/*
* 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.
*/
package org.apache.karaf.cellar.cloud;
import org.apache.karaf.cellar.core.discovery.DiscoveryService;
import org.jclouds.blobstore.BlobStore;
import org.jclouds.blobstore.BlobStoreContext;
import org.jclouds.blobstore.BlobStoreContextFactory;
import org.jclouds.blobstore.domain.Blob;
import org.jclouds.blobstore.domain.PageSet;
import org.jclouds.blobstore.domain.StorageMetadata;
import org.jclouds.blobstore.domain.StorageType;
import org.jclouds.blobstore.options.ListContainerOptions;
import org.joda.time.DateTime;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
* Discovery service that use a cloud blob store.
*/
public class BlobStoreDiscoveryService implements DiscoveryService {
private static final transient Logger LOGGER = LoggerFactory.getLogger(BlobStoreDiscoveryService.class);
private String provider;
private String identity;
private String credential;
private String container;
private Integer validityPeriod = 60;
private String ipAddress = getIpAddress();
BlobStoreContext context;
private BlobStore blobStore;
public BlobStoreDiscoveryService() {
LOGGER.debug("CELLAR CLOUD: blob store discovery service initialized");
}
public void init() {
try {
if (blobStore == null) {
if (context == null) {
context = new BlobStoreContextFactory().createContext(provider, identity, credential);
}
blobStore = context.getBlobStore();
signIn();
}
} catch (Exception ex) {
LOGGER.error("CELLAR CLOUD: error while initializing blob store discovery service", ex);
}
}
public void destroy() {
signOut();
context.close();
}
public void update(Map<String, Object> properties) {
LOGGER.debug("CELLAR CLOUD: updating properties");
}
/**
* Return a {@link Set} of IPs.
*
* @return a set of IPs.
*/
@Override
public Set<String> discoverMembers() {
refresh();
Set<String> members = new HashSet<String>();
ListContainerOptions opt = new ListContainerOptions();
PageSet<? extends StorageMetadata> pageSet = blobStore.list(container, opt);
LOGGER.debug("CELLAR CLOUD: storage contains a page set of size {}", pageSet.size());
for (StorageMetadata md : pageSet) {
if (md.getType() != StorageType.BLOB) {
//skip everything that isn't of type BLOB ...
continue;
}
String ip = md.getName();
Object obj = readBlob(container, ip);
if (obj == null) {
LOGGER.debug("CELLAR CLOUD: no valid object found, skipping it");
continue;
}
// check if the IP hasn't been updated recently
if (obj instanceof DateTime) {
LOGGER.debug("CELLAR CLOUD: retrieved a DateTime from blog store");
DateTime registeredTime = (DateTime) obj;
if (registeredTime != null && registeredTime.plusSeconds(validityPeriod).isAfterNow()) {
LOGGER.debug("CELLAR CLOUD: adding member {}", ip);
members.add(ip);
} else {
LOGGER.debug("CELLAR CLOUD: remove container {}", ip);
blobStore.removeBlob(container, ip);
}
} else if (obj instanceof ServiceContainer) {
LOGGER.debug("CELLAR CLOUD: retrieved a ServiceContainer from blog store");
ServiceContainer serviceContainer = (ServiceContainer) obj;
DateTime registeredTime = serviceContainer.getRegisteredTime();
if (registeredTime != null && registeredTime.plusSeconds(validityPeriod).isAfterNow()) {
LOGGER.debug("CELLAR CLOUD: adding member {} for IP {}", serviceContainer.getHostName(), ip);
members.add(serviceContainer.getHostIp());
} else {
LOGGER.debug("CELLAR CLOUD: remove container {}", ip);
blobStore.removeBlob(container, ip);
}
}
}
LOGGER.debug("CELLAR CLOUD: returning members {}", members);
return members;
}
/**
* Sign in member to the {@link DiscoveryService}.
*/
@Override
public void signIn() {
DateTime now = new DateTime();
createBlob(container, ipAddress, new ServiceContainer(getHostName(), getIpAddress(), now));
}
/**
* Refresh member to the {@link DiscoveryService}.
*/
@Override
public void refresh() {
DateTime now = new DateTime();
createBlob(container, ipAddress, new ServiceContainer(getHostName(), getIpAddress(), now));
}
/**
* Sign out member to the {@link DiscoveryService}.
*/
@Override
public void signOut() {
if (blobStore.blobExists(container, ipAddress)) {
blobStore.removeBlob(container, ipAddress);
} else {
LOGGER.debug("CELLAR CLOUD: unable to find the IP address of the current node in the blob store");
}
}
/**
* Reads from a {@link BlobStore}.
*
* @param container the blob store container.
* @param blobName the blob store name.
* @return the Object read from the blob store.
*/
protected Object readBlob(String container, String blobName) {
Object result = null;
ObjectInputStream ois = null;
blobStore.createContainerInLocation(null, container);
InputStream is = blobStore.getBlob(container, blobName).getPayload().getInput();
try {
ois = new ObjectInputStream(is);
result = ois.readObject();
} catch (IOException e) {
LOGGER.warn("CELLAR CLOUD: failed to read blob", e);
} catch (ClassNotFoundException e) {
LOGGER.warn("CELLAR CLOUD: failed to read blob", e);
} finally {
if (ois != null) {
try {
ois.close();
} catch (IOException e) {
// nothing to do
}
}
if (is != null) {
try {
is.close();
} catch (IOException e) {
// nothing to do
}
}
}
return result;
}
/**
* Create a blob store.
*
* @param container the blob store container.
* @param name the blob store name.
* @param data the blob store data.
*/
public void createBlob(String container, String name, Object data) {
Blob blob;
if (blobStore != null) {
if (!blobStore.containerExists(container)) {
blobStore.createContainerInLocation(null, container);
}
if (blobStore.blobExists(container, name)) {
blob = blobStore.getBlob(container, name);
} else {
blob = blobStore.blobBuilder(name).build();
}
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = null;
try {
oos = new ObjectOutputStream(baos);
oos.writeObject(data);
blob.setPayload(baos.toByteArray());
blobStore.putBlob(container, blob);
} catch (IOException e) {
LOGGER.error("CELLAR CLOUD: failed to write blob", e);
} finally {
if (oos != null) {
try {
oos.close();
} catch (IOException e) {
// nothing to do
}
}
if (baos != null) {
try {
baos.close();
} catch (IOException e) {
// nothing to do
}
}
}
}
}
/**
* Get the IP address of the local node.
*
* @return the IP address of the local node.
*/
protected String getIpAddress() {
try {
return InetAddress.getLocalHost().getHostAddress();
} catch (UnknownHostException ex) {
LOGGER.error("CELLAR CLOUD: unable to determine IP address of the local node", ex);
return null;
}
}
/**
* Get the hostname of the local node.
*
* @return the hostname of the local node.
*/
protected String getHostName() {
try {
return InetAddress.getLocalHost().getHostName();
} catch (UnknownHostException ex) {
LOGGER.error("CELLAR CLOUD: unable to determine host name of the local node", ex);
return null;
}
}
public String getProvider() {
return provider;
}
public void setProvider(String provider) {
this.provider = provider;
}
public String getIdentity() {
return identity;
}
public void setIdentity(String identity) {
this.identity = identity;
}
public String getCredential() {
return credential;
}
public void setCredential(String credential) {
this.credential = credential;
}
public String getContainer() {
return container;
}
public void setContainer(String container) {
this.container = container;
}
public Integer getValidityPeriod() {
return validityPeriod;
}
public void setValidityPeriod(Integer validityPeriod) {
this.validityPeriod = validityPeriod;
}
}