2017-06-15 22:13:59 +08:00
|
|
|
|
# 监控
|
|
|
|
|
|
|
|
|
|
在前面的[安装heapster插件](heapster-addon-installation.md)章节,我们已经谈到Kubernetes本身提供了监控插件作为集群和容器监控的选择,但是在实际使用中,因为种种原因,再考虑到跟我们自身的监控系统集成,我们准备重新造轮子。
|
|
|
|
|
|
|
|
|
|
## 容器的命名规则
|
|
|
|
|
|
|
|
|
|
首先我们需要清楚使用cAdvisor收集的数据的格式和字段信息。
|
|
|
|
|
|
|
|
|
|
当我们通过cAdvisor获取到了容器的信息后,例如访问`${NODE_IP}:4194/api/v1.3/docker`获取的json结果中的某个容器包含如下字段:
|
|
|
|
|
|
|
|
|
|
```json
|
|
|
|
|
"labels": {
|
|
|
|
|
"annotation.io.kubernetes.container.hash": "f47f0602",
|
|
|
|
|
"annotation.io.kubernetes.container.ports": "[{\"containerPort\":80,\"protocol\":\"TCP\"}]",
|
|
|
|
|
"annotation.io.kubernetes.container.restartCount": "0",
|
|
|
|
|
"annotation.io.kubernetes.container.terminationMessagePath": "/dev/termination-log",
|
|
|
|
|
"annotation.io.kubernetes.container.terminationMessagePolicy": "File",
|
|
|
|
|
"annotation.io.kubernetes.pod.terminationGracePeriod": "30",
|
|
|
|
|
"io.kubernetes.container.logpath": "/var/log/pods/d8a2e995-3617-11e7-a4b0-ecf4bbe5d414/php-redis_0.log",
|
|
|
|
|
"io.kubernetes.container.name": "php-redis",
|
|
|
|
|
"io.kubernetes.docker.type": "container",
|
|
|
|
|
"io.kubernetes.pod.name": "frontend-2337258262-771lz",
|
|
|
|
|
"io.kubernetes.pod.namespace": "default",
|
|
|
|
|
"io.kubernetes.pod.uid": "d8a2e995-3617-11e7-a4b0-ecf4bbe5d414",
|
|
|
|
|
"io.kubernetes.sandbox.id": "843a0f018c0cef2a5451434713ea3f409f0debc2101d2264227e814ca0745677"
|
|
|
|
|
},
|
|
|
|
|
```
|
|
|
|
|
|
2017-06-16 11:46:40 +08:00
|
|
|
|
这些信息其实都是kubernetes创建容器时给docker container打的`Labels`,使用`docker inspect $conainer_name`命令同样可以看到上述信息。
|
|
|
|
|
|
2017-06-15 22:13:59 +08:00
|
|
|
|
你是否想过这些label跟容器的名字有什么关系?当你在node节点上执行`docker ps`看到的容器名字又对应哪个应用的Pod呢?
|
|
|
|
|
|
|
|
|
|
在kubernetes代码中pkg/kubelet/dockertools/docker.go中的BuildDockerName方法定义了容器的名称规范。
|
|
|
|
|
|
|
|
|
|
这段容器名称定义代码如下:
|
|
|
|
|
|
|
|
|
|
```go
|
|
|
|
|
// Creates a name which can be reversed to identify both full pod name and container name.
|
|
|
|
|
// This function returns stable name, unique name and a unique id.
|
|
|
|
|
// Although rand.Uint32() is not really unique, but it's enough for us because error will
|
|
|
|
|
// only occur when instances of the same container in the same pod have the same UID. The
|
|
|
|
|
// chance is really slim.
|
|
|
|
|
func BuildDockerName(dockerName KubeletContainerName, container *v1.Container) (string, string, string) {
|
|
|
|
|
containerName := dockerName.ContainerName + "." + strconv.FormatUint(kubecontainer.HashContainerLegacy(container), 16)
|
|
|
|
|
stableName := fmt.Sprintf("%s_%s_%s_%s",
|
|
|
|
|
containerNamePrefix,
|
|
|
|
|
containerName,
|
|
|
|
|
dockerName.PodFullName,
|
|
|
|
|
dockerName.PodUID)
|
|
|
|
|
UID := fmt.Sprintf("%08x", rand.Uint32())
|
|
|
|
|
return stableName, fmt.Sprintf("%s_%s", stableName, UID), UID
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// Unpacks a container name, returning the pod full name and container name we would have used to
|
|
|
|
|
// construct the docker name. If we are unable to parse the name, an error is returned.
|
|
|
|
|
func ParseDockerName(name string) (dockerName *KubeletContainerName, hash uint64, err error) {
|
|
|
|
|
// For some reason docker appears to be appending '/' to names.
|
|
|
|
|
// If it's there, strip it.
|
|
|
|
|
name = strings.TrimPrefix(name, "/")
|
|
|
|
|
parts := strings.Split(name, "_")
|
|
|
|
|
if len(parts) == 0 || parts[0] != containerNamePrefix {
|
|
|
|
|
err = fmt.Errorf("failed to parse Docker container name %q into parts", name)
|
|
|
|
|
return nil, 0, err
|
|
|
|
|
}
|
|
|
|
|
if len(parts) < 6 {
|
|
|
|
|
// We have at least 5 fields. We may have more in the future.
|
|
|
|
|
// Anything with less fields than this is not something we can
|
|
|
|
|
// manage.
|
|
|
|
|
glog.Warningf("found a container with the %q prefix, but too few fields (%d): %q", containerNamePrefix, len(parts), name)
|
|
|
|
|
err = fmt.Errorf("Docker container name %q has less parts than expected %v", name, parts)
|
|
|
|
|
return nil, 0, err
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
nameParts := strings.Split(parts[1], ".")
|
|
|
|
|
containerName := nameParts[0]
|
|
|
|
|
if len(nameParts) > 1 {
|
|
|
|
|
hash, err = strconv.ParseUint(nameParts[1], 16, 32)
|
|
|
|
|
if err != nil {
|
|
|
|
|
glog.Warningf("invalid container hash %q in container %q", nameParts[1], name)
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
podFullName := parts[2] + "_" + parts[3]
|
|
|
|
|
podUID := types.UID(parts[4])
|
|
|
|
|
|
|
|
|
|
return &KubeletContainerName{podFullName, podUID, containerName}, hash, nil
|
|
|
|
|
}
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
我们可以看到容器名称中包含如下几个字段,中间用下划线隔开,至少有6个字段,未来可能添加更多字段。
|
|
|
|
|
|
|
|
|
|
下面的是四个基本字段。
|
|
|
|
|
|
|
|
|
|
```
|
|
|
|
|
containerNamePrefix_containerName_PodFullName_PodUID
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
所有kubernetes启动的容器的containerNamePrefix都是k8s。
|
|
|
|
|
|
|
|
|
|
Kubernetes启动的docker容器的容器名称规范,下面以官方示例guestbook为例,Deployment 名为 frontend中启动的名为php-redis的docker容器的副本书为3。
|
|
|
|
|
|
|
|
|
|
Deployment frontend的配置如下:
|
|
|
|
|
|
|
|
|
|
```yaml
|
|
|
|
|
apiVersion: extensions/v1beta1
|
|
|
|
|
kind: Deployment
|
|
|
|
|
metadata:
|
|
|
|
|
name: frontend
|
|
|
|
|
spec:
|
|
|
|
|
template:
|
|
|
|
|
metadata:
|
|
|
|
|
labels:
|
|
|
|
|
app: guestbook
|
|
|
|
|
tier: frontend
|
|
|
|
|
spec:
|
|
|
|
|
containers:
|
|
|
|
|
- name: php-redis
|
|
|
|
|
image: bj-xg-oam-docker-hub-001.tendcloud.com/library/gb-frontend:v4
|
|
|
|
|
resources:
|
|
|
|
|
requests:
|
|
|
|
|
cpu: 100m
|
|
|
|
|
memory: 100Mi
|
|
|
|
|
env:
|
|
|
|
|
- name: GET_HOSTS_FROM
|
|
|
|
|
value: dns
|
|
|
|
|
ports:
|
|
|
|
|
- containerPort: 80
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
我们选取三个实例中的一个运行php-redis的docker容器。
|
|
|
|
|
|
|
|
|
|
```
|
|
|
|
|
k8s_php-redis_frontend-2337258262-154p7_default_d8a2e2dd-3617-11e7-a4b0-ecf4bbe5d414_0
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
- containerNamePrefix:k8s
|
|
|
|
|
- containerName:php-redis
|
|
|
|
|
- podFullName:frontend-2337258262-154p7
|
|
|
|
|
- computeHash:154p7
|
|
|
|
|
- deploymentName:frontend
|
|
|
|
|
- replicaSetName:frontend-2337258262
|
|
|
|
|
- namespace:default
|
|
|
|
|
- podUID:d8a2e2dd-3617-11e7-a4b0-ecf4bbe5d414
|
|
|
|
|
|
|
|
|
|
kubernetes容器命名规则解析,见下图所示。
|
|
|
|
|
|
2017-06-16 11:46:40 +08:00
|
|
|
|
![kubernetes的容器命名规则示意图](../images/kubernetes-container-naming-rule.jpg)
|