无法将JSON格式API响应转换为Prometheus可读格式求助

我有一个JSON格式的API响应，想要转换成Prometheus可读的指标格式，但用jq尝试转换后失败，Prometheus报错："INVALID" is not a valid start token。API响应内容如下：

{
  "version": "3.0.0",
  "gauges": {
    "gc.G1-Old-Generation.count": {
      "value": 0
    },
    "gc.G1-Old-Generation.time": {
      "value": 0
    },
    "gc.G1-Young-Generation.count": {
      "value": 30
    },
    "gc.G1-Young-Generation.time": {
      "value": 427
    },
    "jvm.name": {
      "value": "7@hubstorage"
    },
    "jvm.uptime": {
      "value": 44799
    },
    "jvm.vendor": {
      "value": "Azul Systems, Inc. OpenJDK 64-Bit Server VM 11.0.8+10-LTS (11)"
    },
    "memory.heap.committed": {
      "value": 208666624
    },
    "memory.heap.init": {
      "value": 65011712
    },
    "memory.heap.max": {
      "value": 1035993088
    },
    "memory.heap.usage": {
      "value": 0.11967882164094129
    },
    "memory.heap.used": {
      "value": 123986432
    },
    "memory.non-heap.committed": {
      "value": 114434048
    },
    "memory.non-heap.init": {
      "value": 7667712
    },
    "memory.non-heap.max": {
      "value": -1
    },
    "memory.non-heap.usage": {
      "value": -108223704
    },
    "memory.non-heap.used": {
      "value": 108223704
    },
    "memory.pools.CodeHeap-'non-nmethods'.committed": {
      "value": 2555904
    },
    "memory.pools.CodeHeap-'non-nmethods'.init": {
      "value": 2555904
    },
    "memory.pools.CodeHeap-'non-nmethods'.max": {
      "value": 5832704
    },
    "memory.pools.CodeHeap-'non-nmethods'.usage": {
      "value": 0.23114905196629212
    },
    "memory.pools.CodeHeap-'non-nmethods'.used": {
      "value": 1348224
    },
    "memory.pools.CodeHeap-'non-profiled-nmethods'.committed": {
      "value": 3670016
    },
    "memory.pools.CodeHeap-'non-profiled-nmethods'.init": {
      "value": 2555904
    },
    "memory.pools.CodeHeap-'non-profiled-nmethods'.max": {
      "value": 122912768
    },
    "memory.pools.CodeHeap-'non-profiled-nmethods'.usage": {
      "value": 0.029816007398027193
    },
    "memory.pools.CodeHeap-'non-profiled-nmethods'.used": {
      "value": 3664768
    },
    "memory.pools.CodeHeap-'profiled-nmethods'.committed": {
      "value": 12517376
    },
    "memory.pools.CodeHeap-'profiled-nmethods'.init": {
      "value": 2555904
    },
    "memory.pools.CodeHeap-'profiled-nmethods'.max": {
      "value": 122912768
    },
    "memory.pools.CodeHeap-'profiled-nmethods'.usage": {
      "value": 0.10141253998933618
    },
    "memory.pools.CodeHeap-'profiled-nmethods'.used": {
      "value": 12464896
    },
    "memory.pools.Compressed-Class-Space.committed": {
      "value": 12267520
    },
    "memory.pools.Compressed-Class-Space.init": {
      "value": 0
    },
    "memory.pools.Compressed-Class-Space.max": {
      "value": 1073741824
    },
    "memory.pools.Compressed-Class-Space.usage": {
      "value": 0.010960675776004791
    },
    "memory.pools.Compressed-Class-Space.used": {
      "value": 11768936
    },
    "memory.pools.G1-Eden-Space.committed": {
      "value": 118489088
    },
    "memory.pools.G1-Eden-Space.init": {
      "value": 15728640
    },
    "memory.pools.G1-Eden-Space.max": {
      "value": -1
    },
    "memory.pools.G1-Eden-Space.usage": {
      "value": 0.6548672566371682
    },
    "memory.pools.G1-Eden-Space.used": {
      "value": 77594624
    },
    "memory.pools.G1-Old-Gen.committed": {
      "value": 82837504
    },
    "memory.pools.G1-Old-Gen.init": {
      "value": 49283072
    },
    "memory.pools.G1-Old-Gen.max": {
      "value": 1035993088
    },
    "memory.pools.G1-Old-Gen.usage": {
      "value": 0.0376950159729251
    },
    "memory.pools.G1-Old-Gen.used": {
      "value": 39051776
    },
    "memory.pools.G1-Survivor-Space.committed": {
      "value": 7340032
    },
    "memory.pools.G1-Survivor-Space.init": {
      "value": 0
    },
    "memory.pools.G1-Survivor-Space.max": {
      "value": -1
    },
    "memory.pools.G1-Survivor-Space.usage": {
      "value": 1
    },
    "memory.pools.G1-Survivor-Space.used": {
      "value": 7340032
    },
    "memory.pools.Metaspace.committed": {
      "value": 83423232
    },
    "memory.pools.Metaspace.init": {
      "value": 0
    },
    "memory.pools.Metaspace.max": {
      "value": -1
    },
    "memory.pools.Metaspace.usage": {
      "value": 0.9467012738130309
    },
    "memory.pools.Metaspace.used": {
      "value": 78976880
    },
    "memory.total.committed": {
      "value": 323100672
    },
    "memory.total.init": {
      "value": 72679424
    },
    "memory.total.max": {
      "value": 1035993087
    },
    "memory.total.used": {
      "value": 232210136
    },
    "threads.blocked.count": {
      "value": 0
    },
    "threads.count": {
      "value": 34
    },
    "threads.daemon.count": {
      "value": 14
    },
    "threads.deadlock.count": {
      "value": 0
    },
    "threads.deadlocks": {
      "value": []
    },
    "threads.new.count": {
      "value": 0
    },
    "threads.runnable.count": {
      "value": 11
    },
    "threads.terminated.count": {
      "value": 0
    },
    "threads.timed_waiting.count": {
      "value": 17
    },
    "threads.waiting.count": {
      "value": 6
    }
  },
  "counters": {
    "counter": {
      "count": 1
    }
  },
  "histograms": {
    "histogram": {
      "count": 3,
      "max": 100,
      "mean": 41.66666666666666,
      "min": 5,
      "p50": 20,
      "p75": 100,
      "p95": 100,
      "p98": 100,
      "p99": 100,
      "p999": 100,
      "stddev": 41.69998667732268
    }
  },
  "meters": {
    "meter": {
      "count": 201,
      "m15_rate": 38.666674566183616,
      "m1_rate": 22.433012859955905,
      "m5_rate": 35.77324719371856,
      "mean_rate": 4.944024762580441,
      "units": "events/second"
    }
  },
  "timers": {}
}

Prometheus只接受文本格式的指标（每行一个指标，格式为metric_name{labels} value），直接返回JSON会触发"INVALID" is not a valid start token错误。以下是用jq将JSON转换为Prometheus可读格式的完整命令：

curl -s "你的API地址" | jq -r '
  # 处理数值型Gauges，替换指标名中的特殊字符
  .gauges | to_entries[] | 
  select(.value.value | type == "number") | 
  (.key | gsub("[\\-'\''\"]"; "_")) + " " + (.value.value | tostring),
  
  # 将JVM字符串信息转换为Prometheus info类型指标
  "jvm_info{name=\"\(.gauges."jvm.name".value)\", vendor=\"\(.gauges."jvm.vendor".value | gsub("\""; "\\\""))\"} 1",
  
  # 处理Counters
  .counters | to_entries[] | 
  (.key + "_count") + " " + (.value.count | tostring),
  
  # 处理Histograms，转换为Prometheus Summary格式（包含分位数）
  .histograms | to_entries[] | 
  (.key + "_count") + " " + (.value.count | tostring),
  (.key + "_sum") + " " + ((.value.mean * .value.count) | tostring),
  (.key + "_min") + " " + (.value.min | tostring),
  (.key + "_max") + " " + (.value.max | tostring),
  (.key + "_stddev") + " " + (.value.stddev | tostring),
  (.key + "{quantile=\"0.5\"}") + " " + (.value.p50 | tostring),
  (.key + "{quantile=\"0.75\"}") + " " + (.value.p75 | tostring),
  (.key + "{quantile=\"0.95\"}") + " " + (.value.p95 | tostring),
  (.key + "{quantile=\"0.98\"}") + " " + (.value.p98 | tostring),
  (.key + "{quantile=\"0.99\"}") + " " + (.value.p99 | tostring),
  (.key + "{quantile=\"0.999\"}") + " " + (.value.p999 | tostring),
  
  # 处理Meters
  .meters | to_entries[] | 
  (.key + "_count") + " " + (.value.count | tostring),
  (.key + "_m1_rate") + " " + (.value.m1_rate | tostring),
  (.key + "_m5_rate") + " " + (.value.m5_rate | tostring),
  (.key + "_m15_rate") + " " + (.value.m15_rate | tostring),
  (.key + "_mean_rate") + " " + (.value.mean_rate | tostring)
'

关键说明 #

1. 指标名规范：Prometheus不允许指标名包含-、'等特殊字符，所以用gsub将这些字符替换为_。
2. 字符串指标处理：JVM名称、厂商这类字符串值，转换为Prometheus的info类型指标（值固定为1，信息存在标签中）。
3. Histogram转换：原JSON中的histogram包含分位数，这里转换为Prometheus的Summary格式，保留分位数统计。
4. 错误原因："INVALID" is not a valid start token是因为Prometheus收到的不是预期的文本指标格式，必须确保转换后的输出每行都是符合规范的指标行。

Prometheus采集配置 #

要让Prometheus采集转换后的指标，可通过以下两种方式：

• 使用Exec Exporter：配置Exec Exporter执行上述curl+jq命令，暴露指标端口给Prometheus。
• Node Exporter Textfile Collector：将转换后的指标写入Node Exporter的textfile目录，由Node Exporter暴露给Prometheus。

内容的提问来源于stack exchange，提问作者shaheer01