add a online prometheus parser and a prometheus-like push style.

common/src/main/java/org/dromara/hertzbeat/common/util/prometheus/Label.java

@@ -0,0 +1,20 @@
+package org.dromara.hertzbeat.common.util.prometheus;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * prometheus label entity
+ *
+ *
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class Label {
+    private String name;
+    private String value;
+}

common/src/main/java/org/dromara/hertzbeat/common/util/prometheus/Metric.java

@@ -0,0 +1,24 @@
+package org.dromara.hertzbeat.common.util.prometheus;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.List;
+
+/**
+ * prometheus metric line entity
+ *
+ *
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class Metric {
+    private String metricName;
+    private List<Label> labelList;
+    private Double value;
+    private Long timestamp;
+}

common/src/main/java/org/dromara/hertzbeat/common/util/prometheus/PrometheusUtil.java

@@ -0,0 +1,233 @@
+package org.dromara.hertzbeat.common.util.prometheus;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.math.BigDecimal;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * prometheus metric sparser
+ *
+ *
+ */
+public class PrometheusUtil {
+
+    private static final int ERROR_FORMAT = -1; //解析过程中出现了未知格式数据，因为无法继续解析或已经到达输入流的末尾
+
+    private static final int NORMAL_END = -2; //输入流正常结束
+
+    private static final int COMMENT_LINE = -3;
+
+
+    private static int parseMetricName(InputStream inputStream, Metric.MetricBuilder metricBuilder) throws IOException {
+        StringBuilder stringBuilder = new StringBuilder();
+        int i;
+        i = inputStream.read();
+        if (i == -1) {
+            return NORMAL_END;
+        }
+        else if (i == '#') {
+            return COMMENT_LINE;
+        }
+
+        while (i != -1) {
+            if (i == ' ' || i == '{') {
+                metricBuilder.metricName(stringBuilder.toString());
+                return i;
+            }
+            stringBuilder.append((char) i);
+            i = inputStream.read();
+        }
+
+        return ERROR_FORMAT;
+    }
+
+    private static int parseLabel(InputStream inputStream, List<Label> labelList) throws IOException {
+        Label.LabelBuilder labelBuilder = new Label.LabelBuilder();
+        int i;
+
+        StringBuilder labelName = new StringBuilder();
+        i = inputStream.read();
+        while (i != -1 && i != '=') {
+            labelName.append((char) i);
+            i = inputStream.read();
+        }
+        if (i == -1) {
+            return ERROR_FORMAT;
+        }
+        labelBuilder.name(labelName.toString());
+
+        if (inputStream.read() != '\"') {
+            return ERROR_FORMAT;
+        }
+
+        StringBuilder labelValue = new StringBuilder();
+        i = inputStream.read();
+        while (i != -1 && i != ',' && i != '}') {
+            labelValue.append((char) i);
+            i = inputStream.read();
+        }
+        if (i == -1 || labelValue.charAt(labelValue.length() - 1) != '\"') {
+            return ERROR_FORMAT;
+        }
+
+        // skip space only in this condition
+        if (i == '}' && inputStream.read() != ' ') {
+            return ERROR_FORMAT;
+        }
+
+        labelValue.deleteCharAt(labelValue.length() - 1);
+        labelBuilder.value(labelValue.toString());
+
+        labelList.add(labelBuilder.build());
+        return i;
+    }
+
+    private static int parseLabelList(InputStream inputStream, Metric.MetricBuilder metricBuilder) throws IOException {
+        List<Label> labelList = new ArrayList<>();
+        int i;
+
+        i = parseLabel(inputStream, labelList);
+        while (i == ',') {
+            i = parseLabel(inputStream, labelList);
+        }
+        if (i == -1) {
+            return ERROR_FORMAT;
+        }
+
+        metricBuilder.labelList(labelList);
+        return i;
+    }
+
+    private static int parseValue(InputStream inputStream, Metric.MetricBuilder metricBuilder) throws IOException {
+        int i;
+
+        StringBuilder stringBuilder = new StringBuilder();
+        i = inputStream.read();
+        while (i != -1 && i != ' ' && i != '\n') {
+            stringBuilder.append((char) i);
+            i = inputStream.read();
+        }
+
+        String string = stringBuilder.toString();
+
+        switch (string) {
+            case "NaN":
+                metricBuilder.value(Double.NaN);
+                break;
+            case "+Inf":
+                metricBuilder.value(Double.POSITIVE_INFINITY);
+                break;
+            case "-Inf":
+                metricBuilder.value(Double.NEGATIVE_INFINITY);
+                break;
+            default:
+                try {
+                    BigDecimal bigDecimal = new BigDecimal(string);
+                    metricBuilder.value(bigDecimal.doubleValue());
+                } catch (NumberFormatException e) {
+                    return ERROR_FORMAT;
+                }
+                break;
+        }
+
+        if (i == -1) {
+            return NORMAL_END;
+        }
+        else {
+            return i; // ' ' or \n'
+        }
+    }
+
+    private static int parseTimestamp(InputStream inputStream, Metric.MetricBuilder metricBuilder) throws IOException {
+        int i;
+
+        StringBuilder stringBuilder = new StringBuilder();
+        i = inputStream.read();
+        while (i != -1 && i != '\n') {
+            stringBuilder.append((char) i);
+            i = inputStream.read();
+        }
+
+        String string = stringBuilder.toString();
+        try {
+            metricBuilder.timestamp(Long.parseLong(string));
+        } catch (NumberFormatException e) {
+            return ERROR_FORMAT;
+        }
+
+        if (i == -1) {
+            return NORMAL_END;
+        }
+        else {
+            return i; // '\n'
+        }
+    }
+
+    // return value:
+    // -1: error format
+    // -2: normal end
+    // '\n': more lines
+    private static int parseMetric(InputStream inputStream, List<Metric> metrics) throws IOException {
+        Metric.MetricBuilder metricBuilder = new Metric.MetricBuilder();
+
+        int i = parseMetricName(inputStream, metricBuilder); // RET: -1, -2, -3, '{', ' '
+        if (i == ERROR_FORMAT || i == NORMAL_END || i == COMMENT_LINE) {
+            return i;
+        }
+
+        if (i == '{') {
+            i = parseLabelList(inputStream, metricBuilder); // RET: -1, '}'
+            if (i == ERROR_FORMAT) {
+                return i;
+            }
+        }
+
+
+        i = parseValue(inputStream, metricBuilder); // RET: -1, -2, '\n', ' '
+        if (i != ' ') {
+            metrics.add(metricBuilder.build());
+            return i;
+        }
+
+        i = parseTimestamp(inputStream, metricBuilder); // RET: -1, -2, '\n'
+
+        metrics.add(metricBuilder.build());
+        return i;
+
+    }
+
+    private static int skipCommentLine(InputStream inputStream) throws IOException {
+        int i = inputStream.read();
+        while (i != -1 && i != '\n') {
+            i = inputStream.read();
+        }
+        if (i == -1) {
+            return NORMAL_END;
+        }
+        return i;
+    }
+
+    public static List<Metric> parseMetrics(InputStream inputStream) throws IOException {
+        List<Metric> metricList= new ArrayList<>();
+        int i = parseMetric(inputStream, metricList);
+        while (i == '\n' || i == COMMENT_LINE) {
+            if (i == COMMENT_LINE) {
+                if (skipCommentLine(inputStream) == NORMAL_END) {
+                    return metricList;
+                }
+
+            }
+            i = parseMetric(inputStream, metricList);
+        }
+        if (i == NORMAL_END) {
+            return metricList;
+        }
+        else {
+            return null;
+        }
+    }
+
+
+}

push/src/main/java/org/dromara/hertzbeat/push/controller/PushGatewayController.java

@@ -0,0 +1,43 @@
+package org.dromara.hertzbeat.push.controller;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.servlet.http.HttpServletRequest;
+import org.dromara.hertzbeat.common.entity.dto.Message;
+import org.dromara.hertzbeat.push.service.PushGatewayService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * push gateway controller
+ *
+ *
+ */
+@Tag(name = "Metrics Push Gateway API | 监控数据推送网关API")
+@RestController
+@RequestMapping(value = "/api/push/pushgateway")
+public class PushGatewayController {
+
+    @Autowired
+    private PushGatewayService pushGatewayService;
+
+    @PostMapping()
+    @Operation(summary = "Push metric data to hertzbeat pushgateway", description = "推送监控数据到hertzbeat推送网关")
+    public ResponseEntity<Message<Void>> pushMetrics(HttpServletRequest request) throws IOException {
+        InputStream inputStream = request.getInputStream();
+        boolean result = pushGatewayService.pushMetricsData(inputStream);
+        if (result) {
+            return ResponseEntity.ok(Message.success("Push success"));
+        }
+        else {
+            return ResponseEntity.ok(Message.success("Push failed"));
+        }
+    }
+
+}

push/src/main/java/org/dromara/hertzbeat/push/service/PushGatewayService.java

@@ -0,0 +1,19 @@
+package org.dromara.hertzbeat.push.service;
+
+import org.springframework.stereotype.Service;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * push gateway metrics
+ *
+ *
+ */
+
+@Service
+public interface PushGatewayService {
+
+    boolean pushMetricsData(InputStream inputStream) throws IOException;
+
+}

push/src/main/java/org/dromara/hertzbeat/push/service/impl/PushGatewayServiceImpl.java

@@ -0,0 +1,28 @@
+package org.dromara.hertzbeat.push.service.impl;
+
+import lombok.extern.slf4j.Slf4j;
+import org.dromara.hertzbeat.common.util.prometheus.Metric;
+import org.dromara.hertzbeat.common.util.prometheus.PrometheusUtil;
+import org.dromara.hertzbeat.push.service.PushGatewayService;
+import org.springframework.stereotype.Service;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.List;
+
+/**
+ * push gateway service impl
+ *
+ *
+ */
+
+@Slf4j
+@Service
+public class PushGatewayServiceImpl implements PushGatewayService {
+
+    @Override
+    public boolean pushMetricsData(InputStream inputStream) throws IOException {
+        List<Metric> metrics = PrometheusUtil.parseMetrics(inputStream);
+        return metrics != null;
+    }
+}