com.predic8.membrane.core.interceptor.prometheus.PrometheusInterceptor Maven / Gradle / Ivy
/*
* Copyright 2017 predic8 GmbH, www.predic8.com
*
* 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 com.predic8.membrane.core.interceptor.prometheus;
import com.predic8.membrane.annot.MCElement;
import com.predic8.membrane.core.exchange.Exchange;
import com.predic8.membrane.core.http.Header;
import com.predic8.membrane.core.http.MimeType;
import com.predic8.membrane.core.http.Response;
import com.predic8.membrane.core.interceptor.AbstractInterceptor;
import com.predic8.membrane.core.interceptor.Outcome;
import com.predic8.membrane.core.rules.Rule;
import com.predic8.membrane.core.rules.StatisticCollector;
import java.util.Map;
import java.util.regex.Pattern;
@MCElement(name = "prometheus")
public class PrometheusInterceptor extends AbstractInterceptor {
@Override
public Outcome handleRequest(Exchange exc) throws Exception {
StringBuilder sb = new StringBuilder();
buildPrometheusStyleResponse(sb);
exc.setResponse(Response.ok(sb.toString()).header(Header.CONTENT_TYPE, MimeType.TEXT_PLAIN_UTF8).build());
return Outcome.RETURN;
}
private void buildPrometheusStyleResponse(StringBuilder sb) {
for (Rule r : router.getRuleManager().getRules())
buildStatuscodeLines(sb, r);
}
private StringBuilder buildStatuscodeLines(StringBuilder sb, Rule rule) {
Map stats = rule.getStatisticsByStatusCodes();
for (Integer code : stats.keySet()) {
buildLine(sb, rule.getName(), String.valueOf(stats.get(code).getCount()), "code", code, "count");
buildLine(sb, rule.getName(), String.valueOf(stats.get(code).getMinTime()), "code", code, "min");
buildLine(sb, rule.getName(), String.valueOf(stats.get(code).getMaxTime()), "code", code, "max");
buildLine(sb, rule.getName(), String.valueOf(stats.get(code).getAvgTime()), "code", code, "avg");
}
return sb;
}
private StringBuilder buildLine(StringBuilder sb, String ruleName, Object value, Object... keys) {
sb.append(toLowerCaseUnderscore(replaceColonWithUnknown(ruleName)));
for (Object key : keys)
sb.append("_").append(String.valueOf(key));
sb.append(" ").append(String.valueOf(value)).append(System.lineSeparator());
return sb;
}
private String replaceColonWithUnknown(String ruleName) {
if (ruleName.startsWith(":"))
return ruleName.replaceFirst(Pattern.quote(":"), "unknown_");
return ruleName;
}
private String toLowerCaseUnderscore(String ruleName) {
StringBuilder sb = new StringBuilder();
String[] split = ruleName.toLowerCase().split(" ");
for (String s : split)
sb.append(s).append("_");
sb.setLength(sb.length() - 1);
return sb.toString();
}
}