allinone—更亲密的接触

历经千辛万苦，终于有了自己的openstack开发环境，查看《allinone—openstack development environment》，就想新交了女朋友一样，是不是想要更进一步的了解她呢？

all到底包含哪些

怀着激动的心情，就让我们一步一步的走进allinone的内心世界吧，在命令行敲入：

systemctl list-unit-files | grep openstack

systemctl的使用可以参考我的另外一篇博客《systemctl介绍》，上面的命令可以列出当前系统中所有已安装的服务。allinone环境会得到如下的输出：

# systemctl list-unit-files | grep openstackopenstack-ceilometer-alarm-evaluator.service  enabled openstack-ceilometer-alarm-notifier.service   enabled openstack-ceilometer-api.service              enabled openstack-ceilometer-central.service          enabled openstack-ceilometer-collector.service        enabled openstack-ceilometer-compute.service          enabled openstack-ceilometer-notification.service     enabled openstack-ceilometer-polling.service          disabledopenstack-cinder-api.service                  enabled openstack-cinder-backup.service               enabled openstack-cinder-scheduler.service            enabled openstack-cinder-volume.service               enabled openstack-glance-api.service                  enabled openstack-glance-registry.service             enabled openstack-glance-scrubber.service             disabledopenstack-keystone.service                    disabledopenstack-losetup.service                     enabled openstack-nova-api.service                    enabled openstack-nova-cert.service                   enabled openstack-nova-compute.service                enabled openstack-nova-conductor.service              enabled openstack-nova-console.service                disabledopenstack-nova-consoleauth.service            enabled openstack-nova-metadata-api.service           disabledopenstack-nova-novncproxy.service             enabled openstack-nova-scheduler.service              enabled openstack-nova-xvpvncproxy.service            disabledopenstack-swift-account-auditor.service       enabled openstack-swift-account-auditor@.service      disabledopenstack-swift-account-reaper.service        enabled openstack-swift-account-reaper@.service       disabledopenstack-swift-account-replicator.service    enabled openstack-swift-account-replicator@.service   disabledopenstack-swift-account.service               enabled openstack-swift-account@.service              disabledopenstack-swift-container-auditor.service     enabled openstack-swift-container-auditor@.service    disabledopenstack-swift-container-reconciler.service  disabledopenstack-swift-container-replicator.service  enabled openstack-swift-container-replicator@.service disabledopenstack-swift-container-updater.service     enabled openstack-swift-container-updater@.service    disabledopenstack-swift-container.service             enabled openstack-swift-container@.service            disabledopenstack-swift-object-auditor.service        enabled openstack-swift-object-auditor@.service       disabledopenstack-swift-object-expirer.service        enabled openstack-swift-object-replicator.service     enabled openstack-swift-object-replicator@.service    disabledopenstack-swift-object-updater.service        enabled openstack-swift-object-updater@.service       disabledopenstack-swift-object.service                enabled openstack-swift-object@.service               disabledopenstack-swift-proxy.service                 enabled # 

细心的读者应该会发现，图中总共包含了ceilometer、cinder、glance、keystone、nova、swift六个组件的单元，另外的neutron去哪儿了？让我们再找找，输入如下的命令：

systemctl list-unit-files | grep neutron

原来是这小子搞特殊化哦

# systemctl list-unit-files | grep neutronneutron-dhcp-agent.service                    enabled neutron-l3-agent.service                      enabled neutron-metadata-agent.service                enabled neutron-netns-cleanup.service                 disabledneutron-openvswitch-agent.service             enabled neutron-ovs-cleanup.service                   enabled neutron-server.service                        enabled #

所有可用的单元文件存放在 /usr/lib/systemd/system/ 和 /etc/systemd/system/ 目录（后者优先级更高），我们再来看看openstack各服务的文件，用户安装的服务一般放在/usr/lib/systemd/system/目录下，命令如下：

ls -lh /usr/lib/systemd/system/ | grep openstack

得到的结果如下：

# ls -lh /usr/lib/systemd/system/ | grep openstack-rw-r--r--. 1 root root  274 Dec 22 06:38 openstack-ceilometer-alarm-evaluator.service-rw-r--r--. 1 root root  274 Dec 22 06:38 openstack-ceilometer-alarm-notifier.service-rw-r--r--. 1 root root  237 Dec 22 06:38 openstack-ceilometer-api.service-rw-r--r--. 1 root root  276 Dec 22 06:38 openstack-ceilometer-central.service-rw-r--r--. 1 root root  256 Dec 22 06:38 openstack-ceilometer-collector.service-rw-r--r--. 1 root root  276 Dec 22 06:38 openstack-ceilometer-compute.service-rw-r--r--. 1 root root  274 Dec 22 06:38 openstack-ceilometer-notification.service-rw-r--r--. 1 root root  316 Dec 22 06:38 openstack-ceilometer-polling.service-rw-r--r--. 1 root root  307 Dec 22 23:27 openstack-cinder-api.service-rw-r--r--. 1 root root  316 Dec 22 23:27 openstack-cinder-backup.service-rw-r--r--. 1 root root  325 Dec 22 23:27 openstack-cinder-scheduler.service-rw-r--r--. 1 root root  316 Dec 22 23:27 openstack-cinder-volume.service-rw-r--r--. 1 root root  261 Feb  5 15:26 openstack-glance-api.service-rw-r--r--. 1 root root  271 Feb  5 15:26 openstack-glance-registry.service-rw-r--r--. 1 root root  267 Feb  5 15:26 openstack-glance-scrubber.service-rw-r--r--. 1 root root  242 Dec 22 02:52 openstack-keystone.service-rw-r--r--. 1 root root  571 Mar 21 17:55 openstack-losetup.service-rwxr-xr-x. 1 root root  230 Jan 25 19:28 openstack-nova-api.service-rwxr-xr-x. 1 root root  232 Jan 25 19:28 openstack-nova-cert.service-rwxr-xr-x. 1 root root  285 Jan 25 19:28 openstack-nova-compute.service-rwxr-xr-x. 1 root root  242 Jan 25 19:28 openstack-nova-conductor.service-rwxr-xr-x. 1 root root  251 Jan 25 19:28 openstack-nova-consoleauth.service-rwxr-xr-x. 1 root root  244 Jan 25 19:28 openstack-nova-console.service-rwxr-xr-x. 1 root root  248 Jan 25 19:28 openstack-nova-metadata-api.service-rwxr-xr-x. 1 root root  285 Jan 25 19:28 openstack-nova-novncproxy.service-rwxr-xr-x. 1 root root  242 Jan 25 19:28 openstack-nova-scheduler.service-rwxr-xr-x. 1 root root  197 Jan 25 19:28 openstack-nova-xvpvncproxy.service-rw-r--r--. 1 root root  286 Oct  1 05:29 openstack-swift-account-auditor.service-rw-r--r--. 1 root root  264 Oct  1 05:29 openstack-swift-account-auditor@.service-rw-r--r--. 1 root root  247 Oct  1 05:29 openstack-swift-account-reaper.service-rw-r--r--. 1 root root  262 Oct  1 05:29 openstack-swift-account-reaper@.service-rw-r--r--. 1 root root  322 Oct  1 05:29 openstack-swift-account-replicator.service-rw-r--r--. 1 root root  270 Oct  1 05:29 openstack-swift-account-replicator@.service-rw-r--r--. 1 root root  282 Oct  1 05:29 openstack-swift-account.service-rw-r--r--. 1 root root  297 Oct  1 05:29 openstack-swift-account@.service-rw-r--r--. 1 root root  255 Oct  1 05:29 openstack-swift-container-auditor.service-rw-r--r--. 1 root root  270 Oct  1 05:29 openstack-swift-container-auditor@.service-rw-r--r--. 1 root root  265 Oct  1 05:29 openstack-swift-container-reconciler.service-rw-r--r--. 1 root root  328 Oct  1 05:29 openstack-swift-container-replicator.service-rw-r--r--. 1 root root  276 Oct  1 05:29 openstack-swift-container-replicator@.service-rw-r--r--. 1 root root  288 Oct  1 05:29 openstack-swift-container.service-rw-r--r--. 1 root root  303 Oct  1 05:29 openstack-swift-container@.service-rw-r--r--. 1 root root  255 Oct  1 05:29 openstack-swift-container-updater.service-rw-r--r--. 1 root root  270 Oct  1 05:29 openstack-swift-container-updater@.service-rw-r--r--. 1 root root  283 Oct  1 05:29 openstack-swift-object-auditor.service-rw-r--r--. 1 root root  261 Oct  1 05:29 openstack-swift-object-auditor@.service-rw-r--r--. 1 root root  247 Oct  1 05:29 openstack-swift-object-expirer.service-rw-r--r--. 1 root root  319 Oct  1 05:29 openstack-swift-object-replicator.service-rw-r--r--. 1 root root  267 Oct  1 05:29 openstack-swift-object-replicator@.service-rw-r--r--. 1 root root  279 Oct  1 05:29 openstack-swift-object.service-rw-r--r--. 1 root root  294 Oct  1 05:29 openstack-swift-object@.service-rw-r--r--. 1 root root  246 Oct  1 05:29 openstack-swift-object-updater.service-rw-r--r--. 1 root root  261 Oct  1 05:29 openstack-swift-object-updater@.service-rw-r--r--. 1 root root  276 Oct  1 05:29 openstack-swift-proxy.service#

查看neutron服务文件，ls -lh /usr/lib/systemd/system/ | grep neutron，得到的结果：

# ls -lh /usr/lib/systemd/system/ | grep neutron-rw-r--r--. 1 root root  497 Dec 22 03:25 neutron-dhcp-agent.service-rw-r--r--. 1 root root  493 Dec 22 03:25 neutron-l3-agent.service-rw-r--r--. 1 root root  517 Dec 22 03:25 neutron-metadata-agent.service-rw-r--r--. 1 root root  987 Dec 22 03:25 neutron-netns-cleanup.service-rw-r--r--. 1 root root  584 Dec 22 03:25 neutron-openvswitch-agent.service-rw-r--r--. 1 root root 1011 Dec 22 03:25 neutron-ovs-cleanup.service-rw-r--r--. 1 root root  532 Dec 22 03:25 neutron-server.service# 

服务到启动脚本

找到了服务文件，就好比找到了女朋友心灵的某个入口，会打开一片新的天地，让你见识一个全新的世界，我们就来撕开这个领口，看一看这个全新的世界，以openstack-ceilometer-api.service为例：

# cat /usr/lib/systemd/system/openstack-ceilometer-api.service [Unit]Description=OpenStack ceilometer API serviceAfter=syslog.target network.target[Service]Type=simpleUser=ceilometerExecStart=/usr/bin/ceilometer-api --logfile /var/log/ceilometer/api.log[Install]WantedBy=multi-user.target# 

重点看一下ExecStart=/usr/bin/ceilometer-api --logfile /var/log/ceilometer/api.log发现跟

# ps -ef | grep ceilometer-apiceilome+  1168     1  3 Mar24 ?        00:14:48 /usr/bin/python2 /usr/bin/ceilometer-api --logfile /var/log/ceilometer/api.log

的输出结果一致，这就是ceilometer-api的启动命令，启动脚本为/usr/bin/ceilometer-api

启动脚本到代码

如果你是一个好奇心很强的程序员，想要刨根究底，那么这就是ceilometer-api的入口了，快去看看里面都写了些什么吧，我的代码是Liberty版本的5.0.2Tag，跟master分支上的代码有较大的差别，后需要将按照master分支上的代码进行整理，我的ceilometer-api启动脚本内容为：

#!/usr/bin/python2# PBR Generated from u'console_scripts'import sysfrom ceilometer.cmd.api import mainif __name__ == "__main__":    sys.exit(main())

你已经从操作系统上正确的找到一个openstack组件服务的入口了，接下来就可以对接上你熟悉的代码了，加油！