Elog version:  ELOG V3.1.4-611489ba

I am running openldap on the localhost.  For some reason now, elogd is segfaulting when (I believe) when a new user is being added to the password file.  For example:

1. I delete user passord file defined in elogd.cfg

2. Bind/Authenticate to LDAP successfully

3.  Segfaults in auth.c ldap_adduser_file()

Makefile:
...
ELOGDIR    = /opt/elog
DESTDIR    = $(ROOT)$(PREFIX)/bin
SDESTDIR   = $(ROOT)$(PREFIX)/sbin
RCDIR      = $(ROOT)/etc/rc.d/init.d
SRVDIR     = $(ROOT)/usr/lib/systemd/system

# flag for SSL support
USE_SSL    = 1

# flag for Kerberos support, please turn off if you don't need Kerberos
USE_KRB5   = 0

# flag for LDAP support, please turn off if you don't need LDAP
USE_LDAP   = 1# flag for PAM support, please turn of if you don't need PAM
USE_PAM    = 0
...

For authentication, I am using openldap in the localhost:

----
Authentication = LDAP
LDAP server = ldap://localhost:389
LDAP userbase = ou=people,dc=example,dc=org
LDAP login attribute = uid
LDAP register = 1
Password file = /opt/elog/users
 

gdb output

----------

(gdb) run -s /opt/elog -c /opt/elog/elogd.cfg -f /var/run/elog/elog.pid
The program being debugged has been started already.
Start it from the beginning? (y or n) y
Starting program: /home/ubuntu/UPGRADE-42221/work-src/elog/elogd -s /opt/elog -c /opt/elog/elogd.cfg -f /var/run/elog/elog.pid
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
elogd 3.1.4 built Apr 22 2021, 19:19:39 revision 611489ba
File "/var/run/elog/elog.pid" exists, overwriting it.
CKeditor detected
ImageMagick detected
Indexing logbooks ... done
Server listening on port 9011 ...

Breakpoint 1, ldap_adduser_file (lbs=0x555556811ad8, user=0x7ffffffd3bd0 "testuser", password=0x5555558ea110 <_value+6000> "testuser", error_str=0x7ffffffd53d0 "", error_size=<optimized out>) at src/auth.c:350
350       if (rc != LDAP_SUCCESS) {
(gdb) n
337       rc = ldap_search_ext_s(
(gdb) n
350       if (rc != LDAP_SUCCESS) {
(gdb) n
358       for(entry = ldap_first_entry(ldap_ld,result);
(gdb) n
371                   if(strcmp(attribute,"mail")==0 || strcmp(attribute,"rfc822Mailbox")==0)
(gdb) n
361          for(attribute = ldap_first_attribute(ldap_ld,entry,&ber);
(gdb) n
365             if((values = ldap_get_values(ldap_ld,entry,attribute)) != NULL ) {
(gdb) n
366                for(i=0; values[i] != NULL; i++) {
(gdb) n

Program received signal SIGSEGV, Segmentation fault.
ldap_adduser_file (lbs=0x555556811ad8, user=0x7ffffffd3bd0 "testuser", password=0x5555558ea110 <_value+6000> "testuser", error_str=<optimized out>, error_size=<optimized out>) at src/auth.c:366
366                for(i=0; values[i] != NULL; i++) {
(gdb) p attribute
$1 = 0x5555567f6a20 "uid"
(gdb) p values
$2 = (char **) 0x567f74f0
 

This user in LDAP:
-------------------------
# TESTUSER, people, example.org
dn: uid=TESTUSER,ou=people,dc=example,dc=org
uid: TESTUSER
cn: TESTUSER
givenName: TESTUSER
sn:: VEVTVFVTRVIg
mail: TESTUSER
uidNumber: 10000
gidNumber: 10000
homeDirectory: /dev/null
objectClass: top
objectClass: posixAccount
objectClass: shadowAccount
objectClass: inetOrgPerson
objectClass: organizationalPerson
objectClass: person
userPassword:: e1NTSEF9Y21ua1lsdFpMZ3ZrZlZ4OUp3MFN3cUY3NWIzdkFCSWY=
 

Hi Mr. Holman,

The problem you are facing is more likely the issue, that the LDAP method is only provided as-is from a different developer.

I had a similar issue with the LDAP of my university.
I can't remember the correct error messages, but it looks similar, which arises from the used c library for LDAP.
The LDAP connection response can have 2 different variable types and only one of them is implemented in the elog, the other one crashes the elog with segfault.

I could fix it with this patch:
https://bitbucket.org/merrx/elog/commits/5a75fdb3e0b723380dae73bb57653946ed72690c
Obviously you have to adapt "displayName" and "postOfficeBox" to represent the name and email attributes of your LDAP structure.

I didn't made a PR for this commit, because it would break the current LDAP implementation, i assume.

Best wishes,
Sebastian

Well, if you find a solution with works for everybody, I'm happy to commit it to the main repository. But unfortunately I cannot test it because I don't have LDAP here, so I'm flying blind.

Stefan

Hi,

Maybe it could be useful to add new parameters in elogd.cfg to define the attribute name to use to retrieve the given name, login name and email from LDAP server.

By example :

LDAP email attribute = mail

LDAP surname attribute = id

LDAP givename attribute = gn

So users can define them according to their exotic LDAP schema ;-)

Laurent

Dear Mr Ritt, Mr Schenk,

Thank you for the responses.  This was indeed my issue and direction to fix the crash.

Thank you,

Gary

Dear experts,

I am trying to use ELOG for my projects which we want to record every daily activities.
I have successful installed the ELOG to the computer (Windows10 -64 bit).
However, I don't know how to make it public or online, that people can access it from their computers.
I am a very newer to the ELOG.
Could you help me on it, please?

Best regards,
Hien.

Hello Hien,

If you are sharing ELOG with users on the same network, here's something you can try.  First, on the machine running ELOG, you need to find the "Computer name".   To do this, locate "This PC", and right click it to get to "Properties" in the drop-down menu.  You need to jot down the "Computer name".  Now, users on the same network should be able to view ELOG by entering the following:

http://computer-name:(port number)

If you are using port 80 (instead of the default 8080) for ELOG, then there is no need to enter the port number.

Give that a try -- that is working well for us.

Cheers!
Frank

> Dear experts, > > I am trying to use ELOG for my projects which we want to record every daily activities. > I have successful installed the ELOG to the computer (Windows10 -64 bit). > However, I don't know how to make it public or online, that people can access it from their computers. > I am a very newer to the ELOG. > Could you help me on it, please? > > Best regards, > Hien.

Hello,

what are the pre-requisites to automatically fill the Author and Author Email fields. The documented method:

Subst Author = $long_name from $remote_host

Subst Email = $user_email

in the elogd.cfg file does not seem to work.

(I see it works here on this platform)

Tnks

G

You need user-level access control, using 

Password file = ...

Stefan

Thank you but that is already  in place. I have the same issue on both Windows 10 and Windows Server 2016 and 2019.

tnks

g

If you would post a minimal config file where the problem occurs, then we could look what the problem is.

[global]

port = 8080

ssl = 0

Password file = passwords.txt

Admin user = user1

SMTP host = smtp. mail.com

SMTP port = 25

SMTP username = user1@mail.com

SMTP Password = GIwbx7UbmkWs5J0P8lVztX7Anje0/21BU/Tmk0aPm.

Logfile = ELog_log.txt

Logging level = 3

[Server]

Logbook dir = Server

Theme = default

Comment = Server Change Log

Attributes = Author, Email, Type, Category, Subject

Subst Author = $long_name from $remote_host

Subst Email = $user_email

Options Type = SRV 1, SRV 2, SRV Sup, BMS content, BMS setpoints, BMS new

Options Category = Config, User, Access, Connection, Change, New, Delete

Extendable Options =

Required Attributes = Author, Type

Page Title = ELOG - $subject

Reverse sort = 1

Quick filter = Date, Type

"Subst xxx" replaces after you submit an entry, while "Preset xxx" replaces before you create an entry. I believe you want the second one.

Stefan

Super, overlooked that one. Works now

g

Sometimes we change the attributes in a config file for a given tab as time goes on, which naturally can get out of sync with the older data in that tab.

I can imagine some other Elog users have encounterd this too at some point so I'm wondering if there's a utilty or some way anyone knows of that I can use to parse a log file DIRECTLY to view the older data, without using the Elog GUI?

Hi Al; if I understand your situation correctly you want to access Elog db (logbooks) via another way. There are many ways depending on your knowledge, type of work needed, and ease of use. I have found that accessing whatever I need via Elog gui is satisfactory in many situations-- by simply exporting. THEN take the raw csv/xml  file and manipulte it more easily from there. There are MANY free web sites that will take your data then, and put it in still another format that you choose (usually manipulating the rows/columns to your liking or doing mail-merge type work on your data). BTW WPS (Windows Office clone) is awesome at further 'mail-merg'  techniques. THEN at that point you may have close to what you are trying to accomplish. I've also used PHP alot in this type of situation and have replicated Elog's data format for it's db (logbooks)..; so PHP is great in this maner, although of course it takes time to 'get-it-right' if you are not well versed in it. If you go into detail more of what type of format you want as the finalized product, maybe  more suggestions will be made.

Happy belated New Years everyone,

John

Hi John. The problem with using the Find-->Export method is that some of the Attributes for the older data are no longer shown on that screen because the Config file has since changed. That's why I'm contemplating somehow parsing the log files directly instead.

Well, you could put the old options back to the config file, do the export, then remove them again.

But have a look at the Elog database files ZZMMDDa.log in your logbook directory, they are pure ASCII files, which are relatively simple to parse.

Hi,

I had similar needs (access and parse logs ) so I'm  a small library in cpp. Have a look on https://github.com/flagarde/elogpp maybe it could be usefull for you too.

Hi all together,

I struggle a lot with the following problem:
I try to prefill certain attributes with the value of exactly the same attribute in the last entry made in the same logbook.

I know I have to go with Preset, tried a view hours and searched the forum but i didn't find a thing. Am I overlooking a flag, an option or whatever, or is there just not such a functionality (which I dont believe)?

I thought about:
Preset Test_Attribute = $Test_attribute
Preset Test_Attribute = Re:$Test_attribute
Preset Test_Attribute = $shell(Command to somehow get last entry and this attributes value)
Not succesful though.

I would be very thankful for help, thanks in advance.

Nope, there is no way to acces the last value of an attribute. Sorry.

Stefan

Sorry Stefan, but it is possible as you have the scripting ability.

The idea is to use "Preset Test_Attribute = $shell(script_to_get_the_last_entry)", where the script asks elog about the details and parses them.
The problem here is, that the elogd already is working to resolve the click on "new entry" request (or similar) and the script can't call elogd until the page is delievered, what is to late.
(If it would, the elogd will hang.)

So the script either has to directly parse all the entry.log files in the logbook folder or you need a second elogd running, which can answer the request from the script.
This second elogd could run on a different port and it doen't need to be public as it only answers internal requests and could use the same config as the "primary" elogd.
My idea for the script uses the python elog module to establish the connection and do the parsing.

I hope this helps as a workaround.
Best wishes,
Sebastian

Hi Stefan, hi Sebastian,

thank you for your help. Ok I see its not that simple.

Is there maybe a way of executing a Script on submitting, writing the values of the Attributes into an temporary file and loading the values from this file via a preset shell script when opening a NEW entry?

Best wishes & thanks in advance

That would actually be my recommendation. There is a "execute new" which you can call when submitting a new entry.

Stefan

Thank you very much.

So far I testet all functionalities and scripts to reach my goal. I will post a dummy of the solution later on for future purposes.

Best wishes 

I am glad, we could help.

I can see a caveat in the recommendation.
By having "Execute New = echo $attrib > /path/last_attrib" and "Preset attrib = $shell(cat /path/last_attrib)" as the most simple construction.
But there are cases, where /path/last_attrib can get out of sync with the elog by e.g. editing or deleting the last entry, which is the most likely one to edit or delete.

I am aware, that you can make the logic more complex to fix this issue,
but basically you have the same information stored in two locations and you have to keep them in sync for the system to be reliable.
I am not sure, if it will be more hassle to construct a script/config system to keep them in sync or to find a solution which gets the information from the elog database.

Just noting that, depending on what you want to achieve, you may be able to use the threading functionality so that a "new" entry is actually a "reply" to a previous entry.  This will allow you to populate attributes with values from that previous entry without having to rely on storing information outside the system, with all the attendant concurrency risks already identified.

Hi,

in our application I want to have, let's say in the simplest case, two logbooks. One as a database of samples we fabricated and one as a logbook for measurements. When a measurement on a sample is done and an entry is submitted to the 2nd logbook, I want to automatically edit or reply to the corresponding entry in the 1st logbook. For example I want to append a line in the free text field to have a full log of what happened to a sample there. We reference our samples with a unique auto-generated ID in both logbooks. Is is somehow possible to search the 1st logbook for that ID or any other attribute and obtain the elog entry ID since the elog client will need that ID for editing an entry?

You would have to do that on the scrip level. Use "curl" to search a logbook. Like following URL would search for all entries in this forum where you are the authoer, then return the entries in CSV format:

https://elog.psi.ch/elogs/Forum/?mode=CSV1&Author=k%F6rner

Then you can parese this CSV file and extract the entry ID, which you can pass to the elog client to submit a new entry to the other logbook.

Stefan

Hi Chris,

Additional the the HTTP request sugested by Stefan you could also use the search functionality of the elog python module.
For the HTTP request you may also need a way to provide credentials or transmit cookies, if the elog needs authentification.

I think your request to alter the samples logbook will be called with "execute new" or similar at submit time of the entry to the measurement logbook.
Then both methods will have the issue that elogd is still processing the submit and can't answer new requests until the old is finished.
Have a look at https://elog.psi.ch/elogs/Forum/69328 for possible workarounds.

Best wishes,
Sebastian

Hi all together,

I struggle a lot with the following problem:
I try to prefill certain attributes with the value of exactly the same attribute in the last entry made in the same logbook.

I know I have to go with Preset, tried a view hours and searched the forum but i didn't find a thing. Am I overlooking a flag, an option or whatever, or is there just not such a functionality (which I dont believe)?

I thought about:
Preset Test_Attribute = $Test_attribute
Preset Test_Attribute = Re:$Test_attribute
Preset Test_Attribute = $shell(Command to somehow get last entry and this attributes value)
Not succesful though.

I would be very thankful for help, thanks in advance.