remote¶
Remote module to execute commands on hosts via Cumin.
-
class
spicerack.remote.
Remote
(config: str, dry_run: bool = True)[source]¶ Bases:
object
Remote class to interact with Cumin.
Initialize the instance.
- Parameters
-
exception
spicerack.remote.
RemoteCheckError
[source]¶ Bases:
spicerack.exceptions.SpicerackCheckError
Custom exception class for check errors of this module.
-
exception
spicerack.remote.
RemoteError
[source]¶ Bases:
spicerack.exceptions.SpicerackError
Custom exception class for errors of this module.
-
exception
spicerack.remote.
RemoteExecutionError
(retcode: int, message: str)[source]¶ Bases:
spicerack.remote.RemoteError
Custom exception class for remote execution errors.
Override parent constructor to add the return code attribute.
-
class
spicerack.remote.
RemoteHosts
(config: cumin.Config, hosts: ClusterShell.NodeSet.NodeSet, dry_run: bool = True)[source]¶ Bases:
object
Remote Executor class.
This class can be extended to customize the interaction with remote hosts passing a custom factory function to spicerack.remote.Remote.query.
Initialize the instance.
- Parameters
config (cumin.Config) -- the configuration for Cumin.
hosts (ClusterShell.NodeSet.NodeSet) -- the hosts to target for the remote execution.
dry_run (bool, optional) -- whether this is a DRY-RUN.
- Raises
spicerack.remote.RemoteError -- if no hosts were provided.
-
hosts
¶ Getter for the hosts property.
- Returns
a copy of the targeted hosts.
- Return type
-
init_system
() → List[Tuple[ClusterShell.NodeSet.NodeSet, str]][source]¶ Detect the init system.
- Returns
a list of 2-element tuples with hosts
ClusterShell.NodeSet.NodeSet
as first item and the init systemstr
as second.- Return type
-
static
results_to_list
(results: Iterator[Tuple[ClusterShell.NodeSet.NodeSet, ClusterShell.MsgTree.MsgTreeElem]], callback: Optional[Callable] = None) → List[Tuple[ClusterShell.NodeSet.NodeSet, Any]][source]¶ Extract execution results into a list converting them with an optional callback.
Todo
move it directly into Cumin.
- Parameters
results (generator) -- generator returned by run_sync() and run_async() to iterate over the results.
callback (callable, optional) -- an optional callable to apply to each result output (it can be multiline). The callback will be called with a the string output as the only parameter and must return the extracted value. The return type can be chosen freely.
- Returns
a list of 2-element tuples with hosts
ClusterShell.NodeSet.NodeSet
as first item and the extracted outputsstr
as second. This is because NodeSet are not hashable.- Return type
- Raises
spicerack.remote.RemoteError -- if unable to run the callback.
-
run_async
(*commands, success_threshold: float = 1.0, batch_size: Union[int, str, None] = None, batch_sleep: Optional[float] = None, is_safe: bool = False) → Iterator[Tuple[ClusterShell.NodeSet.NodeSet, ClusterShell.MsgTree.MsgTreeElem]][source]¶ Execute commands on hosts matching a query via Cumin in async mode.
- Parameters
*commands (str, cumin.transports.Command) -- arbitrary number of commands to execute on the target hosts.
success_threshold (float, optional) -- to consider the execution successful, must be between 0.0 and 1.0.
batch_size (int, str, optional) -- the batch size for cumin, either as percentage (e.g.
25%
) or absolute number (e.g.5
).batch_sleep (float, optional) -- the batch sleep in seconds to use in Cumin before scheduling the next host.
is_safe (bool, optional) -- whether the command is safe to run also in dry-run mode because it's a read-only command that doesn't modify the state.
- Returns
cumin.transports.BaseWorker.get_results to allow to iterate over the results.
- Return type
generator
- Raises
RemoteExecutionError -- if the Cumin execution returns a non-zero exit code.
-
run_sync
(*commands, success_threshold: float = 1.0, batch_size: Union[int, str, None] = None, batch_sleep: Optional[float] = None, is_safe: bool = False) → Iterator[Tuple[ClusterShell.NodeSet.NodeSet, ClusterShell.MsgTree.MsgTreeElem]][source]¶ Execute commands on hosts matching a query via Cumin in sync mode.
- Parameters
*commands (str, cumin.transports.Command) -- arbitrary number of commands to execute on the target hosts.
success_threshold (float, optional) -- to consider the execution successful, must be between 0.0 and 1.0.
batch_size (int, str, optional) -- the batch size for cumin, either as percentage (e.g.
25%
) or absolute number (e.g.5
).batch_sleep (float, optional) -- the batch sleep in seconds to use in Cumin before scheduling the next host.
is_safe (bool, optional) -- whether the command is safe to run also in dry-run mode because it's a read-only command that doesn't modify the state.
- Returns
cumin.transports.BaseWorker.get_results to allow to iterate over the results.
- Return type
generator
- Raises
RemoteExecutionError -- if the Cumin execution returns a non-zero exit code.
-
uptime
() → List[Tuple[ClusterShell.NodeSet.NodeSet, float]][source]¶ Get current uptime.
- Returns
a list of 2-element
tuple
instances with hostsClusterShell.NodeSet.NodeSet
as first item andfloat
uptime as second item.- Return type
-
wait_reboot_since
(since: datetime.datetime) → None[source]¶ Poll the host until is reachable and has an uptime lower than the provided datetime.
- Parameters
since (datetime.datetime) -- the time after which the host should have booted.
- Raises
spicerack.remote.RemoteCheckError -- if unable to connect to the host or the uptime is higher than expected.
-
class
spicerack.remote.
RemoteHostsAdapter
(remote_hosts: spicerack.remote.RemoteHosts)[source]¶ Bases:
object
Base adapter to write classes that expand the capabilities of RemoteHosts.
This adapter class is a helper class to reduce duplication when writing classes that needs to add capabilities to a RemoteHosts instance. The goal is to not extend the RemoteHosts but instead delegate to its instances. This class fits when a single RemoteHosts instance is enough, but for more complex cases, in which multiple RemoteHosts instances should be orchestrated, it's ok to not extend this class and create a standalone one.
Initialize the instance.
- Parameters
remote_hosts (spicerack.remote.RemoteHosts) -- the instance to act on the remote hosts.