APEL/SSM/README010

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This is the README file included in ssm-0.10-1.

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 [[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

The python ldap library
 * yum install python-ldap


You need a certificate and key in PEM format accessible to the SSM.
There are a number of ways to do this.  One is to make a copy of the
hostcert and hostkey files, owned by the apel user:
 * /etc/grid-security/hostcert-ssm.pem
 * /etc/grid-security/hostkey-ssm.pem
These are the default settings in the configuration file ssm.cfg.
You can use a different configuration if you prefer.

You need certificates against which you're going to verify any certs
you use or receive in the directory /etc/grid-security/certificates (or other
configured location).  The easiest way to do this for EGI is:
 * yum install lcg-CA

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 user 'apel' with home directory /opt/apel
3. It installs an init script in /etc/init.d/ssmd
4. It creates the log directory /var/log/apel
5. 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.

Before trying to send any messages, run the SSM once.  This will create the
directory structure within the messages directory.  Check the log file
(/var/log/apel.log) to see if the SSM has successfully connected to a broker.
If so, the SSM should be ready to use.

To run the SSM the first time:
 * export SSM_HOME=/opt/apel/ssm
 * $SSM_HOME/bin/run-ssm

Then, to send your messages:
 * 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
 * yum remove python-ldap

 * rm -rf /var/log/apel
 * rm -rf /var/run/apel
 * userdel apel
 * rm -rf /opt/apel
 * rm -rf /var/spool/mail/apel

 * revert any changes to / copies of the host certificate and key

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.