Quickstart for CentOS

This is a complete getting started guide for CentOS. With this document you should be able to install a Bcfg2 server and a Bcfg2 client.

Install Bcfg2

The fastest way to get Bcfg2 onto your system is to use Yum or your preferred package management tool. We’ll be using the ones that are distributed through EPEL, but depending on your aversion to risk you could download an RPM from other places as well. See Using Bcfg2 With CentOS for information about building Bcfg2 from source and making your own packages.

Using EPEL

Make sure EPEL is a valid repository on your server. The instructions on how to do this basically say:

[root@centos ~]# rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm

Note

You will have to adjust this command to match your architecture and the current EPEL release.

Install the bcfg2-server and bcfg2 RPMs:

[root@centos ~]# yum install bcfg2-server bcfg2

Your system should now have the necessary software to use Bcfg2. The next step is to set up your Bcfg2 repository.

Initialize your repository

Now that you’re done with the install, you need to initialize your repository and setup your /etc/bcfg2.conf. bcfg2-admin init is a tool which allows you to automate this:

[root@centos ~]# bcfg2-admin init
Store bcfg2 configuration in [/etc/bcfg2.conf]:
Location of bcfg2 repository [/var/lib/bcfg2]:
Input password used for communication verification (without echoing; leave blank for a random):
What is the server's hostname: [centos]
Input the server location [https://centos:6789]:
Input base Operating System for clients:
1: Redhat/Fedora/RHEL/RHAS/Centos
2: SUSE/SLES
3: Mandrake
4: Debian
5: Ubuntu
6: Gentoo
7: FreeBSD
: 1
Generating a 2048 bit RSA private key
.........................+++
..................+++
writing new private key to '/etc/bcfg2.key'
-----
Signature ok
subject=/C=US=ST=Illinois/L=Argonne/CN=centos
Getting Private key
Repository created successfuly in /var/lib/bcfg2

Change responses as necessary.

Start the server

You are now ready to start your bcfg2 server for the first time:

[root@centos ~]# /sbin/service bcfg2-server start

To verify that everything started ok, look for the running daemon and check the logs:

[root@centos ~]# /etc/init.d/service bcfg2-server status
[root@centos ~]# tail /var/log/messages
Mar 29 12:42:26 centos bcfg2-server[5093]: service available at https://centos:6789
Mar 29 12:42:26 centos bcfg2-server[5093]: serving bcfg2-server at https://centos:6789
Mar 29 12:42:26 centos bcfg2-server[5093]: serve_forever() [start]
Mar 29 12:42:41 centos bcfg2-server[5093]: Handled 16 events in 0.007s

Run bcfg2 to be sure you are able to communicate with the server:

[root@centos ~]# bcfg2 -vqn
No ca is specified. Cannot authenticate the server with SSL.
No ca is specified. Cannot authenticate the server with SSL.
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Excluding Packages in global exclude list
Finished
Loaded tool drivers:
 Action Chkconfig POSIX YUMng

Phase: initial
Correct entries: 0
Incorrect entries: 0
Total managed entries: 0
Unmanaged entries: 208


Phase: final
Correct entries: 0
Incorrect entries: 0
Total managed entries: 0
Unmanaged entries: 208

No ca is specified. Cannot authenticate the server with SSL.

The ca message is just a warning, meaning that the client does not have sufficient information to verify that it is talking to the correct server. This can be fixed by distributing the ca certificate from the server to all clients. By default, this file is available in /etc/bcfg2.crt on the server. Copy this file to the client (with a bundle) and add the ca option to bcfg2.conf pointing at the file, and the client will be able to verify it is talking to the correct server upon connection:

[root@centos ~]# cat /etc/bcfg2.conf


[communication]
protocol = xmlrpc/ssl
password = N41lMNeW
ca = /etc/bcfg2.crt

[components]
bcfg2 = https://centos:6789

Now if you run the client, no more warning:

[root@centos ~]# bcfg2 -vqn
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Excluding Packages in global exclude list
Finished
Loaded tool drivers:
 Action Chkconfig POSIX YUMng

Phase: initial
Correct entries: 0
Incorrect entries: 0
Total managed entries: 0
Unmanaged entries: 208


Phase: final
Correct entries: 0
Incorrect entries: 0
Total managed entries: 0
Unmanaged entries: 208

Bring your first machine under Bcfg2 control

Now it is time to get your first machine’s configuration into your Bcfg2 repository. Let’s start with the server itself.

Setup the Packages plugin

First, replace Pkgmgr with Packages in the plugins line of bcfg2.conf. Then create Packages layout (as per Example usage) in /var/lib/bcfg2

Note

I am using the RawURL syntax here since we are using mrepo to manage our yum mirrors.

<Sources>
        <!-- CentOS (5.4) sources -->
        <Source type="yum" rawurl="http://mrepo/centos5-x86_64/RPMS.os">
                <Arch>x86_64</Arch>
        </Source>
        <Source type="yum" rawurl="http://mrepo/centos5-x86_64/RPMS.updates">
                <Arch>x86_64</Arch>
        </Source>
        <Source type="yum" rawurl="http://mrepo/centos5-x86_64/RPMS.extras">
                <Arch>x86_64</Arch>
        </Source>
</Sources>

Due to the “Magic Groups”, we need to modify our Metadata. Let’s add a centos5.4 group which inherits a centos group (this should replace the existing redhat group) present in /var/lib/bcfg2/Metadata/groups.xml. The resulting file should look something like this

Note

The reason we are creating a release-specific group in this case is that the YUMSource above is specific to the 5.4 release of centos. That is, it should not apply to other releases (5.1, 5.3, etc).

<Groups version='3.0'>
   <Group profile='true' public='true' default='true' name='basic'>
      <Group name='centos-5.4'/>
   </Group>
   <Group name='centos-5.4'>
      <Group name='centos'/>
   </Group>
   <Group name='ubuntu'/>
   <Group name='debian'/>
   <Group name='freebsd'/>
   <Group name='gentoo'/>
   <Group name='centos'/>
   <Group name='suse'/>
   <Group name='mandrake'/>
   <Group name='solaris'/>
</Groups>

Note

When editing your xml files by hand, it is useful to occasionally run bcfg2-lint to ensure that your xml validates properly.

The final thing we need is for the client to have the proper arch group membership. For this, we will make use of the Dynamic Group Assignment capabilities of the Probes plugin. Add Probes to your plugins line in bcfg2.conf and create the Probe.:

[root@centos ~]# grep plugins /etc/bcfg2.conf
plugins = Base,Bundler,Cfg,...,Probes
[root@centos ~]# mkdir /var/lib/bcfg2/Probes
[root@centos ~]# cat /var/lib/bcfg2/Probes/groups
#!/bin/sh

echo "group:`uname -m`"

Now we restart the bcfg2-server:

[root@centos ~]# /etc/init.d/bcfg2-server restart

If you now tail -f /var/log/messages, you will see the Packages plugin in action, updating the cache.

Start managing packages

Add a base-packages bundle. Let’s see what happens when we just populate it with the yum package.

[root@centos ~]# cat /var/lib/bcfg2/Bundler/base-packages.xml
<Bundle name='base-packages'>
        <Package name='yum'/>
</Bundle>

You need to reference the bundle from your Metadata. The resulting profile group might look something like this

<Group profile='true' public='true' default='true' name='basic'>
   <Bundle name='base-packages'/>
   <Group name='centos5.4'/>
</Group>

Now if we run the client, we can see what this has done for us.:

[root@centos ~]# bcfg2 -vqn
Running probe groups
Probe groups has result:
x86_64
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Excluding Packages in global exclude list
Finished
Loaded tool drivers:
 Action Chkconfig POSIX YUMng
        Package pam failed verification.

Phase: initial
Correct entries: 94
Incorrect entries: 1
Total managed entries: 95
Unmanaged entries: 113

In dryrun mode: suppressing entry installation for:
  Package:pam

Phase: final
Correct entries: 94
Incorrect entries: 1
 Package:pam
Total managed entries: 95
Unmanaged entries: 113

Interesting, our pam package failed verification. What does this mean? Let’s have a look:

[root@centos ~]# rpm --verify pam
....L... c /etc/pam.d/system-auth

Sigh, it looks like the default RPM install for pam fails to verify using its own verification process (trust me, it’s not the only one). At any rate, I was able to get rid of this particular issue by removing the symlink and running yum reinstall pam.

As you can see, the Packages plugin has generated the dependencies required for the yum package automatically. The ultimate goal should be to move all the packages from the Unmanaged entries section to the Managed entries section. So, what exactly are those Unmanaged entries?:

[root@centos ~]# bcfg2 -veqn
Running probe groups
Probe groups has result:
x86_64
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Excluding Packages in global exclude list
Finished
Loaded tool drivers:
 Action Chkconfig POSIX YUMng
Extra Package openssh-clients 4.3p2-36.el5_4.4.x86_64.
Extra Package libuser 0.54.7-2.1el5_4.1.x86_64.
...

Phase: initial
Correct entries: 95
Incorrect entries: 0
Total managed entries: 95
Unmanaged entries: 113


Phase: final
Correct entries: 95
Incorrect entries: 0
Total managed entries: 95
Unmanaged entries: 113
 Package:at
 Package:avahi
 Package:avahi-compat-libdns_sd
 ...

Now you can go through these and continue adding the packages you want to your Bundle. After a while, I ended up with a minimal bundle that looks like this

<Bundle name='base-packages'>
        <Package name='bcfg2-server'/>
        <Package name='exim'/>
        <Package name='grub'/>
        <Package name='kernel'/>
        <Package name='krb5-workstation'/>
        <Package name='m2crypto'/>
        <Package name='openssh-clients'/>
        <Package name='openssh-server'/>
        <Package name='prelink'/>
        <Package name='redhat-lsb'/>
        <Package name='rpm-build'/>
        <Package name='rsync'/>
        <Package name='sysklogd'/>
        <Package name='vim-enhanced'/>
        <Package name='yum'/>
</Bundle>

Now when I run the client, you can see I have only one unmanaged package:

[root@centos ~]# bcfg2 -veqn
Running probe groups
Probe groups has result:
x86_64
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Excluding Packages in global exclude list
Finished
Loaded tool drivers:
 Action Chkconfig POSIX YUMng
Extra Package gpg-pubkey e8562897-459f07a4.None.
Extra Package gpg-pubkey 217521f6-45e8a532.None.

Phase: initial
Correct entries: 187
Incorrect entries: 0
Total managed entries: 187
Unmanaged entries: 16


Phase: final
Correct entries: 187
Incorrect entries: 0
Total managed entries: 187
Unmanaged entries: 16
 Package:gpg-pubkey
 Service:atd
 Service:avahi-daemon
 Service:bcfg2-server
 ...

The gpg-pubkey packages are special in that they are not really packages. Currently, the way to manage them is using BoundEntries. So, after adding them, our Bundle now looks like this

Note

This does not actually control the contents of the files, you will need to do this part separately (see below).

<Bundle name='base-packages'>
        <BoundPackage name="gpg-pubkey" type="rpm" version="foo">
                        <Instance simplefile="/etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5" version="e8562897" release="459f07a4"/>
                        <Instance simplefile="/etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL" version="217521f6" release="45e8a532"/>
        </BoundPackage>
        <Package name='bcfg2-server'/>
        <Package name='exim'/>
        <Package name='grub'/>
        <Package name='kernel'/>
        <Package name='krb5-workstation'/>
        <Package name='m2crypto'/>
        <Package name='openssh-clients'/>
        <Package name='openssh-server'/>
        <Package name='prelink'/>
        <Package name='redhat-lsb'/>
        <Package name='rpm-build'/>
        <Package name='rsync'/>
        <Package name='sysklogd'/>
        <Package name='vim-enhanced'/>
        <Package name='yum'/>
</Bundle>

Note

version=”foo” is just a dummy attribute for the gpg-pubkey Package

To actually push the gpg keys out via Bcfg2, you will need to manage the files as well. This can be done by adding Path entries for each of the gpg keys you want to manage

<Bundle name='base-packages'>
        <Path name='/etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5'/>
        <Path name='/etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL'/>
        <BoundPackage name="gpg-pubkey" type="rpm" version="foo">
                        <Instance simplefile="/etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5" version="e8562897" release="459f07a4"/>
                        <Instance simplefile="/etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL" version="217521f6" release="45e8a532"/>
        </BoundPackage>
        <Package name='bcfg2-server'/>
        <Package name='exim'/>
        <Package name='grub'/>
        <Package name='kernel'/>
        <Package name='krb5-workstation'/>
        <Package name='m2crypto'/>
        <Package name='openssh-clients'/>
        <Package name='openssh-server'/>
        <Package name='prelink'/>
        <Package name='redhat-lsb'/>
        <Package name='rpm-build'/>
        <Package name='rsync'/>
        <Package name='sysklogd'/>
        <Package name='vim-enhanced'/>
        <Package name='yum'/>
</Bundle>

Then add the files to Cfg:

mkdir -p Cfg/etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
cp /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5 !$/RPM-GPG-KEY-CentOS-5
mkdir -p Cfg/etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL
cp /etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL !$/RPM-GPG-KEY-EPEL

You will also want to add an important attribute to these files so that they are installed on the client prior to any attempts to install the gpg-pubkey rpm packages. This is especially important during the bootstrapping phase and can be accomplished using an info.xml file that looks like the following:

<FileInfo>
    <Info owner='root' group='root' mode='0644' important='true'/>
</FileInfo>

Now, running the client shows only unmanaged Service entries. Woohoo!

Manage services

Now let’s clear up the unmanaged service entries by adding the following entries to our bundle.

<!-- basic services -->
<Service name='atd'/>
<Service name='avahi-daemon'/>
<Service name='bcfg2-server'/>
<Service name='crond'/>
<Service name='cups'/>
<Service name='gpm'/>
<Service name='lvm2-monitor'/>
<Service name='mcstrans'/>
<Service name='messagebus'/>
<Service name='netfs'/>
<Service name='network'/>
<Service name='postfix'/>
<Service name='rawdevices'/>
<Service name='sshd'/>
<Service name='syslog'/>

...and bind them in Rules

[root@centos ~]# cat /var/lib/bcfg2/Rules/services.xml
<Rules priority='1'>
        <!-- basic services -->
        <Service type='chkconfig' status='on' name='atd'/>
        <Service type='chkconfig' status='on' name='avahi-daemon'/>
        <Service type='chkconfig' status='on' name='bcfg2-server'/>
        <Service type='chkconfig' status='on' name='crond'/>
        <Service type='chkconfig' status='on' name='cups'/>
        <Service type='chkconfig' status='on' name='gpm'/>
        <Service type='chkconfig' status='on' name='lvm2-monitor'/>
        <Service type='chkconfig' status='on' name='mcstrans'/>
        <Service type='chkconfig' status='on' name='messagebus'/>
        <Service type='chkconfig' status='on' name='netfs'/>
        <Service type='chkconfig' status='on' name='network'/>
        <Service type='chkconfig' status='on' name='postfix'/>
        <Service type='chkconfig' status='on' name='rawdevices'/>
        <Service type='chkconfig' status='on' name='sshd'/>
        <Service type='chkconfig' status='on' name='syslog'/>
</Rules>

Now we run the client and see there are no more unmanaged entries!:

[root@centos ~]# bcfg2 -veqn
Running probe groups
Probe groups has result:
x86_64
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Excluding Packages in global exclude list
Finished
Loaded tool drivers:
 Action Chkconfig POSIX YUMng

Phase: initial
Correct entries: 205
Incorrect entries: 0
Total managed entries: 205
Unmanaged entries: 0


Phase: final
Correct entries: 205
Incorrect entries: 0
Total managed entries: 205
Unmanaged entries: 0

Warning

This basic bundle is created mainly for the purposes of getting you to a completely managed client. It is recommended that you create bundles for appropriate services due to the way bundle updates are managed. Please see Writing Bcfg2 Specification for more details.

Dynamic (web) reports

See installation instructions at Bcfg2 Web Reporting System

Next Steps

Next Steps