Tag Archives: openstack-neutron

Script to create Neutron tenant networks

In my two node OpenStack setup (RDO on Fedora 20), I often have to create multiple Neutron tenant networks (here you can read a more on what’s a tenant network) for various testing purposes.

To alleviate this manual process, a trivial script that’ll create a new Neutron tenant network after you provide a few positional parameters in an existing OpenStack setup. This assumes there’s a working OpenStack setup with Neutron configured. I tested this on Neutron + OVS + GRE. This should work with any other Neutron plugins, as tenant networks is a Neutron concept (and not specific to plugins).


$ ./create-new-tenant-network.sh                \
                    TENANTNAME USERNAME         \
                    SUBNETSPACE ROUTERNAME      \ 

To create a new tenant network with subnet:

$ ./create-new-tenant-network.sh \
  demoten1 tuser1                \ trouter1              \
  priv-net1 priv-subnet1

The script does the below, in that order:

  1. Creates a Keystone tenant called demoten1.
  2. Then, a Keystone user called tuser1 and associates it to the
  3. Creates a Keystone RC file for the user (tuser1) and sources it.
  4. Creates a new private network called priv-net1.
  5. Creates a new private subnet called priv-subnet1 on priv-net1.
  6. Creates a router called trouter1.
  7. Associates the router (trouter1 in this case) to an existing external network (the script assumes it’s called as ext) by setting it as its gateway.
  8. Associates the private network interface (priv-net1) to the router (trouter1).
  9. Adds Neutron security group rules for this test tenant (demoten1) for ICMP and SSH.

To test if it’s all working, try booting a new Nova guest in the tenant network, and it should aquire an IP address from subnet.

Posting the relevant part of the script:

[. . .]
# Source the admin credentials
source keystonerc_admin

# Positional parameters

# Create a tenant, user and associate a role/tenant to it.
keystone tenant-create       \
         --name $tenantname
keystone user-create         \
         --name $username    \
         --pass fedora

keystone user-role-add       \
         --user $username    \
         --role user         \
         --tenant $tenantname

# Create an RC file for this user and source the credentials
cat >> keystonerc_$username<<EOF
export OS_USERNAME=$username
export OS_TENANT_NAME=$tenantname
export OS_PASSWORD=fedora
export OS_AUTH_URL=http://localhost:5000/v2.0/
export PS1='[\u@\h \W(keystone_$username)]\$ '

# Source this user credentials
source keystonerc_$username

# Create new private network, subnet for this user tenant
neutron net-create $privnetname

neutron subnet-create $privnetname \
        $subnetspace/24            \
        --name $privsubnetname     \

# Create a router
neutron router-create $routername

# Associate the router to the external network 
# by setting its gateway.
# NOTE: This assumes, the external network name is 'ext'
EXT_NET=$(neutron net-list     \
| grep ext | awk '{print $2;}')

PRIV_NET=$(neutron subnet-list \
| grep $privsubnetname | awk '{print $2;}')

ROUTER_ID=$(neutron router-list \
| grep $routername | awk '{print $2;}')

neutron router-gateway-set  \
        $ROUTER_ID $EXT_NET \

neutron router-interface-add \
        $ROUTER_ID $PRIV_NET \

# Add Neutron security groups for this test tenant
neutron security-group-rule-create   \
        --protocol icmp              \
        --direction ingress          \
        --remote-ip-prefix \

neutron security-group-rule-create   \
        --protocol tcp               \
        --port-range-min 22          \
        --port-range-max 22          \
        --direction ingress          \
        --remote-ip-prefix \

NOTE: As shell script is executed in a sub-process (of the parent shell), you won’t notice the keystone sourcing of the newly created user. (You can notice it in the stdout of the script in debug mode.)

If it’s helpful for someone, here’s my Neutron configurations & iptables rules for a two node setup with Neutron + OVS + GRE:

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