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Elasticsearch subproject :client:sniffer
/*
* Licensed to Elasticsearch B.V. under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch B.V. 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.elasticsearch.client.sniff;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.elasticsearch.client.Node;
import org.elasticsearch.client.Node.Roles;
import org.elasticsearch.client.Request;
import org.elasticsearch.client.Response;
import org.elasticsearch.client.RestClient;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.TreeSet;
import java.util.concurrent.TimeUnit;
import static java.util.Collections.singletonList;
import static java.util.Collections.unmodifiableList;
import static java.util.Collections.unmodifiableMap;
/**
* Class responsible for sniffing the http hosts from elasticsearch through the nodes info api and returning them back.
* Compatible with elasticsearch 2.x+.
*/
public final class ElasticsearchNodesSniffer implements NodesSniffer {
private static final Log logger = LogFactory.getLog(ElasticsearchNodesSniffer.class);
public static final long DEFAULT_SNIFF_REQUEST_TIMEOUT = TimeUnit.SECONDS.toMillis(1);
private final RestClient restClient;
private final Request request;
private final Scheme scheme;
private final JsonFactory jsonFactory = new JsonFactory();
/**
* Creates a new instance of the Elasticsearch sniffer. It will use the provided {@link RestClient} to fetch the hosts,
* through the nodes info api, the default sniff request timeout value {@link #DEFAULT_SNIFF_REQUEST_TIMEOUT} and http
* as the scheme for all the hosts.
* @param restClient client used to fetch the hosts from elasticsearch through nodes info api. Usually the same instance
* that is also provided to {@link Sniffer#builder(RestClient)}, so that the hosts are set to the same
* client that was used to fetch them.
*/
public ElasticsearchNodesSniffer(RestClient restClient) {
this(restClient, DEFAULT_SNIFF_REQUEST_TIMEOUT, ElasticsearchNodesSniffer.Scheme.HTTP);
}
/**
* Creates a new instance of the Elasticsearch sniffer. It will use the provided {@link RestClient} to fetch the hosts
* through the nodes info api, the provided sniff request timeout value and scheme.
* @param restClient client used to fetch the hosts from elasticsearch through nodes info api. Usually the same instance
* that is also provided to {@link Sniffer#builder(RestClient)}, so that the hosts are set to the same
* client that was used to sniff them.
* @param sniffRequestTimeoutMillis the sniff request timeout (in milliseconds) to be passed in as a query string parameter
* to elasticsearch. Allows to halt the request without any failure, as only the nodes
* that have responded within this timeout will be returned.
* @param scheme the scheme to associate sniffed nodes with (as it is not returned by elasticsearch)
*/
public ElasticsearchNodesSniffer(RestClient restClient, long sniffRequestTimeoutMillis, Scheme scheme) {
this.restClient = Objects.requireNonNull(restClient, "restClient cannot be null");
if (sniffRequestTimeoutMillis < 0) {
throw new IllegalArgumentException("sniffRequestTimeoutMillis must be greater than 0");
}
this.request = new Request("GET", "/_nodes/http");
request.addParameter("timeout", sniffRequestTimeoutMillis + "ms");
this.scheme = Objects.requireNonNull(scheme, "scheme cannot be null");
}
/**
* Calls the elasticsearch nodes info api, parses the response and returns all the found http hosts
*/
@Override
public List sniff() throws IOException {
Response response = restClient.performRequest(request);
return readHosts(response.getEntity(), scheme, jsonFactory);
}
static List readHosts(HttpEntity entity, Scheme scheme, JsonFactory jsonFactory) throws IOException {
try (InputStream inputStream = entity.getContent()) {
JsonParser parser = jsonFactory.createParser(inputStream);
if (parser.nextToken() != JsonToken.START_OBJECT) {
throw new IOException("expected data to start with an object");
}
List nodes = new ArrayList<>();
while (parser.nextToken() != JsonToken.END_OBJECT) {
if (parser.getCurrentToken() == JsonToken.START_OBJECT) {
if ("nodes".equals(parser.getCurrentName())) {
while (parser.nextToken() != JsonToken.END_OBJECT) {
JsonToken token = parser.nextToken();
assert token == JsonToken.START_OBJECT;
String nodeId = parser.getCurrentName();
Node node = readNode(nodeId, parser, scheme);
if (node != null) {
nodes.add(node);
}
}
} else {
parser.skipChildren();
}
}
}
return nodes;
}
}
private static Node readNode(String nodeId, JsonParser parser, Scheme scheme) throws IOException {
HttpHost publishedHost = null;
/*
* We sniff the bound hosts so we can look up the node based on any
* address on which it is listening. This is useful in Elasticsearch's
* test framework where we sometimes publish ipv6 addresses but the
* tests contact the node on ipv4.
*/
Set boundHosts = new HashSet<>();
String name = null;
String version = null;
/*
* Multi-valued attributes come with key = `real_key.index` and we
* unflip them after reading them because we can't rely on the order
* that they arive.
*/
final Map protoAttributes = new HashMap();
boolean sawRoles = false;
final Set roles = new TreeSet<>();
String fieldName = null;
while (parser.nextToken() != JsonToken.END_OBJECT) {
if (parser.getCurrentToken() == JsonToken.FIELD_NAME) {
fieldName = parser.getCurrentName();
} else if (parser.getCurrentToken() == JsonToken.START_OBJECT) {
if ("http".equals(fieldName)) {
while (parser.nextToken() != JsonToken.END_OBJECT) {
if (parser.getCurrentToken() == JsonToken.VALUE_STRING && "publish_address".equals(parser.getCurrentName())) {
String address = parser.getValueAsString();
String host;
URI publishAddressAsURI;
// ES7 cname/ip:port format
if (address.contains("/")) {
String[] cnameAndURI = address.split("/", 2);
publishAddressAsURI = URI.create(scheme + "://" + cnameAndURI[1]);
host = cnameAndURI[0];
} else {
publishAddressAsURI = URI.create(scheme + "://" + address);
host = publishAddressAsURI.getHost();
}
publishedHost = new HttpHost(host, publishAddressAsURI.getPort(), publishAddressAsURI.getScheme());
} else if (parser.currentToken() == JsonToken.START_ARRAY && "bound_address".equals(parser.getCurrentName())) {
while (parser.nextToken() != JsonToken.END_ARRAY) {
URI boundAddressAsURI = URI.create(scheme + "://" + parser.getValueAsString());
boundHosts.add(
new HttpHost(boundAddressAsURI.getHost(), boundAddressAsURI.getPort(), boundAddressAsURI.getScheme())
);
}
} else if (parser.getCurrentToken() == JsonToken.START_OBJECT) {
parser.skipChildren();
}
}
} else if ("attributes".equals(fieldName)) {
while (parser.nextToken() != JsonToken.END_OBJECT) {
if (parser.getCurrentToken() == JsonToken.VALUE_STRING) {
String oldValue = protoAttributes.put(parser.getCurrentName(), parser.getValueAsString());
if (oldValue != null) {
throw new IOException("repeated attribute key [" + parser.getCurrentName() + "]");
}
} else {
parser.skipChildren();
}
}
} else {
parser.skipChildren();
}
} else if (parser.currentToken() == JsonToken.START_ARRAY) {
if ("roles".equals(fieldName)) {
sawRoles = true;
while (parser.nextToken() != JsonToken.END_ARRAY) {
roles.add(parser.getText());
}
} else {
parser.skipChildren();
}
} else if (parser.currentToken().isScalarValue()) {
if ("version".equals(fieldName)) {
version = parser.getText();
} else if ("name".equals(fieldName)) {
name = parser.getText();
}
}
}
// http section is not present if http is not enabled on the node, ignore such nodes
if (publishedHost == null) {
logger.debug("skipping node [" + nodeId + "] with http disabled");
return null;
}
Map> realAttributes = new HashMap<>(protoAttributes.size());
List keys = new ArrayList<>(protoAttributes.keySet());
for (String key : keys) {
if (key.endsWith(".0")) {
String realKey = key.substring(0, key.length() - 2);
List values = new ArrayList<>();
int i = 0;
while (true) {
String value = protoAttributes.remove(realKey + "." + i);
if (value == null) {
break;
}
values.add(value);
i++;
}
realAttributes.put(realKey, unmodifiableList(values));
}
}
for (Map.Entry entry : protoAttributes.entrySet()) {
realAttributes.put(entry.getKey(), singletonList(entry.getValue()));
}
if (version.startsWith("2.")) {
/*
* 2.x doesn't send roles, instead we try to read them from
* attributes.
*/
boolean clientAttribute = v2RoleAttributeValue(realAttributes, "client", false);
Boolean masterAttribute = v2RoleAttributeValue(realAttributes, "master", null);
Boolean dataAttribute = v2RoleAttributeValue(realAttributes, "data", null);
if ((masterAttribute == null && false == clientAttribute) || masterAttribute) {
roles.add("master");
}
if ((dataAttribute == null && false == clientAttribute) || dataAttribute) {
roles.add("data");
}
} else {
assert sawRoles : "didn't see roles for [" + nodeId + "]";
}
assert boundHosts.contains(publishedHost) : "[" + nodeId + "] doesn't make sense! publishedHost should be in boundHosts";
logger.trace("adding node [" + nodeId + "]");
return new Node(publishedHost, boundHosts, name, version, new Roles(roles), unmodifiableMap(realAttributes));
}
/**
* Returns {@code defaultValue} if the attribute didn't come back,
* {@code true} or {@code false} if it did come back as
* either of those, or throws an IOException if the attribute
* came back in a strange way.
*/
private static Boolean v2RoleAttributeValue(Map> attributes, String name, Boolean defaultValue)
throws IOException {
List valueList = attributes.remove(name);
if (valueList == null) {
return defaultValue;
}
if (valueList.size() != 1) {
throw new IOException("expected only a single attribute value for [" + name + "] but got " + valueList);
}
switch (valueList.get(0)) {
case "true":
return true;
case "false":
return false;
default:
throw new IOException("expected [" + name + "] to be either [true] or [false] but was [" + valueList.get(0) + "]");
}
}
public enum Scheme {
HTTP("http"),
HTTPS("https");
private final String name;
Scheme(String name) {
this.name = name;
}
@Override
public String toString() {
return name;
}
}
}