Murano之：集成docker

murano是如何集成docker？提供了怎样的接口以辅助用户快捷的编写package呢？这个得利于murano自身的架构，murano的package提供了自定义lib的功能，即根据自己的需要，根据murano package的定义规则，自己拓展一个即可。关于murano package的解析请移步murano实践之package分析

DockerInterfacesLibrary

DockerInterfacesLibrary 中提供了对于一个已正确安装docker环境的虚拟机操作docker的接口，首先看下package中的manifest.yaml
见：murano-apps/manifest.yaml

Format: 1.0
Type: Library
FullName: io.murano.apps.docker.Interfaces
Name: Docker Interface Library
Description: |The library provides all necessary interface for Dockerand Kubernetes applications
Author: 'Mirantis, Inc'
Tags: [Docker, Kubernetes]Classes:io.murano.apps.docker.DockerApplication: DockerApplication.yamlio.murano.apps.docker.DockerContainer: DockerContainer.yamlio.murano.apps.docker.DockerContainerHost: DockerContainerHost.yamlio.murano.apps.docker.DockerHelpers: DockerHelpers.yamlio.murano.apps.docker.DockerHostVolume: DockerHostVolume.yamlio.murano.apps.docker.DockerTempVolume: DockerTempVolume.yamlio.murano.apps.docker.DockerVolume: DockerVolume.yamlio.murano.apps.docker.ApplicationPort: ApplicationPort.yaml

重点在Classes中，目前这里面主要封装了

DockerApplication
DockerContainer
DockerContainerHost
DockerHelpers
DockerHostVolume
DockerTempVolume
DockerVolume
ApplicationPort

这8个docker相关的接口，我们这里以DockerApplication为例做一个分析，在Classes文件包中找到DockerApplication.yaml
提供了deploy、destroy、getConnectionTo等方法。以deploy为例，显示了虚拟机使用docker安装application的步骤

  deploy:Body:- $.host.deploy()
      - $container: $.getContainer()
      - $repr: $._getContainerRepresentation($container)
      - If: $.getAttr(container, null) != $repr
        Then:- $.onInstallationStart()
        - Try:
          - $.applicationEndpoints: $.host.hostContainer($container)
          - $.setAttr(container, $repr)
          Catch:- As: e
            Do:- $formatString: 'Error: {0}'
            - $._environment.reporter.report_error($, $formatString.format($e.message))
            - Rethrow:
          Else:- $.onInstallationFinish()

首先$.host.deploy()，这个host为DockerStandaloneHost 详见DockerStandaloneHost，具有方法deploy，此处调用的也是deploy方法DockerStandaloneHost的deploy方法如下：

  deploy:Body:- If: not $.getAttr(deployed, false)
        Then:- $._environment.reporter.report($this, 'Create VM for Docker Server')
          - $.instance.deploy()
          - $resources: new(sys:Resources)
          - $template: $resources.yaml('StartDocker.template')
          - $.instance.agent.call($template, $resources)
          - If: $.dockerRegistry != null and $.dockerRegistry != ''
            Then:- $._environment.reporter.report($this, 'Configuring Docker registry')
              - $template: $resources.yaml('SetupDockerRegistry.template').bind(dict(
                    dockerRegistry => $.dockerRegistry))- $.instance.agent.call($template, $resources)
          - $._environment.reporter.report($this, 'Docker Server is up and running')
          - $.setAttr(deployed, true)

从

- $.instance.deploy()
- $resources: new(sys:Resources)
- $template: $resources.yaml('StartDocker.template')
- $.instance.agent.call($template, $resources)

这四步看出，需要拿到StartDocker.template 交给LinuxMuranoInstance，StartDocker.template中的内容如下：
startDocker.template

FormatVersion: 2.0.0
Version: 1.0.0
Name: Start docker serviceBody: |startDocker()Scripts:startDocker:Type: ApplicationVersion: 1.0.0EntryPoint: startDocker.shOptions:captureStdout: falsecaptureStderr: falseverifyExitcode: false

这个template的EntryPoint是startDocker.sh，内容：

#!/bin/bash
#  Licensed under the Apache License, Version 2.0 (the "License"); you may
#  not use this file except in compliance with the License. You may obtain
#  a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#  License for the specific language governing permissions and limitations
#  under the License.service docker start

一句话，启动docker服务，所以$.host.deploy() 其实就是用了启动虚拟机上的docker服务；根据上面的方法，

- $container: $.getContainer()
- $repr: $._getContainerRepresentation($container)

这两步获取container的基础信息
再看- $.host.hostContainer(container)
对应的方法如下：

  hostContainer:Arguments:- container:
          Contract: $.class(DockerContainer).notNull()Body:- $.deploy()
      - $.deleteContainer($container.name)
      - $portBindings: {}
      - $newEndpoints: []
      - $._pullImage(image => $container.image)
      - For: applicationPort
        In: $container.portsDo:- If: $applicationPort.scope != host
            Then:- $hostPort: $._acquirePort($applicationPort, $container.name)
              - $containerPort: $._getPortSpec($applicationPort)
              - $portBindings[$hostPort]: $containerPort
              - If: $applicationPort.scope = public
                Then:- $rule:
                      - ToPort: $hostPort
                        FromPort: $hostPortIpProtocol: toLower($applicationPort.protocol)External: true- $._environment.securityGroupManager.addGroupIngress($rule)
              - $record:
                  port: $hostPortaddress: $.instance.ipAddresses[0]scope: cloudcontainerPort: $applicationPort.portportScope: $applicationPort.scopeprotocol: $applicationPort.protocolapplicationName: $container.name- $newEndpoints: $newEndpoints + list($record)
              - If: $applicationPort.scope = public and $.instance.floatingIpAddress != null
                Then:- $record.address: $.instance.floatingIpAddress
                  - $record.scope: public
                  - $newEndpoints: $newEndpoints + list($record)
- $volumeMap: {}
      - For: path
        In: $container.volumesDo:- $volume: $container.volumes.get($path)
          - If: $volume.getType() = HostDir
            Then:- $hostDir: $volume.getParameters()
              - $volumeMap[$hostDir]: $path
- $._environment.reporter.report($this, 'Adding Docker Application')
      - $resources: new(sys:Resources)
      - $template: $resources.yaml('RunContainer.template').bind(dict(
            appName => $container.name,image => $container.image,env => $container.env,portMap => $portBindings,volumeMap => $volumeMap,commands => $container.commands))- $._removeApplicationEndpoints($container.name)
      - $privateIp: $.instance.agent.call($template, $resources)
      - $record:
          port: $applicationPort.portaddress: $privateIpscope: hostcontainerPort: $applicationPort.portportScope: $applicationPort.scopeprotocol: $applicationPort.protocolapplicationName: $container.name- $newEndpoints: $newEndpoints + list($record)
      - $._environment.stack.push()
- If: not $container.name in $.containers
        Then:- $.containers: $.containers + list($container.name)
      - $.applicationEndpoints: $.applicationEndpoints + $newEndpoints
      - Return: $.getEndpoints($container.name)

前面几步，判断该container是否存在，如果存在，删除- $._pullImage(image => $container.image) 这一步获取$container.image。中间到- $volumeMap: {} 之前的这一段就是为了组装portBindings和newEndpoints，接着组装volumeMap，完事儿之后呢获取RunContainer.template 。- $privateIp: $.instance.agent.call($template, $resources) 到这一步了自然就是告诉虚拟机，你该调用RunContainer.template 工作啦，RunContainer.template 中其实归根到底就是一段拼装好的执行docker run 命令的脚本。

从上面的分析可以看出来，DockerInterfacesLibrary 事实上是依赖DockerStandaloneHost 与 LinuxMuranoInstance 的这两个对象事实需要创建虚拟机的镜像中包含了murano-agent服务和docker服务的，DockerStandaloneHost 中封装了StandaloneHost对docker的一些操作，如docker run、service docker start 等，LinuxMuranoInstance 中封装的是获取组装好的模版执行等功能。

以tomcat为例分析

DockerTomcat

Namespaces:=: io.murano.apps.docker
  std: io.muranoName: DockerTomcatExtends: DockerApplicationProperties:name:Contract: $.string().notNull()publish:Contract: $.bool().notNull()Default: truepassword:Contract: $.string().notNull()Methods:initialize:Body:- $._environment: $.find(std:Environment).require()
      - $._scope: switch($.publish, $ => public, not $ => internal)
getContainer:Body:Return:name: $.nameimage: 'tutum/tomcat'env:TOMCAT_PASS: $.passwordports:- port: 8080
            scope: $._scopeonInstallationStart:Body:- $._environment.reporter.report($this, 'Installing Tomcat')
onInstallationFinish:Body:- If: $.publish
        Then:- $endpoints: $.applicationEndpoints.where($.scope = $this._scope).
              select(format('http://{0}:{1}', $.address, $.port))- $._environment.reporter.report($this, 'Tomcat {0} is available at {1}'.format($.name, join(', ', $endpoints)))
        Else:- $._environment.reporter.report($this, 'Tomcat {0} has deployed but is not accessible from outside'.format($.name))

Extends: DockerApplication 直接表明，继承了DockerApplication，也就是上面分析的DockerApplication实例，此处只需要实现getContainer 和 onInstallationFinish 方法即可，deploy 会自动从DockerApplication继承，deploy 方法完成tomcat的具体安装