Work in Progress

This tutorial is still under development, but nearly finalized. Please try out and post any necessary comment! (smile)


EUROPLANET2020 Research Infrastructure 


Grant agreement no: 654208

Document: VESPA-WP6-2-004-TD-v1.6

EPN-TAP Server Installation for VESPA Data Provider Tutorial


Start date of project: 01 September  2015

 Duration: 48 Months

Responsible WP Leader: OBSPARIS / Stéphane Erard

Project co-funded by the European Union's Horizon 2020 research and innovation programme

Dissemination level





Restricted to other programme participants (including the Commission Service)



Restricted to a group specified by the consortium (including the Commission Services)



Confidential, only for members of the consortium (excluding the Commission Services)


Project Number


Project Title

EPN2020 - RI

Project Duration

48 months: 01 September 2015 – 30 August 2019

Document Number


Delivery date


Title of Document

EPN-TAP Server Installation for VESPA Data Provider Tutorial

Contributing Work package (s)


Dissemination level


Author (s)


Document history (to be deleted before submission to Commission)








First issue (imported from internal MS-Word document)




Updated AWStats and Apache Proxy configuration




Fixed several errors




Simplified the server configuration (no more proxy)



Update of first installation step.
Added comments and updated Apache2 configuration. 

0.6Changed Awstats configuration
0.7Added DaCHS web configuration (title and logos)
Fixed /etc/gavo.rc configuration 
0.8Added screenshots and some adding testing steps
0.9Modification of the ordering of Apache and DaCHS configuration, and various small changes for better clarity.

Added PgAdmin section. Added notes on Virtual Box network configuration. Small modifications

0.11Small modifications
1.0Public Release


1.1Changed PgAdmin configuration.
Changed document name.
1.2Fixed /etc/gavo.rc file
1.3Going back to draft status for updating tutorial.
Including "test" and "prod" set up.

Modified /etc/apt/sources.list input.
Added note about server logo. 
Fixed AWSTATS configuration. 




replay installation tutorial, update the documentation




typos, fixes, etc...



add logFormat: combined to gavo.rc to use awstats in curent DaCHS version


Table of Contents1.

1. Introduction

This document presents the installation procedure to set up data distribution server for VESPA. We propose here to set up three service interfaces on the same physical server (and the same public IP address): a standard web server (Apache) to serve data files, a tool to have access statistics (using AWStats), and a DaCHS server to provide the Virtual Observatory (VO) interfaces (including a TAP service). Two server names have to be set up: one for the data access and the statistics, and the other for the VO access:

Section 2 describes the Debian distribution installation. Section 3 describes the installation of DaCHS and its configuration. Section 4 describes the installation and configuration of AWStats. Section 5 describes the configuration of the Apache server and of DNS.

Further configuration of the VO interface is described in the second part of the tutorial.

In all this document, you will have to replace all text between <<...>> with the value that you have selected for your installation.

In order to prepare the installation, here is a table to be filled with the parameters of you installation:

Parameter NameYour ValueExample Value for tutorial
maintainer_email (1)
authority-ivo-name (2)..................................................................................vopdc.obspm
server_title ..................................................................................My new test DaCHS server

(1) This should be a generic address, rather than a specific person address. 
(2) Read the Service Identifier page when filling these lines. Note that this specific item do not contain "ivo://" at the beginning.

2. Debian Stable (Jessie) Installation

DaCHS (Data Center Helper Suite) must be installed on a fresh Debian Stable distribution .

2.1 Install virtualization software


 The installation demonstration is done on a Virtual Box guest computer, so you first need to install VirtualBox on your computer.

On Debian based systems:

sudo apt-get install virtualbox

On other systems, download VirtualBox and follow the installation instructions.

The Debian installation ISO image must be mounted on boot (see Virtual Box documentation for more details), so that the system can boot from it. If you use a physical server, the installation disk (extracted from the ISO image) must be available to the system on boot. 

For a real installation, a physical server (or a bare metal virtualization framework) should be preferred.

2.2 Download Debian

 The current installation image for this distribution is available here: (under Small CDs or USB sticks). In this example, we used the following ISO image: debian-8.6.0-amd64-netinst.iso

2.3 Virtual machine installation


Click on the New icon, then fill:



Debian8.3_VESPAAs you want


VersionDebian (64bits)
RAM1GoNo more than 50% of your actual RAM.
Virtual HDDCreate a virtual drive now
Drive file typeVDI
Storagedynamically allocated
The default option is usually good.

Click create on the last step, then click on the Configuration icon.

Go to Storage, on IDE controller, click on Add optical drive, Choose a disk, and select your downloaded iso.

Nothing to do.

2.4 Network configuration


Always in Configuration window, go to Network, keep "NAT" for the default network access mode, then click on Port forwarding and add 4 rules as the following:

NameProtocolhost IPhost portguest IPguest port

Note that as part of this tutorial, the DaCHS port is set to 8000 instead of 80 because the host can't access to a guest through ports numbers lower than 1024 for security reasons.

For advanced test purposes, you can configure the network interface of the VM to "Bridged", and then use the "Production" commands.

In this case, the VM will have its own IP address, as provided by the DHCP server (you may need to provide the MAC address of your VM to your network admin to get a proper IP address).

For operation server, you must have a public address. The DNS configuration must be completed.

Ports to be open:

  • 22: Secure shell login for administration and configuration.
  • 80 (open to all): VO interface (DaCHS server)
  • 8080 (open to all): WWW interface (Apache2 server)

2.5 Debian installation

Installation selection
Select "Install"
Language used for the installation process, and for the system, once installed
Select " English "
Location of the installation
Select your country
Locale used for the installation
Select "en-US.UTF-8"
Keyboard map
Select your keyboard map
Hostname for this computer

Type the hostname (here "voparis-test-bc")

replace by <<my_servername>>

Domain name for your institute

Type the domain name (here "")

replace by <<my_domain>>

Root password
 Enter root password (pick a password, which is not easy to guess and don't forget it!)
Main user configuration

Enter Full Name, user name and password

In the following, <<my_user>> will refer to the login of this user, you will need a user account.

Disk configuration
Select "Use entire disk"
Select Disk to partition
Select the main disk (there should be only one).
Partition Scheme
Select "All files in one partition"
Confirmation of partition set up
Select "Finish partioning and write changes to disk"
write partition to disk
select <Yes>
Configuration of package manager
Select a mirror close to your place
Proxy configuration
If needed enter the proxy information to go on internet (if your internet access is via a proxy, otherwise leave it blank).
Configuring popularity-contest
This is up to you (here "No" is selected)
Software selection

Select a minimal set of package, namely "web server", "ssh server", "standard system utilities". Note that no desktop environment is selected here. As a server, only shell access is necessary.

For package selection/unselection, use the "space" key.

In basic configuration, we do not select any desktop environment, but it is possible to do so, it makes you more confident.

If you don't load any desktop environment, you must make sure that your server is reachable through ssh. This may imply configuration on the virtualization software and on the DNS server of your institution.

Installation of GRUB boot loader, part 1
Select "yes"
Installation of GRUB boot loader, part 2
Select the newly created partition.
Installation completion
Select "continue" to finish installation and reboot.
Go to next section

From now, it is recommended to access to your server through ssh:

Test (from a terminal, or use PuTTY on Windows)
ssh -p 2222 <<my_user>>@localhost
ssh <<my_user>>@<<my_servername>>.<<my_domain>>

And you don't need to use the guest interface anymore.

Now you will be able (and you should) to use copy-paste along the tutorial.

To change the keyboard map on your guest, you have to edit a file:

sudo nano /etc/default/keyboard

3. Install and configure sudo 

On the server, login with the <<my_user>> user created during installation (either on the computer itself, or remotely with ssh). 

The first thing is to install and set up the sudo command, which allows a user to issue commands with root rights. Use the su command to log as root, and type the root password. 


Install the sudo package: 

apt-get install sudo 

Set up rights for your regular user to use the sudo command: 

adduser "<<my_user>>" sudo

You have now the log out from your root shell:


and your regular user shell:


(this will disconnect your ssh connection, so you have to connect again)

Now you will be able to use the sudo command. 

4. Apache Configuration

Connect to the server with ssh. Apache should already be installed during initial configuration, otherwise :

sudo apt-get install apache2

Enable ModCGI:

sudo a2enmod cgid

Update the default Apache port to 8080 instead of 80 by changing the /etc/apache2/ports.conf  file, using your preferred command line editor, for instance, you can use the pico editor (useful short cuts: ^O to save, ^X to quit):

(sometimes you have to check the line NameVirtualHost *:8080 in ports.conf and <VirtualHost *:8080> in /etc/apache2/sites-available/default)

sudo pico /etc/apache2/ports.conf

Modify the first line containing the  Listen  command and replace the port number:

Listen 8080

Then restart Apache2:

sudo service apache2 restart

You can check that your regular web server is running connecting to the URL:  http://<<my_servername>>.<<my_domain>>:8080/. You should see a standard splash page:

Fig. 4.1: View of the Apache server web default welcome page.

You can create a regular website that presents your project and database putting HTML code into /var/www/html/

5. DaCHS Installation and Configuration

There are several ways to install DaCHS as presented by his author in [1]. For DaCHs installation you need an Debian Stable distribution, at this time Jessie (see Section 2).

Install DaCHS framework

The repository source list must be updated to include DaCHS packages. Edit the file /etc/apt/sources.list

sudo pico /etc/apt/sources.list 

Add the following line at the end of file (see Fig. 3.1):

deb beta main

Fig. 3.1: Adding GAVO/DaCHS repository into  /etc/apt/sources.list 

  Add the key to use the repository:

wget -qO - | sudo apt-key add -

  Get the latest debian packages:

sudo apt-get update
sudo apt-get upgrade 

 After these first steps, start the installation:

sudo apt-get install gavodachs-server

In order to safely install the various components of the server, we now turn off the Apache web server (we will configure it later):

sudo apachectl stop

Initial DaCHS Configuration

We now configure DaCHS so that the server can run. The registry and data services configuration will be done in the second part of the tutorial.

As we are using DaCHS in a non secure configuration, we need to disable some features: 

sudo cp /var/gavo/etc/trustedquery /var/gavo/etc/untrustedquery 

Create a file /etc/gavo.rc using your preferred editor (for instance pico): 

sudo pico /etc/gavo.rc 

Insert the following content in that file : 

rootDir: /var/gavo 
maintainerAddress: <<maintainer_email>>
serverPort: 8000
sitename: <<server_title>>
corsOriginPat: http.*
logFormat: combined
authority: <<authority-ivo-name>>
rootDir: /var/gavo 
maintainerAddress: <<maintainer_email>>
serverPort: 80
serverURL: http://<<my_servername>>.<<my_domain>>
sitename: <<server_title>>
corsOriginPat: http.*
logFormat: combined
authority: <<authority-ivo-name>>

In this file, replace http://<<my_servername>>.<<my_domain>>  by your actual server name,  <<server_title>> by server title and <<authority-ivo-name>> by your own authority name that you will create during the registration of your service (e.g., at Observatoire de Paris, our authority name is vopdc.obspm). If this is not ready at this time, you may modify it later when your have registered your service with IVOA. The << maintainer_email>>  field is the contact of the technical maintainer of the service, use a generic address if possible.

note: if your server is redirected in https, you will have to set corsOriginPat: https.* and add adaptProtocol: False to your gavo.rc

If you want to add your institute logo on the DaCHS server instead of the default GAVO logo, you have to prepare three PNG files, with width of 200, 120 and 50 pixels, and the following respective names logo_big.png, logo_medium.png and logo_tiny.png. These files should be placed in the /var/gavo/web/nv_static/img/ directory (you will have to create the img/ directory if necessary).

sudo mkdir /var/gavo/web/nv_static/img

The image transfer can be done with the following command, on the server you have prepared your images:

cd /your/local/path/to/img
scp -P 2222 logo_big.png logo_medium.png logo_tiny.png <<my_user>>@ 
cd /your/local/path/to/img
scp logo_big.png logo_medium.png logo_tiny.png <<my_user>>@<<my_servername>>.<<my_domain>>:~ 

This command has copied to your images on the home account of the DaCHS server. Then you have to copy them in the right directory, on your DaCHS server:

cd ~
sudo mkdir /var/gavo/web/nv_static/img
sudo chown dachsroot:gavo /var/gavo/web/nv_static/img
sudo cp logo_big.png logo_medium.png logo_tiny.png /var/gavo/web/nv_static/img/.

 This logo will be displayed in the DaCHS web interface, but will also be used by VESPA clients to display your logo next to your data products, so that the origin of the data is clearly identified.

Finally start Apache and DaCHS servers:

sudo apachectl start
sudo gavo serve start

You can check that your server is running by connecting to the server with a web browser, using the server URL:

TestProduction http://<<my_servername>>.<<my_domain>>

You should see the following welcome page:

Fig. 3.2: View of the welcome DaCHS server.

6. AWStats Installation and Configuration including Apache

Install AWStats:

sudo apt-get install awstats 

Apache Configuration for AWStats

AWStats is a script, which must be enabled in the Apache default configuration file.

Edit the file /etc/apache2/sites-enabled/000-default.conf:

sudo pico /etc/apache2/sites-enabled/000-default.conf

Replace the entire file content by the following lines ( ctrl-K to cut/delete a line on Pico):

<VirtualHost *:8080>

       ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
       <Directory "/usr/lib/cgi-bin">
               Options FollowSymLinks
               AddHandler cgi-script  .pl
               AllowOverride None
               Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
               Order allow,deny
               Allow from all

       ErrorLog ${APACHE_LOG_DIR}/error.log
       CustomLog ${APACHE_LOG_DIR}/access.log combined


Configuration of AWStats

We configure here AWStats to use the DaCHS and Apache log files and eliminate queries coming from monitoring server at ObsParis.

Apache statistics

Go into the /etc/awstats directory and open a new file for edition:

cd /etc/awstats
sudo pico awstats.conf

In this file, edit the following lines (search by keyword - ctrl-W on Pico - : LogFileLogFormat, etc) and replace by the proposed content:

Keyword to searchLine to input
LogFile="/usr/share/awstats/tools/ /var/log/apache2/access.log* |"
HostAliases="localhost <<my_domain>>"

The VESPA technical team plan to monitor the status of all VESPA servers using a Nagios server. Its hits should be removed from the statistics. This is the purpose of the line starting with SkipHosts.

The Apache2 log files must also be readable by AWStats scripts. First we modify the permissions of Apache2 log files. Those permissions are defined in the /etc/logrotate.d/apache2 file. We have to modify the line starting with the create command by:

	create 644 root adm

If you need to fix permissions of already existing log files, the following commands will fix the Apache2 log permissions:

sudo chmod 644 /var/log/apache2/access.log*
sudo chmod 755 /var/log/apache2

DaCHS statistics

Staying in the /etc/awstats directory, copy the file awstats.conf to awstats.dachs.conf:

sudo cp awstats.conf awstats.dachs.conf
sudo pico awstats.dachs.conf

In this file, edit the following lines (search by keyword - ctrl-W on Pico - : LogFileLogFormat, etc):

Keyword to searchLine to input
LogFile="/usr/share/awstats/tools/ /var/gavo/logs/web.log* |"
LogFormat="%other %other %other %host %other %other %time1 %methodurl %code %bytesd %refererquot %uaquot"

Setup a crontab to update statistics every day

First create a file containing the calling sequence to AWStats: 

cd /usr/local/bin
sudo pico run_awstats

In this file, input the three following lines: 

/usr/bin/perl /usr/lib/cgi-bin/ -config=dachs -update
/usr/bin/perl /usr/lib/cgi-bin/ -config=apache -update

Finally, change the access control configuration for this file:

sudo chmod 777 run_awstats

A task can then be added to the crontab of your system using :

sudo crontab -e

Add those lines at the end of the file:

0 0 * * * www-data /usr/local/bin/run_awstats 2>/dev/null

If you use the crontab -e command for the first time, you may have to select en editor. The following lines should then appear in your terminal:

Select an editor.  To change later, run 'select-editor'.
  1. /bin/nano        <---- easiest
  2. /usr/bin/vim.tiny

Choose 1-2 [1]: 

If you are not very familiar with vim, prefer the nano option.

Run AWStats

sudo /usr/local/bin/run_awstats

Access AWStats

The AWStats reports are available at:

Figure 5.1 shows a screenshot of the AWStats monitoring page.

Fig 5.1: View of the AWStats monitoring page.

7. Allowing up external access to database

In order to connect to the PostgreSQL (PgSQL) database that is used by DaCHS, you can either set up an SSH tunnel or configure DaCHS server to allow external access to the database:

Method A: By opening an SSH tunnel

From your host:

ssh <<my_user>>@ -p 2222 -L 5432:

Then leave the console open during the tutorial.

Method B: By configuring DaCHS server

On the DaCHS server, you have to edit 2 files (pg_hba.conf and postgresql.conf). The first file is used to set up which range of IP have access, with which user and what role. Open the file:

sudo pico /etc/postgresql/9.4/main/pg_hba.conf

and at the end of the file add the following line:

host	all		gavoadmin	md5

That configuration will allow all IP address to connect. That's good for a tutorial, but not for real operations. You will have to restrict the range of IPs that are allowed to connect. Check with your local system administrator if needed.

The second file is used to configure which IP range the database is listening to for queries. Open the file:

sudo pico /etc/postgresql/9.4/main/postgresql.conf

and modify the line containing the "listen_addresses" directive:

listen_addresses = '*'

The PgSQL database as well as DaCHS must now be restarted:

sudo /etc/init.d/postgresql restart
sudo gavo serve restart

8. Setting up pgAdmin (optional)


pgAdmin aims to provide a graphical interface to view and manage a database. We will use this tool on section Setting up an EPN-TAP service. If you don't want to install pgAdmin on you computer, you can however use psql commands instead.

First, install pgAdmin on your host machine. If you are on Debian based distribution:

sudo apt-get install pgadmin3

Compiled sources are also available for MacOS and Windows.

You need pgAdmin v. 1.20 or upper in order to deal with postgreSQL 9.4. Once installed, check pgdmin version (Help menu, About).


Check for the gavo user password:

cat /var/gavo/etc/feed

Now start pgAdmin, then click on Add a connection to a server (power socket icon) and fill the fields as the following:

Name DaCHS-testDaCHS As you want
TCP port 5433
Service   leave empty
Base maintenancepostgres 
Use namegavoadmin
password******* Get it with the command above
save password  yes As you want

Checking installation

Now you should be able to see your database:

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  1. Anonymous

    you must verify in postgres configuration :

    that you have the line

    listen_addresses = '*'        # what IP address(es) to listen on;

    on file /etc/postgresql/9.4/main/postgresql.conf

    it allow access from outside


    and may be a line in the file pg_hba.cof to allow gavoadmin access from outside

    host   gavo           gavoadmin       md5

    use that only in a virtual box on the laptop, not in production server




  2. I've checked. I've also restarted postgres and gavo - no way

  3. Did you try not to use the ssh tunnel ? Are you using the "test" or "prod" network settings ("test" = NAT mode + port forwarding / "prod" = bridge mode + regular ports) ? Do you connect directly through PgSQL the port (to localhost 5433 on "test" config or 5432 on "prod" config) ? 

  4. I try with and without tunnel. I'm in test mode (ie NAT, not the opposite) - OK, I was using 5432 as described above. But I have another message with 5433:
    FATAL: no pg_hba.conf entry for host "", user "gavoadmin", database "postgres", SSL on FATAL: no pg_hba.conf entry for host "", user "gavoadmin", database "postgres", SSL off

    But everything is authorized…

  5. Shoud I add

    host    all     gavoadmin   md5
  6. Yes, that's it. I think we have to rework this part of the tutorial, it was deeply misleading for me.

  7. i.e.: TCP port = 5433 in test mode (not 5432)

    + add 

    host all gavoadmin md5

    in pg_hba.conf

  8. It worked without this loose configuration for me. I'm not sure that is the ultimate answer.

  9. This is why I'm not editing it myself (wink) Kind of black magic to me.

  10. I have corrected the line in pg_hba.conf to work and its gavoadmin

  11. cp -P 2
    with respect to section 'initial dachs configuration'
    possibly scp -p 2222 (lowercase) like for ssh above
  12. Our network division blocks access to port 8080 as it is used by Tomcat and proxys. What would be a good replacement? Or would any port number do, e.g. 8081?

  13. Anonymous

    About AWstats:

    sudo chmod 777 run_awstats

    is not really wise to do. I'd prefer chmod 755.

    Further more: the way AWstats is set up, it leaks information about site visitors to the Internet. That poses problems with privacy laws, etc. I would suggest to: either password-protect the stats or restrict access to the stats to computers in your network.

  14. There is a little update to do for the tutorial,  the package gavodachs-server no longer works, but gavodachs2-server does

  15. Thanks for contribution. Indeed this needs complete update & incorporation of the (many) comments.