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// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.vespa.hosted.controller.proxy;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.yahoo.config.provision.Environment;
import com.yahoo.config.provision.RegionName;
import com.yahoo.config.provision.ZoneId;
import com.yahoo.io.IOUtils;
import com.yahoo.jdisc.http.HttpRequest.Method;
import com.yahoo.vespa.hosted.controller.api.integration.zone.ZoneRegistry;
import org.apache.http.Header;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpDelete;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPatch;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.entity.InputStreamEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.nio.charset.StandardCharsets;
import java.time.Duration;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
/**
* @author Haakon Dybdahl
*/
@SuppressWarnings("unused") // Injected
public class ConfigServerRestExecutorImpl implements ConfigServerRestExecutor {
private static final Duration PROXY_REQUEST_TIMEOUT = Duration.ofSeconds(10);
private final ZoneRegistry zoneRegistry;
public ConfigServerRestExecutorImpl(ZoneRegistry zoneRegistry) {
this.zoneRegistry = zoneRegistry;
}
@Override
public ProxyResponse handle(ProxyRequest proxyRequest) throws ProxyException {
if (proxyRequest.isDiscoveryRequest()) {
return createDiscoveryResponse(proxyRequest);
}
ZoneId zoneId = ZoneId.from(proxyRequest.getEnvironment(), proxyRequest.getRegion());
// Make a local copy of the list as we want to manipulate it in case of ping problems.
List<URI> allServers = new ArrayList<>(zoneRegistry.getConfigServerUris(zoneId));
StringBuilder errorBuilder = new StringBuilder();
if (queueFirstServerIfDown(allServers)) {
errorBuilder.append("Change ordering due to failed ping.");
}
for (URI uri : allServers) {
Optional<ProxyResponse> proxyResponse = proxyCall(uri, proxyRequest, errorBuilder);
if (proxyResponse.isPresent()) {
return proxyResponse.get();
}
}
// TODO Add logging, for now, experimental and we want to not add more noise.
throw new ProxyException(ErrorResponse.internalServerError("Failed talking to config servers: "
+ errorBuilder.toString()));
}
private static class DiscoveryResponseStructure {
public List<String> uris = new ArrayList<>();
}
private ProxyResponse createDiscoveryResponse(ProxyRequest proxyRequest) {
ObjectMapper mapper = new ObjectMapper();
DiscoveryResponseStructure responseStructure = new DiscoveryResponseStructure();
List<ZoneId> zones = zoneRegistry.zones();
for (ZoneId zone : zones) {
if (!"".equals(proxyRequest.getEnvironment()) &&
!proxyRequest.getEnvironment().equals(zone.environment().value())) {
continue;
}
responseStructure.uris.add(proxyRequest.getScheme() + "://" + proxyRequest.getControllerPrefix() +
zone.environment().name() + "/" + zone.region().value());
}
JsonNode node = mapper.valueToTree(responseStructure);
return new ProxyResponse(proxyRequest, node.toString(), 200, Optional.empty(), "application/json");
}
private String removeFirstSlashIfAny(String url) {
if (url.startsWith("/")) {
return url.substring(1);
}
return url;
}
private Optional<ProxyResponse> proxyCall(URI uri, ProxyRequest proxyRequest, StringBuilder errorBuilder)
throws ProxyException {
String fullUri = uri.toString() + removeFirstSlashIfAny(proxyRequest.getConfigServerRequest());
final HttpRequestBase requestBase = createHttpBaseRequest(
proxyRequest.getMethod(), fullUri, proxyRequest.getData());
// Empty list of headers to copy for now, add headers when needed, or rewrite logic.
copyHeaders(proxyRequest.getHeaders(), requestBase, new HashSet<>());
RequestConfig config = RequestConfig.custom()
.setConnectTimeout((int) PROXY_REQUEST_TIMEOUT.toMillis())
.setConnectionRequestTimeout((int) PROXY_REQUEST_TIMEOUT.toMillis())
.setSocketTimeout((int) PROXY_REQUEST_TIMEOUT.toMillis()).build();
try (
CloseableHttpClient client = createHttpClient(config);
CloseableHttpResponse response = client.execute(requestBase);
) {
if (response.getStatusLine().getStatusCode() / 100 == 5) {
errorBuilder.append("Talking to server ").append(uri.getHost());
errorBuilder.append(", got ").append(response.getStatusLine().getStatusCode()).append(" ")
.append(streamToString(response.getEntity().getContent())).append("\n");
return Optional.empty();
}
final Header contentHeader = response.getLastHeader("Content-Type");
final String contentType;
if (contentHeader != null && contentHeader.getValue() != null && ! contentHeader.getValue().isEmpty()) {
contentType = contentHeader.getValue().replace("; charset=UTF-8","");
} else {
contentType = "application/json";
}
return Optional.of(new ProxyResponse(
proxyRequest,
streamToString(response.getEntity().getContent()),
response.getStatusLine().getStatusCode(),
Optional.of(uri),
contentType));
// Send response back
} catch (IOException|RuntimeException e) {
errorBuilder.append("Talking to server ").append(uri.getHost());
errorBuilder.append(" got exception ").append(e.getMessage());
return Optional.empty();
}
}
private HttpRequestBase createHttpBaseRequest(String method, String uri, InputStream data) throws ProxyException {
Method enumMethod = Method.valueOf(method);
switch (enumMethod) {
case GET:
return new HttpGet(uri);
case POST:
HttpPost post = new HttpPost(uri);
if (data != null) {
post.setEntity(new InputStreamEntity(data));
}
return post;
case PUT:
HttpPut put = new HttpPut(uri);
if (data != null) {
put.setEntity(new InputStreamEntity(data));
}
return put;
case DELETE:
return new HttpDelete(uri);
case PATCH:
HttpPatch patch = new HttpPatch(uri);
if (data != null) {
patch.setEntity(new InputStreamEntity(data));
}
return patch;
default:
throw new ProxyException(ErrorResponse.methodNotAllowed("Will not proxy such calls."));
}
}
private void copyHeaders(Map<String, List<String>> headers, HttpRequestBase toRequest, Set<String> headersToCopy) {
for (Map.Entry<String, List<String>> headerEntry : headers.entrySet()) {
for (String value : headerEntry.getValue()) {
if (headersToCopy.contains(value)) {
toRequest.addHeader(headerEntry.getKey(), value);
}
}
}
}
public static String streamToString(final InputStream inputStream) throws IOException {
final StringBuilder out = new StringBuilder();
while (true) {
byte[] bytesFromStream = IOUtils.readBytes(inputStream, 1024);
if (bytesFromStream.length == 0) {
return out.toString();
}
out.append(new String(bytesFromStream, StandardCharsets.UTF_8));
}
}
/**
* During upgrade, one server can be down, this is normal. Therefor we do a quick ping on the first server,
* if it is not responding, we try the other servers first. False positive/negatives are not critical,
* but will increase latency to some extent.
*/
private boolean queueFirstServerIfDown(List<URI> allServers) {
if (allServers.size() < 2) {
return false;
}
URI uri = allServers.get(0);
HttpGet httpget = new HttpGet(uri);
int timeout = 500;
RequestConfig config = RequestConfig.custom()
.setConnectTimeout(timeout)
.setConnectionRequestTimeout(timeout)
.setSocketTimeout(timeout).build();
try (
CloseableHttpClient client = createHttpClient(config);
CloseableHttpResponse response = client.execute(httpget);
) {
if (response.getStatusLine().getStatusCode() == 200) {
return false;
}
} catch (IOException e) {
// We ignore this, if server is restarting this might happen.
}
// Some error happened, move this server to the back. The other servers should be running.
allServers.remove(0);
allServers.add(uri);
return true;
}
private static CloseableHttpClient createHttpClient(RequestConfig config) {
return HttpClientBuilder.create()
.setUserAgent("config-server-client")
.setDefaultRequestConfig(config)
.build();
}
}
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