openstack nova 源码分析4
还是有许多地方可能错了 希望大婶们 看见 给予意见 ！这个文件位于\nova\virt，是一个底层的driver.py,源代码如下（和以前一样添加了些注释，另外把我 觉得比较重要的computerDriver类列出来 了，并将下面的每个函数分离 加以注释《见下面图片》！我看见后面好多函数都是继承的ComputerDriver比如nova\virt\libvirt下面的connection.py里面的class LibvirtConnection(driver.ComputeDriver):）：
[*]"""
[*]Driver base-classes:
[*]
[*] (Beginning of) the contract that compute drivers must follow, and shared
[*] types that support that contract
[*]"""
[*]
[*]from nova.compute import power_state
[*]
[*]
[*]class InstanceInfo(object):
[*] def __init__(self, name, state):
[*] self.name = name
[*] assert state in power_state.valid_states(), "Bad state: %s" % state
[*] self.state = state
[*]
[*]
[*]def block_device_info_get_root(block_device_info):
[*] block_device_info = block_device_info or {}
[*] return block_device_info.get('root_device_name')
[*]
[*]
[*]def block_device_info_get_swap(block_device_info):
[*] block_device_info = block_device_info or {}
[*] return block_device_info.get('swap') or {'device_name': None,
[*] 'swap_size': 0}
[*]
[*]
[*]def swap_is_usable(swap):
[*] return swap and swap['device_name'] and swap['swap_size'] > 0
[*]
[*]
[*]def block_device_info_get_ephemerals(block_device_info):
[*] block_device_info = block_device_info or {}
[*] ephemerals = block_device_info.get('ephemerals') or []
[*] return ephemerals
[*]
[*]
[*]def block_device_info_get_mapping(block_device_info):
[*] block_device_info = block_device_info or {}
[*] block_device_mapping = block_device_info.get('block_device_mapping') or []
[*] return block_device_mapping
[*]
[*]
[*]class ComputeDriver(object):
[*] """Base class for compute drivers.
[*]
[*] The interface to this class talks in terms of 'instances' (Amazon EC2 and
[*] internal Nova terminology), by which we mean 'running virtual machine'
[*] (XenAPI terminology) or domain (Xen or libvirt terminology).
[*]
[*] An instance has an ID, which is the identifier chosen by Nova to represent
[*] the instance further up the stack.This is unfortunately also called a
[*] 'name' elsewhere.As far as this layer is concerned, 'instance ID' and
[*] 'instance name' are synonyms.
[*]
[*] Note that the instance ID or name is not human-readable or
[*] customer-controlled -- it's an internal ID chosen by Nova.At the
[*] nova.virt layer, instances do not have human-readable names at all -- such
[*] things are only known higher up the stack.
[*]
[*] Most virtualization platforms will also have their own identity schemes,
[*] to uniquely identify a VM or domain.These IDs must stay internal to the
[*] platform-specific layer, and never escape the connection interface.The
[*] platform-specific layer is responsible for keeping track of which instance
[*] ID maps to which platform-specific ID, and vice versa.
[*]
[*] In contrast, the list_disks and list_interfaces calls may return
[*] platform-specific IDs.These identify a specific virtual disk or specific
[*] virtual network interface, and these IDs are opaque to the rest of Nova.
[*]
[*] Some methods here take an instance of nova.compute.service.Instance.This
[*] is the datastructure used by nova.compute to store details regarding an
[*] instance, and pass them into this layer.This layer is responsible for
[*] translating that generic datastructure into terms that are specific to the
[*] virtualization platform.
[*]
[*] """
[*] #此处为了让大家看的明白 将 ComputerDriver的类图 列出来
[*]
[*] def init_host(self, host):
[*] """Initialize anything that is necessary for the driver to function,
[*] including catching up with currently running VM's on the given host."""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def get_info(self, instance_name):
[*] """Get the current status of an instance, by name (not ID!)
[*]
[*] Returns a dict containing:
[*]
[*] :state: the running state, one of the power_state codes
[*] :max_mem: (int) the maximum memory in KBytes allowed
[*] :mem: (int) the memory in KBytes used by the domain
[*] :num_cpu: (int) the number of virtual CPUs for the domain
[*] :cpu_time: (int) the CPU time used in nanoseconds
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def list_instances(self):
[*] """
[*] Return the names of all the instances known to the virtualization
[*] layer, as a list.
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def list_instances_detail(self):
[*] """Return a list of InstanceInfo for all registered VMs"""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def spawn(self, context, instance,
[*] network_info=None, block_device_info=None):
[*] """
[*] Create a new instance/VM/domain on the virtualization platform.
[*]
[*] Once this successfully completes, the instance should be
[*] running (power_state.RUNNING).
[*]
[*] If this fails, any partial instance should be completely
[*] cleaned up, and the virtualization platform should be in the state
[*] that it was before this call began.
[*]
[*] :param context: security context
[*] :param instance: Instance object as returned by DB layer.
[*] This function should use the data there to guide
[*] the creation of the new instance.
[*] :param network_info:
[*] :py:meth:`~nova.network.manager.NetworkManager.get_instance_nw_info`
[*] :param block_device_info:
[*] """
[*] raise NotImplementedError()
[*]
[*] def destroy(self, instance, network_info, cleanup=True):
[*] """Destroy (shutdown and delete) the specified instance.
[*]
[*] If the instance is not found (for example if networking failed), this
[*] function should still succeed.It's probably a good idea to log a
[*] warning in that case.
[*]
[*] :param instance: Instance object as returned by DB layer.
[*] :param network_info:
[*] :py:meth:`~nova.network.manager.NetworkManager.get_instance_nw_info`
[*] :param cleanup:
[*]
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def reboot(self, instance, network_info):
[*] """Reboot the specified instance.
[*]
[*] :param instance: Instance object as returned by DB layer.
[*] :param network_info:
[*] :py:meth:`~nova.network.manager.NetworkManager.get_instance_nw_info`
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def snapshot_instance(self, context, instance_id, image_id):
[*] raise NotImplementedError()
[*]
[*] def get_console_pool_info(self, console_type):
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def get_console_output(self, instance):
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def get_ajax_console(self, instance):
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def get_diagnostics(self, instance):
[*] """Return data about VM diagnostics"""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def get_host_ip_addr(self):
[*] """
[*] Retrieves the IP address of the dom0
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def attach_volume(self, context, instance_id, volume_id, mountpoint):
[*] """Attach the disk at device_path to the instance at mountpoint"""
[*] raise NotImplementedError()
[*]
[*] def detach_volume(self, context, instance_id, volume_id):
[*] """Detach the disk attached to the instance at mountpoint"""
[*] raise NotImplementedError()
[*]
[*] def compare_cpu(self, cpu_info):
[*] """Compares given cpu info against host 确保vm能运行
[*]
[*] Before attempting to migrate a VM to this host,
[*] compare_cpu is called to ensure that the VM will
[*] actually run here.
[*]
[*] :param cpu_info: (str) JSON structure describing the source CPU.
[*] :returns: None if migration is acceptable
[*] :raises: :py:class:`~nova.exception.InvalidCPUInfo` if migration
[*] is not acceptable.
[*] """
[*] raise NotImplementedError()
[*]
[*] def migrate_disk_and_power_off(self, instance, dest):
[*] """
[*] Transfers the disk of a running instance in multiple phases, turning
[*] off the instance before the end.
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def snapshot(self, context, instance, image_id):
[*] """
[*] Snapshots the specified instance.
[*]
[*] :param context: security context
[*] :param instance: Instance object as returned by DB layer.
[*] :param image_id: Reference to a pre-created image that will
[*] hold the snapshot.
[*] """
[*] raise NotImplementedError()
[*]
[*] def finish_migration(self, context, instance, disk_info, network_info,
[*] resize_instance):
[*] #打开一个迁移的实例，完成一个调整
[*] """Completes a resize, turning on the migrated instance
[*]
[*] :param network_info:
[*] :py:meth:`~nova.network.manager.NetworkManager.get_instance_nw_info`
[*] """
[*] raise NotImplementedError()
[*]
[*] def revert_migration(self, instance):
[*] #返回一个调整，推动回到实例？
[*] """Reverts a resize, powering back on the instance"""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def pause(self, instance, callback):
[*] """Pause the specified instance."""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def unpause(self, instance, callback):
[*] """Unpause paused VM instance"""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def suspend(self, instance, callback):
[*] # 挂起指定的实例
[*] """suspend the specified instance"""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def resume(self, instance, callback):
[*] """resume the specified instance"""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def rescue(self, context, instance, callback, network_info):
[*] #恢复指定的实例
[*] """Rescue the specified instance"""
[*] raise NotImplementedError()
[*]
[*] def unrescue(self, instance, callback, network_info):
[*] """Unrescue the specified instance"""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def update_available_resource(self, ctxt, host):
[*] #在computeNode表中更新电脑资源管理的信息
[*] """Updates compute manager resource info on ComputeNode table.
[*]
[*] This method is called when nova-compute launches, and
[*] whenever admin executes "nova-manage service update_resource".
[*]
[*] :param ctxt: security context
[*] :param host: hostname that compute manager is currently running
[*]
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def live_migration(self, ctxt, instance_ref, dest,
[*] post_method, recover_method):
[*] #分发处理高负荷，当有高负荷操作时候，大量生成 live_mirgration
[*] """Spawning live_migration operation for distributing high-load.
[*]
[*] :param ctxt: security context
[*] :param instance_ref:
[*] nova.db.sqlalchemy.models.Instance object
[*] instance object that is migrated.
[*] :param dest: destination host
[*] :param post_method:
[*] post operation method.
[*] expected nova.compute.manager.post_live_migration.
[*] :param recover_method:
[*] recovery method when any exception occurs.
[*] expected nova.compute.manager.recover_live_migration.
[*]
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def refresh_security_group_rules(self, security_group_id):
[*] #改变安全组之后调用
[*] """This method is called after a change to security groups.
[*]
[*] All security groups and their associated rules live in the datastore,
[*] and calling this method should apply the updated rules to instances
[*] running the specified security group.
[*]
[*] An error should be raised if the operation cannot complete.
[*]
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def refresh_security_group_members(self, security_group_id):
[*] #当一个安全组被添加到一个实例，这个方法被调用
[*] """This method is called when a security group is added to an instance.
[*]
[*] This message is sent to the virtualization drivers on hosts that are
[*] running an instance that belongs to a security group that has a rule
[*] that references the security group identified by `security_group_id`.
[*] It is the responsiblity of this method to make sure any rules
[*] that authorize traffic flow with members of the security group are
[*] updated and any new members can communicate, and any removed members
[*] cannot.
[*]
[*] Scenario:
[*] * we are running on host 'H0' and we have an instance 'i-0'.
[*] * instance 'i-0' is a member of security group 'speaks-b'
[*] * group 'speaks-b' has an ingress rule that authorizes group 'b'
[*] * another host 'H1' runs an instance 'i-1'
[*] * instance 'i-1' is a member of security group 'b'
[*]
[*] When 'i-1' launches or terminates we will recieve the message
[*] to update members of group 'b', at which time we will make
[*] any changes needed to the rules for instance 'i-0' to allow
[*] or deny traffic coming from 'i-1', depending on if it is being
[*] added or removed from the group.
[*]
[*] In this scenario, 'i-1' could just as easily have been running on our
[*] host 'H0' and this method would still have been called.The point was
[*] that this method isn't called on the host where instances of that
[*] group are running (as is the case with
[*] :method:`refresh_security_group_rules`) but is called where references
[*] are made to authorizing those instances.
[*]
[*] An error should be raised if the operation cannot complete.
[*]
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def refresh_provider_fw_rules(self, security_group_id):
[*] #这触发一个基于数据库改变的防火墙的更新
[*] """This triggers a firewall update based on database changes.
[*]
[*] When this is called, rules have either been added or removed from the
[*] datastore.You can retrieve rules with
[*] :method:`nova.db.api.provider_fw_rule_get_all`.
[*]
[*] Provider rules take precedence over security group rules.If an IP
[*] would be allowed by a security group ingress rule, but blocked by
[*] a provider rule, then packets from the IP are dropped.This includes
[*] intra-project traffic in the case of the allow_project_net_traffic
[*] flag for the libvirt-derived classes.
[*]
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def reset_network(self, instance):
[*] """reset networking for specified instance"""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] pass
[*]
[*] def ensure_filtering_rules_for_instance(self, instance_ref, network_info):
[*] #设置过滤规则,并等待它完成
[*] """Setting up filtering rules and waiting for its completion.
[*]
[*] To migrate an instance, filtering rules to hypervisors
[*] and firewalls are inevitable on destination host.
[*] ( Waiting only for filtering rules to hypervisor,
[*] since filtering rules to firewall rules can be set faster).
[*]
[*] Concretely, the below method must be called.
[*] - setup_basic_filtering (for nova-basic, etc.)
[*] - prepare_instance_filter(for nova-instance-instance-xxx, etc.)
[*]
[*] to_xml may have to be called since it defines PROJNET, PROJMASK.
[*] but libvirt migrates those value through migrateToURI(),
[*] so , no need to be called.
[*]
[*] Don't use thread for this method since migration should
[*] not be started when setting-up filtering rules operations
[*] are not completed.
[*]
[*] :params instance_ref: nova.db.sqlalchemy.models.Instance object
[*]
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def unfilter_instance(self, instance, network_info):
[*] """Stop filtering instance"""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def set_admin_password(self, context, instance_id, new_pass=None):
[*] """
[*] Set the root password on the specified instance.
[*]
[*] The first parameter is an instance of nova.compute.service.Instance,
[*] and so the instance is being specified as instance.name. The second
[*] parameter is the value of the new password.
[*] """
[*] raise NotImplementedError()
[*]
[*] def inject_file(self, instance, b64_path, b64_contents):
[*] """在指定的实例上写文件
[*] Writes a file on the specified instance.
[*]
[*] The first parameter is an instance of nova.compute.service.Instance,
[*] and so the instance is being specified as instance.name. The second
[*] parameter is the base64-encoded path to which the file is to be
[*] written on the instance; the third is the contents of the file, also
[*] base64-encoded.
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def agent_update(self, instance, url, md5hash):
[*] #在指定的实例中更新代理
[*] """
[*] Update agent on the specified instance.
[*]
[*] The first parameter is an instance of nova.compute.service.Instance,
[*] and so the instance is being specified as instance.name. The second
[*] parameter is the URL of the agent to be fetched and updated on the
[*] instance; the third is the md5 hash of the file for verification
[*] purposes.
[*] """
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def inject_network_info(self, instance, nw_info):
[*] #为指定的实例注入网络信息
[*] """inject network info for specified instance"""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] pass
[*]
[*] def poll_rescued_instances(self, timeout):
[*] #轮询已经恢复的实例
[*] """Poll for rescued instances"""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def host_power_action(self, host, action):
[*] """Reboots, shuts down or powers up the host."""
[*] raise NotImplementedError()
[*]
[*] def set_host_enabled(self, host, enabled):
[*] #设置指定的主机有能力接受新的实例
[*] """Sets the specified host's ability to accept new instances."""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def plug_vifs(self, instance, network_info):
[*] """Plugs in VIFs to networks."""
[*] # TODO(Vek): Need to pass context in for access to auth_token
[*] raise NotImplementedError()
[*]
[*] def update_host_status(self):
[*] """Refresh host stats"""
[*] raise NotImplementedError()
[*]
[*] def get_host_stats(self, refresh=False):
[*] """Return currently known host stats"""
[*] raise NotImplementedError()
[*]
[*] def list_disks(self, instance_name):
[*] """
[*] Return the IDs of all the virtual disks attached to the specified
[*] instance, as a list.These IDs are opaque to the caller (they are
[*] only useful for giving back to this layer as a parameter to
[*] disk_stats).These IDs only need to be unique for a given instance.
[*]
[*] Note that this function takes an instance ID.
[*] """
[*] raise NotImplementedError()
[*]
[*] def list_interfaces(self, instance_name):
[*] """
[*] Return the IDs of all the virtual network interfaces attached to the
[*] specified instance, as a list.These IDs are opaque to the caller
[*] (they are only useful for giving back to this layer as a parameter to
[*] interface_stats).These IDs only need to be unique for a given
[*] instance.
[*]
[*] Note that this function takes an instance ID.
[*] """
[*] raise NotImplementedError()
[*]
[*] def resize(self, instance, flavor):
[*] """
[*] Resizes/Migrates the specified instance.
[*]
[*] The flavor parameter determines whether or not the instance RAM and
[*] disk space are modified, and if so, to what size.
[*] """
[*] raise NotImplementedError()
[*]
[*] def block_stats(self, instance_name, disk_id):
[*] """
[*] Return performance counters associated with the given disk_id on the
[*] given instance_name.These are returned as [rd_req, rd_bytes, wr_req,
[*] wr_bytes, errs], where rd indicates read, wr indicates write, req is
[*] the total number of I/O requests made, bytes is the total number of
[*] bytes transferred, and errs is the number of requests held up due to a
[*] full pipeline.
[*]
[*] All counters are long integers.
[*]
[*] This method is optional.On some platforms (e.g. XenAPI) performance
[*] statistics can be retrieved directly in aggregate form, without Nova
[*] having to do the aggregation.On those platforms, this method is
[*] unused.
[*]
[*] Note that this function takes an instance ID.
[*] """
[*] raise NotImplementedError()
[*]
[*] def interface_stats(self, instance_name, iface_id):
[*] """
[*] Return performance counters associated with the given iface_id on the
[*] given instance_id.These are returned as [rx_bytes, rx_packets,
[*] rx_errs, rx_drop, tx_bytes, tx_packets, tx_errs, tx_drop], where rx
[*] indicates receive, tx indicates transmit, bytes and packets indicate
[*] the total num
[*]ber of bytes or packets transferred, and errs and dropped
[*] is the total number of packets failed / dropped.
[*]
[*] All counters are long integers.
[*]
[*] This method is optional.On some platforms (e.g. XenAPI) performance
[*] statistics can be retrieved directly in aggregate form, without Nova
[*] having to do the aggregation.On those platforms, this method is
[*] unused.
[*]
[*] Note that this function takes an instance ID.
[*] """
[*] raise NotImplementedError()
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