ngrok.enabled` config flag is set, we want to initialize `java-ngrok` when Spring is booting. An easy way to do

this is by creating [a `Component` with an `EventListener`](https://github.com/alexdlaird/java-ngrok-example-spring/blob/main/src/main/java/com/github/alexdlaird/ngrok/example/spring/NgrokWebServerEventListener.java)

that is executed when `WebServerInitializedEvent` is emitted.

```java

@Component

@Profile("dev")

public class NgrokWebServerEventListener {

    private static final Logger LOGGER = LoggerFactory.getLogger(NgrokWebServerEventListener.class);

    private final Environment environment;

    private final NgrokConfiguration ngrokConfiguration;

    @Autowired

    public NgrokWebServerEventListener(final Environment environment,

                                       final NgrokConfiguration ngrokConfiguration) {

        this.environment = environment;

        this.ngrokConfiguration = ngrokConfiguration;

    }

    @EventListener

    public void onApplicationEvent(final WebServerInitializedEvent event) {

        // java-ngrok will only be installed, and should only ever be initialized, in a dev environment

        if (ngrokConfiguration.isEnabled() && isNotBlank(System.getenv("NGROK_AUTHTOKEN"))) {

            final JavaNgrokConfig javaNgrokConfig = new JavaNgrokConfig.Builder()

                    .withRegion(nonNull(ngrokConfiguration.getRegion()) ? Region.valueOf(ngrokConfiguration.getRegion().toUpperCase()) : null)

                    .build();

            final NgrokClient ngrokClient = new NgrokClient.Builder()

                    .withJavaNgrokConfig(javaNgrokConfig)

                    .build();

            final int port = event.getWebServer().getPort();

            final CreateTunnel createTunnel = new CreateTunnel.Builder()

                    .withAddr(port)

                    .build();

            final Tunnel tunnel = ngrokClient.connect(createTunnel);

            LOGGER.info(String.format("ngrok tunnel \"%s\" -> \"http://127.0.0.1:%d\"", tunnel.getPublicUrl(), port));

            // Update any base URLs or webhooks to use the public ngrok URL

            initWebhooks(tunnel.getPublicUrl());

        }

    }

    private void initWebhooks(final String publicUrl) {

        // Update inbound traffic via APIs to use the public-facing ngrok URL

    }

}

```

Now Spring can be started by the usual means, setting `ngrok.enabled` in the config to open a tunnel.

1. Run `make build` to build the application

1. Start application with `java -jar build/libs/java-ngrok-example-spring-1.0.0-SNAPSHOT.jar`

1. Check the logs for the `ngrok` tunnel's public URL, which should tunnel to  `http://localhost:8080`