EXAMPLE WITH DEPENDENCY AND SCRIPTS

Let's see a simple example with two VNFs: vnf-server and vnf-database.
The vnf-server needs the IP address of the vnf-database to be able to connect properly. The following figure shows the source (vnf-database), the target (vnf-server) and the dependency (IP). The VNFs are connected to the same virtual network called "vnet".

INSTANTIATE scripts

To start the VNFs we have two scripts instantiate-vnf-server.sh and instantiate-vnf-database.sh (more scripts are possible). Here is the content of the instantiate-vnf-server.sh script:

#!/bin/bash

echo "INSTANTIATION of the VNF server"
echo "The following parameters are available:"

echo "Out-of-the-box parameters:"
echo "Hostname: ${hostname}"
echo "Private IP: ${vnet}"
echo "Floating IP (if requested otherwise it does not exist): ${vnet_floatingIp}"

echo "Configuration parameters:"
echo "The answer to everything is.. ${ANSWER_TO_EVERYTHING}"

# ... Add the code to start the vnf_server ...

CONFIGURE script

After the instantiation of the vnf-server we can configure it with the following database_connectToDb.sh script:

#!/bin/bash

echo "This is the ip of the vnf-database: ${database_vnet}"
echo "This is the floating ip of the vnf-database: ${database_vnet_floatingIp}"
echo "This is the hostname of the vnf-database: ${database_hostname}"

# ... Add the code to connect to the vnf-database with the ip: ${database_vnet} ...

Note1: It is important that the name of the configure script starts with the type of the source VNF (in this case database) followed by an underscore. For accessing the parameters from the source VNF we have to use environment variables following this pattern: sourceVnfType_parameterName

Note2: All the scripts need to be in a repository or in the vnf package (see the vnf package structure here).

In order to deploy the VNFs we have to create both the VNF descriptor: vnf-database-descriptor.json and vnf-server-descriptor.json. Below you can see the the most relevant part of them:

vnf-database-descriptor.json

{
    "name":"vnf-database",
    "type":"database",
    "endpoint":"generic",
    ...
    "lifecycle_event":[
        {
            "event":"INSTANTIATE",
            "lifecycle_events":[
                "instantiate-vnf-database.sh"
            ]
        }
    ],
    ...
}

Note: to use the Generic VNFM for managing a VNF just set "generic" in the endpoint field.

vnf-server-descriptor.json

{
    "name":"vnf-server",
    "type":"server",
    "endpoint":"generic",
    ...
    "configurations":{
            "name":"config_name",
            "configurationParameters":[
            {
                "confKey":"ANSWER_TO_EVERYTHING",
                "value":"42"
            }
            ]
    },
    ...
    "lifecycle_event":[
        {
            "event":"INSTANTIATE",
            "lifecycle_events":[
                "instantiate-vnf-server.sh"
            ]
        },
        {
            "event":"CONFIGURE",
            "lifecycle_events":[
                "database_connectToDb.sh"
            ]
        }
    ],
    ...
}

The Network Service Descriptor has to include both VNFDs from above and the dependency:

{
    "name":"simple-nsd",
    "vnfd":[
        {
            "id":"29d918b9-6245-4dc4-abc6-b7dd6e84f2c1"
        },
        {
            "id":"87820607-4048-4fad-b02b-dbcab8bb5c1c"
        }
    ],
    "vld":[
        {
            "name":"vnet"
        }
    ],
    "vnf_dependency":[
        {
            "source" : {
                "name": "vnf-database"
            },
            "target":{
                "name": "vnf-server"
            },
            "parameters":[
                "vnet"
            ]
        }
    ]
}