Author: | Nathan Cutler |
---|---|
Code license: | BSD 3 Clause |
Documentation license: | Creative Commons Attribution-ShareAlike (CC BY-SA) |
Contents
- Acknowledgements
- Introduction
- Prerequisites and assumptions
- Early steps
- Configuration
- Virtual Private Cloud
- Subnets
- Role and cluster definition
- Keypairs
- Delegates
- Stop and start clusters
- Wipeout clusters
- Spin up a Delegate Cluster
- Lessons Learned from Snow Unix 2016
- Other miscellaneous notes
- Logging user-data script output
- SaltStack notes
- Windows change administrator password via user-data script
Several parts of this application - especially the command-line interface design and code - are derived from Loic Dachary's work in ceph-workbench.
This document describes the ceph-auto-aws software for automating deployment of Ceph clusters in Amazon Web Services (AWS) - specifically the Elastic Computing Cloud (EC2) and Virtual Private Cloud (VPC) services.
The software enables an arbitrary number of identical clusters from 1 to 251 to be so deployed.
So far, the software has been used in "hands-on" sessions, to provide each attendee with their own cluster to play with. It could also facilitate deployment of one-off clusters to test various Ceph configurations.
Scripting is provided for automating the provisioning of:
- a VPC instance
- subnets within the VPC
- cluster instances (nodes) within each subnet
- Salt Master instance (used to control the cluster instances)
The scripting is written in Python and relies on boto ("An integrated interface to current and future infrastructural services offered by Amazon Web Services") and SaltStack (a configuration management and distributed remote execution system).
Configuration and state are stored in YAML file. YAML is a human friendly data serialization standard for all programming languages.
We assume that you have access to Amazon Web Services (AWS) Elastic Computing Cloud (EC2) and Virtual Private Cloud (VPC). That means you can login via a web browser and access the EC2 and VPC dashboards.
We further assume that you have a relatively recent version of Python and virtualenv installed on your system. On openSUSE, Python should already be installed and installing virtualenv should be as simple as running the following command as root:
# zypper install python-virtualenv
If something in this software (or this document) doesn't work for you, open a bug report in the GitHub issue tracker:
If you are already logged in as an AWS IAM user, you can skip this section.
Set up an IAM user using the Creating an IAM User in Your AWS Account section of the AWS documentation.
We placed our user in the "ec2_full_access" group.
Access to AWS via boto requires an access key (Access Key ID and Secret Access Key). For detailed instructions, see the Getting Your Access Key ID and Secret Access Key section of the AWS documentation.
The access key comes in a file called "credentials.csv". Put this in a safe place.
Put your AWS credentials in ~/.boto
as described in the
Configuring boto credentials section of the boto documentation.
Sample ~/.boto
file:
[Credentials] aws_access_key_id = [gobbledygook] aws_secret_access_key = [even_longer_gobbledygook]
Clone this repo to your local machine:
$ git clone https://github.com/smithfarm/ceph-auto-aws
All of the following instructions assume you are in the directory containing the local clone.
This software is designed to be installed in the standalone virtual Python environment, implemented with virtualenv.
Installation is a two-step process. First, run the bootstrap
script:
$ ./bootstrap
This installs the virtual environment in the virtualenv/
directory. The
second step is to activate the virtualenv. The shell prompt changes to
indicate that the virtual environment is active:
$ source virtualenv/bin/activate (virtualenv)$
Use the deactivate
command to leave:
(virtualenv)$ deactivate $
All scripting features are implemented as subcommands of a single script:
ho
(an abbreviation of "hands-on"):
(virtualenv)$ ho --help
Run the following command to test whether you have your AWS credentials in order:
(virtualenv)$ ho probe aws 2016-03-27 20:30:16,554 INFO Connected to AWS EC2
Interaction with AWS is controlled by a configuration file called aws.yaml
.
By default, this file is searched for in the current directory. If it is not
found, a new one will be created.
We assume that you are starting from scratch. To get started, run the following command:
(virtualenv)$ ho probe yaml 2016-03-30 21:35:12,105 INFO Probing 'subnets' stanza 2016-03-30 21:35:12,105 INFO Loaded yaml tree from './aws.yaml' 2016-03-30 21:35:12,106 INFO Probing 'keyname' stanza 2016-03-30 21:35:12,106 INFO Probing 'vpc' stanza 2016-03-30 21:35:12,108 INFO Probing 'role-definitions' stanza 2016-03-30 21:35:12,111 INFO Detected roles ['admin', 'windows', 'master', 'mon', 'defaults', 'osd'] 2016-03-30 21:35:12,111 INFO Probing 'region' stanza 2016-03-30 21:35:12,113 INFO Probing 'cluster-definition' stanza 2016-03-30 21:35:12,115 INFO Detected cluster-definition stanza 2016-03-30 21:35:12,115 INFO Detected role 'admin' in cluster definition 2016-03-30 21:35:12,115 INFO Probing 'delegates' stanza 2016-03-30 21:35:12,117 INFO Probing 'types' stanza 2016-03-30 21:35:12,117 INFO YAML tree is sane
You can see that the YAML file has been created:
(virtualenv)$ file aws.yaml aws.yaml: ASCII text
You can run ho probe yaml
anytime to check your configuration file, and
especially after any manual modifications.
The next step is to configure the AWS Region. The default is eu-west-1
,
i.e. "EU (Ireland)". If you want to use a different region, edit the YAML file
(aws.yaml
in current directory) and edit the following line:
region: availability_zone: region_str: eu-west-1
If you don't care about the availability zone, just leave it unset. AWS will assign one.
If you want to set an availability zone, you must do so before subnets are
created, since subnets exist within an availability zone. Once subnets are
created the availability zone cannot be changed (or, more accurately, it can
be changed but ho install delegates
will then fail because of the
availability zone mismatch).
Next, verify that you can connect to that region by running the command:
(virtualenv)$ ho probe region 2016-10-18 13:51:58,156 INFO Loaded yaml tree from './aws.yaml' 2016-10-18 13:51:58,156 INFO Testing connectivity to AWS Region {'region_str': 'us-east-1', 'availability_zone': None} 2016-10-18 13:51:58,404 INFO Detected 5 VPCs 2016-10-18 13:51:58,404 INFO Availability zone not set in YAML
To ensure that our demo clusters do not interfere with other AWS projects, we use a Virtual Private Cloud (VPC) containing a number of subnets.
All the delegates will share a single VPC 10.0.0.0/16. Within that VPC there
will be a /24
subnet for each delegate, plus one for the Salt Master.
The Salt Master resides in its own subnet: 10.0.0.0/24.
Each delegate will be assigned a number, e.g. 12. The subnet of delegate 12 will be 10.0.12.0/24.
If you are setting up a VPC for the first time, run the following command to create one:
(virtualenv)$ ho install vpc 2016-03-30 23:20:34,407 INFO Loaded yaml tree from './aws.yaml' 2016-03-30 23:20:34,686 INFO New VPC ID vpc-cfd7c9aa created with CIDR block 10.0.0.0/16 2016-03-30 23:20:34,816 INFO Object VPC:vpc-cfd7c9aa tagged with Name=handson
Once the VPC has been created, the vpc
stanza will look like this:
vpc: cidr_block: 10.0.0.0/16 id: cfd7c9aa
Note that ho install vpc
is idempotent: you can run it as many times as you
want. Try running it a second time:
(virtualenv)$ ho install vpc 2016-03-30 23:22:00,612 INFO Loaded yaml tree from './aws.yaml' 2016-03-30 23:22:00,613 INFO VPC ID according to yaml is vpc-cfd7c9aa 2016-03-30 23:22:00,907 INFO VPC ID is vpc-cfd7c9aa, CIDR block is 10.0.0.0/16
Any other output (and especially any traceback) probably means your VPC is not set up properly.
Initially, the VPC will not have an Internet Gateway, and so it will not be able to communicate with the outside world in any way (regardless of Security Group settings in any instances running inside the VPC). This includes SSH access into the VPC from outside.
The fact that VPCs are by default completely isolated from the outside world is by design, but it is not appropriate for a hands-on demonstration.
To remedy this, first create an Internet Gateway and attach it to the VPC.
The steps to create the internet gateway are explained in detail at the aws official docs. You can create an internet gateway from https://console.aws.amazon.com/vpc/ and add it to the the vpc (handson by default) created from the previous steps.
WARNING: The scripting does not do this step for you!
Even with the Internet Gateway in place, no packets originating from the VPC will be routed to the outside until a default route is added. This is because the default Route Table looks like this:
Destination | Target | Status | Propagated |
---|---|---|---|
10.0.0.0/16 | local | Active | No |
Add a "default route" line to this table, so it looks like this:
Destination | Target | Status | Propagated |
---|---|---|---|
10.0.0.0/16 | local | Active | No |
0.0.0.0/0 | igw-... | Active | No |
WARNING: The scripting does not do this step for you!
Network ACLs are like firewalls at the subnet level. For more information, see the Network ACLs chapter of the AWS documentation.
Even with the Internet Gateway and the Route Table set up, networking may still not work as expected inside the VPC. If this is the case, check if there is a Network ACL associated with your VPC, and check the settings:
"Security" -> "Network ACLs" in VPC Dashboard
WARNING: The scripting does not do this step for you!
Security Groups are like firewalls at the instance (individual VM) level. For more information, see the Security Groups for Your VPC chapter of the AWS documentation.
Even with the Internet Gateway and the Route Table set up, and Network ACL wide open (or disabled), you will still not be able to ping your AWS nodes unless you edit the Inbound Rules table of your VPC's default Security Group.
You will find it under:
"Security" -> "Security Groups" in VPC Dashboard
By default, the Inbound Rules table will look like this:
Type | Protocol | Port Range | Source |
---|---|---|---|
ALL Traffic | ALL | ALL | sg-... |
Note that only packets originating from within the same Security Group are accepted. All others are dropped.
Edit the line so Source is set to 0.0.0.0/0
:
Type | Protocol | Port Range | Source |
---|---|---|---|
ALL Traffic | ALL | ALL | 0.0.0.0/0 |
Such a setup means the machines in your VPC will be exposed to scanning, and if they have any unpatched vulnerabilities evil people might take control of them.
To address this, replace the 0.0.0.0/0
line in the Inbound Rules table with
lines covering all the public network segments from which people will be
accessing your VPC.
WARNING: The scripting does not do this step for you!
As explained in the introduction to the Virtual Private Cloud chapter,
each delegate will have their own "Class C" /24
virtual network, or
"subnet".
Initially, the subnets
stanza of your aws.yaml
file should be empty:
subnets: {}
Do not add anything here: the scripting will create subnets automatically based
on the number of delegates given in the delegates
stanza, e.g.:
delegates: 1
If you want more than one cluster, change the delegates
stanza in the YAML
file now.
To ensure that the subnets are created for each delegate plus the Salt Master, you should run:
(virtualenv)$ ho install subnets --all --master 2016-04-03 07:59:03,992 INFO Loaded yaml tree from './aws.yaml' 2016-04-03 07:59:03,992 INFO Delegate list is [0, 1] 2016-04-03 07:59:03,992 INFO Installing subnet for delegate 0 ...
This will create a 10.0.0.0/24
subnet for the Salt Master and one
additional /24
for each delegate (one in the default case). It will also
add the appropriate tags to the subnet objects.
Like ho install vpc
, this command is idempotent.
AWS reserves both the first four IP addresses and the last IP address in
each subnet's CIDR block. For example, in the 10.0.0.0/24
subnet, these IP
addresses are not available for use:
- 10.0.0.0: Network address.
- 10.0.0.1: Reserved by AWS for the VPC router.
- 10.0.0.2: Reserved by AWS for mapping to the Amazon-provided DNS.
- 10.0.0.3: Reserved by AWS for future use.
- 10.0.0.255: Network broadcast address. We do not support broadcast in a VPC, therefore we reserve this address.
For this reason, instances must not be assigned last_octet
values 0, 1, 2,
3, or 255.
Once the subnets are set up, the next step is to define the cluster each delegate will receive.
This software assumes that each delegate will have one cluster and all the clusters will be identical.
Each cluster consists of some number of instances, and each instance has a "role" that it plays in the cluster.
NOTE: As far as this software is concerned, the term "role" is interchangeable with "node", "instance" or "virtual machine"!
Before you can install a cluster (or twelve!), you must first edit the cluster definition and role definitions in the yaml.
Roles are defined in the role-definitions
stanza of the YAML. This stanza
is a mapping, the keys of which are the names of the respective roles.
There are two special roles: defaults
and master
. The former defines
the set of permissible role attributes and their default values. The latter
defines the attributes of the Salt Master node.
Each role definition may contain one or more of the following attributes:
Role definition attribute | Description |
---|---|
ami-id | AMI ID of image from which to create the instance |
last-octet | value of last octet of instance IP address (10.0.0.x) |
node-no | arbitrary number that can optionally be associated with a node |
replace-from-environment | FIXME |
type | the Instance Type |
user-data | file containing user-data |
volume | disk volume to be attached to the instance (optional) |
If you are setting up a hands-on, now would be a good time to define your roles. The following sections should help.
The ami-id
is the ID of the Amazon Machine Image (AMI) to use when
provisioning the node. Basically, it should be a recent Linux image that you
are capable of installing Ceph on.
This attribute should be an integer value between 4 and 254 (inclusive) - see
Subnet caveat. Together with the delegate number, it determines the IP
address of the node. For example, if the delegate number is 3 and
last-octet
is 8, the IP address will be 10.0.3.8/24
.
This is an entirely optional value that can be associated with a node. This
number determines what @@NODE_NO@@
in the user-data will be replaced with.
FIXME
This determines the Instance Type of the node. If all the nodes will have
the same Instance Type, you can just set it once in the defaults
section.
It does not need to be set individually for each role.
The instance types are described at https://aws.amazon.com/ec2/instance-types/
I am using t2.small for cluster nodes and t2.micro for the Salt Master. Both are single CPU, t2.small has 2 GB of memory and t2.micro has 1 GB.
There are two "types" of instance types: "ebs" and "paravirtual". All the t2.xxx types are EBS-only. EBS stands for "Elastic Block Store". This is important to know if you make a snapshot and want to create an AMI from that snapshot. (Also, I think any volumes you create must be EBS if you want to use them with t2.xxx instances.)
After the image boots for the first time, we need to run a custom setup script. In Cloud terminology this is known as "user-data". Often the user-data takes form of "cloud-init" YAML. However, with AWS it can be an ordinary shell script.
For testing, you can type or cut-and-paste user-data in the web console, into the box located at the very bottom of the "3. Configure Instance" dialog, hidden under "Advanced Details".
Once you have developed just the right user-data for your application, put it
in a file, and set the user-data
YAML attribute to the absolute or relative
path to this file. Whatever it is, the user-data
in that file will be run
in the instance when it first launches. See Running Commands on Your Linux
Instance at Launch.
This value is optional in the sense that ho
will instantiate nodes without
it, but you will probably need it if you want to automate the process of
installing and starting the Salt Minion service on the nodes.
Each node has a root volume, the size of which is defined by the Instance Type (VERIFY). This is sufficient for admin nodes and monitor-only nodes. If you want to run an OSD on a node, though, a separate volume will be necessary. Typically this will be an Amazon Elastic Block Store (EBS) volume.
The volume
attribute takes an integer value which is interpreted as the
volume size in Gigabytes.
If the attribute is missing, or has no value, or has a zero value, no separate volume is created.
Once you have defined the roles, the next step is to stipulate the set of roles that will constitute a cluster. Remember, each delegate will get one cluster (one set of roles).
The cluster is defined in the cluster-definition
stanza of the yaml. This
stanza consists of a "collection" (list, array) of instance definitions. Each
instance definition must contain a role
attribute defining the instance
role, which should be a very short string (e.g., "mon1") describing the role
this instance will play in the cluster.
The value of each role
attribute must match one of roles defined in the
role-definitions
YAML stanza (see Role definitions).
For example, a reasonable demo cluster might consist of three MON/OSD nodes
(roles mon1
, mon2
, and mon3
, respectively) and an "admin node" with
a public IP address:
cluster-definition: - role: admin - role: mon1 - role: mon2 - role: mon3
Provided the roles are properly defined in the role-definitions
stanza,
this is a legal cluster definition.
Before you actually try to spin up a cluster, it's a good idea to validate your YAML:
(virtualenv)$ ho probe yaml
This command loads the YAML file and performs various validations checks,
including basic sanity checks on the cluster-definition
and
role-definitions
stanzas.
Before you spin up any Delegate Clusters, you will need to generate delegate (SSH) keypairs and import them to AWS.
The keyname
stanza in the YAML file determines how the keypairs will be
named. If you do nothing, it will be set to your username. If your username is
"regnaw", the Salt Master's keypair will be named regnaw-d0
, Delegate 1's
keypair will be regnaw-d1
, etc.
If you want the keypair names to be based on some other string, just set the
keyname
attribute in the YAML file before continuing.
Each delegate will have its own keypair. To generate keypairs for all the delegates, do:
$ ./generate-keys.sh
Then, to import them into AWS, do:
$ ho install keypairs --all --master
When newly instantiated nodes boot up for the first time, a script called
user-data
is run as root. The idea is for this script to bring the nodes
into a "SaltStack-ready" state - i.e. Salt Master service running on the Salt
Master node, Salt Minion services running on the Delegate Cluster nodes, and
minions communicating with, and accepting orders from, the Salt Master. SSH
access should also be possible using the respective delegate keypair.
To get Ceph running on the cluster nodes, additional steps are necessary. These steps are accomplished by running SaltStack commands on the Salt Master node.
At this point, you should have completed the following steps:
ho probe aws
ho probe yaml
ho probe region
ho install vpc
- create Internet Gateway in VPC Console
ho install subnets --all --master
- define roles (by editing the YAML file)
- define cluster (by editing the YAML file)
./generate-keys.sh
ho install keypairs --all --master
- write user-data script for the Salt Master
- set
user-data
attribute ofmaster
role to filename of Salt Master user-data script - write user-data scripts for all your roles
- set
user-data
attribute of all roles to the appropriate filename
Now you are ready to instantiate nodes. We start with the Salt Master node.
Delegate 0 is the Salt Master, but we do not write, e.g., ho install delegates
0
. Instead, we pass the --master
option like so:
$ ho install delegates --master
It is a good idea to wait until the Salt Master boots up for the first time and finishes running its user-data script before installing any Delegate Clusters.
This software is capable of automating the installation of multiple Delegate
Clusters - up to the number set in the delegates
stanza of the YAML file.
If you are just testing the software, it's probably a good idea not to set
delegates
too high. You could set a value of 1 to start with:
cluster-definition: - role: admin delegates: 1 ...
The delegates
stanza limits the number of clusters that can be instantiated
at once (or at all). A value of 1 means that the ho install delegates
command will only take an argument of 1. Any other argument will fail. If you
specify --all
, it will mean 1.
With the above YAML a single Delegate Cluster will be installed when you run:
$ ho install delegates 1
The cluster will consist of a single admin node which will be instantiated in
the 10.0.1.0/24
subnet.
Automatically, each cluster instance will be tagged as follows:
Tag | Description |
---|---|
Name | the value of the nametag yaml attribute |
Delegate | the delegate number |
Role | the instance role |
You can stop and start clusters using the ho stop delegates
and ho start
delegates
commands, respectively. "Stop" in this context triggers an orderly
shutdown, so it involves a transition to "powered-off" state. "Start", then, is
conceptually similar to powering up.
For example:
$ ho stop delegates 1 $ ho stop delegates 1,3,5-7 $ ho stop delegates --all $ ho stop delegates --all --master $ ho start delegates 1 $ ho start delegates 1,3,5-7 $ ho start delegates --all $ ho start delegates --all --master
The --master
option adds delegate 0 (the Salt Master) to the list of
delegates to which the operation (start or stop) is applied.
When you are finished with a cluster (or clusters), you can delete it/them by:
$ ho wipeout delegates [DELEGATE_LIST]
where [DELEGATE_LIST]
is something like 1-12
for Delegate Clusters one
through twelve, 5
for Delegate Cluster five, or 1,3,7-9
for Delegate
Clusers one, three, seven, eight, and nine.
Sticking to our minimal example from Install Delegate Clusters, we could wipe out that cluster by:
$ ho wipeout delegates 1
When you are finished with the Salt Master, you can delete it by adding
the --master
option, e.g.:
$ ho wipeout delegates --master
You can wipe out all instances, i.e all Delegate Clusters and the Salt Master, like so:
$ ho wipeout delegates --all --master
NOTE: The wipeout commands discussed in this section remove cluster nodes and EBS volumes only. They do not have any effect on subnets or the VPC. (If needed, those must be wiped out separately.)
Take the following example:
cluster-definition: - role: admin - role: mon1 - role: mon2 - role: mon3 - role: windows ... role-definitions: admin: last-octet: 10 volume: defaults: ami-id: ami-ff63dd8c last-octet: replace-from-environment: [] type: t2.small user-data: data/user-data-minions volume: 20 master: last-octet: 10 user-data: data/user-data-master volume: mon1: last-octet: 11 volume: 20 mon2: last-octet: 12 volume: 20 mon3: last-octet: 13 volume: 20 osd: last-octet: 14 volume: 20 windows: ami-id: ami-c6972fb5 last-octet: 15 user-data: data/user-data-windows volume:
The user-data-minions
script updates each cluster node and adds the repo
containing the latest versions of the ceph
and ceph-deploy
packages.
It also configures and enables the ntp
and salt-minion
services.
One can follow progress of the user-data script on a given node by sshing into the node and doing:
(Cluster Node)# tail -n 100 -f /var/log/cloud-init-output.log
Once all the cluster nodes have finished running their user-data scripts, you can SSH to the Salt Master and list the minion keys:
(Salt Master)# salt-key -L
This shows the unaccepted keys. Accept them by doing:
(Salt Master)# salt-key -A -y
If there are stale keys from clusters that have been wiped out, you can just delete all keys and wait for the live minions to re-connect:
(Salt Master)# salt-key -A -y
The next step is to run the ceph-admin
Salt State on all the nodes. In this
example we are spinning up a cluster for Delegate 2:
(Salt Master)# salt -C "G@delegate:2" state.sls ceph-admin
Examine all the output. If there are failures, just run the command over
again. Once it is completing without any failures, remotely run the
ceph-deploy-sh
Salt State on the admin node to deploy a Ceph cluster:
(Salt Master)# salt -C "G@delegate:2 and G@role:admin" state.sls ceph-deploy-sh
This will take a minute or two to complete. If all goes well, it will succeed. If it fails, you have no choice but to wipe out the delegate and start over.
Of course, the gold standard of a well-functioning Ceph cluster is
HEALTH_OK
. Check the cluster health by running the ceph-s
Salt State:
(Salt Master)# salt -C "G@delegate:2 and G@role:admin" state.sls ceph-s
If you want to fill the cluster partially up with some data, do:
(Salt Master)# salt -C "G@delegate:2 and G@role:mon1" state.sls owen-data-sh
At this point, you can SSH into the Delegate 2 admin node and become user "ceph" by doing:
(Delegate 2 admin node)# su - ceph
The following lessons were learned:
- double-check instance limit
- practice spinning up the full number of delegates (not just once, but several times in a row)
- figure out how best to freeze the state so we no longer run "zypper up", exposing ourselves to the risk of a new kernel, etc. coming out
Once a SLES image boots up, the first thing you need to do is "zypper up". Once nice feature of AWS is that it has its own internal SMT server. However, it takes some seconds after boot for the the associated zypper service to appear. Therefore, we use the following loop in the user-data script:
while sleep 10 ; do zypper services | grep 'SMT-http_smt-ec2_susecloud_net' if [[ $? = 0 ]] ; then break fi done
After that completes, you can assume that the basic repos are available, so you can do "zypper up" as follows:
while sleep 5 ; do zypper -n update if [[ $? = 0 ]] ; then break fi done
Unfortunately, the AWS SMT server only has the basic SLES pool and update repos. No SUSE Enterprise Storage or any other add-ons for that matter. So we have to make our own installation sources. The way I ended up doing that was to loop mount the SES2 GA ISO on the Salt Master and run an apache2 server there to farm it out to the delegate instances.
First, append the ISO to /etc/fstab:
$MEDIA_FULL_PATH /srv/repos/SES2-media1 iso9660 loop 0 0
Second, mount the ISO:
mount /srv/repos/SES2-media1
Third, set up Apache:
# zypper in apache2 # systemctl enable apache2.service # echo "I am a puppet" > /srv/repos/puppet.txt # vim /etc/apache2/vhosts.d/admin.conf <VirtualHost *:80> ServerAdmin presnypreklad@gmail.com ServerName admin DocumentRoot /srv/repos HostnameLookups Off UseCanonicalName Off ServerSignature On <Directory /srv/repos> Options Indexes FollowSymLinks AllowOverride All Require all granted </Directory> </VirtualHost> # systemctl restart apache2.service # curl http://localhost/puppet.txt I am a puppet
Fourth, try the curl command from another machine in the cluster.
Fifth, add the repo on the cluster nodes:
# zypper ar http://localhost/SES2/ SES2 Adding repository 'SES2' ......................................................[done] Repository 'SES2' successfully added Enabled : Yes Autorefresh : No GPG Check : Yes URI : http://localhost/SES2
Sixth, install Ceph packages from the ISO on the cluster nodes (use SaltStack for this).
Source: https://alestic.com/2010/12/ec2-user-data-output/
As the user-data script runs, its output is logged to a file called:
/var/log/cloud-init-output.log
http://stackoverflow.com/questions/8070186/boto-ec2-create-an-instance-with-tags
Ping all machines belonging to a given delegate:
salt -G 'delegate:12' test.ping
Get IP addresses of all machines belonging to the delegate:
salt -G 'delegate:12' network.ip_addrs
Compound match: get IP address of Delegate 12's admin node:
salt -C 'G@delegate:1 and G@role:admin' network.ip_addrs
<script>net user Administrator GieGh7ie</script>