DTrove Datastore Base Classes¶

The base classes that define the interface for all datastores.

If you wish to create your own datastore, simply subclass the base and override the methods you need to for example:

from dtrove.datastores import base
from dtrove.commands import run

class MyBackyardDBManager(base.BaseManager):

    def backup():
        with self.conn as connection:
            run('/bin/bash my_backup.sh')

    @property
    def name():
        return 'ClassNameOverriddenDB'

Templates for the managers live in dtrove/datastores/<manager_name> where manager name by default is the lowercase manager name with the ‘Manager’ removed. For example ‘MySQLManager’ would be ‘mysql’.

More on templates later.

class dtrove.datastores.base.BaseManager(datastore)¶

Manager Base

Parameters:	datastore – The actual datastore version that is being managed. The datastores have the image and package information to install on the guest vm’s.

backup(instance)¶

Preform a backup on the remote instance.

name¶

Returns the name of the manager ex: MySQLManager = mysql

prepare(instance)¶

Install and configure the datastore on the instance.

render_config_file(instance)¶

Load and render a config file for this datastore.

restart()¶

Restart the datastore.

service_name = None¶

Name of the service ie ‘mysql’

start()¶

Start the datastore

stop()¶

Stop the datastore

Implementations¶

This is a list of the current built in Managers

• dtrove.datastores.mysql.MySQLManager
• dtrove.datastores.redis.RedisManager
• dtrove.datastores.pgsql.PostgresManager

Execution Tasks¶

We can use the perform task to run any command on the remote systems.

dtrove.tasks.perform(instance_id, name, *cmds)¶

Execute a remote task

Parameters:	instance_id (int) – ID of the instance to connect to name (str) – Identifier of this task cmds (str) – The actual commands to run

For example (To ruin someones day):

perform.delay(1, 'destory', 'rm -rf /', 'echo everything gone')

Will produce
[root@10.0.0.1] run: rm -rf /
out:
[root@10.0.0.1] run: echo everything gone
out: everything gone
Disconnecting from 127.0.0.1...
done.

Build Tasks¶

These tasks handle creating and managing the servers themselves.

dtrove.tasks.create_server(instance_id, volume_id=None)¶

Create a nova server instance

Parameters:	instance_id (int) – ID of the instance to build volume_id (str) – Optional volume id to attach

dtrove.tasks.create_volume(instance_id)¶

Create a volume for the instance

Parameters:	instance_id (int) – ID of the instance

dtrove.tasks.attach_volume(instance_id, volume_id)¶

Attach a volume to a nova server instance

Parameters:	instance_id (int) – ID of the instance to build volume_id (str) – Optional volume id to attach

Available models¶

class dtrove.models.Cluster(*args, **kwargs)¶

Datastore Cluster

This is the Main User facing object it defines the datastore type along with the size of the cluster and the other user options.

Parameters:	name (str) – Name of the cluster datastore (dtrove.models.Datastore) – Datastore of the cluster size (int) – Number of nodes in the cluster

When a user creates a new Cluster the system handles provisioning the underlining instances and checking on the health of them.

After the cluster is created the user can then use the datastores, or perform certain actions:

• Schedule automated backups
• Import from a previous datastore export
• Export the data into a transportable type
• Change configuration parameters

The posibilities are endless!

add_node(count=1)¶

Add a node to the cluster.

class dtrove.models.Datastore(*args, **kwargs)¶

Datastore

This represents a version of a specific datastore that is available

Parameters:	manager_class (dtrove.config.DTROVE_DATASTORE_MANAGERS) – The dotted path to the actual manager object version (str) – The version of the datastore ex: 5.6 image (str) – The id of the VM image to use to create new instances packages (str) – Comma separated list of packages to install

The main purpose of this object is to link the datastore manager to a list of packages to install and the base image that is used to create instances.

By creating an datastore that makes it available for users to select and install a cluster from it.

The manager_class property should be an importable subclass of the dtrove.datastores.base.BaseManager class.

manager¶

The manager object initialize with this datastores information

name¶

The display name of the datastore (manager.name - version)

class dtrove.models.Instance(*args, **kwargs)¶

Instance

This contains the information about the actual server instance that runs the datastore in the cluster.

Parameters:	name (str) – Name of the instance cluster (dtrove.models.Cluster) – Cluster that this instance is a part of key (dtrove.models.Key) – SSH Key pair object for this instance user (str) – The user which the SSH Key is connected to addr (ipaddr) – IP Address of this server server (str) – UUID of the nova server instance

Note

This model is internal only, all interactions are handled thought the cluster model and or the manager class on the cluster

Remote operations can be preformed on this instance by using the connection_info property like so:

from fabric.api import sudo, settings
from fabric.network import disconnect_all
from dtrove.models import Instance

instance = Instance.objects.first()

with settings(**instance.connection_info):
    sudo('rm -rf /etc/trove/*')

# Always remember to disconnect ssh sessions
disconnect_all()

See the dtrove.datastores.base.BaseManager class for more examples.

connection_info¶

Provides the connection info from the key stored for this server

message¶

Error message of the last server task

progress¶

Progress of the current server task

server_status¶

Status of the server

class dtrove.models.Key(*args, **kwargs)¶

SSH Key Pair

This holds the public and private keys for connecting to a remote host.

Note

This should have encrypted fields. Don’t put anything really secure in here. This is just a proof of concept.

Parameters:	name (str) – Name of the key passphrase (str) – Passphrase for the key private (str) – Text of the private key public (str) – Text of the public key

These keys are attached to an instance, the idea is that each cluster would have it’s own ssh key assigned to it. That way there isn’t a single master key that own’s your entire network.

You should also use a passphrase for each key even though it is not a required field.

You can access the information in this key in the dtrove.models.Instance.connection_info property on the instance(s) the key is attached to.

classmethod create(save=True)¶

Factory method to create a new private/public key pair