https://github.com/marcaurele/ansible-exoscale-privnet
Deploy a DHCP server to configure VMs using their privnet
https://github.com/marcaurele/ansible-exoscale-privnet
ansible cloudstack dhcp-server exoscale isc-dhcp playbook
Last synced: 2 months ago
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Deploy a DHCP server to configure VMs using their privnet
- Host: GitHub
- URL: https://github.com/marcaurele/ansible-exoscale-privnet
- Owner: marcaurele
- License: mit
- Created: 2017-06-23T12:59:43.000Z (almost 8 years ago)
- Default Branch: master
- Last Pushed: 2019-01-08T09:27:58.000Z (over 6 years ago)
- Last Synced: 2025-03-19T23:04:53.657Z (2 months ago)
- Topics: ansible, cloudstack, dhcp-server, exoscale, isc-dhcp, playbook
- Homepage:
- Size: 54.7 KB
- Stars: 2
- Watchers: 1
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Ansible playbook to deploy a DHCP server for private networking on Exoscale
On [Exoscale](https://www.exoscale.ch), you can attach a
[private network](https://community.exoscale.ch/documentation/compute/privnet/)
to your VMs, which comes unmanaged. To ease the communication between your
instances on this private link, let's setup a DHCP server answering requests on
the private interface for all your VMs using this second network.
We are going to use Ansible to ease the process of deploying one DHCP server
and 3 sample virtual machines to validate the setup.
If you're not familiar with [Ansible](https://www.ansible.com), it's an open
source automation tool for your infrastructure as a code.
The only language you'll need is
[YAML](https://docs.ansible.com/ansible/latest/YAMLSyntax.html) to write the
configuration files.
## Setup
First you have to clone the repository:
$ git clone https://github.com/marcaurele/ansible-exoscale-privnet.git
$ cd ansible-exoscale-privnet
Create a new [virtual environment for Python](https://virtualenv.pypa.io):
# For python 2
$ virtualenv -p venv
# For python 3
$ python3 -m venv venv
# Activate the virtual environment
$ . ./venv/bin/activate
Install the requirements for the playbook
([ansible](https://pypi.python.org/pypi/ansible) *(>=2.4)*,
[cs](https://pypi.python.org/pypi/cs),
[sshpubkeys](https://pypi.python.org/pypi/sshpubkeys)):
$ pip install -r requirements.txt
In your shell you need to export those 3 variables, as per
[cs documentation](https://github.com/exoscale/cs/):
- `export CLOUDSTACK_ENDPOINT=https://api.exoscale.ch/compute`
- `export CLOUDSTACK_KEY=`
- `export CLOUDSTACK_SECRET=`
Or if you're alread using a `.cloudstack.ini` file, you only need to export:
- `export CLOUDSTACK_REGION=`
*Your API key can be found at https://portal.exoscale.ch/account/profile/api.*
Now you are all set to run the playbook. To verify the setup, from your
terminal run:
$ cs listZones
You should get a JSON output of the current zones available on Exoscale.
```json
{
"count": 3,
"zone": [
{
"allocationstate": "Enabled",
"dhcpprovider": "VirtualRouter",
"id": "1128bd56-b4d9-4ac6-a7b9-c715b187ce11",
"localstorageenabled": true,
"name": "ch-gva-2",
"networktype": "Basic",
"securitygroupsenabled": true,
"tags": [],
"zonetoken": "ccb0a60c-79c8-3230-ab8b-8bdbe8c45bb7"
},
{
"allocationstate": "Enabled",
"dhcpprovider": "VirtualRouter",
"id": "91e5e9e4-c9ed-4b76-bee4-427004b3baf9",
"localstorageenabled": true,
"name": "ch-dk-2",
"networktype": "Basic",
"securitygroupsenabled": true,
"tags": [],
"zonetoken": "fe63f9cb-ff75-31d3-8c46-3631f7fcd533"
},
{
"allocationstate": "Enabled",
"dhcpprovider": "VirtualRouter",
"id": "4da1b188-dcd6-4ff5-b7fd-bde984055548",
"localstorageenabled": true,
"name": "at-vie-1",
"networktype": "Basic",
"securitygroupsenabled": true,
"tags": [],
"zonetoken": "26d84c22-f66d-377e-93ab-987ef477cab3"
}
]
}
```
## Quick run
I will discuss the playbook setup afterwards. If you're eager to run the playbook
and see the result, run:
$ ansible-playbook deploy-privnet-dhcp.yml
If you wish to deploy those virtual machines in another zone/region, for example
`de-fra-1` you can overwrite the `zone` variable on the command line:
$ ansible-playbook deploy-privnet-dhcp.yml -e "zone=de-fra-1"
## Playbook roles
### Common
This role creates an SSH key "privnet" to be used on all virtual machines
deployed by this playbook to authenticate, instead of using a password. This
new key generated by CloudStack is saved under `~/.ssh/id_rsa_privnet` on your
local machine.
### Infra
This role provisions the VMs on Exoscale, as well as a new SSH key, security
groups, and adds the private networking interface to each of them. What you
might not see often is the `user_data` provided for the VM deployment in
[`create_vm.yml`](https://github.com/marcaurele/ansible-exoscale-privnet/blob/master/roles/infra/tasks/create_vm.yml)
which is used to let cloud-init manage the hostname nicely as done when starting
a VM from Exsocale portal:
```yaml
user_data: |
#cloud-config
manage_etc_hosts: true
fqdn: {{ zone }}-{{ dhcp_name }}
```
The private networking interface is added through
[`create_private_nic.yml`](https://github.com/marcaurele/ansible-exoscale-privnet/blob/master/roles/infra/tasks/create_private_nic.yml)
using Ansible
[`cs_instance_nic`](http://docs.ansible.com/ansible/latest/cs_instance_nic_module.html)
module:
```yaml
- name: "dhcp server : add privnet nic"
local_action:
module: cs_instance_nic
network: "{{ private_network }}"
vm: "{{ zone }}-{{ dhcp_name }}"
zone: "{{ zone }}"
```
It can also be directly attached to the VM on the deployment step in
[`create_vm.yml`](https://github.com/marcaurele/ansible-exoscale-privnet/blob/master/roles/infra/tasks/create_vm.yml)
with the `networks` attribute:
```yaml
- name: "dhcp server : create"
local_action:
module: cs_instance
name: "{{ zone }}-{{ dhcp_name }}"
template: "{{ template }}"
root_disk_size: "{{ root_disk_size }}"
service_offering: "{{ instance_type }}"
ssh_key: "{{ ssh_key }}"
security_groups: [ '{{ security_group_name }}' ]
networks:
- "{{ private_network }}"
user_data: |
#cloud-config
manage_etc_hosts: true
fqdn: {{ zone }}-{{ dhcp_name }}
zone: "{{ zone }}"
```
This instructs Ansible to attach a new NIC to VM `{{ dhcp_name }}` in the
`{{zone }}` zone on the `privNetForBasicZone` network. A new `eth1` interface
comes up on your Linux Ubuntu box for the DHCP server to bind to.
### DHCP/server
This role configures the DHCP server. We configure a static IP address for
its privnet interface `eth1` in
[`configure_private_nic.yml`](https://github.com/marcaurele/ansible-exoscale-privnet/blob/master/roles/dhcp/server/tasks/configure_private_nic.yml)
and activate the interface:
```yaml
- name: upload network interface configuration
template:
src: privnet.cfg.j2
dest: /etc/network/interfaces.d/01-privnet.cfg
force: yes
register: privnet_cfg
- name: enable privnet interface
shell: "ifup eth1"
when: privnet_cfg.changed
```
In [`setup_dhcp_server.yml`](https://github.com/marcaurele/ansible-exoscale-privnet/blob/master/roles/dhcp/server/tasks/setup_dhcp_server.yml)
we install ISC DHCP server with a basic configuration to serve IP addresses
in the range `10.11.12.2` - `10.11.12.30`:
```yaml
- name: install packages
apt:
name:
- isc-dhcp-server
state: present
- name: set listening interfaces
lineinfile:
path: /etc/default/isc-dhcp-server
line: "INTERFACES=\"eth1\""
regexp: "^INTERFACES"
notify: restart dhcp server
- name: set configuration
template:
dest: /etc/dhcp/dhcpd.conf
src: dhcpd.conf.j2
owner: root
group: root
notify: restart dhcp server
```
### DHCP/client
This role is the simplest through
[`configure_private_nic.yml`](https://github.com/marcaurele/ansible-exoscale-privnet/blob/master/roles/dhcp/client/tasks/configure_private_nic.yml): it uploads the
[network interface configuration file](https://github.com/marcaurele/ansible-exoscale-privnet/blob/master/roles/dhcp/client/files/privnet.cfg)
for the privnet and enables it:
```yaml
- name: copy network interface configuration
copy:
src: privnet.cfg
dest: /etc/network/interfaces.d/01-privnet.cfg
force: yes
register: privnet_cfg
- name: enable privnet interface
shell: "ifup eth1"
when: privnet_cfg.changed
```
## Going further
This setup could be extended to also configure the DHCP server with static
DHCP mappings for your VMs based on their private interface MAC address.