Add a scheduled task to ping home (#560)

* Add a scheduled task to ping home

* Removed commented logging code

* Add docstrings to ping scheduled task

* Move IP address API URI to a constant

Author: sharat87

app/server/appsmith-server/src/main/java/com/appsmith/server/ServerApplication.java

@@ -2,8 +2,10 @@
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.scheduling.annotation.EnableScheduling;
 
 @SpringBootApplication
+@EnableScheduling
 public class ServerApplication {
 
     public static void main(String[] args) {

app/server/appsmith-server/src/main/java/com/appsmith/server/solutions/PingScheduledTask.java

@@ -0,0 +1,76 @@
+package com.appsmith.server.solutions;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.http.MediaType;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.BodyInserters;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Schedulers;
+
+import java.net.URI;
+import java.util.Map;
+
+/**
+ * This class represents a scheduled task that pings a data point indicating that this server installation is live.
+ */
+@Component
+@ConditionalOnProperty(prefix = "is", name = "self-hosted")
+@Slf4j
+public class PingScheduledTask {
+
+    public static final URI GET_IP_URI = URI.create("https://api6.ipify.org");
+
+    /**
+     * Gets the external IP address of this server and pings a data point to indicate that this server instance is live.
+     */
+    // Number of milliseconds between the start of each scheduled calls to this method.
+    @Scheduled(fixedRate = 6 * 60 * 60 * 1000 /* six hours */)
+    public void pingSchedule() {
+        getInstallationId()
+                .flatMap(this::doPing)
+                .doOnError(error -> log.debug("Error pinging home", error))
+                .subscribeOn(Schedulers.single())
+                .subscribe();
+    }
+
+    /**
+     * This method hits an API endpoint that returns the external IP address of this server instance.
+     * @return A publisher that yields the IP address.
+     */
+    private Mono<String> getInstallationId() {
+        return WebClient
+                .create()
+                .get()
+                .uri(GET_IP_URI)
+                .retrieve()
+                .bodyToMono(String.class);
+    }
+
+    /**
+     * Given a unique ID (called a `userId` here), this method hits the Segment API to save a data point on this server
+     * instance being live.
+     * @param userId A unique identifier for this server instance (usually, the external IP address of the server).
+     * @return A publisher that yields the string response of recording the data point.
+     */
+    private Mono<String> doPing(String userId) {
+        // Note: Hard-coding Segment auth header and the event name intentionally. These are not intended to be
+        // environment specific values, instead, they are common values for all self-hosted environments. As such, they
+        // are not intended to be configurable.
+        return WebClient
+                .create("https://api.segment.io")
+                .post()
+                .uri("/v1/track")
+                .header("Authorization", "Basic QjJaM3hXRThXdDRwYnZOWDRORnJPNWZ3VXdnYWtFbk06")
+                .contentType(MediaType.APPLICATION_JSON)
+                .body(BodyInserters.fromValue(Map.of(
+                        "userId", userId,
+                        "event", "Instance Active"
+                )))
+                .retrieve()
+                .bodyToMono(String.class);
+    }
+
+}

app/server/appsmith-server/src/main/resources/application.properties

@@ -57,6 +57,9 @@ marketplace.base-url = ${APPSMITH_MARKETPLACE_URL:}
 marketplace.username=${APPSMITH_MARKETPLACE_USERNAME:}
 marketplace.password=${APPSMITH_MARKETPLACE_PASSWORD:}
 
+# Is this a self-hosted instance?
+is.self-hosted = ${APPSMITH_IS_SELF_HOSTED:true}
+
 # MANDATORY!! No default properties are being provided for encryption password and salt for security.
 # The server would not come up without these values provided through the environment variables.
 encrypt.password=${APPSMITH_ENCRYPTION_PASSWORD:}