NAME¶
VM::EC2::Staging::Manager - Automate VMs and volumes for moving data in and out
of cloud.
SYNOPSIS¶
use VM::EC2::Staging::Manager;
my $ec2 = VM::EC2->new(-region=>'us-east-1');
my $staging = $ec2->staging_manager(-on_exit => 'stop', # default, stop servers when process exists
-verbose => 1, # default, verbose progress messages
-scan => 1, # default, scan region for existing staging servers and volumes
-image_name => 'ubuntu-precise-12.04', # default server image
-user_name => 'ubuntu', # default server login name
);
# Assuming an EBS image named ami-12345 is located in the US, copy it into
# the South American region, returning the AMI ID in South America
my $new_image = $staging->copy_image('ami-12345','sa-east-1');
# provision a new server, using defaults. Name will be assigned automatically
my $server = $staging->provision_server(-availability_zone => 'us-east-1a');
# retrieve a new server named "my_server", if one exists. If not, it creates one
# using the specified options
my $server = $staging->get_server(-name => 'my_server',
-availability_zone => 'us-east-1a',
-instance_type => 't1.micro');
# open up an ssh session in an xterm
$server->shell;
# run a command over ssh on the server. See VM::EC2::Staging::Server
$server->ssh('whoami');
# run a command over ssh on the server, returning the result as an array of lines or a
# scalar string, similar to backticks (``)
my @password_lines = $server->scmd('cat /etc/passwd');
# run a command on the server and read from it using a filehandle
my $fh = $server->scmd_read('ls -R /usr/lib');
while (<$fh>) { # do something }
# run a command on the server and write to it using a filehandle
my $fh = $server->scmd_write('sudo -s "cat >>/etc/fstab"');
print $fh "/dev/sdf3 /mnt/demo ext3 0 2\n";
close $fh;
# Provision a new volume named "Pictures". Will automatically be mounted to a staging server in
# the specified zone. Server will be created if needed.
my $volume = $staging->provision_volume(-name => 'Pictures',
-fstype => 'ext4',
-availability_zone => 'us-east-1a',
-size => 2) or die $staging->error_str;
# gets an existing volume named "Pictures" if it exists. Otherwise provisions a new volume;
my $volume = $staging->get_volume(-name => 'Pictures',
-fstype => 'ext4',
-availability_zone => 'us-east-1a',
-size => 2) or die $staging->error_str;
# copy contents of local directory /opt/test to remote volume $volume using rsync
# See VM::EC2::Staging::Volume
$volume->put('/opt/test/');
# same thing, but first creating a subdirectory on the remote volume
$volume->put('/opt/test/' => './mirrors/');
# copy contents of remote volume $volume to local directory /tmp/test using rsync
$volume->get('/tmp/test');
# same thing, but from a subdirectory of the remote volume
$volume->get('./mirrors/' => '/tmp/test');
# server to server transfer (works both within and between availability regions)
my $south_america = VM::EC2->new(-region=>'sa-east-1')->staging_manager; # create a staging manager in Sao Paolo
my $volume2 = $south_america->provision_volume(-name => 'Videos',
-availability_zone => 'sa-east-1a',
-size => 2);
$staging->rsync("$volume/mirrors" => "$volume2/us-east");
$staging->stop_all_servers();
$staging->start_all_servers();
$staging->terminate_all_servers();
$staging->force_terminate_all_servers();
DESCRIPTION¶
VM::EC2::Staging::Manager manages a set of EC2 volumes and servers in a single
AWS region. It was primarily designed to simplify the process of provisioning
and populating volumes, but it also provides a handy set of ssh commands that
allow you to run remote commands programmatically.
The manager also allows you to copy EBS-backed AMIs and their attached volumes
from one region to another, something that is otherwise difficult to do.
The main classes are:
VM::EC2::Staging::Manager -- A set of volume and server resources in
a single AWS region.
VM::EC2::Staging::Server -- A staging server running somewhere in the
region. It is a VM::EC2::Instance
extended to provide remote command and
copy facilities.
VM::EC2::Staging::Volume -- A staging disk volume running somewhere in the
region. It is a VM::EC2::Volume
extended to provide remote copy
facilities.
Staging servers can provision volumes, format them, mount them, copy data
between local and remote (virtual) machines, and execute secure shell
commands. Staging volumes can mount themselves on servers, run a variety of
filesystem-oriented commands, and invoke commands on the servers to copy data
around locally and remotely.
See VM::EC2::Staging::Server and VM::EC2::Staging::Volume for the full details.
Constructors¶
The following methods allow you to create new VM::EC2::Staging::Manager
instances. Be aware that only one manager is allowed per EC2 region;
attempting to create additional managers in the same region will return the
same one each time.
$manager = $ec2->staging_manager(@args)¶
This is a simplified way to create a staging manager. First create the EC2
object in the desired region, and then call its
staging_manager()
method:
$manager = VM::EC2->new(-region=>'us-west-2')->staging_manager()
The
staging_manager() method is only known to VM::EC2 objects if you
first "use" VM::EC2::Staging::Manager.
- Required Arguments
- None.
- Optional Arguments
- The optional arguments change the way that the manager creates new servers
and volumes.
-on_exit What to do with running servers when the manager goes
out of scope or the script exits. One of 'run',
'stop' (default), or 'terminate'. "run" keeps all
created instances running, so beware!
-architecture Architecture for newly-created server
instances (default "i386"). Can be overridden in calls to get_server()
and provision_server().
-instance_type Type of newly-created servers (default "m1.small"). Can be overridden
in calls to get_server() and provision_server().
-root_type Root type for newly-created servers (default depends
on the -on_exit behavior; "ebs" for exit behavior of
"stop" and "instance-store" for exit behavior of "run"
or "terminate".
-image_name Name or ami ID of the AMI to use for creating the
instances of new servers. Defaults to 'ubuntu-precise-12.04'.
If the image name begins with "ami-", then it is
treated as an AMI ID. Otherwise it is treated as
a name pattern and will be used to search the AMI
name field using the wildcard search "*$name*".
Names work better than AMI ids here, because the
latter change from one region to another. If multiple
matching image candidates are found, then an alpha
sort on the name is used to find the image with the
highest alpha sort value, which happens to work with
Ubuntu images to find the latest release.
-availability_zone Availability zone for newly-created
servers. Default is undef, in which case a random
zone is selected.
-username Username to use for ssh connections. Defaults to
"ubuntu". Note that this user must be able to use
sudo on the instance without providing a password,
or functionality of this module will be limited.
-verbose Integer level of verbosity. Level 1 prints warning
messages. Level 2 (the default) adds informational
messages as well. Level 3 adds verbose debugging
messages. Level 0 suppresses all messages.
-quiet (deprecated) If true, turns off all verbose messages.
-scan Boolean, default true. If true, scans region for
volumes and servers created by earlier manager
instances.
-reuse_key Boolean, default true. If true, creates a single
ssh keypair for each region and reuses it. Note that
the private key is kept on the local computer in the
directory ~/.vm-ec2-staging, and so additional
keypairs may be created if you use this module on
multiple local machines. If this option is false,
then a new keypair will be created for every server
you partition.
-reuse_volumes Boolean, default true. If this flag is true, then
calls to provision_volume() will return existing
volumes if they share the same name as the requested
volume. If no suitable existing volume exists, then
the most recent snapshot of this volume is used to
create it in the specified availability zone. Only
if no volume or snapshot exist will a new volume be
created from scratch.
-dotdir Path to the directory that contains keyfiles and other
stable configuration information for this module.
Defaults to ~/.vm_ec2_staging. You may wish to change
this to, say, a private dropbox directory or an NFS-mount
in order to share keyfiles among machines. Be aware of
the security implications of sharing private key files.
-server_class By default, staging server objects created by the manager
are of class type VM::EC2::Staging::Server. If you create
a custom server subclass, you need to let the manager know
about it by passing the class name to this argument.
-volume_class By default, staging volume objects created by the manager
are of class type VM::EC2::Staging::Volume. If you create
a custom volume subclass, you need to let the manager know
about it by passing the class name to this argument.
$manager = VM::EC2::Staging::Manager(-ec2 => $ec2,@args)¶
This is a more traditional constructur for the staging manager.
- Required Arguments
-
-ec2 A VM::EC2 object.
- Optional Arguments
- All of the arguments listed in the description of VM::EC2->
staging_manager().
Interzone Copying of AMIs and Snapshots¶
This library provides convenience methods for copying whole AMIs as well as
individual snapshots from one zone to another. It does this by gathering
information about the AMI/snapshot in the source zone, creating staging
servers in the source and target zones, and then copying the volume data from
the source to the target. If an AMI/snapshot does not use a recognized
filesystem (e.g. it is part of an LVM or RAID disk set), then block level
copying of the entire device is used. Otherwise,
rsync() is used to
minimize data transfer fees.
Note that interzone copying of instance-backed AMIs is
not supported.
Only EBS-backed images can be copied in this way.
See also the command-line script migrate-ebs-image.pl that comes with this
package.
$new_image_id = $manager->copy_image($source_image,$destination_zone,@register_options)¶
This method copies the AMI indicated by $source_image from the zone that
$manager belongs to, into the indicated $destination_zone, and returns the AMI
ID of the new image in the destination zone.
$source_image may be an AMI ID, or a VM::EC2::Image object.
$destination_zone may be a simple region name, such as "us-west-2", or
a VM::EC2::Region object (as returned by VM::EC2->describe_regions), or a
VM::EC2::Staging::Manager object that is associated with the desired region.
The latter form gives you control over the nature of the staging instances
created in the destination zone. For example, if you wish to use 'm1.large'
high-I/O instances in both the source and destination reasons, you would
proceed like this:
my $source = VM::EC2->new(-region=>'us-east-1'
)->staging_manager(-instance_type=>'m1.large',
-on_exit =>'terminate');
my $destination = VM::EC2->new(-region=>'us-west-2'
)->staging_manager(-instance_type=>'m1.large',
-on_exit =>'terminate');
my $new_image = $source->copy_image('ami-123456' => $destination);
If present, the named argument list @register_options will be passed to
register_image() and used to override options in the destination image.
This can be used to set ephemeral device mappings, which cannot currently be
detected and transferred automatically by
copy_image():
$new_image =$source->copy_image('ami-123456' => 'us-west-2',
-description => 'My AMI western style',
-block_devices => '/dev/sde=ephemeral0');
$dest_kernel = $manager->match_kernel($src_kernel,$dest_zone)¶
Find a kernel in $dest_zone that matches the $src_kernel in the current zone.
$dest_zone can be a VM::EC2::Staging manager object, a region name, or a
VM::EC2::Region object.
$new_snapshot_id = $manager->copy_snapshot($source_snapshot,$destination_zone)¶
This method copies the EBS snapshot indicated by $source_snapshot from the zone
that $manager belongs to, into the indicated $destination_zone, and returns
the ID of the new snapshot in the destination zone.
$source_snapshot may be an string ID, or a VM::EC2::Snapshot object.
$destination_zone may be a simple region name, such as "us-west-2", or
a VM::EC2::Region object (as returned by VM::EC2->describe_regions), or a
VM::EC2::Staging::Manager object that is associated with the desired region.
Note that this call uses the Amazon CopySnapshot API call that was introduced in
2012-12-01 and no longer involves the creation of staging servers in the
source and destination regions.
Instance Methods for Managing Staging Servers¶
These methods allow you to create and interrogate staging servers. They each
return one or more VM::EC2::Staging::Server objects. See
VM::EC2::Staging::Server for more information about what you can do with these
servers once they are running.
$server = $manager->provision_server(%options)¶
Create a new VM::EC2::Staging::Server object according to the passed options,
which override the default options provided by the Manager object.
-name Name for this server, which can be used to retrieve
it later with a call to get_server().
-architecture Architecture for the newly-created server
instances (e.g. "i386"). If not specified, then defaults
to the default_architecture() value. If explicitly
specified as undef, then the architecture of the matching
image will be used.
-instance_type Type of the newly-created server (e.g. "m1.small").
-root_type Root type for the server ("ebs" or "instance-store").
-image_name Name or ami ID of the AMI to use for creating the
instance for the server. If the image name begins with
"ami-", then it is treated as an AMI ID. Otherwise it
is treated as a name pattern and will be used to
search the AMI name field using the wildcard search
"*$name*". Names work better than AMI ids here,
because the latter change from one region to
another. If multiple matching image candidates are
found, then an alpha sort on the name is used to find
the image with the highest alpha sort value, which
happens to work with Ubuntu images to find the latest
release.
-availability_zone Availability zone for the server, or undef to
choose an availability zone randomly.
-username Username to use for ssh connections. Defaults to
"ubuntu". Note that this user must be able to use
sudo on the instance without providing a password,
or functionality of this server will be limited.
In addition, you may use any of the options recognized by VM::EC2->
run_instances() (e.g. -block_devices).
$server = $manager->get_server(-name=>$name,%other_options)¶
$server = $manager->get_server($name)¶
Return an existing VM::EC2::Staging::Server object having the indicated symbolic
name, or create a new server if one with this name does not already exist. The
server's instance characteristics will be configured according to the options
passed to the manager at create time (e.g. -availability_zone,
-instance_type). These options can be overridden by %other_args. See
provision_volume() for details.
$server = $manager->get_server_in_zone(-zone=>$availability_zone,%other_options)¶
$server = $manager->get_server_in_zone($availability_zone)¶
Return an existing VM::EC2::Staging::Server running in the indicated symbolic
name, or create a new server if one with this name does not already exist. The
server's instance characteristics will be configured according to the options
passed to the manager at create time (e.g. -availability_zone,
-instance_type). These options can be overridden by %other_args. See
provision_server() for details.
$server = $manager->find_server_by_instance($instance_id)¶
Given an EC2 instanceId, return the corresponding VM::EC2::Staging::Server, if
any.
@servers $manager->servers¶
Return all registered VM::EC2::Staging::Servers in the zone managed by the
manager.
$manager->start_all_servers¶
Start all VM::EC2::Staging::Servers that are currently in the "stop"
state.
$manager->stop_all_servers¶
Stop all VM::EC2::Staging::Servers that are currently in the "running"
state.
$manager->terminate_all_servers¶
Terminate all VM::EC2::Staging::Servers and unregister them.
$manager->force_terminate_all_servers¶
Force termination of all VM::EC2::Staging::Servers, even if the internal
registration system indicates that some may be in use by other Manager
instances.
$manager->wait_for_servers(@servers)¶
Wait until all the servers on the list @servers are up and able to accept ssh
commands. You may wish to wrap this in an eval{} and timeout in order to avoid
waiting indefinitely.
Instance Methods for Managing Staging Volumes¶
These methods allow you to create and interrogate staging volumes. They each
return one or more VM::EC2::Staging::Volume objects. See
VM::EC2::Staging::Volume for more information about what you can do with these
staging volume objects.
$volume = $manager->provision_volume(%options)¶
Create and register a new VM::EC2::Staging::Volume and mount it on a staging
server in the appropriate availability zone. A new staging server will be
created for this purpose if one does not already exist.
If you provide a symbolic name for the volume and the manager has previously
snapshotted a volume by the same name, then the snapshot will be used to
create the volume (this behavior can be suppressed by passing -reuse=>0).
This allows for the following pattern for efficiently updating a snapshotted
volume:
my $vol = $manager->provision_volume(-name=>'MyPictures',
-size=>10);
$vol->put('/usr/local/my_pictures/'); # will do an rsync from local directory
$vol->create_snapshot; # write out to a snapshot
$vol->delete;
You may also explicitly specify a volumeId or snapshotId. The former allows you
to place an existing volume under management of VM::EC2::Staging::Manager and
returns a corresponding staging volume object. The latter creates the staging
volume from the indicated snapshot, irregardless of whether the snapshot was
created by the staging manager at an earlier time.
Newly-created staging volumes are automatically formatted as ext4 filesystems
and mounted on the staging server under /mnt/Staging/$name, where $name is the
staging volume's symbolic name. The filesystem type and the mountpoint can be
modified with the -fstype and -mount arguments, respectively. In addition, you
may specify an -fstype of "raw", in which case the volume will be
attached to a staging server (creating the server first if necessary) but not
formatted or mounted. This is useful when creating multi-volume RAID or LVM
setups.
Options:
-name Name of the staging volume. A fatal error issues if a staging
volume by this name already exists (use get_volume() to
avoid this). If no name is provided, then a random
unique one is chosen for you.
-availability_zone
Availability zone in which to create this
volume. If none is specified, then a zone is chosen that
reuses an existing staging server, if any.
-size Size of the desired volume, in GB.
-fstype Filesystem type for the volume, ext4 by default. Supported
types are ext2, ext3, ext4, xfs, reiserfs, jfs, hfs,
ntfs, vfat, msdos, and raw.
-mount Mount point for this volume on the staging server (e.g. /opt/bin).
Use with care, as there are no checks to prevent you from mounting
two staging volumes on top of each other or mounting over essential
operating system paths.
-label Volume label. Only applies to filesystems that support labels
(all except hfs, vfat, msdos and raw).
-volume_id Create the staging volume from an existing EBS volume with
the specified ID. Most other options are ignored in this
case.
-snapshot_id
Create the staging volume from an existing EBS
snapshot. If a size is specified that is larger than the
snapshot, then the volume and its filesystem will be
automatically extended (this only works for ext volumes
at the moment). Shrinking of volumes is not currently
supported.
-reuse If true, then the most recent snapshot created from a staging
volume of the same name is used to create the
volume. This is the default. Pass 0 to disable this
behavior.
The
-reuse argument is intended to support the following use case in
which you wish to rsync a directory on a host system somewhere to an EBS
snapshot, without maintaining a live server and volume on EC2:
my $volume = $manager->provision_volume(-name=>'backup_1',
-reuse => 1,
-fstype => 'ext3',
-size => 10);
$volume->put('fred@gw.harvard.edu:my_music');
$volume->create_snapshot('Music Backup '.localtime);
$volume->delete;
The next time this script is run, the "backup_1" volume will be
recreated from the most recent snapshot, minimizing copying. A new snapshot is
created, and the staging volume is deleted.
$volume = $manager->get_volume(-name=>$name,%other_options)¶
$volume = $manager->get_volume($name)¶
Return an existing VM::EC2::Staging::Volume object with the indicated symbolic
name, or else create a new volume if one with this name does not already
exist. The volume's characteristics will be configured according to the
options in %other_args. See
provision_volume() for details. If called
with no arguments, this method returns Volume object with default
characteristics and a randomly-assigned name.
$result = $manager->rsync($src1,$src2,$src3...,$dest)¶
This method provides remote synchronization (rsync) file-level copying between
one or more source locations and a destination location via an ssh tunnel.
Copying among arbitrary combinations of local and remote filesystems is
supported, with the caveat that the remote filesystems must be contained on
volumes and servers managed by this module (see below for a workaround).
You may provide two or more directory paths. The last path will be treated as
the copy destination, and the source paths will be treated as copy sources.
All copying is performed using the -avz options, which activates recursive
directory copying in which ownership, modification times and permissions are
preserved, and compresses the data to reduce network usage. Verbosity is set
so that the names of copied files are printed to STDERR. If you do not wish
this, then use call the manager's
quiet() method with a true value.
Source paths can be formatted in one of several ways:
/absolute/path
Copy the contents of the directory /absolute/path located on the
local machine to the destination. This will create a
subdirectory named "path" on the destination disk. Add a slash
to the end of the path (i.e. "/absolute/path/") in order to
avoid creating this subdirectory on the destination disk.
./relative/path
Relative paths work the way you expect, and depend on the current
working directory. The terminating slash rule applies.
$staging_volume
Pass a VM::EC2::Staging::Volume to copy the contents of the
volume to the destination disk starting at the root of the
volume. Note that you do *not* need to have any knowledge of the
mount point for this volume in order to copy its contents.
$staging_volume:/absolute/path
$staging_volume:absolute/path
$staging_volume/absolute/path
All these syntaxes accomplish the same thing, which is to
copy a subdirectory of a staging volume to the destination disk.
The root of the volume is its top level, regardless of where it
is mounted on the staging server. Because of string
interpolation magic, you can enclose staging volume object names
in quotes in order to construct the path, as in
"$picture_volume:/family/vacations/". As in local paths, a
terminating slash indicates that the contents of the last
directory in the path are to be copied without creating the
enclosing directory on the desetination. Note that you do *not*
need to have any knowledge of the mount point for this volume in
order to copy its contents.
$staging_server:/absolute/path
Pass a staging server object and absolute path to copy the contents
of this path to the destination disk. Because of string interpolation
you can include server objects in quotes: "$my_server:/opt"
$staging_server:relative/path
This form will copy data from paths relative to the remote user's home
directory on the staging server. Typically not very useful, but supported.
The same syntax is supported for destination paths, except that it makes no
difference whether a path has a trailing slash or not.
As with the rsync command, if you proceed a path with a single colon
(:/my/path), it is a short hand to use the previous server/volume/host in the
source list.
When specifying multiple source directories, all source directories must reside
on the same local or remote machine. This is legal:
$manager->rsync("$picture_volume:/family/vacations",
"$picture_volume:/family/picnics"
=> "$backup_volume:/recent_backups");
This is not:
$manager->rsync("$picture_volume:/family/vacations",
"$audio_volume:/beethoven"
=> "$backup_volume:/recent_backups");
When specifying multiple sources, you may give the volume or server once for the
first source and then start additional source paths with a ":" to
indicate the same volume or server is to be used:
$manager->rsync("$picture_volume:/family/vacations",
":/family/picnics"
=> "$backup_volume:/recent_backups");
When copying to/from the local machine, the rsync process will run as the user
that the script was launched by. However, on remote servers managed by the
staging manager, the rsync process will run as superuser.
The
rsync() method will also accept regular remote DNS names and IP
addresses, optionally preceded by a username:
$manager->rsync("$picture_volume:/family/vacations" => 'fred@gw.harvard.edu:/tmp')
When called in this way, the method does what it can to avoid prompting for a
password or passphrase on the non-managed host (gw.harvard.edu in the above
example). This includes turning off strict host checking and forwarding the
user agent information from the local machine.
$result = $manager->rsync(\@options,$src1,$src2,$src3...,$dest)¶
This is a variant of the rsync command in which extra options can be passed to
rsync by providing an array reference as the first argument. For example:
$manager->rsync(['--exclude' => '*~'],
'/usr/local/backups',
"$my_server:/usr/local");
$manager->dd($source_vol=>$dest_vol)¶
This method performs block-level copying of the contents of $source_vol to
$dest_vol by using dd over an SSH tunnel, where both source and destination
volumes are VM::EC2::Staging::Volume objects. The volumes must be attached to
a server but not mounted. Everything in the volume, including its partition
table, is copied, allowing you to make an exact image of a disk.
The volumes do
not actually need to reside on this server, but can be
attached to any staging server in the zone.
$volume = $manager->find_volume_by_volid($volume_id)¶
Given an EC2 volumeId, return the corresponding VM::EC2::Staging::Volume, if
any.
$volume = $manager->find_volume_by_name($name)¶
Given a staging name (assigned at volume creation time), return the
corresponding VM::EC2::Staging::Volume, if any.
@volumes = $manager->volumes¶
Return all VM::EC2::Staging::Volumes managed in this zone.
Instance Methods for Accessing Configuration Options¶
This section documents accessor methods that allow you to examine or change
configuration options that were set at create time. Called with an argument,
the accessor changes the option and returns the option's previous value.
Called without an argument, the accessor returns the option's current value.
$on_exit = $manager->on_exit([$new_behavior])¶
Get or set the "on_exit" option, which specifies what to do with
existing staging servers when the staging manager is destroyed. Valid values
are "terminate", "stop" and "run".
$reuse_key = $manager->reuse_key([$boolean])¶
Get or set the "reuse_key" option, which if true uses the same
internally-generated ssh keypair for all running instances. If false, then a
new keypair will be created for each staging server. The keypair will be
destroyed automatically when the staging server terminates (but only if the
staging manager initiates the termination itself).
$username = $manager->username([$new_username])¶
Get or set the username used to log into staging servers.
$architecture = $manager->architecture([$new_architecture])¶
Get or set the architecture (i386, x86_64) to use for launching new staging
servers.
$root_type = $manager->root_type([$new_type])¶
Get or set the instance root type for new staging servers
("instance-store", "ebs").
$instance_type = $manager->instance_type([$new_type])¶
Get or set the instance type to use for new staging servers (e.g.
"t1.micro"). I recommend that you use "m1.small" (the
default) or larger instance types because of the extremely slow I/O of the
micro instance. In addition, micro instances running Ubuntu have a known bug
that prevents them from unmounting and remounting EBS volumes repeatedly on
the same block device. This can lead to hangs when the staging manager tries
to create volumes.
$reuse_volumes = $manager->reuse_volumes([$new_boolean])¶
This gets or sets the "reuse_volumes" option, which if true causes the
provision_volumes() call to create staging volumes from existing EBS
volumes and snapshots that share the same staging manager symbolic name. See
the discussion under VM::EC2->
staging_manager(), and
VM::EC2::Staging::Manager->
provision_volume().
$name = $manager->image_name([$new_name])¶
This gets or sets the "image_name" option, which is the AMI ID or AMI
name to use when creating new staging servers. Names beginning with
"ami-" are treated as AMI IDs, and everything else is treated as a
pattern match on the AMI name.
$zone = $manager->availability_zone([$new_zone])¶
Get or set the default availability zone to use when creating new servers and
volumes. An undef value allows the staging manager to choose the zone in a way
that minimizes resources.
$class_name = $manager->volume_class([$new_class])¶
Get or set the name of the perl package that implements staging volumes,
VM::EC2::Staging::Volume by default. Staging volumes created by the manager
will have this class type.
$class_name = $manager->server_class([$new_class])¶
Get or set the name of the perl package that implements staging servers,
VM::EC2::Staging::Server by default. Staging servers created by the manager
will have this class type.
$boolean = $manager->scan([$boolean])¶
Get or set the "scan" flag, which if true will cause the zone to be
scanned quickly for existing managed servers and volumes when the manager is
first created.
$path = $manager->dot_directory([$new_directory])¶
Get or set the dot directory which holds private key files.
Internal Methods¶
This section documents internal methods that are not normally called by end-user
scripts but may be useful in subclasses. In addition, there are a number of
undocumented internal methods that begin with the "_" character.
Explore the source code to learn about these.
$ok = $manager->environment_ok¶
This performs a check on the environment in which the module is running. For
this module to work properly, the ssh, rsync and dd programs must be found in
the PATH. If all three programs are found, then this method returns true.
This method can be called as an instance method or class method.
$name = $manager->default_verbosity¶
Returns the default verbosity level (2: warning+informational messages). This is
overridden using -verbose at create time.
$name = $manager->default_exit_behavior¶
Return the default exit behavior ("stop") when the manager terminates.
Intended to be overridden in subclasses.
$name = $manager->default_image_name¶
Return the default image name ('ubuntu-precise-12.04') for use in creating new
instances. Intended to be overridden in subclasses.
$name = $manager->default_user_name¶
Return the default user name ('ubuntu') for use in creating new instances.
Intended to be overridden in subclasses.
$name = $manager->default_architecture¶
Return the default instance architecture ('i386') for use in creating new
instances. Intended to be overridden in subclasses.
$name = $manager->default_root_type¶
Return the default instance root type ('instance-store') for use in creating new
instances. Intended to be overridden in subclasses. Note that this value is
ignored if the exit behavior is "stop", in which case an ebs-backed
instance will be used. Also, the m1.micro instance type does not come in an
instance-store form, so ebs will be used in this case as well.
$name = $manager->default_instance_type¶
Return the default instance type ('m1.small') for use in creating new instances.
Intended to be overridden in subclasses. We default to m1.small rather than a
micro instance because the I/O in m1.small is far faster than in t1.micro.
$name = $manager->default_reuse_keys¶
Return the default value of the -reuse_keys argument ('true'). This value allows
the manager to create an ssh keypair once, and use the same one for all
servers it creates over time. If false, then a new keypair is created for each
server and then discarded when the server terminates.
$name = $manager->default_reuse_volumes¶
Return the default value of the -reuse_volumes argument ('true'). This value
instructs the manager to use the symbolic name of the volume to return an
existing volume whenever a request is made to provision a new one of the same
name.
$path = $manager->default_dot_directory_path¶
Return the default value of the -dotdir argument
("$ENV{HOME}/.vm-ec2-staging"). This value instructs the manager to
use the symbolic name of the volume to return an existing volume whenever a
request is made to provision a new one of the same name.
$class_name = $manager->default_volume_class¶
Return the class name for staging volumes created by the manager,
VM::EC2::Staging::Volume by default. If you wish a subclass of
VM::EC2::Staging::Manager to create a different type of volume, override this
method.
$class_name = $manager->default_server_class¶
Return the class name for staging servers created by the manager,
VM::EC2::Staging::Server by default. If you wish a subclass of
VM::EC2::Staging::Manager to create a different type of volume, override this
method.
$server = $manager->register_server($server)¶
Register a VM::EC2::Staging::Server object. Usually called internally.
$manager->unregister_server($server)¶
Forget about the existence of VM::EC2::Staging::Server. Usually called
internally.
$manager->register_volume($volume)¶
Register a VM::EC2::Staging::Volume object. Usually called internally.
$manager->unregister_volume($volume)¶
Forget about a VM::EC2::Staging::Volume object. Usually called internally.
$pid = $manager->pid([$new_pid])¶
Get or set the process ID of the script that is running the manager. This is
used internally to detect the case in which the script has forked, in which
case we do not want to invoke the manager class's destructor in the child
process (because it may stop or terminate servers still in use by the parent
process).
$path = $manager->dotdir([$new_dotdir])¶
Low-level version of
dot_directory(), differing only in the fact that
dot_directory will automatically create the path, including subdirectories.
$manager->scan_region¶
Synchronize internal list of managed servers and volumes with the EC2 region.
Called automatically during
new() and needed only if servers &
volumes are changed from outside the module while it is running.
$group = $manager->security_group¶
Returns or creates a security group with the permissions needed used to manage
staging servers. Usually called internally.
$keypair = $manager->keypair¶
Returns or creates the ssh keypair used internally by the manager to to access
staging servers. Usually called internally.
$name = $manager->new_volume_name¶
Returns a new random name for volumes provisioned without a -name argument.
Currently names are in of the format "volume-12345678", where the
numeric part are 8 random hex digits. Although no attempt is made to prevent
naming collisions, the large number of possible names makes this unlikely.
$name = $manager->new_server_name¶
Returns a new random name for server provisioned without a -name argument.
Currently names are in of the format "server-12345678", where the
numeric part are 8 random hex digits. Although no attempt is made to prevent
naming collisions, the large number of possible names makes this unlikely.
$description = $manager->volume_description($volume)¶
This method is called to assign a description to newly-created volumes. The
current format is "Staging volume for Foo created by
VM::EC2::Staging::Manager", where Foo is the volume's symbolic name.
$manager->debug("Debugging message\n")¶
$manager->warn("Warning message\n")¶
Prints an informational message to standard error if current
verbosity()
level allows.
$verbosity = $manager->verbosity([$new_value])¶
The
verbosity() method get/sets a flag that sets the level of
informational messages.
SEE ALSO¶
VM::EC2 VM::EC2::Staging::Server VM::EC2::Staging::Volume migrate-ebs-image.pl
AUTHOR¶
Lincoln Stein <lincoln.stein@gmail.com>.
Copyright (c) 2012 Ontario Institute for Cancer Research
This package and its accompanying libraries is free software; you can
redistribute it and/or modify it under the terms of the GPL (either version 1,
or at your option, any later version) or the Artistic License 2.0. Refer to
LICENSE for the full license text. In addition, please see DISCLAIMER.txt for
disclaimers of warranty.