MIDAS Web Services Installation Guide

MIDAS Web Services Installation Guide (MessageLogger)

In these notes replace [MIDASBASE] with the base of your software installation (default is /MIDAS).
Normally you will install the client package and (optionally) the server package.

Server
The file [MIDASBASE]/TclHttpd/Linux/TclHttpd-server is a shell script which starts tclsh with the script [MIDASBASE]/TclHttpd/bin/httpd-Server.tcl. During startup the file [MIDASBASE]/config/TclHttpd/[SystemName]/startup.tcl is searched for where [SystemName] can be the result of the command uname -n; localhost or omitted. This startup script loads the system specific services required. The following would load the implementation of the MessageLoggerServer.
```
    package require MessageLoggerServer
```
There are a number of configuration options. The following shows these with the default settings.
```
global env

global MIDAS_MessageLoggerServer_UseElog MIDAS_MessageLoggerServer_UseFile MIDAS_MessageLoggerServer_ElogCmd

set MIDAS_MessageLoggerServer_UseFile 1     ;#    write to /MIDAS/log
set MIDAS_MessageLoggerServer_UseELog 0     ;#    no send to ELog
set MIDAS_MessageLoggerServer_ElogCmd [file join $env(MIDASBASE) config TclHttpd Samples Elog.cmd]

set env(MessageLoggerBase) "/MIDAS/log"      ;#  not required if no write to /MIDAS/log

    package require MessageLoggerServer
```
The MessageLogger can be configured to write messages to dated files within the [MIDASBASE]/log directory; to logbooks within the Elog system or both. Set the appropiate Use flags.
If Elog is enabled then the file [MIDASBASE]/config/TclHttpd/Samples/Elog.cmd contains the command to be executed in order to send a message to the Elog system. For example:
```
#!/bin/csh -f
/usr/local/bin/elog -h nndhcp077 -p 8080 -l "DataAcq" -u username password \
      -a Author=MIDAS -a Source=$3  -a Category=$2  -a Subject=$1 -m $4
```
Obviously in order to use this feature the Elog package must be loaded. See the Elog website for further information.

Client
You can split the client interface from the server implementation. The client software is distributed also with the web server core. To install the client components add
```
 global MessageLoggerServerHost
   set MessageLoggerServerHost  nndhcp077

    package require  MessageLoggerClient
```
where MessageLoggerServerHost contains the name of a host running a server installation. The definition of MessageLoggerServerHost is optional: if omitted the default is localhost - that is you have installed the server interface in this system.

Httpd
From a Web Browser contact the URL http://[SystemName]:8015. This returns a page containing the WSDL file descriptions of the services available and a menu of available services.
The URL http://[SystemName]:8015/MessageLogger will directly enter the service.
The Httpd interface allows messages to be generated. In order to browse existing messages it is recommended that the Elog package is used.

V Pucknell; STFC; Daresbury Lab 9 July 2009