前言：
最近在部署prometheus的過程中遇到的這個問題，感覺比較的經(jīng)典，有必要記錄一下。
現(xiàn)象是部署prometheus主服務(wù)的時候，看不到pod，只能看到deployment，由于慌亂，一度以為是集群有毛病了，然后重新做了集群，具體情況如下圖：
注：up-to-date表示沒有部署，available表示無可用pod
[root@node4 yaml]# k get deployments.apps -n monitor-sa
NAME READY UP-TO-DATE AVAILABLE AGE
prometheus-server 0/2 0 0 2m5s
[root@node4 yaml]# k get po -n monitor-sa
NAME READY STATUS RESTARTS AGE
node-exporter-6ttbl 1/1 Running 0 23h
node-exporter-7ls5t 1/1 Running 0 23h
node-exporter-r287q 1/1 Running 0 23h
node-exporter-z85dm 1/1 Running 0 23h
部署文件如下；
注意注意，有一個sa的引用哦??serviceAccountName: monitor
[root@node4 yaml]# cat prometheus-deploy.yaml
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: prometheus-server
namespace: monitor-sa
labels:
app: prometheus
spec:
replicas: 2
selector:
matchLabels:
app: prometheus
component: server
#matchExpressions:
#- {key: app, operator: In, values: [prometheus]}
#- {key: component, operator: In, values: [server]}
template:
metadata:
labels:
app: prometheus
component: server
annotations:
prometheus.io/scrape: 'false'
spec:
nodeName: node4
serviceAccountName: monitor
containers:
- name: prometheus
image: prom/prometheus:v2.2.1
imagePullPolicy: IfNotPresent
command:
- prometheus
- --config.file=/etc/prometheus/prometheus.yml
- --storage.tsdb.path=/prometheus
- --storage.tsdb.retention=720h
ports:
- containerPort: 9090
protocol: TCP
volumeMounts:
- mountPath: /etc/prometheus/prometheus.yml
name: prometheus-config
subPath: prometheus.yml
- mountPath: /prometheus/
name: prometheus-storage-volume
volumes:
- name: prometheus-config
configMap:
name: prometheus-config
items:
- key: prometheus.yml
path: prometheus.yml
mode: 0644
- name: prometheus-storage-volume
hostPath:
path: /data
type: Directory
?
解決方案：
那么，遇到這種情況，我們應(yīng)該怎么做呢？當然了，第一點就是不要慌，其次deployment控制器有一個比較不讓人注意的地方，就是編輯deployment可以看到該deployment的當前狀態(tài)詳情，會有非常詳細的信息給我們看，也就是status字段
具體的命令是?kubectl?edit?deployment -n?命名空間? deployment名稱，在本例中是這樣的：
。。。。。。略略略
path: prometheus.yml
name: prometheus-config
name: prometheus-config
- hostPath:
path: /data
type: Directory
name: prometheus-storage-volume
status:
conditions:
- lastTransitionTime: "2023-11-22T15:21:06Z"
lastUpdateTime: "2023-11-22T15:21:06Z"
message: Deployment does not have minimum availability.
reason: MinimumReplicasUnavailable
status: "False"
type: Available
- lastTransitionTime: "2023-11-22T15:21:06Z"
lastUpdateTime: "2023-11-22T15:21:06Z"
message: 'pods "prometheus-server-78bbb77dd7-" is forbidden: error looking up
service account monitor-sa/monitor: serviceaccount "monitor" not found'
reason: FailedCreate
status: "True"
type: ReplicaFailure
- lastTransitionTime: "2023-11-22T15:31:07Z"
lastUpdateTime: "2023-11-22T15:31:07Z"
message: ReplicaSet "prometheus-server-78bbb77dd7" has timed out progressing.
reason: ProgressDeadlineExceeded
status: "False"
type: Progressing
observedGeneration: 1
unavailableReplicas: 2
可以看到有三個message，第一個是標題里提到的報錯信息，在dashboard里這個信息會優(yōu)先顯示，如果是報錯的時候，第二個message是進一步解釋錯誤問題在哪，本例里是說有個名叫?monitor的sa沒有找到，第三個信息說的是這個deployment控制的rs部署失敗，此信息無關(guān)緊要了，那么，重要的是第二個信息，這個信息是解決問題的關(guān)鍵。
附：一個正常的deployment?的status：
這個status告訴我們，他是一個副本，部署成功的，因此，第一個message是Deployment has minimum availability
serviceAccount: kube-state-metrics
serviceAccountName: kube-state-metrics
terminationGracePeriodSeconds: 30
status:
availableReplicas: 1
conditions:
- lastTransitionTime: "2023-11-21T14:56:14Z"
lastUpdateTime: "2023-11-21T14:56:14Z"
message: Deployment has minimum availability.
reason: MinimumReplicasAvailable
status: "True"
type: Available
- lastTransitionTime: "2023-11-21T14:56:13Z"
lastUpdateTime: "2023-11-21T14:56:14Z"
message: ReplicaSet "kube-state-metrics-57794dcf65" has successfully progressed.
reason: NewReplicaSetAvailable
status: "True"
type: Progressing
observedGeneration: 1
readyReplicas: 1
replicas: 1
updatedReplicas: 1
具體的解決方案：
根據(jù)以上報錯信息，那么，我們就需要一個sa，當然了，如果不想給太高的權(quán)限，就需要自己編寫權(quán)限文件了，這里我偷懶?使用cluster-admin，具體的命令如下：
[root@node4 yaml]# k create sa -n monitor-sa monitor
serviceaccount/monitor created
[root@node4 yaml]# k create clusterrolebinding monitor-clusterrolebinding -n monitor-sa --clusterrole=cluster-admin --serviceaccount=monitor-sa:monitor再次部署就成功了：
[root@node4 yaml]# k get po -n monitor-sa -owide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
node-exporter-6ttbl 1/1 Running 0 24h 192.168.123.12 node2 <none> <none>
node-exporter-7ls5t 1/1 Running 0 24h 192.168.123.11 node1 <none> <none>
node-exporter-r287q 1/1 Running 1 (2m57s ago) 24h 192.168.123.14 node4 <none> <none>
node-exporter-z85dm 1/1 Running 0 24h 192.168.123.13 node3 <none> <none>
prometheus-server-78bbb77dd7-6smlt 1/1 Running 0 20s 10.244.41.19 node4 <none> <none>
prometheus-server-78bbb77dd7-fhf5k 1/1 Running 0 20s 10.244.41.18 node4 <none> <none>
總結(jié)來了：
那么，其實缺少sa可能會導(dǎo)致pod被隱藏，可以得出，sa是這個deployment的必要非顯性依賴，同樣的，如果部署文件內(nèi)有寫configmap，但configmap并沒有提前創(chuàng)建也會出現(xiàn)這種錯誤，就是創(chuàng)建了deployment，但pod創(chuàng)建不出來，不像namespace沒有提前創(chuàng)建的情況，namespace是必要顯性依賴，沒有會直接不讓創(chuàng)建。
配額設(shè)置也是和sa一樣的必要非顯性依賴。
例如，下面創(chuàng)建一個針對default這個命名空間的配額文件，此文件定義如下：
定義的內(nèi)容為規(guī)定default命名空間下最多4個pods，最多20個services，只能使用10G的內(nèi)存，5.5的CPU
[root@node4 yaml]# cat quota-nginx.yaml
apiVersion: v1
kind: ResourceQuota
metadata:
name: quota
namespace: default
spec:
hard:
requests.cpu: "5.5"
limits.cpu: "5.5"
requests.memory: 10Gi
limits.memory: 10Gi
pods: "4"
services: "20"
下面創(chuàng)建一個deployment，副本是6個的nginx：
[root@node4 yaml]# cat nginx.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
annotations:
deployment.kubernetes.io/revision: "1"
creationTimestamp: "2023-11-22T16:13:33Z"
generation: 1
labels:
app: nginx
name: nginx
namespace: default
resourceVersion: "16411"
uid: e9a5cdc5-c6f0-45fb-a001-fcdd695eb925
spec:
progressDeadlineSeconds: 600
replicas: 6
revisionHistoryLimit: 10
selector:
matchLabels:
app: nginx
strategy:
rollingUpdate:
maxSurge: 25%
maxUnavailable: 25%
type: RollingUpdate
template:
metadata:
creationTimestamp: null
labels:
app: nginx
spec:
containers:
- image: nginx:1.18
imagePullPolicy: IfNotPresent
name: nginx
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
resources:
limits:
cpu: 1
memory: 1Gi
requests:
cpu: 500m
memory: 512Mi
dnsPolicy: ClusterFirst
restartPolicy: Always
schedulerName: default-scheduler
securityContext: {}
terminationGracePeriodSeconds: 30
創(chuàng)建完畢后，發(fā)現(xiàn)只有四個pod，配額有效：
[root@node4 yaml]# k get po
NAME READY STATUS RESTARTS AGE
nginx-54f9858f64-g65pk 1/1 Running 0 4m50s
nginx-54f9858f64-h42vf 1/1 Running 0 4m50s
nginx-54f9858f64-s776t 1/1 Running 0 4m50s
nginx-54f9858f64-wl7wz 1/1 Running 0 4m50s
那么，還有兩個pod呢？文章來源：http://www.zghlxwxcb.cn/news/detail-774521.html
[root@node4 yaml]# k get deployments.apps nginx -oyaml |grep message
message: Deployment does not have minimum availability.
message: 'pods "nginx-54f9858f64-p8rxf" is forbidden: exceeded quota: quota, requested:
message: ReplicaSet "nginx-54f9858f64" is progressing.
那么解決的方法也很簡單，也就是調(diào)整quota啦，怎么調(diào)整就不在這里廢話了吧！?。。。。。。?！~~~~~~文章來源地址http://www.zghlxwxcb.cn/news/detail-774521.html
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