构建镜像
默认tomcat镜像不提供普罗米修斯相关的支持，所以需要自己制作镜像。
在tomcat发布目录下需要有一个metrics.war，这样接口地址才能暴露tomcat的一些指标，以及采集指标的tomcat_exporter_client-0.0.12.jar
[root@master tomcat]# cat Dockerfile
FROM tomcat
ADD metrics.war /usr/local/tomcat/webapps/
ADD simpleclient-0.8.0.jar /usr/local/tomcat/lib/
ADD simpleclient_common-0.8.0.jar /usr/local/tomcat/lib/
ADD simpleclient_hotspot-0.8.0.jar /usr/local/tomcat/lib/
ADD simpleclient_servlet-0.8.0.jar /usr/local/tomcat/lib/
ADD tomcat_exporter_client-0.0.12.jar /usr/local/tomcat/lib/[root@master tomcat]# docker build -t 'tomcat_prometheus:v1' .
Sending build context to Docker daemon 128kB
Step 1/7 : FROM tomcat
latest: Pulling from library/tomcat
5e0b432e8ba9: Pull complete
a84cfd68b5ce: Pull complete
e8b8f2315954: Pull complete
Digest: sha256:429d5c140820d5eba38042823501d5f4e0f03b282133513e29c22d6358daa7c7
Status: Downloaded newer image for tomcat:latest---> 24207ccc9cce
Step 2/7 : ADD metrics.war /usr/local/tomcat/webapps/---> 65f67a4763ea
Step 3/7 : ADD simpleclient-0.8.0.jar /usr/local/tomcat/lib/---> 72d7414ff158
Step 4/7 : ADD simpleclient_common-0.8.0.jar /usr/local/tomcat/lib/---> 8e58e81f047f
Step 5/7 : ADD simpleclient_hotspot-0.8.0.jar /usr/local/tomcat/lib/---> 2324ee685ac8
Step 6/7 : ADD simpleclient_servlet-0.8.0.jar /usr/local/tomcat/lib/---> deb785fb6740
Step 7/7 : ADD tomcat_exporter_client-0.0.12.jar /usr/local/tomcat/lib/---> 92539e485933
Successfully built 92539e485933
Successfully tagged tomcat_prometheus:v1放在公有仓库上面了。
docker pull xianchao/tomcat_prometheus:v1 #在k8s的node节点拉取镜像拉取镜像
基于上面的镜像创建一个tomcat实例
pod里面这个字段也就是说我们创建的pod可以被Prometheus抓取到。
annotations:prometheus.io/scrape: 'true'[root@master tomcat]# cat deploy.yaml
apiVersion: apps/v1
kind: Deployment
metadata:name: tomcat-deploymentnamespace: monitor
spec:selector: matchLabels: app: tomcatreplicas: 1 # tells deployment to run 2 pods matching the templatetemplate: # create pods using pod definition in this templatemetadata:labels:app: tomcatannotations:prometheus.io/scrape: 'true'spec:containers:- name: tomcatimage: xianchao/tomcat_prometheus:v1ports:- containerPort: 8080securityContext: privileged: true[root@master prometheus]# kubectl get pod -n monitor -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
grafana-757fcd5f7c-n6sj7 1/1 Running 19 26d 10.233.96.236 node2 <none> <none>
node-exporter-26849 1/1 Running 21 36d 192.168.100.5 master <none> <none>
node-exporter-jbbcq 1/1 Running 23 36d 192.168.100.6 node1 <none> <none>
node-exporter-mh78s 1/1 Running 21 36d 192.168.100.7 node2 <none> <none>
prometheus-server-5775f99578-6pxsj 1/1 Running 0 89s 10.233.90.131 node1 <none> <none>
tomcat-deployment-699d65b574-6zzcn 1/1 Running 0 10m 10.233.96.242 node2 <none> <none>我们可以看到 kubernetes-pods下面出现了很多实例，这是因为这里我们使用的是 pod 类型的服务发现，那么我们应该怎样来过滤出这个pod来呢？
keep，就是只把符合我们要求的给保留下来，哪些才是符合我们要求的呢？
我们可以把鼠标放置在任意一个 target 上，可以查看到Before relabeling里面所有的元数据
- job_name: 'kubernetes-pods-tomcat'kubernetes_sd_configs:- role: podrelabel_configs:- source_labels: [__meta_kubernetes_namespace,__meta_kubernetes_pod_label_app]action: keepregex: monitor;tomcat
可以看到最后被监控上了。 指标如下
[root@master prometheus]# curl http://10.233.96.242:8080/metrics/
# HELP jvm_classes_loaded The number of classes that are currently loaded in the JVM
# TYPE jvm_classes_loaded gauge
jvm_classes_loaded 2760.0
# HELP jvm_classes_loaded_total The total number of classes that have been loaded since the JVM has started execution
# TYPE jvm_classes_loaded_total counter
jvm_classes_loaded_total 2760.0
# HELP jvm_classes_unloaded_total The total number of classes that have been unloaded since the JVM has started execution
# TYPE jvm_classes_unloaded_total counter
jvm_classes_unloaded_total 0.0
# HELP process_cpu_seconds_total Total user and system CPU time spent in seconds.
# TYPE process_cpu_seconds_total counter
process_cpu_seconds_total 7.53
# HELP process_start_time_seconds Start time of the process since unix epoch in seconds.
# TYPE process_start_time_seconds gauge
process_start_time_seconds 1.639707011452E9
最后这个通过访问物理机ip和端口访问tomcat界面service可以创建也可以不创建。
cat tomcat-service.yaml
kind: Service #service 类型
apiVersion: v1
metadata:
# annotations:
# prometheus.io/scrape: 'true'name: tomcat-service
spec:selector:app: tomcatports:- nodePort: 31360port: 80protocol: TCPtargetPort: 8080type: NodePort