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6.1. BACK-END SERVER
Listing 6.3. DHCP configuration
auto e t h 0
i f a c e e t h 0 i n e t dhcp
Listing 6.4. static IP configuration
auto e t h 0
i f a c e eth0 i n e t
address
netmask
gateway
static
X.X.X.X
X.X.X.X
X.X.X.X
The combination of the file injection together with the modification of the Libvirt
XML file will let the instance boot with the correct settings for all network interfaces,
on both the virtual machine and the hypervisor.
6.1.4
User Management
As described in section 5.1.5, Nova has multiple user roles with different rights. As
a regular user you will only receive the instances related to your projects when a list
command is sent to the OpenStack API server. If a system administrator performs
the same call, the complete list of running virtual machines is returned to the user.
To keep the difference between the different types of users, the Back-end server
uses the Nova API and will receive the correct instances on demand. Also different
calls to this project’s web service may filter the administrators from regular users
and return more data. An example of this filtering is the authenticate request which
is used to determine if the user application should provide certain modules or not.
Another example is the get request to the URL /users which will return all users in
the system if the call is made by an administrator and only return project-specific
users if a regular user is making the call.
6.1.5
Instance Configurations
When the back-end server receives the network map with all the virtual machines,
the instance types, described in section 5.1.6, are also specified. If a predefined
instance type is selected, its data can be fetched from Nova’s database. If the
instance type is a custom created one, the system must create a new instance type
with the parameters specified by the user. First the instance type is created in the
Nova database and then the new id is used when the machine is launched. By doing
this, the user can specify any type of instance type (As long as the numbers are
valid, e.g. An instance type must have at least one virtual CPU).
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