| /* |
| * 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 ASF 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.solr.prometheus.exporter; |
| |
| import java.util.Objects; |
| import java.util.Optional; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| public class MetricsQueryTemplate { |
| /* |
| A regex with named groups is used to match template references to template + vars using the basic pattern: |
| |
| $jq:<TEMPLATE>( <UNIQUE>, <KEYSELECTOR>, <METRIC>, <TYPE> ) |
| |
| For instance, |
| |
| $jq:core(requests_total, endswith(".requestTimes"), count, COUNTER) |
| |
| TEMPLATE = core |
| UNIQUE = requests_total (unique suffix for this metric, results in a metric named "solr_metrics_core_requests_total") |
| KEYSELECTOR = endswith(".requestTimes") (filter to select the specific key for this metric) |
| METRIC = count |
| TYPE = COUNTER |
| */ |
| private static final Pattern matchJqTemplate = |
| Pattern.compile("^\\$jq:(?<TEMPLATE>.*?)\\(\\s?(?<UNIQUE>[^,]*),\\s?(?<KEYSELECTOR>[^,]*)(,\\s?(?<METRIC>[^,]*)\\s?)?(,\\s?(?<TYPE>[^,]*)\\s?)?\\)$"); |
| |
| public static Optional<Matcher> matches(String jsonQuery) { |
| Optional<Matcher> maybe = Optional.empty(); |
| if (jsonQuery != null) { |
| String toMatch = jsonQuery.replaceAll("\\s+", " ").trim(); |
| Matcher m = matchJqTemplate.matcher(toMatch); |
| if (m.matches()) { |
| maybe = Optional.of(m); |
| } |
| } |
| return maybe; |
| } |
| |
| private final String name; |
| private final String defaultType; |
| private final String template; |
| |
| public MetricsQueryTemplate(String name, String template, String defaultType) { |
| Objects.requireNonNull(name, "jq template must have a name"); |
| Objects.requireNonNull(template, "jq template is required"); |
| |
| this.name = name; |
| this.template = template.replaceAll("\\s+", " ").trim(); |
| if (this.template.isEmpty()) { |
| throw new IllegalArgumentException("jq template must not be empty"); |
| } |
| this.defaultType = defaultType != null ? defaultType : "GAUGE"; |
| } |
| |
| public String getName() { |
| return name; |
| } |
| |
| public String applyTemplate(final Matcher matched) { |
| String keySelector = matched.group("KEYSELECTOR"); |
| if (keySelector == null) keySelector = ""; |
| |
| String unique = matched.group("UNIQUE"); |
| unique = unique != null ? unique.trim() : ""; |
| |
| String type = matched.group("TYPE"); |
| if (type == null) { |
| type = defaultType; |
| } |
| |
| String metric = matched.group("METRIC"); |
| if (metric == null) { |
| metric = unique; |
| } |
| |
| // could be a simple field name or some kind of function here |
| if (!metric.contains("$")) { |
| if ("object.value".equals(metric)) { |
| metric = "$object.value"; // don't require the user to supply the $ |
| } else if (!metric.contains("$object")) { |
| if (Character.isDigit(metric.charAt(0))) { |
| // jq doesn't like fields that start with a number |
| metric = "$object.value[\"" + metric + "\"]"; |
| } else { |
| // just a simple field reference in the value object |
| metric = "$object.value." + metric; |
| } |
| } // else some kind of function, pass thru as-is |
| } // else there's a $ so just assume it is a fully qualified reference to the desired value, leave as-is |
| |
| return template |
| .replace("{UNIQUE}", unique) |
| .replace("{KEYSELECTOR}", keySelector.trim()) |
| .replace("{METRIC}", metric.trim()) |
| .replace("{TYPE}", type.trim()); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) return true; |
| if (o == null || getClass() != o.getClass()) return false; |
| MetricsQueryTemplate that = (MetricsQueryTemplate) o; |
| return name.equals(that.name) && |
| Objects.equals(defaultType, that.defaultType) && |
| template.equals(that.template); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(name, defaultType, template); |
| } |
| } |