在 groovy 中将指标发布到 prometheus pushgateway 失败，出现 400答案

【问题标题】：POSTing metrics to prometheus pushgateway in groovy fails with 400在 groovy 中将指标发布到 prometheus pushgateway 失败，出现 400
【发布时间】：2021-10-11 07:46:00
【问题描述】：

我正在尝试将一个有效的 curl 命令转换为 groovy，因此我可以在我的 Jenkins 管道中本地执行它。我的问题是 curl 命令有效，但是我的 groovy 请求失败，来自 prometheus 的 pushgateway 的 400 错误。我在 groovy 中的代码如下所示：

def post = new URL("https://prometheus_url").openConnection();
def message = '''
# TYPE some_metric counter
some_metric{label="val1"} 42
# TYPE another_metric gauge
# HELP another_metric Just an example.
another_metric 2398.283
''';

post.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
post.with {
  doOutput = true
  requestMethod = 'POST'
  outputStream.withWriter { writer ->
    writer << message.bytes.encodeBase64().toString()
  }
  println content.text
}
assert post.responseCode == 200

我收到的错误是

Caught: java.io.IOException: Server returned HTTP response code: 400 for URL: https://prometheus_url
java.io.IOException: Server returned HTTP response code: 400 for URL: https://prometheus_url

我试图复制的工作 curl 命令如下

cat <<EOF | curl --data-binary @- 'https://prometheus_url' -vvv
# TYPE some_metric counter
some_metric{label="val1"} 42
# TYPE another_metric gauge
# HELP another_metric Just an example.
another_metric 2398.283
EOF

所以我的问题是，在我的 groovy 代码和接收此错误的 curl 命令之间缺少什么？

编辑：我正在添加来自工作 curl 操作的详细文本

cat <<EOF | curl --data-binary @- 'https://prometheus_url' -vvv
# TYPE some_metric counter
some_metric{label="val1"} 42
# TYPE another_metric gauge
# HELP another_metric Just an example.
another_metric 2398.283
EOF
*   Trying X.X.X.X...
* TCP_NODELAY set
* Connected to prometheus_url (X.X.X.X) port XYZ (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* successfully set certificate verify locations:
*   CAfile: /etc/ssl/cert.pem
  CApath: none
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / --------------------
* ALPN, server did not agree to a protocol
* Server certificate:
*  subject: CN=--------------------
*  start date: Jun 17 00:00:00 2021 GMT
*  expire date: Jul 16 23:59:59 2022 GMT
*  subjectAltName: host "prometheus_url" matched cert's "----------------"
*  issuer: C=--; O=--------; OU=-------- CA 1B; CN=--------
*  SSL certificate verify ok.
> POST ------------------------ HTTP/1.1
> Host: prometheus_url
> User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)
> Accept: */*
> Referer:
> Content-Length: 147
> Content-Type: application/x-www-form-urlencoded
>
* upload completely sent off: 147 out of 147 bytes
< HTTP/1.1 200 OK
< Date: Fri, 06 Aug 2021 13:18:39 GMT
< Content-Length: 0
< Connection: keep-alive
< 
* Connection #0 to host prometheus_url left intact
* Closing connection 0

【问题讨论】：

内容类型不应该是application/octet-stream吗？
嘿@tim_yates，是吗？我也试过这个，它似乎没有做任何不同的事情。谢谢你的想法。
我不相信application/x-www-form-urlencoded 是对的... curl 示例没有这样做，是吗？为什么要编码为base64？不确定 curl 示例是否也这样做？
可能也是个问题。我的理解是，这就是普罗米修斯所期待的？
去阅读 curl 的文档 ;-) curl.se/docs/manpage.html#--data-binary 所以 AFAIK，您的内容类型很好，但您不需要对字节进行编码，只需使用 @987654328 将它们发送到 OutputStream @

标签： java curl groovy prometheus prometheus-pushgateway

【解决方案1】：

在进一步摆弄代码之后，似乎根本不需要 base64 编码。因此，更简化和有效的代码如下：

def post = new URL("https://prometheus_url").openConnection();
def message = """
# TYPE some_metric counter
some_metric{label="val1"} 42
# TYPE another_metric gauge
# HELP another_metric Just an example.
another_metric 2398.283
""";

post.setRequestMethod("POST");
post.setDoOutput(true);
post.getOutputStream().write(message.bytes);

assert post.responseCode == 200

【讨论】：