This section describes the customization options/tools for the configuration of Qlustar cluster-nodes.
Dynamic Configuration Settings
As explained above, a number of configuration options are configured dynamically by the QluMan
execution server when a node boots. These settings will be stored either in the file
/etc/qlustar/options or in a separate file in the directory
/etc/qlustar/options.d of the
nodes root filesystem. Usual BASH shell syntax is used for the options.
The settings in
The dhclient process started during the boot process of compute-nodes will configure the IP addresses and other parameters given. By default, only the network interface from which the node boots is managed by DHCP.
Cluster-wide Configuration Directory
/etc/qlustar/common contains cluster-wide configuration files for the nodes. At
an early stage of the boot process, this directory is mounted via NFS from the head-node. If
required, the path on the head-node this directory is exported from, can be
customized with QluMan.
NFS boot scripts
To allow for flexible configuration of compute-nodes, a specific NFS directory
/etc/qlustar/common/rc.boot) is searched for executable scripts in a late phase of the boot
process (after unionFS is fully initialized, so that you can use programs from the chroot here
as well). The scripts found are then executed one by one. You can use this mechanism to perform
arbitrary modifications/customization of the compute node OS.
The scripts placed into
Adding directories, files, links
/lib/qlustar/copy-files, which is also executed at boot, consults a configuration
/etc/qlustar/common/image-files/destinations, where each line describes a directory to
be created, a file to be copied from an NFS path to a local path, or a link that needs to be
created in the RAMdisk. Example:
# remotefile is a path relative to /etc/qlustar/common/image-files # and destdir is the absolute path of the directory where remotefile # should be copied to. mode is used as input to chmod. # Example: # authorized_keys /root/.ssh root:root 600 # Directories /etc/ldap # remotefile destdir owner permissions ssh/authorized_keys /root/.ssh root:root 644 etc/nsswitch.conf /etc root:root 644 etc/ldap.conf /etc root:root 644 etc/timezone /etc root:root 644 # Symbolic links # Source target /l/home /home
This mechanism also allows to specify additional files to be processed by adding an
line like this:
In this example, the file
ldapfile will be consulted just like the
Furthermore, if the file
/etc/qlustar/common/softgroups exists, it may specify a group name
directly (without white-space) followed by a colon, followed by a hostlist. An example
softgroups file may look like this:
version2: beo-[01-04] version3: beo-[05-08]
This will make hosts beo-[01-04] additionally consult the file
/etc/qlustar/common/image-files/destinations.version2 and hosts beo-[05-08] the file
/etc/qlustar/common/image-files/destinations.version3. The group name defined in the
softgroups is the extension to the destinations file. The files could look like this:
# destinations.version2 - use version2 of the program: /apps/local/bin/program.version2 /usr/bin/program # destinations.version3 - use version3 of the program: /apps/local/bin/program.version3 /usr/bin/program
Hence, with this mechanism, you can e.g. have parts of your cluster use different versions of the same program.
Mail Transport Agent
By default the compute-nodes do not send mail. You can however activate the simple MTA ssmtp by assigning the QluMan generic property _Activate Mail to cluster nodes.
The configuration of ssmtp needs to be done in the directory
consists of two files,
ssmtp.conf you should set the
The address to send mail to for users with id less than 1000.
The host to send all mail to.
Make all mail look like originating from this domain.
Allow users to override the domain, must be “yes” or “no”.
The fully qualified name of this host
An example configuration file would be:
Rootemail@example.com Mailhub=relayhost RewriteDomain=domain.com FromLineOverride=Yes Hostname=thishost.domain.com
In the file
revaliases, you can specify how mails to local accounts should be forwarded to
outgoing addresses and which mail server to use. Example:
LDAP integration with sssd
The sssd daemon is used if LDAP integration is required for the cluster. The sssd config file
/etc/sssd/sssd.conf of the head-node is automatically imported into generated Qlustar images,
if one is found. So all you have to do is configure sssd correctly for the head-node, then all
other nodes will have a functioning configuration as well, provided they can reach the LDAP
server specified in the sssd configuration file.
If a different