利用prometheus文件服务发现功能，可以方便自定义主机或虚

利用prometheus文件服务发现功能，可以方便自定义主机或虚拟机的监控。

1. /etc/prometheus/prometheus.yml配置文件

文件服务发现配置参考 job_name: 'vm' 段

# my global configglobal:  scrape_interval:15s# Set the scrape interval to every 15 seconds. Default is every 1 minute.  evaluation_interval:15s# Evaluate rules every 15 seconds. The default is every 1 minute.# scrape_timeout is set to the global default (10s).# Attach these labels to any time series or alerts when communicating with# external systems (federation, remote storage, Alertmanager).  external_labels:      monitor:'codelab-monitor'# Load rules once and periodically evaluate them according to the global 'evaluation_interval'.rule_files:# - "first.rules"# - "second.rules"# A scrape configuration containing exactly one endpoint to scrape:# Here it's Prometheus itself.scrape_configs:# The job name is added as a label `job=` to any timeseries scraped from this config.  - job_name:'prometheus'# metrics_path defaults to '/metrics'# scheme defaults to 'http'.    static_configs:      - targets:['localhost:9090']scrape_configs:  - job_name:'vm'    file_sd_configs:      - files:          -/etc/prometheus/files/vm.yml        refresh_interval:5s

2. /etc/prometheus/files/vm.yml配置文件内容

[  {"targets": ["192.168.1.6:9273"],"labels": {"hosttype":"vm"}  }]

3. 通过docker启动prometheus

docker run-d-p9090:9090\-v/etc/prometheus/prometheus.yml:/etc/prometheus/prometheus.yml \-v/etc/prometheus/files:/etc/prometheus/files \prom/prometheus:v1.8.2

4. 检查prometheus的target，是否包含files.yml文件中配置的target

http://192.168.1.6:9090/targets

5.动态生成/etc/prometheus/files.yml 

如果想动态修改target，可以通过http请求，获取主机列表，然后动态生成/etc/prometheus/files/vm.yml文件。

下面是动态生成vm.yml例子。通过http请求，获取虚拟机的ip地址列表，然后动态生成vm.yml文件。

#!/usr/bin/pythonimportjsonimportloggingimportosimportrequestsimporttimelogging.basicConfig(level=logging.INFO,                    format='%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s',                    datefmt='%Y-%m-%d %H:%M:%S',                    filename='/var/log/prometheus-vm-http.log',                    filemode='w')console = logging.StreamHandler()console.setLevel(logging.INFO)formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s')console.setFormatter(formatter)logging.getLogger('').addHandler(console)def refresh():url ="http://域名/api/vm/ip"resp = requests.get(url, timeout=10)ifresp.status_code ==200:        logging.info("get "+ url +" ok")        data = [            {"targets": map(lambdax: x +":9273", resp.json()),"labels": {"hosttype":"vm"}            }        ]withopen('/etc/prometheus/files/vm.yml.new','w')asf:            json.dump(data, f, indent=2)            f.flush()            os.fsync(f.fileno())        os.rename('/etc/prometheus/files/vm.yml.new','/etc/prometheus/files/vm.yml')else:        logging.error("get "+ url +" failed. status_code=%d, resp=%s"% (resp.status_code, resp.text))if__name__ =='__main__':whileTrue:try:            refresh()exceptException, e:            logging.error(e)        time.sleep(10)