将 Docker Compose 文件转换为 Kubernetes 资源
Kompose 是什么?它是个转换工具,可将 compose(即 Docker Compose)所组装的所有内容转换成容器编排器(Kubernetes 或 OpenShift)可识别的形式。
更多信息请参考 Kompose 官网 http://kompose.io。
准备开始
你必须拥有一个 Kubernetes 的集群,同时你的 Kubernetes 集群必须带有 kubectl 命令行工具。 如果你还没有集群,你可以通过 Minikube 构建一 个你自己的集群,或者你可以使用下面任意一个 Kubernetes 工具构建:
要获知版本信息,请输入 kubectl version
.
安装 Kompose
我们有很多种方式安装 Kompose。首选方式是从最新的 GitHub 发布页面下载二进制文件。
GitHub 发布版本
Kompose 通过 GitHub 发布版本,发布周期为三星期。您可以在GitHub 发布页面上看到所有当前版本。
# Linux
curl -L https://github.com/kubernetes/kompose/releases/download/v1.16.0/kompose-linux-amd64 -o kompose
# macOS
curl -L https://github.com/kubernetes/kompose/releases/download/v1.16.0/kompose-darwin-amd64 -o kompose
# Windows
curl -L https://github.com/kubernetes/kompose/releases/download/v1.16.0/kompose-windows-amd64.exe -o kompose.exe
chmod +x kompose
sudo mv ./kompose /usr/local/bin/kompose
或者,您可以下载 tarball。
Go
用 go get
命令从主分支拉取最新的开发变更的方法安装 Kompose。
go get -u github.com/kubernetes/kompose
CentOS
Kompose 位于 EPEL CentOS 代码仓库。 如果您还没有安装启用 EPEL 代码仓库,请运行命令 sudo yum install epel-release
。
如果您的系统中已经启用了 EPEL,您就可以像安装其他软件包一样安装 Kompose。
sudo yum -y install kompose
Fedora
Kompose 位于 Fedora 24、25 和 26 的代码仓库。您可以像安装其他软件包一样安装 Kompose。
sudo dnf -y install kompose
macOS
在 macOS 上您可以通过 Homebrew 安装 Kompose 的最新版本:
brew install kompose
使用 Kompose
再需几步,我们就把你从 Docker Compose 带到 Kubernetes。 您只需要一个现有的 docker-compose.yml
文件。
进入
docker-compose.yml
文件所在的目录。如果没有,请使用下面这个进行测试。version: "2"
services:
redis-master:
image: k8s.gcr.io/redis:e2e
ports:
- "6379"
redis-slave:
image: gcr.io/google_samples/gb-redisslave:v3
ports:
- "6379"
environment:
- GET_HOSTS_FROM=dns
frontend:
image: gcr.io/google-samples/gb-frontend:v4
ports:
- "80:80"
environment:
- GET_HOSTS_FROM=dns
labels:
kompose.service.type: LoadBalancer
运行
kompose up
命令直接部署到 Kubernetes,或者跳到下一步,生成kubectl
使用的文件。$ kompose up
We are going to create Kubernetes Deployments, Services and PersistentVolumeClaims for your Dockerized application.
If you need different kind of resources, use the 'kompose convert' and 'kubectl create -f' commands instead.
INFO Successfully created Service: redis
INFO Successfully created Service: web
INFO Successfully created Deployment: redis
INFO Successfully created Deployment: web
Your application has been deployed to Kubernetes. You can run 'kubectl get deployment,svc,pods,pvc' for details.
要将
docker-compose.yml
转换为kubectl
可用的文件,请运行kompose convert
命令进行转换,然后运行kubectl create -f <output file>
进行创建。$ kompose convert
INFO Kubernetes file "frontend-service.yaml" created
INFO Kubernetes file "redis-master-service.yaml" created
INFO Kubernetes file "redis-slave-service.yaml" created
INFO Kubernetes file "frontend-deployment.yaml" created
INFO Kubernetes file "redis-master-deployment.yaml" created
INFO Kubernetes file "redis-slave-deployment.yaml" created
$ kubectl create -f frontend-service.yaml,redis-master-service.yaml,redis-slave-service.yaml,frontend-deployment.yaml,redis-master-deployment.yaml,redis-slave-deployment.yaml
service/frontend created
service/redis-master created
service/redis-slave created
deployment.apps/frontend created
deployment.apps/redis-master created
deployment.apps/redis-slave created
您部署的应用在 Kubernetes 中运行起来了。
访问您的应用。
如果您在开发过程中使用
minikube
,请执行:$ minikube service frontend
否则,我们要查看一下您的服务使用了什么 IP!
$ kubectl describe svc frontend
Name: frontend
Namespace: default
Labels: service=frontend
Selector: service=frontend
Type: LoadBalancer
IP: 10.0.0.183
LoadBalancer Ingress: 192.0.2.89
Port: 80 80/TCP
NodePort: 80 31144/TCP
Endpoints: 172.17.0.4:80
Session Affinity: None
No events.
如果您使用的是云提供商,您的 IP 将在
LoadBalancer Ingress
字段给出。$ curl http://192.0.2.89
用户指南
Kompose 支持两种驱动:OpenShift 和 Kubernetes。 您可以通过全局选项 --provider
选择驱动方式。如果没有指定,会将 Kubernetes 作为默认驱动。
kompose convert
Kompose 支持将 V1、V2 和 V3 版本的 Docker Compose 文件转换为 Kubernetes 和 OpenShift 资源对象。
Kubernetes
$ kompose --file docker-voting.yml convert
WARN Unsupported key networks - ignoring
WARN Unsupported key build - ignoring
INFO Kubernetes file "worker-svc.yaml" created
INFO Kubernetes file "db-svc.yaml" created
INFO Kubernetes file "redis-svc.yaml" created
INFO Kubernetes file "result-svc.yaml" created
INFO Kubernetes file "vote-svc.yaml" created
INFO Kubernetes file "redis-deployment.yaml" created
INFO Kubernetes file "result-deployment.yaml" created
INFO Kubernetes file "vote-deployment.yaml" created
INFO Kubernetes file "worker-deployment.yaml" created
INFO Kubernetes file "db-deployment.yaml" created
$ ls
db-deployment.yaml docker-compose.yml docker-gitlab.yml redis-deployment.yaml result-deployment.yaml vote-deployment.yaml worker-deployment.yaml
db-svc.yaml docker-voting.yml redis-svc.yaml result-svc.yaml vote-svc.yaml worker-svc.yaml
您也可以同时提供多个 docker-compose 文件进行转换:
$ kompose -f docker-compose.yml -f docker-guestbook.yml convert
INFO Kubernetes file "frontend-service.yaml" created
INFO Kubernetes file "mlbparks-service.yaml" created
INFO Kubernetes file "mongodb-service.yaml" created
INFO Kubernetes file "redis-master-service.yaml" created
INFO Kubernetes file "redis-slave-service.yaml" created
INFO Kubernetes file "frontend-deployment.yaml" created
INFO Kubernetes file "mlbparks-deployment.yaml" created
INFO Kubernetes file "mongodb-deployment.yaml" created
INFO Kubernetes file "mongodb-claim0-persistentvolumeclaim.yaml" created
INFO Kubernetes file "redis-master-deployment.yaml" created
INFO Kubernetes file "redis-slave-deployment.yaml" created
$ ls
mlbparks-deployment.yaml mongodb-service.yaml redis-slave-service.jsonmlbparks-service.yaml
frontend-deployment.yaml mongodb-claim0-persistentvolumeclaim.yaml redis-master-service.yaml
frontend-service.yaml mongodb-deployment.yaml redis-slave-deployment.yaml
redis-master-deployment.yaml
当提供多个 docker-compose 文件时,配置将会合并。任何通用的配置都将被后续文件覆盖。
OpenShift
$ kompose --provider openshift --file docker-voting.yml convert
WARN [worker] Service cannot be created because of missing port.
INFO OpenShift file "vote-service.yaml" created
INFO OpenShift file "db-service.yaml" created
INFO OpenShift file "redis-service.yaml" created
INFO OpenShift file "result-service.yaml" created
INFO OpenShift file "vote-deploymentconfig.yaml" created
INFO OpenShift file "vote-imagestream.yaml" created
INFO OpenShift file "worker-deploymentconfig.yaml" created
INFO OpenShift file "worker-imagestream.yaml" created
INFO OpenShift file "db-deploymentconfig.yaml" created
INFO OpenShift file "db-imagestream.yaml" created
INFO OpenShift file "redis-deploymentconfig.yaml" created
INFO OpenShift file "redis-imagestream.yaml" created
INFO OpenShift file "result-deploymentconfig.yaml" created
INFO OpenShift file "result-imagestream.yaml" created
kompose 还支持为服务中的构建指令创建 buildconfig。 默认情况下,它使用当前 git 分支的 remote 仓库作为源仓库,使用当前分支作为构建的源分支。 您可以分别使用 --build-repo
和 --build-branch
选项指定不同的源仓库和分支。
$ kompose --provider openshift --file buildconfig/docker-compose.yml convert
WARN [foo] Service cannot be created because of missing port.
INFO OpenShift Buildconfig using git@github.com:rtnpro/kompose.git::master as source.
INFO OpenShift file "foo-deploymentconfig.yaml" created
INFO OpenShift file "foo-imagestream.yaml" created
INFO OpenShift file "foo-buildconfig.yaml" created
注意:
如果使用
oc create -f
手动推送 Openshift 工件,则需要确保在构建配置工件之前推送 imagestream 工件,以解决 Openshift 的这个问题:https://github.com/openshift/origin/issues/4518 。
kompose up
Kompose 支持通过 kompose up
直接将您的”复合的(composed)” 应用程序部署到 Kubernetes 或 OpenShift。
Kubernetes
$ kompose --file ./examples/docker-guestbook.yml up
We are going to create Kubernetes deployments and services for your Dockerized application.
If you need different kind of resources, use the 'kompose convert' and 'kubectl create -f' commands instead.
INFO Successfully created service: redis-master
INFO Successfully created service: redis-slave
INFO Successfully created service: frontend
INFO Successfully created deployment: redis-master
INFO Successfully created deployment: redis-slave
INFO Successfully created deployment: frontend
Your application has been deployed to Kubernetes. You can run 'kubectl get deployment,svc,pods' for details.
$ kubectl get deployment,svc,pods
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
deployment.extensions/frontend 1 1 1 1 4m
deployment.extensions/redis-master 1 1 1 1 4m
deployment.extensions/redis-slave 1 1 1 1 4m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/frontend ClusterIP 10.0.174.12 <none> 80/TCP 4m
service/kubernetes ClusterIP 10.0.0.1 <none> 443/TCP 13d
service/redis-master ClusterIP 10.0.202.43 <none> 6379/TCP 4m
service/redis-slave ClusterIP 10.0.1.85 <none> 6379/TCP 4m
NAME READY STATUS RESTARTS AGE
pod/frontend-2768218532-cs5t5 1/1 Running 0 4m
pod/redis-master-1432129712-63jn8 1/1 Running 0 4m
pod/redis-slave-2504961300-nve7b 1/1 Running 0 4m
注意:
- 您必须有一个运行正常的 Kubernetes 集群,该集群具有预先配置的 kubectl 上下文。
- 此操作仅生成 Deployment 和 Service 对象并将其部署到 Kubernetes。如果需要部署其他不同类型的资源,请使用
kompose convert
和kubectl create -f
命令。
OpenShift
$ kompose --file ./examples/docker-guestbook.yml --provider openshift up
We are going to create OpenShift DeploymentConfigs and Services for your Dockerized application.
If you need different kind of resources, use the 'kompose convert' and 'oc create -f' commands instead.
INFO Successfully created service: redis-slave
INFO Successfully created service: frontend
INFO Successfully created service: redis-master
INFO Successfully created deployment: redis-slave
INFO Successfully created ImageStream: redis-slave
INFO Successfully created deployment: frontend
INFO Successfully created ImageStream: frontend
INFO Successfully created deployment: redis-master
INFO Successfully created ImageStream: redis-master
Your application has been deployed to OpenShift. You can run 'oc get dc,svc,is' for details.
$ oc get dc,svc,is
NAME REVISION DESIRED CURRENT TRIGGERED BY
dc/frontend 0 1 0 config,image(frontend:v4)
dc/redis-master 0 1 0 config,image(redis-master:e2e)
dc/redis-slave 0 1 0 config,image(redis-slave:v1)
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
svc/frontend 172.30.46.64 <none> 80/TCP 8s
svc/redis-master 172.30.144.56 <none> 6379/TCP 8s
svc/redis-slave 172.30.75.245 <none> 6379/TCP 8s
NAME DOCKER REPO TAGS UPDATED
is/frontend 172.30.12.200:5000/fff/frontend
is/redis-master 172.30.12.200:5000/fff/redis-master
is/redis-slave 172.30.12.200:5000/fff/redis-slave v1
注意:
- 您必须有一个运行正常的 OpenShift 集群,该集群具有预先配置的
oc
上下文 (oc login
)。
kompose down
您一旦将”复合(composed)” 应用部署到 Kubernetes,$ kompose down
命令将能帮您通过删除 Deployment 和 Service 对象来删除应用。如果需要删除其他资源,请使用 ‘kubectl’ 命令。
$ kompose --file docker-guestbook.yml down
INFO Successfully deleted service: redis-master
INFO Successfully deleted deployment: redis-master
INFO Successfully deleted service: redis-slave
INFO Successfully deleted deployment: redis-slave
INFO Successfully deleted service: frontend
INFO Successfully deleted deployment: frontend
注意:
- 您必须有一个运行正常的 Kubernetes 集群,该集群具有预先配置的 kubectl 上下文。
构建和推送 Docker 镜像
Kompose 支持构建和推送 Docker 镜像。如果 Docker Compose 文件中使用了 build
关键字,您的镜像将会:
- 使用文档中指定的
image
键自动构建 Docker 镜像 - 使用本地凭据推送到正确的 Docker 仓库
version: "2"
services:
foo:
build: "./build"
image: docker.io/foo/bar
使用带有 build
键的 kompose up
命令:
$ kompose up
INFO Build key detected. Attempting to build and push image 'docker.io/foo/bar'
INFO Building image 'docker.io/foo/bar' from directory 'build'
INFO Image 'docker.io/foo/bar' from directory 'build' built successfully
INFO Pushing image 'foo/bar:latest' to registry 'docker.io'
INFO Attempting authentication credentials 'https://index.docker.io/v1/
INFO Successfully pushed image 'foo/bar:latest' to registry 'docker.io'
INFO We are going to create Kubernetes Deployments, Services and PersistentVolumeClaims for your Dockerized application. If you need different kind of resources, use the 'kompose convert' and 'kubectl create -f' commands instead.
INFO Deploying application in "default" namespace
INFO Successfully created Service: foo
INFO Successfully created Deployment: foo
Your application has been deployed to Kubernetes. You can run 'kubectl get deployment,svc,pods,pvc' for details.
要想禁用该功能,或者使用 BuildConfig 中的版本(在 OpenShift 中),可以通过传递 --build (local|build-config|none)
参数来实现。
# Disable building/pushing Docker images
$ kompose up --build none
# Generate Build Config artifacts for OpenShift
$ kompose up --provider openshift --build build-config
其他转换方式
默认的 kompose
转换会生成 yaml 格式的 Kubernetes Deployment 和 Service 对象。 您可以选择通过 -j
参数生成 json 格式的对象。 您也可以替换生成 Replication Controllers 对象、Daemon Sets 或 Helm charts。
$ kompose convert -j
INFO Kubernetes file "redis-svc.json" created
INFO Kubernetes file "web-svc.json" created
INFO Kubernetes file "redis-deployment.json" created
INFO Kubernetes file "web-deployment.json" created
*-deployment.json
文件中包含 Deployment 对象。
$ kompose convert --replication-controller
INFO Kubernetes file "redis-svc.yaml" created
INFO Kubernetes file "web-svc.yaml" created
INFO Kubernetes file "redis-replicationcontroller.yaml" created
INFO Kubernetes file "web-replicationcontroller.yaml" created
*-replicationcontroller.yaml
文件包含 Replication Controller 对象。如果您想指定副本数(默认为 1),可以使用 --replicas
参数:$ kompose convert --replication-controller --replicas 3
$ kompose convert --daemon-set
INFO Kubernetes file "redis-svc.yaml" created
INFO Kubernetes file "web-svc.yaml" created
INFO Kubernetes file "redis-daemonset.yaml" created
INFO Kubernetes file "web-daemonset.yaml" created
*-daemonset.yaml
文件包含 Daemon Set 对象。
如果您想生成 Helm 可用的 Chart,只需简单的执行下面的命令:
$ kompose convert -c
INFO Kubernetes file "web-svc.yaml" created
INFO Kubernetes file "redis-svc.yaml" created
INFO Kubernetes file "web-deployment.yaml" created
INFO Kubernetes file "redis-deployment.yaml" created
chart created in "./docker-compose/"
$ tree docker-compose/
docker-compose
├── Chart.yaml
├── README.md
└── templates
├── redis-deployment.yaml
├── redis-svc.yaml
├── web-deployment.yaml
└── web-svc.yaml
这个图标结构旨在为构建 Helm Chart 提供框架。
标签
kompose
支持 docker-compose.yml
文件中用于 Kompose 的标签,以便在转换时明确定义 Service 的行为。
kompose.service.type
定义要创建的 Service 类型。version: "2"
services:
nginx:
image: nginx
dockerfile: foobar
build: ./foobar
cap_add:
- ALL
container_name: foobar
labels:
kompose.service.type: nodeport
kompose.service.expose
定义 是否允许从集群外部访问 Service。如果该值被设置为 “true”,提供程序将自动设置端点,对于任何其他值,该值将被设置为主机名。如果在 Service 中定义了多个端口,则选择第一个端口作为公开端口。- 对于 Kubernetes 驱动程序,创建了一个 Ingress 资源,并且假定已经配置了相应的 Ingress 控制器。
- 对于 OpenShift 驱动程序, 创建一个 route。
例如:
version: "2"
services:
web:
image: tuna/docker-counter23
ports:
- "5000:5000"
links:
- redis
labels:
kompose.service.expose: "counter.example.com"
redis:
image: redis:3.0
ports:
- "6379"
当前支持的选项有:
键 | 值 |
---|---|
kompose.service.type | nodeport / clusterip / loadbalancer |
kompose.service.expose | true / hostname |
注意:
kompose.service.type
标签应该只用ports
来定义,否则kompose
会失败。
重启
如果你想创建没有控制器的普通 Pod,可以使用 docker-compose 的 restart
结构来定义它。请参考下表了解 restart
的不同参数。
docker-compose restart | 创建的对象 | Pod restartPolicy |
---|---|---|
“” | 控制器对象 | Always |
always | 控制器对象 | Always |
on-failure | Pod | OnFailure |
no | Pod | Never |
注意:
控制器对象可以是
deployment
或replicationcontroller
等。
例如,pival
Service 将在这里变成 Pod。这个容器的计算值为 pi
。
version: '2'
services:
pival:
image: perl
command: ["perl", "-Mbignum=bpi", "-wle", "print bpi(2000)"]
restart: "on-failure"
关于 Deployment Config 的提醒
如果 Docker Compose 文件中为服务声明了卷,Deployment (Kubernetes) 或 DeploymentConfig (OpenShift) 的策略会从 “RollingUpdate” (默认) 变为 “Recreate”。 这样做的目的是为了避免服务的多个实例同时访问卷。
如果 Docker Compose 文件中的服务名包含 _
(例如 web_service
),那么将会被替换为 -
,服务也相应的会重命名(例如 web-service
)。 Kompose 这样做的原因是 “Kubernetes” 不允许对象名称中包含 _
。
Docker Compose 版本
Kompose 支持的 Docker Compose 版本包括:1、2 和 3。有限支持 2.1 和 3.2 版本,因为它们还在实验阶段。
所有三个版本的兼容性列表请查看我们的 转换文档,文档中列出了所有不兼容的 Docker Compose 关键字。