/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The SF licenses this file
* to you 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.
*/
package org.apache.sling.hc.core.impl;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.ConfigurationPolicy;
import org.apache.felix.scr.annotations.Deactivate;
import org.apache.felix.scr.annotations.Properties;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.PropertyUnbounded;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.Service;
import org.apache.sling.commons.osgi.PropertiesUtil;
import org.apache.sling.hc.api.HealthCheck;
import org.apache.sling.hc.api.Result;
import org.apache.sling.hc.api.Result.Status;
import org.apache.sling.hc.api.execution.HealthCheckExecutionResult;
import org.apache.sling.hc.api.execution.HealthCheckExecutor;
import org.apache.sling.hc.util.FormattingResultLog;
import org.apache.sling.hc.util.HealthCheckFilter;
import org.apache.sling.hc.util.HealthCheckMetadata;
import org.osgi.framework.BundleContext;
import org.osgi.framework.Constants;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;
import org.osgi.service.component.ComponentConstants;
import org.osgi.service.component.ComponentContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** {@link HealthCheck} that executes a number of other HealthChecks,
* selected by their tags, and merges their Results.
*/
@Component(
configurationFactory=true,
policy=ConfigurationPolicy.REQUIRE,
metatype=true,
label="Apache Sling Composite Health Check",
description="Executes a set of health checks, selected by tags.")
@Properties({
@Property(name=HealthCheck.NAME,
label="Name",
description="Name of this health check."),
@Property(name=HealthCheck.TAGS, unbounded=PropertyUnbounded.ARRAY,
label="Tags",
description="List of tags for this health check, used to select " +
"subsets of health checks for execution e.g. by a composite health check."),
@Property(name=HealthCheck.MBEAN_NAME,
label="MBean Name",
description="Name of the MBean to create for this health check. If empty, no MBean is registered.")
})
@Service(value=HealthCheck.class)
public class CompositeHealthCheck implements HealthCheck {
private final Logger log = LoggerFactory.getLogger(getClass());
@Property(unbounded=PropertyUnbounded.ARRAY,
label="Filter Tags",
description="Tags used to select which health checks the composite health check executes.")
static final String PROP_FILTER_TAGS = "filter.tags";
private String [] filterTags;
@Reference
private HealthCheckExecutor healthCheckExecutor;
private BundleContext bundleContext;
private ServiceReference referenceToThis;
private HealthCheckFilter healthCheckFilter;
@Activate
protected void activate(final ComponentContext ctx) {
bundleContext = ctx.getBundleContext();
healthCheckFilter = new HealthCheckFilter(bundleContext);
referenceToThis = getReferenceByPid(PropertiesUtil.toString(ctx.getProperties().get(Constants.SERVICE_PID), "-1"));
filterTags = PropertiesUtil.toStringArray(ctx.getProperties().get(PROP_FILTER_TAGS), new String[] {});
log.debug("Activated, will select HealthCheck having tags {}", Arrays.asList(filterTags));
}
@Deactivate
protected void deactivate() {
bundleContext = null;
healthCheckFilter = null;
referenceToThis = null;
}
@Override
public Result execute() {
Result result = checkForRecursion(referenceToThis, new HashSet<String>());
if(result != null) {
// return recursion error
return result;
}
FormattingResultLog resultLog = new FormattingResultLog();
List<HealthCheckExecutionResult> executionResults = healthCheckExecutor.execute(filterTags);
resultLog.debug("Executing {} HealthChecks selected by tags {}", executionResults.size(), Arrays.asList(filterTags));
result = new CompositeResult(resultLog, executionResults);
return result;
}
Result checkForRecursion(ServiceReference hcReference, Set<String> alreadyBannedTags) {
HealthCheckMetadata thisCheckMetadata = new HealthCheckMetadata(hcReference);
Set<String> bannedTagsForThisCompositeCheck = new HashSet<String>();
bannedTagsForThisCompositeCheck.addAll(alreadyBannedTags);
bannedTagsForThisCompositeCheck.addAll(thisCheckMetadata.getTags());
String[] tagsForIncludedChecksArr = PropertiesUtil.toStringArray(hcReference.getProperty(PROP_FILTER_TAGS), new String[0]);
Set<String> tagsForIncludedChecks = new HashSet<String>(Arrays.asList(tagsForIncludedChecksArr));
log.debug("HC {} has banned tags {}", thisCheckMetadata.getName(), bannedTagsForThisCompositeCheck);
log.debug("tagsForIncludedChecks {}", tagsForIncludedChecks);
// is this HC ok?
Set<String> intersection = new HashSet<String>();
intersection.addAll(bannedTagsForThisCompositeCheck);
intersection.retainAll(tagsForIncludedChecks);
if (!intersection.isEmpty()) {
return new Result(Status.HEALTH_CHECK_ERROR,
"INVALID CONFIGURATION: Cycle detected in composite health check hierarchy. Health check '" + thisCheckMetadata.getName()
+ "' (" + hcReference.getProperty(Constants.SERVICE_PID) + ") must not have tag(s) " + intersection
+ " as a composite check in the hierarchy is itself already tagged alike (tags assigned to composite checks: "
+ bannedTagsForThisCompositeCheck + ")");
}
// check each sub composite check
ServiceReference[] hcRefsOfCompositeCheck = healthCheckFilter.getTaggedHealthCheckServiceReferences(tagsForIncludedChecksArr);
for (ServiceReference hcRefOfCompositeCheck : hcRefsOfCompositeCheck) {
if (CompositeHealthCheck.class.getName().equals(hcRefOfCompositeCheck.getProperty(ComponentConstants.COMPONENT_NAME))) {
log.debug("Checking sub composite HC {}, {}", hcRefOfCompositeCheck, hcRefOfCompositeCheck.getProperty(ComponentConstants.COMPONENT_NAME));
Result result = checkForRecursion(hcRefOfCompositeCheck, bannedTagsForThisCompositeCheck);
if (result != null) {
// found recursion
return result;
}
}
}
// no recursion detected
return null;
}
private ServiceReference getReferenceByPid(String servicePid) {
if (servicePid == null) {
return null;
}
String filterString = "(" + Constants.SERVICE_PID + "=" + servicePid + ")";
ServiceReference[] refs = null;
try {
refs = bundleContext.getServiceReferences(HealthCheck.class.getName(), filterString);
} catch (InvalidSyntaxException e) {
log.error("Invalid filter " + filterString, e);
}
if (refs == null || refs.length == 0) {
return null;
} else if (refs.length == 1) {
return refs[0];
} else {
throw new IllegalStateException("OSGi Framework returned more than one service reference for unique service pid =" + servicePid);
}
}
void setHealthCheckFilter(HealthCheckFilter healthCheckFilter) {
this.healthCheckFilter = healthCheckFilter;
}
void setFilterTags(String[] filterTags) {
this.filterTags = filterTags;
}
void setHealthCheckExecutor(HealthCheckExecutor healthCheckExecutor) {
this.healthCheckExecutor = healthCheckExecutor;
}
void setReferenceToThis(ServiceReference referenceToThis) {
this.referenceToThis = referenceToThis;
}
}