Electronic Logbook (ELOG)

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Introduction

The Electronic LogBook (ELOG) is a utility built-in the web server. It is available and operational once the web-server is running. A dedicated button "ELOG" will be present on the main Midas status page for creating new entries. This mode is referred as the Built-in Elog.

This tool can replace the experimental logbook for daily entries. The main advantage of the Elog over a paper logbook is the possiblity to access it remotely, and provide a general knowledge of the experiment.

More recently, the independent Elog package can be linked to a Midas experiment. Its advantage over the built-in version is its flexibility. This package is used worldwide and improvements are constantly being made. A full-features documentation and standalone installation can be found at the Elog web site.

Built-in Elog

The ELOG page (accessed by clicking the Elog button if present on the main status page ) provides access to an electronic logbook. the Elog is not limited strictly to experiments. Worldwide Elog implementations can be found on the internet. This internal implementation doesn't requires any setup to be operational. The Elog is customized through the ODB /Elog tree.

External Elog

The external implementation requires a proper Elog installation which is fully described on the Elog web site. The External Elog implementation also requires a dedicated entry in the /Elog ODB tree as shown in the code below. It also requires the package Elog to be already installed, and properly configured. Once the ODB entry is present, the internal ELOG is disabled.

The External Elog is customized through the configuration file elogd.cfg (see Installation below).

Installation of External Elog

Installation requires requires several steps described below.

Build Elog package

On Linux and Mac, we recommend building elog from git sources: 

mkdir -p $HOME/packages
cd $HOME/packages
git clone https://bitbucket.org/ritt/elog --recursive
cd elog
git pull ### update to latest version
make -j
ls -l elogd

Installation

Elog will run from it's build directory, an "install" step is not needed.

We will use Elog in conjunction with MIDAS mhttpd and Apache httpd. mhttpd will run on TCP port 8080, elogd on port 8082, apache httpd will provide HTTPS encryption and password protection, see https://daq00.triumf.ca/DaqWiki/index.php/Ubuntu#Install_apache_httpd_proxy_for_midas_and_elog

Make sure "ProxyPass /elog/" is uncommented in apache config file, restart apache after making this change.

Try https://yourhostname/elog/, after entering correct password, error should be: "Service Unavailable"

Configuration file elogd.cfg

  • copy the default midas/src/elogd.cfg from the MIDAS distrbution to your operating directory.
  • modify the elogd.cfg to reflect your configuration
 # This is a simple elogd configuration file to work with MIDAS
 # 
 [global]
 ; port under which elogd should run
 port = 8081                             
 ; password file, created under 'logbook dir'
 password file = elog.pwd                
 ; directory under which elog was installed (themes etc.)
 resource dir = /elog_installation_dir     
 ; directory where the password file will end up
 logbook dir = /myexpt/logbook     
 ; anyone can create it's own account
 self register = 1                       
 ; URL under which elogd is accessible
 url = http://NodeB.triumf.ca:8081      
 ; the "main" tab will bring you back to mhttpd
 main tab = Xenon                        
 ; this is the URL of mhttpd which must run on a different port
 main tab url = http://NodeA:8080
 ; only needed for email notifications
 smtp host = your.smtp.host              
 ; Define one logbook for online use. Severl logbooks can be defined here
 [MyOnline]
 ; directory where the logfiles will be written to
 Data dir = /myexpt/logbook            
 Comment = My MIDAS Experiment Electronic Logbook
 ; mimic old mhttpd behaviour
 Attributes = Run number, Author, Type, System, Subject     
 Options Type = Routine, Shift Summary, Minor Error, Severe Error, Fix, Question, Info, Modification, Alarm, Test, Other, 
 Options System = General, DAQ, Detector, Electronics, Target, Beamline
 Extendable Options = Type, System
 ; This substitution will enter the current run number
 Preset Run number = $shell(odbedit -e myexpt -h NodeA -d Runinfo -c 'ls -v \"run number\"')    
 Preset Author = $long_name
 Required Attributes = Type, Subject
 ; Run number and Author cannot be changed
 Locked Attributes = Run number, Author  
 Page Title = ELOG - $subject
 Reverse sort = 1
 Quick filter = Date, Type, Author
 ; Don't send any emails
 Suppress email to users = 1

Start the Elog daemon

  • start the elog daemon. -x is for the shell substitution of the command Preset Run number = $shell(...)
  • The argument invokes the odbedit remotely if needed to retrieve the current run number. You will have to ensure the proper path to the odbedit and the proper -e, -h arguments for the experiment and host.

You may want to verify this command from the console. 

 NodeB:~>/installation_elog_dir/elogd -c elogd.cfg -x<cr> starts the mhttpd at its correct port and possibly in the daemon form.
 NodeA:~>mhttpd -p 8080 -D

Activate External Elog

At this point the Elog from the MIDAS web page is accessing the [[[#Built-in Elog|Built-in]]] (internal) Elog. To activate the external Elog you need to edit two ODB variables (which mhttpd automatically created):

  • the ODB string "/Elog/URL" needs to be set to the URL of the external ELOG.
  • the ODB bool "/Elog/External Elog" needs to be set to 'y'

Note that after changing the ODB variable 'External Elog' from 'n' to 'y' you will need to reload the elog page in order to get the external elog.

Confirm proper operation of the external Elog by creating an entry. You will be prompted for a username and password. Click on New registration. Full control of these features are described in the Elog documentation. Stop and restart the Elogd in the background. 

  NodeB:~>/installation_elog_dir/elogd -c elogd.cfg -x -D

How to convert Built-in Elog files to External files

In the event you had a previous entry under the internal elog, you can convert the internal to external using the elconv tool. 

  NodeB:~> cp internal/elog_logbook/*.log /myexpt/logbook/.
  NodeB:~> cd /myexpt/logbook
  NodeB:~> /installation_elog_dir/elconv

How to send entries to the Elog from a script

Utilities exist to send elog entries automatically (e.g. from a script run at begin-of-run). Use melog to send an entry to a Built-in elog, or elog to send an entry to an external elog.

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