Adding /ping resource for deep health checks

8 files changed, 178 insertions, 1 deletions

diff --git a/src/main/java/com/p4square/f1oauth/FellowshipOneIntegrationDriver.java b/src/main/java/com/p4square/f1oauth/FellowshipOneIntegrationDriver.java
index 865f5d6..d3690af 100644
--- a/src/main/java/com/p4square/f1oauth/FellowshipOneIntegrationDriver.java
+++ b/src/main/java/com/p4square/f1oauth/FellowshipOneIntegrationDriver.java
@@ -52,4 +52,11 @@ public class FellowshipOneIntegrationDriver implements IntegrationDriver {
     public ProgressReporter getProgressReporter() {
         return mProgressReporter;
     }
+
+    @Override
+    public boolean doHealthCheck() {
+        // Since I no longer have access to an F1 account,
+        // this will remain unimplemented until it's needed.
+        throw new UnsupportedOperationException("Health check is not yet implemented for the F1 driver.");
+    }
 }
diff --git a/src/main/java/com/p4square/grow/backend/GrowBackend.java b/src/main/java/com/p4square/grow/backend/GrowBackend.java
index c7b9f42..a51c04a 100644
--- a/src/main/java/com/p4square/grow/backend/GrowBackend.java
+++ b/src/main/java/com/p4square/grow/backend/GrowBackend.java
@@ -30,12 +30,12 @@ import com.p4square.grow.model.UserRecord;
 
 import com.p4square.grow.backend.resources.AccountResource;
 import com.p4square.grow.backend.resources.BannerResource;
+import com.p4square.grow.backend.resources.HealthCheckResource;
 import com.p4square.grow.backend.resources.SurveyResource;
 import com.p4square.grow.backend.resources.SurveyResultsResource;
 import com.p4square.grow.backend.resources.TrainingRecordResource;
 import com.p4square.grow.backend.resources.TrainingResource;
 
-import com.p4square.grow.backend.feed.FeedDataProvider;
 import com.p4square.grow.backend.feed.ThreadResource;
 import com.p4square.grow.backend.feed.TopicResource;
 
@@ -98,6 +98,7 @@ public class GrowBackend extends Application implements GrowData, ProvidesNotifi
 
         // Misc.
         router.attach("/banner", BannerResource.class);
+        router.attach("/ping", HealthCheckResource.class);
 
         // Feed
         router.attach("/feed/{topic}", TopicResource.class);
diff --git a/src/main/java/com/p4square/grow/backend/resources/HealthCheckResource.java b/src/main/java/com/p4square/grow/backend/resources/HealthCheckResource.java
new file mode 100644
index 0000000..7d43af4
--- /dev/null
+++ b/src/main/java/com/p4square/grow/backend/resources/HealthCheckResource.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.backend.resources;
+
+import java.io.IOException;
+
+import org.restlet.data.Status;
+import org.restlet.representation.Representation;
+import org.restlet.representation.StringRepresentation;
+import org.restlet.resource.ServerResource;
+
+import org.apache.log4j.Logger;
+
+import com.p4square.grow.backend.GrowBackend;
+import com.p4square.grow.provider.Provider;
+
+/**
+ * Check if dependencies are healthy.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class HealthCheckResource extends ServerResource {
+    private static final Logger LOG = Logger.getLogger(HealthCheckResource.class);
+
+    private Provider<String, String> mStringProvider;
+
+    @Override
+    public void doInit() {
+        super.doInit();
+
+        final GrowBackend backend = (GrowBackend) getApplication();
+        mStringProvider = backend.getStringProvider();
+    }
+
+    /**
+     * Handle GET Requests.
+     */
+    @Override
+    protected Representation get() {
+        try {
+            // Try loading the banner string
+            mStringProvider.get("banner");
+
+            // If nothing exploded, we'll say it works.
+            return new StringRepresentation("SUCCESS");
+
+        } catch (IOException e) {
+            LOG.warn("Health Check Failed: " + e);
+            setStatus(Status.SERVER_ERROR_INTERNAL);
+            return new StringRepresentation("FAIL");
+        }
+    }
+}
diff --git a/src/main/java/com/p4square/grow/ccb/ChurchCommunityBuilderIntegrationDriver.java b/src/main/java/com/p4square/grow/ccb/ChurchCommunityBuilderIntegrationDriver.java
index 3704fdc..dd62401 100644
--- a/src/main/java/com/p4square/grow/ccb/ChurchCommunityBuilderIntegrationDriver.java
+++ b/src/main/java/com/p4square/grow/ccb/ChurchCommunityBuilderIntegrationDriver.java
@@ -6,9 +6,11 @@ import com.p4square.ccbapi.CCBAPIClient;
 import com.p4square.grow.config.Config;
 import com.p4square.grow.frontend.IntegrationDriver;
 import com.p4square.grow.frontend.ProgressReporter;
+import org.apache.log4j.Logger;
 import org.restlet.Context;
 import org.restlet.security.Verifier;
 
+import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
 
@@ -17,6 +19,8 @@ import java.net.URISyntaxException;
  */
 public class ChurchCommunityBuilderIntegrationDriver implements IntegrationDriver {
 
+    private static final Logger LOG = Logger.getLogger(ChurchCommunityBuilderIntegrationDriver.class);
+
     private final Context mContext;
     private final MetricRegistry mMetricRegistry;
     private final Config mConfig;
@@ -65,4 +69,18 @@ public class ChurchCommunityBuilderIntegrationDriver implements IntegrationDrive
     public ProgressReporter getProgressReporter() {
         return mProgressReporter;
     }
+
+    @Override
+    public boolean doHealthCheck() {
+        try {
+            // Try something benign, like getting the custom field labels,
+            // to verify that we can talk to CCB.
+            mAPI.getCustomFieldLabels();
+            return true;
+
+        } catch (IOException e) {
+            LOG.warn("CCB Health Check Failed: " + e.getMessage(), e);
+            return false;
+        }
+    }
 }
diff --git a/src/main/java/com/p4square/grow/frontend/GrowFrontend.java b/src/main/java/com/p4square/grow/frontend/GrowFrontend.java
index ebaa8df..29f7e14 100644
--- a/src/main/java/com/p4square/grow/frontend/GrowFrontend.java
+++ b/src/main/java/com/p4square/grow/frontend/GrowFrontend.java
@@ -118,6 +118,7 @@ public class GrowFrontend extends FMFacade {
         router.attach("/login.html", LoginPageResource.class);
         router.attach("/newaccount.html", NewAccountResource.class);
         router.attach("/newbeliever", NewBelieverResource.class);
+        router.attach("/ping", HealthCheckPage.class);
 
         final Router accountRouter = new MetricRouter(getContext(), mMetricRegistry);
         accountRouter.attach("/authenticate", AuthenticatedResource.class);
diff --git a/src/main/java/com/p4square/grow/frontend/HealthCheckPage.java b/src/main/java/com/p4square/grow/frontend/HealthCheckPage.java
new file mode 100644
index 0000000..7469b09
--- /dev/null
+++ b/src/main/java/com/p4square/grow/frontend/HealthCheckPage.java
@@ -0,0 +1,82 @@
+/*
+ * Copyright 2018 Jesse Morgan
+ */
+
+package com.p4square.grow.frontend;
+
+import org.restlet.Request;
+import org.restlet.Response;
+import org.restlet.data.Method;
+import org.restlet.data.Status;
+import org.restlet.representation.Representation;
+import org.restlet.representation.StringRepresentation;
+
+import org.apache.log4j.Logger;
+
+import com.p4square.grow.config.Config;
+import org.restlet.resource.ServerResource;
+
+/**
+ * This page verifies all of the dependencies are working.
+ * If so, it returns a 200, otherwise a 500.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class HealthCheckPage extends ServerResource {
+    private static final Logger LOG = Logger.getLogger(HealthCheckPage.class);
+
+    private GrowFrontend mGrowFrontend;
+    private Config mConfig;
+
+    @Override
+    public void doInit() {
+        super.doInit();
+
+        mGrowFrontend = (GrowFrontend) getApplication();
+        mConfig = mGrowFrontend.getConfig();
+    }
+
+    /**
+     * Health check
+     */
+    @Override
+    protected Representation get() {
+        try {
+            // Check the backend
+            boolean backendOk = checkBackend();
+
+            // Check the Third-Party Integration driver
+            boolean integrationOk = mGrowFrontend.getThirdPartyIntegrationFactory().doHealthCheck();
+
+            if (backendOk && integrationOk) {
+                return new StringRepresentation("SUCCESS");
+            }
+
+        } catch (Exception e) {
+            LOG.fatal("Health check exception: " + e.getMessage(), e);
+        }
+
+        // Something went wrong...
+        setStatus(Status.SERVER_ERROR_INTERNAL);
+        return new StringRepresentation("FAIL");
+    }
+
+    private boolean checkBackend() {
+        final Request request = new Request(Method.GET, getBackendEndpoint() + "/ping");
+        final Response response = getContext().getClientDispatcher().handle(request);
+
+        if (response.getStatus().isSuccess()) {
+            return true;
+        } else {
+            LOG.warn("Backend health check failed. Got " + response.getStatus().toString());
+            return false;
+        }
+    }
+
+    /**
+     * @return The backend endpoint URI
+     */
+    private String getBackendEndpoint() {
+        return mConfig.getString("backendUri", "riap://component/backend");
+    }
+}
diff --git a/src/main/java/com/p4square/grow/frontend/IntegrationDriver.java b/src/main/java/com/p4square/grow/frontend/IntegrationDriver.java
index b9c3508..8ea2600 100644
--- a/src/main/java/com/p4square/grow/frontend/IntegrationDriver.java
+++ b/src/main/java/com/p4square/grow/frontend/IntegrationDriver.java
@@ -23,4 +23,14 @@ public interface IntegrationDriver {
      * @return The ProgressReporter.
      */
     ProgressReporter getProgressReporter();
+
+    /**
+     * Check if the IntegrationDriver is configured correctly and working.
+     *
+     * This method should try to contact the CMS to ensure endpoints,
+     * credentials, etc. are working correctly.
+     *
+     * @return true for success.
+     */
+    boolean doHealthCheck();
 }
diff --git a/src/main/resources/com/p4square/grow/backend/apiinfo.html b/src/main/resources/com/p4square/grow/backend/apiinfo.html
index a3637c9..1e44348 100644
--- a/src/main/resources/com/p4square/grow/backend/apiinfo.html
+++ b/src/main/resources/com/p4square/grow/backend/apiinfo.html
@@ -31,6 +31,9 @@
 <dt>/backend/banner</dt>
 <dd>GET the info banner or PUT new banner info.</dd>
 
+<dt>/backend/ping</dt>
+<dd>GET the current status of the backend dependencies.</dd>
+
 <dt>/backend/feed/{topic}</dt>
 <dd>Get all threads for forum <em>topic</em>.</dd>