kubernetes核心实战（四）--- Deployments
6、Deployments（重点）
一个 Deployment 控制器为 Pods和 ReplicaSets提供描述性的更新方式。
描述 Deployment 中的 desired state，并且 Deployment 控制器以受控速率更改实际状态，以达到期望状态。可以定义 Deployments 以创建新的 ReplicaSets ，或删除现有 Deployments ，并通过新的 Deployments 使用其所有资源。
用例
以下是典型的 Deployments 用例：
创建 Deployment 以展开 ReplicaSet 。ReplicaSet 在后台创建 Pods。检查 ReplicaSet 展开的状态，查看其是否成功。
声明 Pod 的新状态 通过更新 Deployment 的 PodTemplateSpec。将创建新的 ReplicaSet ，并且 Deployment 管理器以受控速率将 Pod 从旧 ReplicaSet 移动到新 ReplicaSet 。每个新的 ReplicaSet 都会更新 Deployment 的修改历史。
回滚到较早的 Deployment 版本，如果 Deployment 的当前状态不稳定。每次回滚都会更新 Deployment 的修改。
扩展 Deployment 以承担更多负载.
暂停 Deployment 对其 PodTemplateSpec 进行修改，然后恢复它以启动新的展开。
使用 Deployment 状态 作为卡住展开的指示器。
清理较旧的 ReplicaSets ，那些不再需要的。
1）创建 Deployment
[root@k8s-master-node1 ~/yaml/test]# vim deployments.yaml
[root@k8s-master-node1 ~/yaml/test]# cat deployments.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
labels:
app: nginx
spec:
replicas: 3
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.14.2
ports:
- containerPort: 80
[root@k8s-master-node1 ~/yaml/test]#
[root@k8s-master-node1 ~/yaml/test]# kubectl apply -f deployments.yaml
deployment.apps/nginx-deployment created
[root@k8s-master-node1 ~/yaml/test]#
[root@k8s-master-node1 ~/yaml/test]#含义介绍：
在该例中：将创建名为 nginx-deployment 的 Deployment ，由 .metadata.name 字段指示。
Deployment 创建三个复制的 Pods，由 replicas 字段指示。
selector 字段定义 Deployment 如何查找要管理的 Pods。在这种情况下，只需选择在 Pod 模板（app: nginx）中定义的标签。但是，更复杂的选择规则是可能的，只要 Pod 模板本身满足规则。
说明：
matchLabels 字段是 {key,value} 的映射。单个 {key,value}在 matchLabels 映射中的值等效于 matchExpressions 的元素，其键字段是“key”，运算符为“In”，值数组仅包含“value”。所有要求，从 matchLabels 和 matchExpressions，必须满足才能匹配。
template 字段包含以下子字段：
Pod 标记为app: nginx，使用labels字段。
Pod 模板规范或 .template.spec 字段指示 Pods 运行一个容器， nginx，运行 nginx Docker Hub版本1.7.9的镜像 。
创建一个容器并使用name字段将其命名为 nginx。
查看详细的字段解释：
[root@k8s-master-node1 ~]# kubectl explain Deployment.spec
KIND: Deployment
VERSION: apps/v1
RESOURCE: spec <Object>
DESCRIPTION:
Specification of the desired behavior of the Deployment.
DeploymentSpec is the specification of the desired behavior of the
Deployment.
FIELDS:
minReadySeconds<integer>
Minimum number of seconds for which a newly created pod should be ready
without any of its container crashing, for it to be considered available.
Defaults to 0 (pod will be considered available as soon as it is ready)
paused<boolean>
Indicates that the deployment is paused.
progressDeadlineSeconds<integer>
The maximum time in seconds for a deployment to make progress before it is
considered to be failed. The deployment controller will continue to process
failed deployments and a condition with a ProgressDeadlineExceeded reason
will be surfaced in the deployment status. Note that progress will not be
estimated during the time a deployment is paused. Defaults to 600s.
replicas<integer>
Number of desired pods. This is a pointer to distinguish between explicit
zero and not specified. Defaults to 1.
revisionHistoryLimit<integer>
The number of old ReplicaSets to retain to allow rollback. This is a
pointer to distinguish between explicit zero and not specified. Defaults to
10.
selector <Object> -required-
Label selector for pods. Existing ReplicaSets whose pods are selected by
this will be the ones affected by this deployment. It must match the pod
template's labels.
strategy<Object>
The deployment strategy to use to replace existing pods with new ones.
template <Object> -required-
Template describes the pods that will be created.
[root@k8s-master-node1 ~]#查看pod
[root@k8s-master-node1 ~/yaml/test]# kubectl get pod
NAME READY STATUS RESTARTS AGE
ingress-demo-app-694bf5d965-q4l7m 1/1 Terminating 0 23h
ingress-demo-app-694bf5d965-v28sl 1/1 Running 0 3m9s
ingress-demo-app-694bf5d965-v652j 1/1 Running 0 23h
nfs-client-provisioner-dc5789f74-nnk77 1/1 Running 1 (8h ago) 22h
nginx-deployment-66b6c48dd5-5hhjq 1/1 Running 0 3m9s
nginx-deployment-66b6c48dd5-9z2n5 1/1 Running 0 3m19s
nginx-deployment-66b6c48dd5-llq7c 1/1 Running 0 9m10s
[root@k8s-master-node1 ~/yaml/test]#查看deployments
[root@k8s-master-node1 ~/yaml/test]# kubectl get deployments.apps
NAME READY UP-TO-DATE AVAILABLE AGE
ingress-demo-app 2/2 2 2 23h
nfs-client-provisioner 1/1 1 1 22h
nginx-deployment 3/3 3 3 9m45s
[root@k8s-master-node1 ~/yaml/test]#解释说明：
检查集群中的 Deployments 时，将显示以下字段：
NAME 列出了集群中 Deployments 的名称。
DESIRED 显示应用程序的所需 副本 数，在创建 Deployment 时定义这些副本。这是 期望状态。
CURRENT显示当前正在运行的副本数。
UP-TO-DATE显示已更新以实现期望状态的副本数。
AVAILABLE显示应用程序可供用户使用的副本数。
AGE 显示应用程序运行的时间量。
查看rs
[root@k8s-master-node1 ~/yaml/test]# kubectl get replicasets.apps
NAME DESIRED CURRENT READY AGE
ingress-demo-app-694bf5d965 2 2 2 23h
nfs-client-provisioner-dc5789f74 1 1 1 23h
nginx-deployment-66b6c48dd5 3 3 3 19m
[root@k8s-master-node1 ~/yaml/test]#查看pods的标签
[root@k8s-master-node1 ~/yaml/test]# kubectl get pods --show-labels
NAME READY STATUS RESTARTS AGE LABELS
ingress-demo-app-694bf5d965-q4l7m 1/1 Terminating 0 23h app=ingress-demo-app,pod-template-hash=694bf5d965
ingress-demo-app-694bf5d965-v28sl 1/1 Running 0 15m app=ingress-demo-app,pod-template-hash=694bf5d965
ingress-demo-app-694bf5d965-v652j 1/1 Running 0 23h app=ingress-demo-app,pod-template-hash=694bf5d965
nfs-client-provisioner-dc5789f74-nnk77 1/1 Running 1 (8h ago) 23h app=nfs-client-provisioner,pod-template-hash=dc5789f74
nginx-deployment-66b6c48dd5-48k9j 0/1 Terminating 0 21m app=nginx,pod-template-hash=66b6c48dd5
nginx-deployment-66b6c48dd5-5hhjq 1/1 Running 0 15m app=nginx,pod-template-hash=66b6c48dd5
nginx-deployment-66b6c48dd5-9z2n5 1/1 Running 0 15m app=nginx,pod-template-hash=66b6c48dd5
nginx-deployment-66b6c48dd5-kvzft 0/1 Terminating 0 21m app=nginx,pod-template-hash=66b6c48dd5
nginx-deployment-66b6c48dd5-llq7c 1/1 Running 0 21m app=nginx,pod-template-hash=66b6c48dd5
[root@k8s-master-node1 ~/yaml/test]#2）更新回滚 Deployment
命令行行升级使用镜像
[root@k8s-master-node1 ~/yaml/test]# kubectl get deployments -o wide
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
ingress-demo-app 2/2 2 2 23h whoami traefik/whoami:v1.6.1 app=ingress-demo-app
nfs-client-provisioner 1/1 1 1 23h nfs-client-provisioner registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/nfs-subdir-external-provisioner:v4.0.2 app=nfs-client-provisioner
nginx-deployment 3/3 3 3 18m nginx nginx:1.14.2 app=nginx
[root@k8s-master-node1 ~/yaml/test]#
[root@k8s-master-node1 ~/yaml/test]# kubectl --record deployment.apps/nginx-deployment set image deployment.v1.apps/nginx-deployment nginx=nginx:1.20.1
Flag --record has been deprecated, --record will be removed in the future
deployment.apps/nginx-deployment image updated
deployment.apps/nginx-deployment image updated
[root@k8s-master-node1 ~/yaml/test]#
[root@k8s-master-node1 ~/yaml/test]# kubectl get deployments -o wide
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
ingress-demo-app 2/2 2 2 23h whoami traefik/whoami:v1.6.1 app=ingress-demo-app
nfs-client-provisioner 1/1 1 1 23h nfs-client-provisioner registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/nfs-subdir-external-provisioner:v4.0.2 app=nfs-client-provisioner
nginx-deployment 3/3 1 3 24m nginx nginx:1.20.1 app=nginx
[root@k8s-master-node1 ~/yaml/test]#yaml方式修改镜像
[root@k8s-master-node1 ~/yaml/test]# kubectl edit deployments.apps nginx-deployment
Edit cancelled, no changes made.
[root@k8s-master-node1 ~/yaml/test]#查看更新过程
[root@k8s-master-node1 ~/yaml/test]# kubectl rollout status deployment.v1.apps/nginx-deployment
Waiting for deployment "nginx-deployment" rollout to finish: 1 out of 3 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 1 out of 3 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 1 out of 3 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 1 old replicas are pending termination...
Waiting for deployment "nginx-deployment" rollout to finish: 1 old replicas are pending termination...
deployment "nginx-deployment" successfully rolled out
[root@k8s-master-node1 ~/yaml/test]#查看详细信息
[root@k8s-master-node1 ~/yaml/test]# kubectl describe deployments
Name: ingress-demo-app
Namespace: default
CreationTimestamp: Tue, 16 Nov 2021 13:28:26 +0800
Labels: app=ingress-demo-app
Annotations: deployment.kubernetes.io/revision: 1
Selector: app=ingress-demo-app
Replicas: 2 desired | 2 updated | 2 total | 2 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 25% max unavailable, 25% max surge
Pod Template:
Labels: app=ingress-demo-app
Containers:
whoami:
Image: traefik/whoami:v1.6.1
Port: 80/TCP
Host Port: 0/TCP
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Progressing True NewReplicaSetAvailable
Available True MinimumReplicasAvailable
OldReplicaSets: <none>
NewReplicaSet: ingress-demo-app-694bf5d965 (2/2 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 23h deployment-controller Scaled up replica set ingress-demo-app-694bf5d965 to 2
Name: nfs-client-provisioner
Namespace: default
CreationTimestamp: Tue, 16 Nov 2021 14:07:33 +0800
Labels: app=nfs-client-provisioner
Annotations: deployment.kubernetes.io/revision: 1
Selector: app=nfs-client-provisioner
Replicas: 1 desired | 1 updated | 1 total | 1 available | 0 unavailable
StrategyType: Recreate
MinReadySeconds: 0
Pod Template:
Labels: app=nfs-client-provisioner
Service Account: nfs-client-provisioner
Containers:
nfs-client-provisioner:
Image: registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/nfs-subdir-external-provisioner:v4.0.2
Port: <none>
Host Port: <none>
Environment:
PROVISIONER_NAME: k8s-sigs.io/nfs-subdir-external-provisioner
NFS_SERVER: 192.168.1.66
NFS_PATH: /nfs/
Mounts:
/persistentvolumes from nfs-client-root (rw)
Volumes:
nfs-client-root:
Type: NFS (an NFS mount that lasts the lifetime of a pod)
Server: 192.168.1.66
Path: /nfs/
ReadOnly: false
Conditions:
Type Status Reason
---- ------ ------
Progressing True NewReplicaSetAvailable
Available True MinimumReplicasAvailable
OldReplicaSets: <none>
NewReplicaSet: nfs-client-provisioner-dc5789f74 (1/1 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 23h deployment-controller Scaled up replica set nfs-client-provisioner-dc5789f74 to 1
Name: nginx-deployment
Namespace: default
CreationTimestamp: Wed, 17 Nov 2021 12:54:46 +0800
Labels: app=nginx
Annotations: deployment.kubernetes.io/revision: 3
kubernetes.io/change-cause:
kubectl deployment.apps/nginx-deployment set image deployment.v1.apps/nginx-deployment nginx=nginx:1.20.1 --record=true
Selector: app=nginx
Replicas: 3 desired | 3 updated | 3 total | 3 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 25% max unavailable, 25% max surge
Pod Template:
Labels: app=nginx
Containers:
nginx:
Image: nginx:1.16.1
Port: 80/TCP
Host Port: 0/TCP
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
Progressing True NewReplicaSetAvailable
OldReplicaSets: <none>
NewReplicaSet: nginx-deployment-559d658b74 (3/3 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 30m deployment-controller Scaled up replica set nginx-deployment-66b6c48dd5 to 3
Normal ScalingReplicaSet 5m55s deployment-controller Scaled up replica set nginx-deployment-58b9b8ff79 to 1
Normal ScalingReplicaSet 5m27s deployment-controller Scaled down replica set nginx-deployment-66b6c48dd5 to 2
Normal ScalingReplicaSet 5m27s deployment-controller Scaled up replica set nginx-deployment-58b9b8ff79 to 2
Normal ScalingReplicaSet 5m deployment-controller Scaled down replica set nginx-deployment-66b6c48dd5 to 1
Normal ScalingReplicaSet 5m deployment-controller Scaled up replica set nginx-deployment-58b9b8ff79 to 3
Normal ScalingReplicaSet 4m56s deployment-controller Scaled down replica set nginx-deployment-66b6c48dd5 to 0
Normal ScalingReplicaSet 78s deployment-controller Scaled up replica set nginx-deployment-559d658b74 to 1
Normal ScalingReplicaSet 63s deployment-controller Scaled down replica set nginx-deployment-58b9b8ff79 to 2
Normal ScalingReplicaSet 63s deployment-controller Scaled up replica set nginx-deployment-559d658b74 to 2
Normal ScalingReplicaSet 49s (x3 over 61s) deployment-controller (combined from similar events): Scaled down replica set nginx-deployment-58b9b8ff79 to 0
[root@k8s-master-node1 ~/yaml/test]#
[root@k8s-master-node1 ~/yaml/test]#
[root@k8s-master-node1 ~/yaml/test]#3） Deployment历史记录
查看历史
[root@k8s-master-node1 ~/yaml/test]# kubectl rollout history deployment.v1.apps/nginx-deployment
deployment.apps/nginx-deployment
REVISION CHANGE-CAUSE
1 <none>
2 kubectl deployment.apps/nginx-deployment set image deployment.v1.apps/nginx-deployment nginx=nginx:1.20.1 --record=true
3 kubectl deployment.apps/nginx-deployment set image deployment.v1.apps/nginx-deployment nginx=nginx:1.20.1 --record=true
[root@k8s-master-node1 ~/yaml/test]#回滚到上次
[root@k8s-master-node1 ~/yaml/test]# kubectl rollout undo deployment.v1.apps/nginx-deployment
deployment.apps/nginx-deployment rolled back
[root@k8s-master-node1 ~/yaml/test]# kubectl rollout status deployment.v1.apps/nginx-deployment
Waiting for deployment "nginx-deployment" rollout to finish: 1 old replicas are pending termination...
Waiting for deployment "nginx-deployment" rollout to finish: 1 old replicas are pending termination...
deployment "nginx-deployment" successfully rolled out
[root@k8s-master-node1 ~/yaml/test]#回滚到指定版本
[root@k8s-master-node1 ~/yaml/test]# kubectl rollout undo deployment.v1.apps/nginx-deployment --to-revision=3
deployment.apps/nginx-deployment rolled back
[root@k8s-master-node1 ~/yaml/test]# kubectl rollout status deployment.v1.apps/nginx-deployment
Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 1 old replicas are pending termination...
Waiting for deployment "nginx-deployment" rollout to finish: 1 old replicas are pending termination...
deployment "nginx-deployment" successfully rolled out
[root@k8s-master-node1 ~/yaml/test]#4）缩放 Deployment
扩容到十个pod
[root@k8s-master-node1 ~/yaml/test]# kubectl scale deployment.v1.apps/nginx-deployment --replicas=10
deployment.apps/nginx-deployment scaled
[root@k8s-master-node1 ~/yaml/test]#
[root@k8s-master-node1 ~/yaml/test]# kubectl get deployments.apps
NAME READY UP-TO-DATE AVAILABLE AGE
ingress-demo-app 0/2 2 0 24h
nfs-client-provisioner 0/1 1 0 23h
nginx-deployment 5/10 10 5 45m
[root@k8s-master-node1 ~/yaml/test]#假设启用水平自动缩放 Pod在集群中，可以为 Deployment 设置自动缩放器，并选择最小和最大 要基于现有 Pods 的 CPU 利用率运行的 Pods。
[root@k8s-master-node1 ~/yaml/test]# kubectl autoscale deployment.v1.apps/nginx-deployment --min=10 --max=15 --cpu-percent=80
horizontalpodautoscaler.autoscaling/nginx-deployment autoscaled
[root@k8s-master-node1 ~/yaml/test]#
[root@k8s-master-node1 ~/yaml/test]#
https://blog.csdn.net/qq_33921750
https://my.oschina.net/u/3981543
https://www.zhihu.com/people/chen-bu-yun-2
https://segmentfault.com/u/hppyvyv6/articles
https://juejin.cn/user/3315782802482007
https://space.bilibili.com/352476552/article
https://cloud.tencent.com/developer/column/93230
知乎、CSDN、开源中国、思否、掘金、哔哩哔哩、腾讯云
kubernetes核心实战（四）--- Deployments的更多相关文章
- k8s kubernetes 核心笔记 镜像仓库 项目k8s改造(含最新k8s v1.16.2版本)
k8s kubernetes 核心笔记 镜像仓库 项目k8s改造 2019/10/24 Chenxin 一 基本资料 一 参考: https://kubernetes.io/ 官网 https://k ...
- 第3 章 ： Kubernetes 核心概念
Kubernetes 核心概念 本文整理自 CNCF 和阿里巴巴联合举办的云原生技术公开课的课时 3:Kubernetes 核心概念.本次课程中,阿里巴巴资深技术专家.CNCF 9个 TCO 之一 李 ...
- gRPC学习之四：实战四类服务方法
欢迎访问我的GitHub https://github.com/zq2599/blog_demos 内容:所有原创文章分类汇总及配套源码,涉及Java.Docker.Kubernetes.DevOPS ...
- coreseek实战(四)：php接口的使用，完善php脚本代码
coreseek实战(四):php接口的使用,完善php脚本代码 在上一篇文章 coreseeek实战(三)中,已经能够正常搜索到结果,这篇文章主要是把 index.php 文件代码写得相对完整一点点 ...
- Kubernetes 核心概念
什么是Kubernetes? Kubernetes(k8s)是自动化容器操作的开源平台,这些操作包括部署,调度和节点集群间扩展.如果你曾经用过Docker容器技术部署容器,那么可以将Docker看成K ...
- 十分钟带你理解Kubernetes核心概念
什么是Kubernetes? Kubernetes(k8s)是自动化容器操作的开源平台,这些操作包括部署,调度和节点集群间扩展.如果你曾经用过Docker容器技术部署容器,那么可以将Docker看成K ...
- Python爬虫实战四之抓取淘宝MM照片
原文:Python爬虫实战四之抓取淘宝MM照片其实还有好多,大家可以看 Python爬虫学习系列教程 福利啊福利,本次为大家带来的项目是抓取淘宝MM照片并保存起来,大家有没有很激动呢? 本篇目标 1. ...
- Kubernetes核心概念简介
本文将会简单介绍Kubernetes的核心概念.因为这些定义可以在Kubernetes的文档中找到,所以文章也会避免用大段的枯燥的文字介绍.相反,我们会使用一些图表(其中一些是动画)和示例来解释这些概 ...
- 后端技术杂谈11：十分钟理解Kubernetes核心概念
本系列文章将整理到我在GitHub上的<Java面试指南>仓库,更多精彩内容请到我的仓库里查看 本文转自 https://github.com/h2pl/Java-Tutorial 喜欢的 ...
- 01 . 容器编排简介及Kubernetes核心概念
Kubernetes简介 Kubernetes是谷歌严格保密十几年的秘密武器-Borg的一个开源版本,是Docker分布式系统解决方案.2014年由Google公司启动. Kubernetes提供了面 ...
随机推荐
- verilog 硬件描述语言
第一章 绪论 verilog--数字电路设计技术--ASIC/SOC芯片设计--协议pcie SATA USB--系统知识(个人计算机,芯片组,网络连接,嵌入式系统,硬件和软件的互操作) 第二章 寄存 ...
- 4组-Alpha冲刺-6/6
一.基本情况 队名:摸鲨鱼小队 组长博客:https://www.cnblogs.com/smallgrape/p/15574385.html 小组人数:8人 二.冲刺概况汇报 组长:许雅萍 过去两天 ...
- pwm 理解
PWM: 假设PWM的时钟主频是 PWM_CLK_FREQ Hz,则如果需要输出频率为 xHz,占空比为 y% 的波形时, 则只需要在定时器的周期寄存器中写入(PWM_CLK_FREQ / x),在 ...
- Windows 解决teamview远程必须mstsc连接
真实原因是你的TeamViewer一直在用远程桌面的ID进行登录,所以一旦远程桌面断开,TeamViewer就无法连接了.因此我们只需要切换为服务器的TeamViewer ID即可,服务器的TeamV ...
- Crypto入门 （七） Railfence （栏栅密码，正常型和W型）
前言: Crypto中分三类,分别是编码.古典密码.现代密码,栏栅密码属于古典密码中得特殊移位密码,密钥只有 一个k,表示栏栅得长度.所谓栏栅密码就是将要加密得明文分成k个一组,然后取每组得第一个字符 ...
- 关于TIdTCPClient的几种方法
关于TIdTCPClient的几种方法 收藏 其实Indy比较简单,但是可以提供的方法太多了.我找了很久,才搞明白. 比方说这个读取缓冲区的数据,就有很多种方法.相对于TTcpClient的几种方法 ...
- Centos 配置网络自启和静态IP和主机名
1. 修改配置文件 vim /etc/sysconfig/network-scripts 2. vim /etc/sysconfig/network-scripts/ifcfg-eth0 BOOTPR ...
- 2.Vue模板语法
1.模板语法的概述 (1)如何理解前端渲染 将数据填充到HTML标签中,生成静态的HTML内容 2.前端渲染方式 (1)原生JS拼接字符串 (2)使用前端模板引擎 (3)使用Vue特有的模板语法 3. ...
- filebeat+elasticsearch+kibana
一.到elasticsearch官网下载 filebeat+elasticsearch+kibana http://www.elasticsearch.cn/ 二.安装filebeat tar -xz ...
- String的Equals()和==比较
String的Equals()和==比较 常量池(Constant Pool):指的是在编译期被确定,并被保存在已编译的.class文件中的一些数据.JVM虚拟机为每个被装载的类型维护一个常量池.常量 ...