The OCCI connector requires the configuration for the EGI certificate infrastructure and access to the OCCI client. You must execute the following script to install all required dependencies:

# EPEL release
echo "Installing EPEL release..."
yum install -y yum-utils epel-release
yum-config-manager --enable epel

# Install dependencies
echo "Installing dependencies..."
yum install -y yum-priorities libxslt libxml2 libyaml dos2unix

# Install EGI UMD release
echo "Installing EGI UMD 3 release (check for other updates) ..."
rpm -ivH http://repository.egi.eu/sw/production/umd/4/centos7/x86_64/base/umd-release-4.0.0-1.el7.noarch.rpm

# Install FedCloud CA Certificates
echo "Installing FedCloud CA Certificates release..."
yum install -y lcg-CA &>/dev/null

# NB! Disable UMD 3 repositories.
# MyProxy and VOMS in UMD are too far out of date and do not work!!!
sed -i -e 's/^enabled.*/enabled=0/g' /etc/yum.repos.d/UMD-3-*

# Install CRL renewal
yum install -y fetch-crl
# run it immediately (it can take some time...)
# enable the periodic fetch-crl cron job
systemctl enable fetch-crl-cron
systemctl start fetch-crl-cron

# Provider of rOCCI client -- occi-cli RPM.
wget -O /etc/yum.repos.d/rocci.repo http://repository.egi.eu/community/software/rocci.cli/4.3.x/releases/repofiles/sl-7-x86_64.repo
yum install -y occi-cli

The server must also be configured to support the virtual organizations (VOs) of the cloud users. The following shows the configuration for the “fedcloud.egi.eu” VO.

mkdir -p /etc/grid-security/vomsdir/fedcloud.egi.eu
cd /etc/grid-security/vomsdir/fedcloud.egi.eu

cat > voms1.egee.cesnet.cz.lsc <<EOF
/DC=org/DC=terena/DC=tcs/OU=Domain Control Validated/CN=voms1.egee.cesnet.cz

cat > voms2.grid.cesnet.cz <<EOF
/DC=org/DC=terena/DC=tcs/OU=Domain Control Validated/CN=voms2.grid.cesnet.cz

cat >> /etc/vomses <<EOF
"fedcloud.egi.eu" "voms1.egee.cesnet.cz" "15002" "/DC=org/DC=terena/DC=tcs/OU=Domain Control Validated/CN=voms1.egee.cesnet.cz" "fedcloud.egi.eu" "24"
"fedcloud.egi.eu" "voms2.grid.cesnet.cz" "15002" "/DC=org/DC=terena/DC=tcs/OU=Domain Control Validated/CN=voms2.grid.cesnet.cz" "fedcloud.egi.eu" "24"


You can install the OCCI connector with:

$ yum install slipstream-connector-occi

With the software installed, you need to restart the SlipStream service in order for it to take the new connector into account:

$ systemctl restart slipstream

Now we need to configure SlipStream to take advantage of the new connector.


To allow users to take advantage of this connector, you must add one or more instances of this connector by either:

  1. Using the UI.
  2. Drop a configuration file and restart the service.

With the UI

Instanciate one or more instances of the connector

Once logged-in with a privileged user (e.g. super), open the configuration page by clicking on Configuration -> System at the top of the page. Then open the SlipStream Basics section and define a new instance of the connector with the following format:


Here is an example:


You can also instantiate the connector several times (in compliance with your license) by comma separating the connector string. Here is an example:

occi-a:occi, occi-b:occi, ...

Here is a screenshot of the parameter to define:

SlipStream Configuation - Basics section

SlipStream Configuation - Basics section

Don’t forget to save the configuration!

Now that the connector is loaded, you need to configure it.

Configure the connector instance

With the connector loaded in SlipStream, a new section in the configuration page will appear, allowing you to configure how the connector is to communicate with the IaaS cloud endpoint.

[SlipStream Configuation - OCCI section]

You can find a detailed description of each parameter as well as an explaination of how to find the right value of them in the `Parameters <#parameters>`__ paragraph below.

With a configuration file

Please see Configuration Files for details about this method of configuration.

Here is an example, which will configure the EC2 connector to interact with the region eu-central-1:

> cat /etc/slipstream/connectors/fedcloud-egi-eu.conf
cloud.connector.class = fedcloud-egi-eu:occi

You can find a detailed description of each parameter as well as an explaination of how to find the right value of them in the `Parameters <#parameters>`__ paragraph below.



Configure native images for this connector instance

Now you need to update SlipStream native images to add the image id and some parameters specific to OCCI.

This can be done via the UI or via configuration file. Documentation about how to do it via configuration file can be found here Unique Cloud Identifier Configuration Files.

Please go on a SlipStream base image (e.g. Ubuntu 12.04) and click on the Edit button. Add the image id for the OCCI Cloud in the section named Cloud Image Identifiers and Image Hierarchy.

And then configure the default amount of CPU and RAM on the tab fedcloud-egi-eu (or the name you gave your OCCI connector earlier) of the section Cloud Configuration.

User credentials

Now that the connector is configured and the native images updated, inform your users that they need to configure their credentials for the OCCI Cloud in their user profile to take advantage of your new connector.