OpenStack —— 虚拟机的启动过程简述(八)
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Dashboard or CLI gets the user credential and does the REST call to Keystone for authentication.
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Keystone authenticate the credentials and generate & send back auth-token which will be used for sending request to other Components through REST-call.
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Dashboard or CLI convert the new instance request specified in ‘launch instance’ or ‘nova-boot’ form to REST API request and send it to nova-api.
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nova-api receive the request and sends the request for validation auth-token and access permission to keystone.
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Keystone validates the token and sends updated auth headers with roles and permissions.
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nova-api interacts with nova-database.
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Creates initial db entry for new instance.
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nova-api sends the rpc.call request to nova-scheduler excepting to get updated instance entry with host ID specified.
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nova-scheduler picks the request from the queue.
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nova-scheduler interacts with nova-database to find an appropriate host via filtering and weighing.
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Returns the updated instance entry with appropriate host ID after filtering and weighing.
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nova-scheduler sends the rpc.cast request to nova-compute for ‘launching instance’ on appropriate host .
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nova-compute picks the request from the queue.
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nova-compute send the rpc.call request to nova-conductor to fetch the instance information such as host ID and flavor( Ram , CPU ,Disk).
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nova-conductor picks the request from the queue.
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nova-conductor interacts with nova-database.
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Return the instance information.
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nova-compute picks the instance information from the queue.
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nova-compute does the REST call by passing auth-token to glance-api to get the Image URI by Image ID from glance and upload image from image storage.
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glance-api validates the auth-token with keystone.
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nova-compute get the image metadata.
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nova-compute does the REST-call by passing auth-token to Network API to allocate and configure the network such that instance gets the IP address.
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quantum-server validates the auth-token with keystone.
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nova-compute get the network info.
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nova-compute does the REST call by passing auth-token to Volume API to attach volumes to instance.
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cinder-api validates the auth-token with keystone.
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nova-compute gets the block storage info.
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nova-compute generates data for hypervisor driver and executes request on Hypervisor( via libvirt or api).
本文转自 wzlinux 51CTO博客,原文链接:http://blog.51cto.com/wzlinux/1964195,如需转载请自行联系原作者