APEL/SSM/README08

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This is the README file included in ssm-0.8.

Installing and running the SSM
==============================

The Secure Stomp Messenger (SSM) is designed to give a reliable message
transfer mechanism using the STOMP protocol.  Messages are encrypted
during transit, and are sent sequentially, the next message being sent
only when the previous one has been acknowledged.

The SSM is written in python.  It is designed and packaged for SL5.

For more aboupt the SSM, see https://wiki.egi.eu/wiki/APEL/SSM

Installing the RPM
------------------

  Prerequisites
  -------------

The EPEL repository must be enabled.  This can be done by installing
the RPM for your version of SL, which is available on this page:
http://fedoraproject.org/wiki/EPEL

The python stomp library
 * yum install stomppy

The python daemon library
 * yum install python-daemon

You need a certificate and key in PEM format in the following files:
 * /etc/grid-security/hostcert.pem
 * /etc/grid-security/hostkey.pem

If you want to check CRLs when verifying certificates, you need
fetch_crl installed:
 * yum install fetch-crl
 * service fetch-crl-cron start
 * chkconfig fetch-crl-cron on
fetch-crl must have run once for the certificates to be verified
successfully.

 Installation
 ------------

* rpm -i ssm-<version>.noarch.rpm

What the RPM does
-----------------

The RPM carries out a number of steps to run the SSM in a specific way.

1. It installs the core files in /opt/apel/ssm
2. It creates a group 'hostcert', which has read access to the hostkey
3. It creates a user 'apel' with home directory /opt/apel, in the
   hostcert group
4. It installs an init script in /etc/init.d/ssmd
5. It creates the log directory /var/log/apel
6. It creates the pidfile directory /var/run/apel

Running the SSM
---------------

It is recommended to run the SSM only when you need to send messages.
This is so that all SSM clients do not remain connected to the broker
at all times, causing it to slow.

The init script ssmd is designed for the server SSM which must run
continuously.

To run the SSM once:
 * Write all the messages to the /opt/apel/ssm/messages/outgoing directory
 * export SSM_HOME=/opt/apel/ssm
 * $SSM_HOME/bin/run-ssm

Removing the RPM
----------------

 * rpm -e ssm-0.8

Cleaning the system
-------------------

 * yum remove stomppy
 * yum remove python-daemon

 * rm -rf /var/log/apel
 * rm -rf /var/run/apel
 * chown root:root /etc/grid-security/hostkey.pem /etc/grid-security/hostcert.pem
 * chmod 400 /etc/grid-security/hostkey.pem
 * groupdel hostcert
 * userdel apel
 * rm -rf /opt/apel
 * rm -rf /var/spool/mail/apel

Building the RPM
----------------

This is only useful if you want to modify the spec file to build a different RPM,
and you have a zip of the SSM source.

It's recommended to build RPMs as a user other than root.  This user must have
access to the directory /usr/src/redhat.  Then:

 * the directory containing the SSM files must be named ssm-<version>
 * zip -r ssm-<version>.zip ssm-<version>
 * cp ssm-<version>.zip /usr/src/redhat/SOURCES
 * cp ssm-<version>/ssm.spec /usr/src/redhat/SPECS
 * rpmbuild -ba /usr/src/redhat/SPECS/ssm.spec

There are of course many variations on this method.