consolidate Policy Health Check into PAP

Issue-ID: POLICY-1689
Change-Id: I3b84094e217c8cda115efdbf3444e92f08013a7c
Signed-off-by: Hengye <yehui.wang@est.tech>

1 files changed, 174 insertions, 0 deletions

diff --git a/main/src/main/java/org/onap/policy/pap/main/rest/PolicyComponentsHealthCheckProvider.java b/main/src/main/java/org/onap/policy/pap/main/rest/PolicyComponentsHealthCheckProvider.java
new file mode 100644
index 00000000..ddcab778
--- /dev/null
+++ b/main/src/main/java/org/onap/policy/pap/main/rest/PolicyComponentsHealthCheckProvider.java
@@ -0,0 +1,174 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2019 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.pap.main.rest;
+
+import java.net.HttpURLConnection;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.core.Response.Status;
+import org.apache.commons.lang3.tuple.Pair;
+import org.onap.policy.common.endpoints.event.comm.bus.internal.BusTopicParams;
+import org.onap.policy.common.endpoints.http.client.HttpClient;
+import org.onap.policy.common.endpoints.http.client.HttpClientConfigException;
+import org.onap.policy.common.endpoints.http.client.HttpClientFactory;
+import org.onap.policy.common.endpoints.http.client.HttpClientFactoryInstance;
+import org.onap.policy.common.endpoints.parameters.RestServerParameters;
+import org.onap.policy.common.endpoints.report.HealthCheckReport;
+import org.onap.policy.common.parameters.ParameterService;
+import org.onap.policy.common.utils.services.Registry;
+import org.onap.policy.models.base.PfModelException;
+import org.onap.policy.models.pdp.concepts.Pdp;
+import org.onap.policy.models.pdp.concepts.PdpGroup;
+import org.onap.policy.models.pdp.concepts.PdpSubGroup;
+import org.onap.policy.models.pdp.enums.PdpHealthStatus;
+import org.onap.policy.models.provider.PolicyModelsProvider;
+import org.onap.policy.pap.main.PapConstants;
+import org.onap.policy.pap.main.PolicyModelsProviderFactoryWrapper;
+import org.onap.policy.pap.main.parameters.PapParameterGroup;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Provider for PAP to fetch health status of all Policy components, including PAP, API,
+ * Distribution, and PDPs. Note: a new provider {@link PolicyComponentsHealthCheckProvider} must be
+ * created for each request.
+ *
+ * @author Yehui Wang (yehui.wang@est.tech)
+ */
+public class PolicyComponentsHealthCheckProvider {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(PolicyComponentsHealthCheckProvider.class);
+    private static final String PAP_GROUP_PARAMS_NAME = "PapGroup";
+    private static final String HEALTH_STATUS = "healthy";
+    private static final Pattern IP_REPLACEMENT_PATTERN = Pattern.compile("//(\\S+):");
+    private static final String POLICY_PAP_HEALTHCHECK_URI = "/policy/pap/v1/healthcheck";
+    private PapParameterGroup papParameterGroup = ParameterService.get(PAP_GROUP_PARAMS_NAME);
+    private boolean isHealthy = true;
+    private Map<String, Object> result = new HashMap<>();
+
+    /**
+     * Returns health status of all Policy components.
+     *
+     * @return a pair containing the status and the response
+     * @throws PfModelException in case of errors
+     */
+    public Pair<Status, Map<String, Object>> fetchPolicyComponentsHealthStatus() {
+        getHttpClients(papParameterGroup.getHealthCheckRestClientParameters()).parallelStream()
+                .forEach(this::fetchPolicyComponentHealthStatus);
+        HealthCheckReport papReport = new HealthCheckProvider().performHealthCheck();
+        RestServerParameters restServerParameters = papParameterGroup.getRestServerParameters();
+        papReport.setUrl((restServerParameters.isHttps() ? "https://" : "http://") + papReport.getUrl() + ":"
+                + restServerParameters.getPort() + POLICY_PAP_HEALTHCHECK_URI);
+        result.put(PapConstants.POLICY_PAP, papReport);
+        try {
+            Map<String, List<Pdp>> pdpListWithType = fetchPdpsHealthStatus();
+            if (isHealthy && (pdpListWithType.isEmpty() || pdpListWithType.values().stream().flatMap(List::stream)
+                    .anyMatch(pdp -> !PdpHealthStatus.HEALTHY.equals(pdp.getHealthy())))) {
+                isHealthy = false;
+            }
+            result.put(PapConstants.POLICY_PDPS, pdpListWithType);
+        } catch (final PfModelException exp) {
+            result.put(PapConstants.POLICY_PDPS, exp.getErrorResponse());
+            isHealthy = false;
+        }
+        result.put(HEALTH_STATUS, isHealthy);
+        LOGGER.debug("Policy Components HealthCheck Response - {}", result);
+        return Pair.of(Response.Status.OK, result);
+    }
+
+    private Map<String, List<Pdp>> fetchPdpsHealthStatus() throws PfModelException {
+        Map<String, List<Pdp>> pdpListWithType = new HashMap<>();
+        final PolicyModelsProviderFactoryWrapper modelProviderWrapper =
+                Registry.get(PapConstants.REG_PAP_DAO_FACTORY, PolicyModelsProviderFactoryWrapper.class);
+        try (PolicyModelsProvider databaseProvider = modelProviderWrapper.create()) {
+            final List<PdpGroup> groups = databaseProvider.getPdpGroups(null);
+            for (final PdpGroup group : groups) {
+                for (final PdpSubGroup subGroup : group.getPdpSubgroups()) {
+                    List<Pdp> pdpList = new ArrayList<>(subGroup.getPdpInstances());
+                    pdpListWithType.computeIfAbsent(subGroup.getPdpType(), k -> new ArrayList<>()).addAll(pdpList);
+                }
+            }
+        }
+        return pdpListWithType;
+    }
+
+    private List<HttpClient> getHttpClients(List<BusTopicParams> restClientParameters) {
+        HttpClientFactory clientFactory = HttpClientFactoryInstance.getClientFactory();
+        for (BusTopicParams params : restClientParameters) {
+            try {
+                params.setManaged(true);
+                clientFactory.build(params);
+            } catch (HttpClientConfigException e) {
+                LOGGER.warn("{} httpClient creation error", params.getClientName());
+                String url = (params.isUseHttps() ? "https://" : "http://") + params.getHostname() + ":"
+                        + params.getPort() + "/" + params.getBasePath();
+                storeUnHealthCheckReport(params.getClientName(), url, HttpURLConnection.HTTP_BAD_REQUEST,
+                        e.getMessage());
+            }
+        }
+        return clientFactory.inventory();
+    }
+
+    private void fetchPolicyComponentHealthStatus(HttpClient httpClient) {
+        try {
+            Response resp = httpClient.get();
+            if (resp.getStatus() != HttpURLConnection.HTTP_OK) {
+                isHealthy = false;
+                result.put(httpClient.getName(),
+                        replaceIpWithHostname(resp.readEntity(HealthCheckReport.class), httpClient.getBaseUrl()));
+            } else {
+                result.put(httpClient.getName(),
+                        replaceIpWithHostname(resp.readEntity(HealthCheckReport.class), httpClient.getBaseUrl()));
+            }
+        } catch (RuntimeException e) {
+            LOGGER.warn("{} connection error", httpClient.getName());
+            storeUnHealthCheckReport(httpClient.getName(), httpClient.getBaseUrl(),
+                    HttpURLConnection.HTTP_INTERNAL_ERROR, e.getMessage());
+        }
+    }
+
+
+    private void storeUnHealthCheckReport(String name, String url, int code, String message) {
+        HealthCheckReport report = new HealthCheckReport();
+        report.setName(name);
+        report.setUrl(url);
+        report.setHealthy(false);
+        isHealthy = false;
+        report.setCode(code);
+        report.setMessage(message);
+        result.put(name, report);
+    }
+
+    private HealthCheckReport replaceIpWithHostname(HealthCheckReport report, String baseUrl) {
+        Matcher matcher = IP_REPLACEMENT_PATTERN.matcher(baseUrl);
+        String ip = "";
+        if (matcher.find()) {
+            ip = matcher.group(1);
+            report.setUrl(baseUrl.replace(ip, report.getUrl()));
+        }
+        return report;
+    }
+}