Collaborative Edition on Alfresco using LibreOffice Online

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Collaborative Edition on Alfresco using LibreOffice Online

alxgomz
Established Member
10 20 3,022

Being able to edit a file concurrently by multiple users is a need we’re coming across more and more when dicussing with customers on the field.
At the time of writing, the out-of-the-box solution to deliver this kind of feature within Alfresco is to use the GoogleDocs module.
This module allows for content stored in Alfresco to be collaboratively edited using Google’s online application suite (text editor, spreasheet editor, presentations) and saved back in the repository.
However some customer may not want to use Google services for different reasons (e.g, cost or data sensitivity), in which case there are far less options.
If you’re concerned about your data being sent to a public cloud and prefer having them securely stored on-premise in Alfresco instead, there may be a solution to help you.

LibreOffice OnLine (LOOL)

Alfresco uses LibreOffice (and formerly OpenOffice) for a very long time. This is one of the component providing our out-of-the-box transformation service (either through OODirect or jodconverter).
After delivering an opensource productivity Suite on the desktop, the Libreoffice team has started working on a similar feature set with a more SaaS approach: LibreOffice OnLine (LOOL).
Don’t get me wrong here: LOOL is not a SaaS solution you have to subscribe to, and that’s the intersting thing with it. LOOL is a service you can install on-premise in order to provide edition tools for office documents. And of course, as that’s what’s our main interest here, it provide collaborative edition capabilities. LOOL itself already provides a solution to having collaborative edition, while keeping your data in compliance with your SSI company policy!
Here I’ll detail how to integrate LOOL with your prefered on-premise content management system, thus bringing the collaborative edition feature inside Alfresco!

Alfresco integration

LibreOffice OnLine is actually a WOPI client and needs to talk to a WOPI server.

If you want to know more about the WOPi protocol you can check its definition here

The WOPI server role will be endorsed by Alfresco itself using 2 modules (one for the repo and one for Share). Those AMPs have been created by Magenta. All credits goes to them, here, I’m just giving guidance on how to install and configure it for Alfresco Content Services:

In terms of network flows, the following diagram shows what conenction are used

network flows Alfresco Libreofice Online

In this document we’ll use Alfresco Content Service 5.2.4.

Installation

LOOL installation

Fortunately it is now very simple to install LOOL (using the CODE distribution). The simple commands bellow should work for a Debian based Linux distribution.
Alongside this document we’ll use Debian 9.

$ echo 'deb https://www.collaboraoffice.com/repos/CollaboraOnline/CODE-debian9 ./' | sudo tee /etc/apt/sources.list.d/code.list
$ sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 0C54D189F4BA284D
$ sudo apt update
$ sudo apt install loolwsd code-brand

If you’re just testing you’ll probably be interested in using the docker image available at docker hub

LOOL configuration

By default the office online suite is configured to use SSL but the certificates are not provided. We then have to create those (or disable SSL if not targeting production).

$ sudo mkdir /etc/loolwsd/ssl

Copy to this newly created folder:

  • the certificate private key: /etc/loolwsd/ssl/loolwsd.key (make sure it’s only readable to the user runnning LOOL: lool)
  • the certificate itself: /etc/loolwsd/ssl/loolwsd.crt
  • the public CA certificate: /etc/loolwsd/ssl/cacert.pem

If you want ot use selfsigned certificates, this is a bit more tricky but do-able. Start with the commands bellow to generate the self-signed certificate:

$ sudo openssl genrsa -out /etc/loolwsd/ssl/loolwsd.key
$ sudo chown lool /etc/loolwsd/ssl/loolwsd.key
$ sudo chmod 400 /etc/loolwsd/ssl/loolwsd.key
$ cp /etc/ssl/openssl.cnf /tmp/loolwsd_ssl.cnf
$ cat >> /tmp/loolwsd_ssl.cnf <<EOT
[ san ]
subjectAltName = @alt_names
[alt_names]
IP.1 = 192.168.0.185
EOT
$ sudo openssl req -new -x509 -sha256 -nodes -key /etc/loolwsd/ssl/loolwsd.key -days 9999 -out /etc/loolwsd/ssl/loolwsd.crt -config /tmp/loolwsd_ssl.cnf -extensions san

IP.1 must match the IP address where the libreoffice online service is available. Change it to match your needs

Additionnally, if you’re using self signed certificate, it is required the Alfresco JVM trusts this certificate .

$ keytool -importcert -alias lool -file /etc/loolwsd/ssl/loolwsd.crt -keystore $JAVA_HOME/lib/security/cacerts -storepass changeit -storetype JKS

Of course, keystore path, type and passwords must match your environment

The client browser must also trust this certificate!

If LOOL traffic is wrapped in SSL, you’ll also need to have Alfresco protected by SSL. This is because most browser today will prevent pages with mixed content (http & https) from being displayed.
It means you have to configure Alfresco for SSL. Please refer to the official documentation in order to do that: https://docs.alfresco.com/5.2/concepts/configure-ssl-intro.html.
Again if you use a selfsigned certificate (or a certificate from a private pki ) for Alfresco, it is required to let LOOL trust that certificate. The way to do it depends on the distribution the service is running on. On Debian-like systems you can do:

$ keytool -exportcert -alias ssl.alfresco.ca -keystore alf_data/keystore/ssl.keystore -storetype JCEKS -storepass kT9X6oe68t | openssl x509 -inform DER -outform PEM -in - | sudo tee /usr/local/ca-certificates/alfresco.crt
$ sudo update-ca-certificates

The example command above uses the default Alfresco Keystore, path and password which you should have changed. Make sure to use the correct ones for your environment.

Now open the service configuration file /etc/loolwsd/loolwsd.xml and edit the ssl section as shown bellow:

...
<ssl desc="SSL settings">
 <enable type="bool" desc="Controls whether SSL encryption is enable (do not disable for production deployment). If default is false, must first be compiled with SSL support to enable." default="true">true</enable>
 <termination desc="Connection via proxy where loolwsd acts as working via https, but actually uses http." type="bool" default="true">false</termination>
 <cert_file_path desc="Path to the cert file" relative="false">/etc/loolwsd/ssl/loolwsd.crt</cert_file_path>
 <key_file_path desc="Path to the key file" relative="false">/etc/loolwsd/ssl/loolwsd.key</key_file_path>
 <ca_file_path desc="Path to the ca file" relative="false">/etc/loolwsd/ca-chain.cert.pem</ca_file_path>
 <cipher_list desc="List of OpenSSL ciphers to accept" default="ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH"></cipher_list>
 <hpkp desc="Enable HTTP Public key pinning" enable="false" report_only="false">
  <max_age desc="HPKP's max-age directive - time in seconds browser should remember the pins" enable="true">1000</max_age>
<report_uri desc="HPKP's report-uri directive - pin validation failure are reported at this URL" enable="false"></report_uri>
 <pins desc="Base64 encoded SPKI fingerprints of keys to be pinned">
 <pin></pin>
 </pins>
 </hpkp>
</ssl>
...

Also edit the net section to match your needs:

...
<net desc="Network settings">
 <proto type="string" default="all" desc="Protocol to use IPv4, IPv6 or all for both">all</proto>
 <listen type="string" default="any" desc="Listen address that loolwsd binds to. Can be 'any' or 'loopback'.">any</listen>
 <service_root type="path" default="" desc="Prefix all the pages, websockets, etc. with this path."></service_root>
 <post_allow desc="Allow/deny client IP address for POST(REST)." allow="true">
 <host desc="The IPv4 private 192.168 block as plain IPv4 dotted decimal addresses.">192\.168\.[0-9]{1,3}\.[0-9]{1,3}</host>
 <host desc="Ditto, but as IPv4-mapped IPv6 addresses">::ffff:192\.168\.[0-9]{1,3}\.[0-9]{1,3}</host>
 <host desc="The IPv4 loopback (localhost) address.">127\.0\.0\.1</host>
 <host desc="Ditto, but as IPv4-mapped IPv6 address">::ffff:127\.0\.0\.1</host>
 <host desc="The IPv6 loopback (localhost) address.">::1</host>
 </post_allow>
 <frame_ancestors desc="Specify who is allowed to embed the LO Online iframe (loolwsd and WOPI host are always allowed). Separate multiple hosts by space.">alfresco.myecm.org:1800</frame_ancestors>
</net>
...

Pay attention to the post_allow element, its value has to match the IP of your clients (all the browser which may request to edit files). The default configuration is to allow local access and access from a 192.168.0.0/16 network.

The frame_ancestors element should be left alone as the wopi host (alfresco) is normally part of it by default. However there may be cases where it is required (e.g if running on a non-default network port)

Now make sure to have you alfresco host declared as an authorized wopi host in the storage section:

<storage desc="Backend storage">
    <filesystem allow="false" />
    <wopi desc="Allow/deny wopi storage. Mutually exclusive with webdav." allow="true">
       <host desc="Allow from Alfresco" allow="true">alfresco.myecm.org</host>
        <max_file_size desc="Maximum document size in bytes to load. 0 for unlimited." type="uint">0</max_file_size>                                                                      
    </wopi>
    <webdav desc="Allow/deny webdav storage. Mutually exclusive with wopi." allow="false">
        <host desc="Hostname to allow" allow="false">localhost</host>
    </webdav>
</storage>

the wopi host specified must match you alfresco hostname as used by web browsers

On the Alfresco side add the following properties to the alfresco-global.properties file:

...
lool.wopi.url=https://loolhost:9980
lool.wopi.url.discovery=https://loolhost:9980/hosting/discovery
lool.wopi.alfresco.host=https://alfrescohost:8443/alfresco/s
...

Where loolhost is the server name where you installed LOOL, and alfrescohost the local server where alfresco is running
It is possible to install both on the same server of course.

Only use FQDN names (matching the certificates CN if using SSL), do not use localhost.

Use appropriate ports

Applying AMPs

There are 2 AMPs available. In order to turn Alfresco into a WOPI host you’ll need the repo AMP, and to add the necessary Share pages and buttons to allow UI integration the share AMP is needed.
We’ll first need to get the sources and build them:

$ git clone https://github.com/magenta-aps/alfresco-repo-libreoffice-online-module.git_
$ cd alfresco-repo-libreoffice-online-module
$ vim pom.xml
$ mvn package

When editing the pom.xml make sure to:

  • set alfresco.platform.version & alfresco.share.version to your version in the repo pom.xml
  • set alfresco.surf.version to the surf version matching you alfresco version in the share pom.xml
  • set maven.alfresco.edition to enterprise

Copy the resulting .amp files located in target/ to the amps and amps_share folders of your alfresco installation and run:

$ ./bin/apply_amps.sh

You can now restart the services:

$ sudo systemctl restart loolwsd
$ ./alfresco.sh restart tomcat

You can now test editing Office documents simultaneously with differents users and see how convenient LibreOffice OnLine makes it.

Below examples of spreadsheet and presentations concurrent edition by "Administrator" and "Alex" users:

Each user can see what the others are doing and who's editing.

calc collab

impress collabAs you can see in the screenshot above, the share module needs some tweaking if you're not using english locale. But that should really just be a matter of adding the right message bundle. to the share AMP

20 Comments
bguesdon
Member II

Bonjour Alexandre,

Je suis actuellement en stage à Nantes et j'ai pour objectif d'intégrer LibreOffice Online à Alfresco et votre tutoriel à l'air d'être exactement ce que je recherche. J'ai donc effectué les étapes précisées au dessus mais j'ai un problème au moment où je souhaite ouvrir le document.

En effet, l'amp s'installe bien puisque l'option "Edit in LibreOffice online" apparaît bien dans les options du document mais lorsque la fenêtre s'ouvre je n'ai pas accès au document et une fenêtre s'ouvre avec écris:

"Échec de la lecture du document à partir du stockage. Veuillez contacter votre administrateur de serveur de stockage (alfedu.magenta.dk)." J'imagine que le problème viens donc du serveur libreoffice online mais je voulais savoir si vous aviez déjà rencontré ce problème ou si vous auriez une petite idée d'où viens le problème que je rencontre.

Bien cordialement,

Bastien Guesdon - BlueXML 44000 Nantes

bguesdon
Member II

Ci-dessous une capture d'écran du message d'erreur:

alxgomz
Established Member

Hi Bastien,

It looks to me like the LOOL UI can't read/open the file from the wopi host.

Double check you can access the URL specified as `lool.wopi.alfresco.host` from the LOOL host.

I find it surprising you have alfedu.magenta.dk host mentionned in the error message... this is the default it could be you haven't added the necessary properties to the alfresco-global.properties files or your instance is not able to read it

Regards,

bguesdon
Member II

Hi,

Thank you for your answer, I've not really understood the first part of it. I don't know what is "the URL specified as `lool.wopi.alfresco.host`" and how to access to it but I've achieved to open a local file with LOOL which is a good start I think.

I also found the problem about alfresco, it actually was a certificate issue but it still doesn't work as needed cause now a new page appear telling me that a problem had arisen (see the picture below) and I just have a little clue about the issue when looking for loolwsd logs telling me: "[ websrv_poll ] ERR Looks like SSL/TLS traffic on plain http port| wsd/LOOLWSD.cpp:2031". I use self-signed certificate so I looked for real certificates of Libre Office but couldn't find any. Do you have any clue about how to fix this ?

Bastien Guesdon - BlueXML

bguesdon
Member II

Oh my bad, I just found out what "lool.wopi.alfresco.host" means and it link me to a blank page with unprintable character written on it. Is it normal ?

bguesdon
Member II

I managed to make it work with alfresco but I had to launch it on http without any security so I'll try to make it work on https but all my problem came from it so it will be really tough I think.

alxgomz
Established Member

Hi Bastien,

Happy that you narrowed it down!

This blog post is essentially about making it all wrok with self signed certificates. If you follow it step by step and carefully reads it it should just.

Let me know if you think some parts of the post are not clear enough.

wshomeworker10
Active Member

Hi, I've gone through these instructions, but I can't find a way to actually edit a file with Lool. I assume there's supposed to be an 'edit' button of some kind? If so, where is it supposed to be?

Also: the "Alfresco is running without Share Services. See your System Administrator for more details." message appears, is that preventing Lool from working?

Thanks.

alxgomz
Established Member

Having this message surely doesn't help!

Make sure the alfresco-share-services module is installed on the repo by checking the "module packages" displayed in the "system summary" menu in the repo admin console. (you need to have one match your repo/share version)

Once installed and provided you installed the share AMP mentionned in this article you should have a link in the document-details page or even in the doclib (in the "more" menu)

wshomeworker10
Active Member

All I have is this: I assume that the shared-services module is supposed to be here?Module Browser

wshomeworker10
Active Member

Also:
java/bin/java -jar ./bin/alfresco-mmt.jar list ./tomcat/webapps/share.war
Module 'resetPassword-share' installed in './tomcat/webapps/share.war'
- Title: resetPassword-share AMP project
- Version: 1.0.1602231755
- Install Date: Thu Jun 20 10:46:32 IST 2019
- Description: Manages the lifecycle of the resetPassword-share AMP (Alfresco Module Package)
Module 'org.alfresco.integrations.share.google.docs' installed in './tomcat/webapps/share.war'
- Title: Alfresco / Google Docs Share Module
- Version: 3.0.4
- Install Date: Thu Jun 20 10:46:30 IST 2019
- Description: The Share side artifacts of the Alfresco / Google Docs Integration.

and:

java -jar ./bin/alfresco-mmt.jar list ./tomcat/webapps/alfresco.war
Module 'resetPassword' installed in './tomcat/webapps/alfresco.war'
- Title: resetPassword Repository AMP project
- Version: 1.0.1602231755
- Install Date: Thu Jun 20 10:46:28 IST 2019
- Description: Manages the lifecycle of the resetPassword Repository AMP (Alfresco Module Package)
Module 'alfresco-aos-module' installed in './tomcat/webapps/alfresco.war'
- Title: Alfresco Office Services Module
- Version: 1.1.6
- Install Date: Thu Jun 20 10:46:26 IST 2019
- Description: Allows applications that can talk to a SharePoint server to talk to your Alfresco installation
Module 'org.alfresco.integrations.google.docs' installed in './tomcat/webapps/alfresco.war'
- Title: Alfresco / Google Docs Integration
- Version: 3.0.4
- Install Date: Thu Jun 20 10:46:25 IST 2019
- Description: The Repository side artifacts of the Alfresco / Google Docs Integration.
Module 'alfresco-share-services' installed in './tomcat/webapps/alfresco.war'
- Title: Alfresco Share Services AMP
- Version: 5.2.0
- Install Date: Thu Jun 20 10:46:24 IST 2019
- Description: Module to be applied to alfresco.war, containing APIs for Alfresco Share
Module 'libreoffice-online-repo' installed in './tomcat/webapps/alfresco.war'
- Title: libreoffice-online-repo Repository AMP project
- Version: 1.0-SNAPSHOT
- Install Date: Thu Jun 20 10:46:23 IST 2019
- Description: Manages the lifecycle of the libreoffice-online-repo Repository AMP (Alfresco Module Package)

Are the entries in alfresco.war supposed to appear in the module browser?

alxgomz
Established Member

Steve Pratt‌, you're looking at the Share admin console, so all you'll see are the share modules. Repo modules are visible in the repo admin console.

The repo AMP for Share services seems to be installed hence I'm not sure why you have this warning message (you can ask for help on this in the forum).

However, the share webapp misses the libre-office-online AMP I mention in this thread. Make sure to installl one AMP to the repo (seems like it's done), but also to the Share UI (doesn't look like you did it)

wshomeworker10
Active Member

Hi, Thanks, I found the missing amp and installed it to the share ui. Now, when I click the 'Edit in LibreOffice Online' button, nothing happens for a while and then eventually I get a message saying 'host took too long to respond'.

alxgomz
Established Member

Check your logs for errors or try using the web developer console inyour browser to troubleshoot but at first sight thtat looks like a firewalling issue...

Please remember blog comments are not the best place to troubleshoot issues. You should instead use the help forum.

wshomeworker10
Active Member

Ok, thanks.

Steve

wshomeworker10
Active Member

Is there something missing here?missing entries in alfresco-global.properties

alxgomz
Established Member

Indeed! Thanks for letting me know.

It should be fixed now.

wshomeworker10
Active Member

This might be a silly question but... Where is the help forum? I can't find it anywhere.

alxgomz
Established Member

check the "Ask my question" buttton at   

wshomeworker10
Active Member

Thanks.