ceph-deploy -- Deploy Ceph with minimal infrastructure
ceph-deploy
is a way to deploy Ceph relying on just SSH access to
the servers, sudo
, and some Python. It runs fully on your
workstation, requiring no servers, databases, or anything like that.
If you set up and tear down Ceph clusters a lot, and want minimal extra bureaucracy, this is for you.
This README
provides a brief overview of ceph-deploy, for thorough
documentation please go to https://docs.ceph.com/projects/ceph-deploy/en/latest/
What this tool is not
It is not a generic deployment system, it is only for Ceph, and is designed for users who want to quickly get Ceph running with sensible initial settings without the overhead of installing Chef, Puppet or Juju.
It does not handle client configuration beyond pushing the Ceph config file and users who want fine-control over security settings, partitions or directory locations should use a tool such as Chef or Puppet.
Installation
Depending on what type of usage you are going to have with ceph-deploy
you
might want to look into the different ways to install it. For automation, you
might want to bootstrap
directly. Regular users of ceph-deploy
would
probably install from the OS packages or from the Python Package Index.
Python Package Index
If you are familiar with Python install tools (like pip
and
easy_install
) you can easily install ceph-deploy
like:
pip install ceph-deploy
or:
easy_install ceph-deploy
It should grab all the dependencies for you and install into the current user's environment.
We highly recommend using virtualenv
and installing dependencies in
a contained way.
DEB
All new releases of ceph-deploy
are pushed to all ceph
DEB release
repos.
The DEB release repos are found at:
http://ceph.com/debian-{release} http://ceph.com/debian-testing
This means, for example, that installing ceph-deploy
from
http://ceph.com/debian-giant will install the same version as from
http://ceph.com/debian-firefly or http://ceph.com/debian-testing.
RPM
All new releases of ceph-deploy
are pushed to all ceph
RPM release
repos.
The RPM release repos are found at:
http://ceph.com/rpm-{release} http://ceph.com/rpm-testing
Make sure you add the proper one for your distribution (i.e. el7 vs rhel7).
This means, for example, that installing ceph-deploy
from
http://ceph.com/rpm-giant will install the same version as from
http://ceph.com/rpm-firefly or http://ceph.com/rpm-testing.
bootstrapping
To get the source tree ready for use, run this once:
./bootstrap
You can symlink the ceph-deploy
script in this somewhere
convenient (like ~/bin
), or add the current directory to PATH
,
or just always type the full path to ceph-deploy
.
SSH and Remote Connections
ceph-deploy
will attempt to connect via SSH to hosts when the hostnames do
not match the current host's hostname. For example, if you are connecting to
host node1
it will attempt an SSH connection as long as the current host's
hostname is not node1
.
ceph-deploy at a minimum requires that the machine from which the script is being run can ssh as root without password into each Ceph node.
To enable this generate a new ssh keypair for the root user with no passphrase
and place the public key (id_rsa.pub
or id_dsa.pub
) in:
/root/.ssh/authorized_keys
and ensure that the following lines are in the sshd config:
PermitRootLogin without-password PubkeyAuthentication yes
The machine running ceph-deploy does not need to have the Ceph packages
installed unless it needs to admin the cluster directly using the ceph
command line tool.
usernames
When not specified the connection will be done with the same username as the
one executing ceph-deploy
. This is useful if the same username is shared in
all the nodes but can be cumbersome if that is not the case.
A way to avoid this is to define the correct usernames to connect with in the
SSH config, but you can also use the --username
flag as well:
ceph-deploy --username ceph install node1
ceph-deploy
then in turn would use ceph@node1
to connect to that host.
This would be the same expectation for any action that warrants a connection to a remote host.
Managing an existing cluster
You can use ceph-deploy to provision nodes for an existing cluster.
To grab a copy of the cluster configuration file (normally
ceph.conf
):
ceph-deploy config pull HOST
You will usually also want to gather the encryption keys used for that cluster:
ceph-deploy gatherkeys MONHOST
At this point you can skip the steps below that create a new cluster (you already have one) and optionally skip installation and/or monitor creation, depending on what you are trying to accomplish.
Creating a new cluster
Creating a new configuration
To create a new configuration file and secret key, decide what hosts
will run ceph-mon
, and run:
ceph-deploy new MON [MON..]
listing the hostnames of the monitors. Each MON
can be
- a simple hostname. It must be DNS resolvable without the fully qualified domain name.
- a fully qualified domain name. The hostname is assumed to be the leading component up to the first
.
.- a
HOST:FQDN
pair, of both the hostname and a fully qualified domain name or IP address. For example,foo
,foo.example.com
,foo:something.example.com
, andfoo:1.2.3.4
are all valid. Note, however, that the hostname should match that configured on the hostfoo
.
The above will create a ceph.conf
and ceph.mon.keyring
in your
current directory.
Edit initial cluster configuration
You want to review the generated ceph.conf
file and make sure that
the mon_host
setting contains the IP addresses you would like the
monitors to bind to. These are the IPs that clients will initially
contact to authenticate to the cluster, and they need to be reachable
both by external client-facing hosts and internal cluster daemons.
Installing packages
To install the Ceph software on the servers, run:
ceph-deploy install HOST [HOST..]
This installs the current default stable release. You can choose a different release track with command line options, for example to use a release candidate:
ceph-deploy install --testing HOST
Or to test a development branch:
ceph-deploy install --dev=wip-mds-now-works-no-kidding HOST [HOST..]
Proxy or Firewall Installs
If attempting to install behind a firewall or through a proxy you can
use the --no-adjust-repos
that will tell ceph-deploy to skip any changes
to the distro's repository in order to install the packages and it will go
straight to package installation.
That will allow an environment without internet access to point to its own repositories. This means that those repositories will need to be properly setup (and mirrored with all the necessary dependencies) before attempting an install.
Another alternative is to set the wget
env variables to point to the right
hosts, for example, put following lines into /root/.wgetrc
on each node
(since ceph-deploy runs wget as root):
http_proxy=http://host:port ftp_proxy=http://host:port https_proxy=http://host:port
Deploying monitors
To actually deploy ceph-mon
to the hosts you chose, run:
ceph-deploy mon create HOST [HOST..]
Without explicit hosts listed, hosts in mon_initial_members
in the
config file are deployed. That is, the hosts you passed to
ceph-deploy new
are the default value here.
Gather keys
To gather authenticate keys (for administering the cluster and bootstrapping new nodes) to the local directory, run:
ceph-deploy gatherkeys HOST [HOST...]
where HOST
is one of the monitor hosts.
Once these keys are in the local directory, you can provision new OSDs etc.
Deploying OSDs
To prepare a node for running OSDs, run:
ceph-deploy osd create HOST:DISK[:JOURNAL] [HOST:DISK[:JOURNAL] ...]
After that, the hosts will be running OSDs for the given data disks.
If you specify a raw disk (e.g., /dev/sdb
), partitions will be
created and GPT labels will be used to mark and automatically activate
OSD volumes. If an existing partition is specified, the partition
table will not be modified. If you want to destroy the existing
partition table on DISK first, you can include the --zap-disk
option.
If there is already a prepared disk or directory that is ready to become an OSD, you can also do:
ceph-deploy osd activate HOST:DIR[:JOURNAL] [...]
This is useful when you are managing the mounting of volumes yourself.
Admin hosts
To prepare a host with a ceph.conf
and ceph.client.admin.keyring
keyring so that it can administer the cluster, run:
ceph-deploy admin HOST [HOST ...]
Forget keys
The new
and gatherkeys
put some Ceph authentication keys in keyrings in
the local directory. If you are worried about them being there for security
reasons, run:
ceph-deploy forgetkeys
and they will be removed. If you need them again later to deploy additional nodes, simply re-run:
ceph-deploy gatherkeys HOST [HOST...]
and they will be retrieved from an existing monitor node.
Multiple clusters
All of the above commands take a --cluster=NAME
option, allowing
you to manage multiple clusters conveniently from one workstation.
For example:
ceph-deploy --cluster=us-west new vi us-west.conf ceph-deploy --cluster=us-west mon
FAQ
Before anything
Make sure you have the latest version of ceph-deploy
. It is actively
developed and releases are coming weekly (on average). The most recent versions
of ceph-deploy
will have a --version
flag you can use, otherwise check
with your package manager and update if there is anything new.
Why is feature X not implemented?
Usually, features are added when/if it is sensible for someone that wants to
get started with ceph and said feature would make sense in that context. If
you believe this is the case and you've read "what this tool is not" and
still think feature X
should exist in ceph-deploy, open a feature request
in the ceph tracker: http://tracker.ceph.com/projects/ceph-deploy/issues
A command gave me an error, what is going on?
Most of the commands for ceph-deploy
are meant to be run remotely in a host
that you have configured when creating the initial config. If a given command
is not working as expected try to run the command that failed in the remote
host and assert the behavior there.
If the behavior in the remote host is the same, then it is probably not
something wrong with ceph-deploy
per-se. Make sure you capture the output
of both the ceph-deploy
output and the output of the command in the remote
host.
Issues with monitors
If your monitors are not starting, make sure that the {hostname}
you used
when you ran ceph-deploy mon create {hostname}
match the actual hostname -s
in the remote host.
Newer versions of ceph-deploy
should warn you if the results are different
but that might prevent the monitors from reaching quorum.
Developing ceph-deploy
Now that you have cracked your teeth on Ceph, you might find that you want to contribute to ceph-deploy.
Resources
Bug tracking: http://tracker.ceph.com/projects/ceph-deploy/issues
Mailing list and IRC info is the same as ceph http://ceph.com/resources/mailing-list-irc/
Submitting Patches
Please add test cases to cover any code you add. You can test your changes
by running tox
(You will also need mock
and pytest
) from inside
the git clone
When creating a commit message please use git commit -s
or otherwise add
Signed-off-by: Your Name <email@address.dom>
to your commit message.
Patches can then be submitted by a pull request on GitHub.