Assets: objects
- workload: Pod,ReplicaSet,Deployment,StatefulSet,DaemonSet,Job,Cronjob,...
- Service discovery and balance: service and progress
- Configuration and storage: Volume, CSI
- ConfigMap,Secret
- DownwardAPI
- Cluster level resources
- NameSpace,Node,Role,ClusterRole,RoleBinding,ClusterRoleBinding
- Metadata resource
- HPA,PodTemplate,LimitRange
#Get apiversion supported by apiServer
[root@master ~]# kubectl api-versions
admissionregistration.k8s.io/v1
apiextensions.k8s.io/v1
apiregistration.k8s.io/v1
apps/v1
authentication.k8s.io/v1
authorization.k8s.io/v1
autoscaling/v1
autoscaling/v2beta1
autoscaling/v2beta2
batch/v1
batch/v1beta1
certificates.k8s.io/v1
coordination.k8s.io/v1
discovery.k8s.io/v1
discovery.k8s.io/v1beta1
events.k8s.io/v1
events.k8s.io/v1beta1
flowcontrol.apiserver.k8s.io/v1beta1
networking.k8s.io/v1
node.k8s.io/v1
node.k8s.io/v1beta1
policy/v1
policy/v1beta1
rbac.authorization.k8s.io/v1
scheduling.k8s.io/v1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1
[root@master ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
client 0/1 Error 0 23h
client-7c75c79d7c-h9994 0/1 CrashLoopBackOff 19 (2m14s ago) 23h
nginx 1/1 Running 2 (9m13s ago) 37h
nginx-deploy-7c948bcff4-jclqg 1/1 Running 1 (9m11s ago) 24h
nginx-deploy-7c948bcff4-mczxp 1/1 Running 1 (9m13s ago) 24h
#Output in yaml format
[root@master ~]# kubectl get pods nginx -o yaml
#Version number, group / version number. The default group is the core group
apiVersion: v1
#kind indicates what resources are used
kind: Pod
#metadata
metadata:
creationTimestamp: "2021-11-07T00:16:21Z"
labels:
run: nginx
name: nginx
namespace: default
resourceVersion: "17833"
uid: 8f1cd26f-b981-428f-a156-a92b7dee2cfd
#characteristic
spec:
containers:
#Image used by container
- image: nginx:1.14
imagePullPolicy: IfNotPresent
#Container name
name: nginx
ports:
- containerPort: 80
protocol: TCP
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
volumeMounts:
- mountPath: /var/run/secrets/kubernetes.io/serviceaccount
name: kube-api-access-85lz5
readOnly: true
dnsPolicy: ClusterFirst
enableServiceLinks: true
nodeName: node2
preemptionPolicy: PreemptLowerPriority
priority: 0
restartPolicy: Always
schedulerName: default-scheduler
securityContext: {}
serviceAccount: default
serviceAccountName: default
terminationGracePeriodSeconds: 30
tolerations:
- effect: NoExecute
key: node.kubernetes.io/not-ready
operator: Exists
tolerationSeconds: 300
- effect: NoExecute
key: node.kubernetes.io/unreachable
operator: Exists
tolerationSeconds: 300
volumes:
- name: kube-api-access-85lz5
projected:
defaultMode: 420
sources:
- serviceAccountToken:
expirationSeconds: 3607
path: token
- configMap:
items:
- key: ca.crt
path: ca.crt
name: kube-root-ca.crt
- downwardAPI:
items:
- fieldRef:
apiVersion: v1
fieldPath: metadata.namespace
path: namespace
#The current state of the current resource
status:
conditions:
- lastProbeTime: null
lastTransitionTime: "2021-11-07T00:16:21Z"
status: "True"
type: Initialized
- lastProbeTime: null
lastTransitionTime: "2021-11-08T14:01:53Z"
status: "True"
type: Ready
- lastProbeTime: null
lastTransitionTime: "2021-11-08T14:01:53Z"
status: "True"
type: ContainersReady
- lastProbeTime: null
lastTransitionTime: "2021-11-07T00:16:21Z"
status: "True"
type: PodScheduled
containerStatuses:
- containerID: docker://ef084460d6dc3183abd768dc89dbbbb0d9a0fab5809220d02f97e9230819ddff
image: nginx:1.14
imageID: docker-pullable://nginx@sha256:f7988fb6c02e0ce69257d9bd9cf37ae20a60f1df7563c3a2a6abe24160306b8d
lastState:
terminated:
containerID: docker://05be395a286ac086568ec8a80a8ce017c8165a46e0e27e2f7be1e302e1c5c2d2
exitCode: 255
finishedAt: "2021-11-08T14:01:16Z"
reason: Error
startedAt: "2021-11-07T13:18:48Z"
name: nginx
ready: true
restartCount: 2
started: true
state:
running:
startedAt: "2021-11-08T14:01:52Z"
hostIP: 192.168.88.103
phase: Running
podIP: 10.244.1.6
podIPs:
- ip: 10.244.1.6
qosClass: BestEffort
startTime: "2021-11-07T00:16:21Z"
#The kubectl proxy command enables the API server to listen on the local port 8001
[root@master ~]# kubectl proxy
Starting to serve on 127.0.0.1:8001
#Accessing local resources through curl will return json format configuration information
[root@master ~]# curl http://localhost:8001/api/v1/namespaces/default/pods/myapp-7b595df7fc-9d92c
How to create a resource:
- apiServer only receives resource definitions in JSON format
- The configuration list is provided in yaml format, and apiserver is automatically converted to JSON format and submitted
Configuration list of resources
- apiVersion[group/version]
- kind: resource category
- Metadata: metadata
- name: must be unique
- Namespace: namespace
- Labels: labels
- annotation: annotation
- Reference PATH for each resource
- /api/GROUP/version/namespaces/namespace/type/name
- spec: desired state
- status: current state this field is maintained by the kubernetes cluster
#Use explain to see how pods resources are defined
[root@master ~]# kubectl explain pods
KIND: Pod
VERSION: v1
DESCRIPTION:
Pod is a collection of containers that can run on a host. This resource is
created by clients and scheduled onto hosts.
FIELDS:
... ...
metadata <Object>
Standard object's metadata. More info:
https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
... ...
#View resource secondary definitions
[root@master ~]# kubectl explain pods.metadata
KIND: Pod
VERSION: v1
RESOURCE: metadata <Object>
DESCRIPTION:
Standard object's metadata. More info:
https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
ObjectMeta is metadata that all persisted resources must have, which
includes all objects users must create.
FIELDS:
annotations <map[string]string>
Annotations is an unstructured key value map stored with a resource that
may be set by external tools to store and retrieve arbitrary metadata. They
are not queryable and should be preserved when modifying objects. More
info: http://kubernetes.io/docs/user-guide/annotations
Creating a pod through yaml
#yaml file
apiVersion: v1
kind: Pod
metadata:
name: pod-demo
namespace: default
labels:
app: myapp
tier: frontend
spec:
containers:
- name: nginx-new
image: nginx:1.14
- name: busybox
image: busybox:latest
command:
- "/bin/sh"
- "-c"
- "sleep 3600"
#Creating a pod through yaml
[root@master manifests]# kubectl create -f nginx.yaml
pod/pod-demo created
[root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
client 0/1 Error 0 24h
client-7c75c79d7c-h9994 0/1 Completed 32 (5m25s ago) 24h
nginx 1/1 Running 2 (73m ago) 38h
nginx-deploy-7c948bcff4-jclqg 1/1 Running 1 (73m ago) 25h
nginx-deploy-7c948bcff4-mczxp 1/1 Running 1 (73m ago) 25h
pod-demo 2/2 Running 0 8s
#The first method to delete a pod
[root@master manifests]# kubectl delete -f nginx.yaml
pod "pod-demo" deleted
#The second method of deleting pod
[root@master manifests]# kubectl delete pod-demo
#view log
[root@master manifests]# kubectl logs pod-demo busybox
/bin/sh: can't create /usr/share/nginx/html/index.html: nonexistent directory
#-l or -- selector tag filtering to obtain the resource list of the corresponding tag
[root@master ~]# kubectl get pods --selector app=nginx-deploy
NAME READY STATUS RESTARTS AGE
nginx-deploy-7c948bcff4-jclqg 1/1 Running 2 (46m ago) 2d
nginx-deploy-7c948bcff4-mczxp 1/1 Running 2 (46m ago) 2d
#-L displays the values of multiple labels
[root@master ~]# kubectl get pods -L app,run
NAME READY STATUS RESTARTS AGE APP RUN
client 0/1 Error 0 47h client
client-7c75c79d7c-h9994 0/1 CrashLoopBackOff 47 (20s ago) 47h client
nginx 1/1 Running 3 (48m ago) 2d14h nginx
nginx-deploy-7c948bcff4-jclqg 1/1 Running 2 (48m ago) 2d nginx-deploy
nginx-deploy-7c948bcff4-mczxp 1/1 Running 2 (48m ago) 2d nginx-deploy
#kubectl label labels the specified resource
[root@master ~]# kubectl label pods nginx release=tye
pod/nginx labeled
# View label settings
[root@master ~]# kubectl get pods -l release --show-labels
NAME READY STATUS RESTARTS AGE LABELS
nginx 1/1 Running 3 (52m ago) 2d14h release=tye,run=nginx
#If the value of the label already exists when setting the label, you need to use the -- overwrite parameter, otherwise it cannot be modified
[root@master ~]# kubectl label pods nginx release=edison
error: 'release' already has a value (tye), and --overwrite is false
[root@master ~]# kubectl label pods nginx release=edison --overwrite
pod/nginx labeled
[root@master ~]# kubectl get pods -l release --show-labels
NAME READY STATUS RESTARTS AGE LABELS
nginx 1/1 Running 3 (54m ago) 2d14h release=edison,run=nginx
[root@master ~]# kubectl label pods nginx-deploy-7c948bcff4-jclqg release=tye
pod/nginx-deploy-7c948bcff4-jclqg labeled
[root@master ~]# kubectl get pods -l release
NAME READY STATUS RESTARTS AGE
nginx 1/1 Running 3 (61m ago) 2d14h
nginx-deploy-7c948bcff4-jclqg 1/1 Running 2 (61m ago) 2d
[root@master ~]# kubectl get pods -l release --show-labels
NAME READY STATUS RESTARTS AGE LABELS
nginx 1/1 Running 3 (61m ago) 2d14h release=edison,run=nginx
nginx-deploy-7c948bcff4-jclqg 1/1 Running 2 (61m ago) 2d app=nginx-deploy,pod-template-hash=7c948bcff4,release=tye
[root@master ~]# kubectl get pods -l release,app --show-labels
NAME READY STATUS RESTARTS AGE LABELS
nginx-deploy-7c948bcff4-jclqg 1/1 Running 2 (62m ago) 2d app=nginx-deploy,pod-template-hash=7c948bcff4,release=tye
[root@master ~]# kubectl get pods -l release=edison,run=nginx --show-labels
NAME READY STATUS RESTARTS AGE LABELS
nginx 1/1 Running 3 (62m ago) 2d14h release=edison,run=nginx
[root@master ~]# kubectl get pods -l release!=edison --show-labels
NAME READY STATUS RESTARTS AGE LABELS
client 0/1 Error 0 47h run=client
client-7c75c79d7c-h9994 0/1 CrashLoopBackOff 49 (4m54s ago) 47h app=client,pod-template-hash=7c75c79d7c
nginx-deploy-7c948bcff4-jclqg 1/1 Running 2 (63m ago) 2d app=nginx-deploy,pod-template-hash=7c948bcff4,release=tye
nginx-deploy-7c948bcff4-mczxp 1/1 Running 2 (63m ago) 2d app=nginx-deploy,pod-template-hash=7c948bcff4
#Find the pod with the label release edison or type
[root@master ~]# kubectl get pods -l " release in (edison,tye)" --show-labels
NAME READY STATUS RESTARTS AGE LABELS
nginx 1/1 Running 3 (76m ago) 2d14h release=edison,run=nginx
nginx-deploy-7c948bcff4-jclqg 1/1 Running 2 (76m ago) 2d app=nginx-deploy,pod-template-hash=7c948bcff4,release=tye
#Find the pod with label release other than edison and type
[root@master ~]# kubectl get pods -l " release notin (edison,tye)" --show-labels
NAME READY STATUS RESTARTS AGE LABELS
client 0/1 Error 0 2d run=client
client-7c75c79d7c-h9994 0/1 CrashLoopBackOff 52 (4m5s ago) 2d app=client,pod-template-hash=7c75c79d7c
nginx-deploy-7c948bcff4-mczxp 1/1 Running 2 (77m ago) 2d app=nginx-deploy,pod-template-hash=7c948bcff4,release=dizzy
#View the node list and display the label
[root@master ~]# kubectl get node --show-labels
NAME STATUS ROLES AGE VERSION LABELS
master Ready control-plane,master 2d23h v1.22.3 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=master,kubernetes.io/os=linux,node-role.kubernetes.io/control-plane=,node-role.kubernetes.io/master=,node.kubernetes.io/exclude-from-external-load-balancers=
node1 Ready <none> 2d23h v1.22.3 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=node1,kubernetes.io/os=linux
node2 Ready <none> 2d23h v1.22.3 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=node2,kubernetes.io/os=linux
Resource allocation list
Autonomous Pod resources
Pod resources:
spec.containers <[]Object>
- name
image
imagePullPolicy
Always: if the mirror image is: latest, this item is used by default
Never: never download
IfNotPresent: this option is used if the image does not use latest. If it exists locally, it will not be downloaded. If it does not exist, it will be downloaded from the registry.
command:
labels:
key = value
key: letters, numbers,;, -
value: can be blank, beginning and end of letters and numbers, and letters, numbers and underscores can be used in the middle
Label selector:
Equivalence relation: =, = ==
Set relationship:
key in (value1,value2...)
key not in (value1,value2...)
key
! key does not exist
Many resources support inline field definition label selectors
matchLabels: give key values directly
matchExpressions: define the use label selector based on the given expression, {key: "key", operator: "operator", values:[value1,value2...]}
Operator:
In, not in: values field must be a non empty list
Exists,NotExists: the value of the values field must be an empty list
[root@master ~]# kubectl explain pods.spec | grep nodeSelector nodeSelector <map[string]string>
Node label selector: the resource runs on the specified node node
nodeSelector <map[string]string>
NodeSelector is a selector which must be true for the pod to fit on a node.
Selector which must match a node's labels for the pod to be scheduled on
that node. More info:
https://kubernetes.io/docs/concepts/configuration/assign-pod-node/
Specify node run resources
nodeName
NodeName is a request to schedule this pod onto a specific node. If it is
non-empty, the scheduler simply schedules this pod onto that node, assuming
that it fits resource requirements.
annotations:
Unlike label, it cannot be used to select resource objects, but only to provide "metadata" for objects
#Add the following line to the metadata of the yaml file
annotations:
tye.com/createby: cluster admin
[root@master manifests]# kubectl describe pods pod-demo
Name: pod-demo
Namespace: default
Priority: 0
Node: node2/192.168.88.103
Start Time: Tue, 09 Nov 2021 10:07:07 -0500
Labels: app=myapp
tier=frontend
Annotations: tye.com/createby: cluster admin
Pod life cycle:
Status:
Pending: debugging has not been completed
Running: running status
Failed: failed
Successed:
Unknown:
Important behaviors in Pod life cycle:
Primary container
Container detection
liveness: survival detection
readiness:
Restart policy: restart policy
Always: automatic restart
OnFailure:
Never: do not restart
Default to Always:
https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle/#restart-policy
Probe type
- ExecAction
- TCPSocketAction
- HTTPGetAction
#Exec probes yaml files to determine whether the directory exists
apiVersion: v1
kind: Pod
metadata:
name: liveness-exec-pod
namespace: default
spec:
containers:
- name: liveness-exec-container
image: busybox:latest
imagePullPolicy: IfNotPresent
command: ["/bin/sh","-c","touch /tmp/healty;sleep 30;rm -rf /tmp/healty;sleep 3600"]
livenessProbe:
exec:
command: ["test","-e","/tmp/healty"]
initialDelaySeconds: 2
periodSeconds: 3
#View pod information
[root@master manifests]# kubectl describe pod liveness-exec-pod
Name: liveness-exec-pod
Namespace: default
Priority: 0
Node: node1/192.168.88.102
Start Time: Wed, 10 Nov 2021 08:51:30 -0500
Labels: <none>
Annotations: <none>
Status: Running
IP: 10.244.3.14
IPs:
IP: 10.244.3.14
Containers:
liveness-exec-container:
Container ID: docker://09cfbe11120e3ff96c0cacfc5f83569a599dcfad1486581ce3215f3bc36d6343
Image: busybox:latest
Image ID: docker-pullable://busybox@sha256:139abcf41943b8bcd4bc5c42ee71ddc9402c7ad69ad9e177b0a9bc4541f14924
Port: <none>
Host Port: <none>
Command:
/bin/sh
-c
touch /tmp/healty;sleep 30;rm -rf /tmp/healty;sleep 3600
State: Running
Started: Wed, 10 Nov 2021 08:53:48 -0500
Last State: Terminated
Reason: Error
Exit Code: 137
Started: Wed, 10 Nov 2021 08:52:39 -0500
Finished: Wed, 10 Nov 2021 08:53:48 -0500
Ready: True
Restart Count: 2
Liveness: exec [test -e /tmp/healty] delay=2s timeout=1s period=3s #success=1 #failure=3
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-t76fk (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
kube-api-access-t76fk:
Type: Projected (a volume that contains injected data from multiple sources)
TokenExpirationSeconds: 3607
ConfigMapName: kube-root-ca.crt
ConfigMapOptional: <nil>
DownwardAPI: true
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 2m44s default-scheduler Successfully assigned default/liveness-exec-pod to node1
Warning Unhealthy 56s (x6 over 2m11s) kubelet Liveness probe failed:
Normal Killing 56s (x2 over 2m5s) kubelet Container liveness-exec-container failed liveness probe, will be restarted
Normal Pulled 26s (x3 over 2m44s) kubelet Container image "busybox:latest" already present on machine
Normal Created 26s (x3 over 2m44s) kubelet Created container liveness-exec-container
Normal Started 26s (x3 over 2m44s) kubelet Started container liveness-exec-container
readiness
#Readiness yaml file
apiVersion: v1
kind: Pod
metadata:
name: readiness-httpget-pod
namespace: default
spec:
containers:
- name: readiness-exec-container
image: nginx:1.14
imagePullPolicy: IfNotPresent
ports:
- name: http
containerPort: 80
readinessProbe:
httpGet:
port: http
path: /index.html
initialDelaySeconds: 2
periodSeconds: 3
Pod controller
ReplicaSet: manages stateless Pod replicas
- Number of Pod copies expected by the user
- Tag selector to service and manage Pod resources
- Pod template:
Deployment: control ReplicaSet
DaemonSet:
Job: one time job
CronJob:
StatefulSet:
TPR(Third Party Resources)
CDR(Custom Defined Resources)
Operator:
Helm:
Creating a ReplicaSet from a yaml file
apiVersion: apps/v1
kind: ReplicaSet
metadata:
name: myapp
namespace: default
spec:
replicas: 2
selector:
matchLabels:
app: myapp
release: tye
template:
metadata:
name: myapp-pod
labels:
app: myapp
release: tye
enviroment: qa
spec:
containers:
- name: myapp-container
image: nginx:1.14
ports:
- name: http
containerPort: 80
[root@master manifests]# kubectl create -f rs-demo.yaml
replicaset.apps/myapp created
#View ReplicaSet
[root@master manifests]# kubectl get rs
NAME DESIRED CURRENT READY AGE
client-7c75c79d7c 1 1 0 3d
myapp 2 2 2 5s
nginx-deploy-7c948bcff4 2 2 2 3d1h
[root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
myapp-5v76c 1/1 Running 0 8m16s
myapp-ftfnd 1/1 Running 0 8m16s
#RS expansion
#Modify the number of replicas = [num] via kubectl edit rs [rsname]
#deploy-pod.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: myapp-deploy
namespace: default
spec:
replicas: 3
selector:
matchLabels:
app: myapp
release: tye
template:
metadata:
labels:
app: myapp
release: tye
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v2
ports:
- name: http
containerPort: 80
#Apply a configuration to the resource, create if the resource does not exist, and update if it exists
[root@master manifests]# kubectl apply -f deploy-pod.yaml
#kubectl patch patching
[root@master ~]# kubectl patch deploy myapp-deploy -p '{"spec":{"replicas":5}}'
deployment.apps/myapp-deploy patched
[root@master ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
myapp-deploy-545b89888c-6gd2h 1/1 Running 0 11m
myapp-deploy-545b89888c-r49rk 1/1 Running 0 10m
myapp-deploy-545b89888c-svswl 1/1 Running 0 4s
myapp-deploy-545b89888c-vz967 1/1 Running 0 4s
myapp-deploy-545b89888c-zxcr5 1/1 Running 0 10m
[root@master manifests]# kubectl patch deployment myapp-deploy -p '{"spec":{"strategy":{"rollingUpdate":{"maxSurge":1,"maxUnavailable":0}}}}'
deployment.apps/myapp-deploy patched
[root@master manifests]# kubectl describe deploy myapp-deploy
Name: myapp-deploy
Namespace: default
CreationTimestamp: Thu, 11 Nov 2021 08:57:29 -0500
Labels: <none>
Annotations: deployment.kubernetes.io/revision: 2
Selector: app=myapp,release=tye
Replicas: 5 desired | 5 updated | 5 total | 5 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 0 max unavailable, 1 max surge
[root@master manifests]# kubectl set image deployment myapp-deploy myapp=ikubernetes/myapp:v3 && kubectl rollout pause deployment myapp-deploy
deployment.apps/myapp-deploy image updated
deployment.apps/myapp-deploy paused
[root@master ~]# kubectl get pods -l app=myapp -w
NAME READY STATUS RESTARTS AGE
myapp-deploy-545b89888c-6gd2h 1/1 Running 0 21m
myapp-deploy-545b89888c-r49rk 1/1 Running 0 20m
myapp-deploy-545b89888c-svswl 1/1 Running 0 10m
myapp-deploy-545b89888c-vz967 1/1 Running 0 10m
myapp-deploy-545b89888c-zxcr5 1/1 Running 0 20m
myapp-deploy-fbd4c499b-m9258 0/1 Pending 0 0s
myapp-deploy-fbd4c499b-m9258 0/1 Pending 0 0s
myapp-deploy-fbd4c499b-m9258 0/1 ContainerCreating 0 0s
myapp-deploy-fbd4c499b-m9258 1/1 Running 0 18s
#Continue update
[root@master manifests]# kubectl rollout resume deployment myapp-deploy
deployment.apps/myapp-deploy resumed
#Monitor deployment
[root@master manifests]# kubectl rollout status deployment myapp-deploy
Waiting for deployment "myapp-deploy" rollout to finish: 1 out of 5 new replicas have been updated...
[root@master manifests]# kubectl get rs -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
myapp-deploy-545b89888c 0 0 0 28m myapp ikubernetes/myapp:v2 app=myapp,pod-template-hash=545b89888c,release=tye
myapp-deploy-7dfc7b4f66 0 0 0 52m myapp ikubernetes/myapp:v1 app=myapp,pod-template-hash=7dfc7b4f66,release=tye
myapp-deploy-fbd4c499b 5 5 5 4m24s myapp ikubernetes/myapp:v3 app=myapp,pod-template-hash=fbd4c499b,release=tye
#View rollback history version
[root@master manifests]# kubectl rollout history deployment myapp-deploy
deployment.apps/myapp-deploy
REVISION CHANGE-CAUSE
1 <none>
2 <none>
3 <none>
#Rollback to version 1
[root@master manifests]# kubectl rollout undo deployment myapp-deploy --to-revision=1
deployment.apps/myapp-deploy rolled back
[root@master manifests]# kubectl rollout history deployment myapp-deploy
deployment.apps/myapp-deploy
REVISION CHANGE-CAUSE
2 <none>
3 <none>
4 <none>
#Check that the deployment currently working is v1
[root@master manifests]# kubectl get rs -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
myapp-deploy-545b89888c 0 0 0 34m myapp ikubernetes/myapp:v2 app=myapp,pod-template-hash=545b89888c,release=tye
myapp-deploy-7dfc7b4f66 5 5 5 58m myapp ikubernetes/myapp:v1 app=myapp,pod-template-hash=7dfc7b4f66,release=tye
myapp-deploy-fbd4c499b 0 0 0 10m myapp ikubernetes/myapp:v3 app=myapp,pod-template-hash=fbd4c499b,release=tye
DeamonSet
[root@node1 ~]# docker pull ikubernetes/filebeat:5.6.5-alpine
5.6.5-alpine: Pulling from ikubernetes/filebeat
e6faa08065ed: Pull complete
1956334c4aa9: Pull complete
f3f537aca9dd: Pull complete
Digest: sha256:530f31ebf9194b0400303320579cafe21da890bd06446746fcedc2b65875e4eb
Status: Downloaded newer image for ikubernetes/filebeat:5.6.5-alpine
docker.io/ikubernetes/filebeat:5.6.5-alpine
# yaml file for DaemonSet
apiVersion: apps/v1
kind: Deployment
metadata:
name: redis
namespace: default
spec:
replicas: 1
selector:
matchLabels:
app: redis
role: logstor
template:
metadata:
labels:
app: redis
role: logstor
spec:
containers:
- name: redis
image: redis:4.0-alpine
ports:
- name: redis
containerPort: 6379
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: myapp-ds
namespace: default
spec:
selector:
matchLabels:
app: filebeat
release: stable
template:
metadata:
labels:
app: filebeat
release: stable
spec:
containers:
- name: myapp
image: ikubernetes/filebeat:5.6.5-alpine
env:
- name: REDIS_HOST
value: redis.default.svc.cluster.local
- name: REDIS_LOG_LEVEL
value: info
[root@master manifests]# kubectl apply -f ds-demo.yaml
daemonset.apps/myapp-ds created