Vagrant allows to play with multiple VMs easily, but with
multiple VMs, it is dizzy to switch VMs back and forth, it is easy to do
something on VM B when the intended VM is A.
Ansible comes to the rescue. With Ansible, you sit
comfortably at one VM and control other VMs. In this blog, I will show you how
to setup Ansible on Vagrant.
The eventual setup will be like this:
My physical machine is win7,
on it, I start 4 VMs. VM mgmt is
my management VM, which I will install ansible
and rule over other VMs. VM infra
is where I install infrastructure tools, such consul
and other monitoring tools, the rest VMs app1
and app2 is where I install
applications.
I do development work on win7,
after testing out, I deploy them into VMs. A shared folder is setup between win7 and mgmt, so it is easy to move things around between win7 and VMs.
Vagrantfile
Vagrant.configure("2") do
|config|
if Vagrant.has_plugin?("vagrant-proxyconf")
#replace with your proxies
config.proxy.http= " https://<user>:<password>@<proxy-host>:<proxy-port>"
config.proxy.https= " https://<user>:<password>@<proxy-host>:<proxy-port>
"
config.proxy.ftp= " https://<user>:<password>@<proxy-host>:<proxy-port>
"
config.proxy.no_proxy = "localhost,127.0.0.1"
end
if Vagrant.has_plugin?("vagrant-timezone")
config.timezone.value="Asia/Shanghai"
end
config.vm.box = "ubuntu14.04-amd64"
config.vm.box_url = "https://github.com/kraksoft/vagrant-box-ubuntu/releases/download/14.04/ubuntu-14.04-amd64.box"
config.ssh.forward_agent = true
config.vm.provider "virtualbox" do |vb|
vb.gui
= true
vb.customize ["modifyvm",
:id, "--natdnshostresolver1", "on"]
vb.customize
["modifyvm", :id, "--natdnsproxy1" , "on"]
vb.customize
["modifyvm", :id, "--memory", 8192]
vb.customize
['modifyvm', :id, '--nicpromisc1', 'allow-all']
vb.customize
['modifyvm', :id, '--nicpromisc2', 'allow-all']
vb.customize
["modifyvm", :id, "--ioapic" , "on"]
vb.customize
["modifyvm", :id, "--cpus" , 2]
vb.customize
["modifyvm", :id, "--pae" , "on"]
vb.customize
["modifyvm", :id, "--nictype1", "virtio"]
vb.customize
["modifyvm", :id, "--nictype2", "virtio"]
vb.customize
["modifyvm", :id, "--chipset" , "ich9"]
end
# create mgmt node
config.vm.define :mgmt do |mgmt_config|
mgmt_config.vm.hostname =
"mgmt"
mgmt_config.vm.network :private_network,
ip: "192.168.33.10"
mgmt_config.vm.provision :shell, path:
"bootstrap-mgmt.sh"
mgmt_config.vm.synced_folder
"../../devops", "/devops"
end
# create infra node
config.vm.define :infra do |infra_config|
infra_config.vm.hostname =
"infra"
infra_config.vm.network :private_network,
ip: "192.168.33.11"
end
# create app nodes
(1..2).each do |i|
config.vm.define "app#{i}" do |node|
node.vm.hostname = "app#{i}"
node.vm.network :private_network, ip:
"192.168.33.2#{i}"
if
Vagrant.has_plugin?("vagrant-proxyconf")
node.proxy.no_proxy =
"localhost,127.0.0.1,192.168.33.2#{i},app#{i}"
end
end
end
end
I’ve shared the Vagrantfile techniques in my previous blogs,
there are only a couple of differences:
- This single Vagrant file creates 4 VMs: mgmt, infra, app1, app2
- This Vagrant installs ansible on VM mgmt using bootstrap-mgmt.sh.
And here is the content of bootstrap-mgmt.sh:
#!/usr/bin/env
bash
# install
ansible (http://docs.ansible.com/intro_installation.html)
apt-get
update
apt-get
-y install software-properties-common
apt-add-repository
-y ppa:ansible/ansible
apt-get
update
apt-get
-y install ansible
cat
>> /etc/hosts <<EOL
# vagrant
environment nodes
192.168.33.10 mgmt
192.168.33.11 infra
192.168.33.21 app1
192.168.33.22 app2
EOL
Note, when you run this Vagrantfile using vagrant up,
Vagrant will fail for each VM complaining shared folder can’t be setup, refer
to my previous blogs for the solution.
vagrant up will create and start all 4 VMs, you can also
use vagrant
up hostname
to start one VM, and use vagrant ssh hostname to log on one VM.
Ansible
Now vagrant ssh mgmt, and verify ansible is
installed correctly:
vagrant@mgmt:~$ ansible --version
ansible 2.0.0.2
config file = /etc/ansible/ansible.cfg
configured module search path = Default w/o overrides
Now configure Ansible to work on infra and app1, app2
nodes. To do so, we need to setup inventory.ini and ansible.cfg,
here is my file structure:
inventory.ini configures the nodes that are under the
control of Ansible:
[infra]
infra
[app]
app1
app2
ansible.cfg configures Ansible properties:
[defaults]
inventory = /devops/SaaS-Example/ansible/inventory.ini
callback_plugins = /devops/SaaS-Example/ansible/callback_plugins
(this callback will be explained
later)
Let us say hello from mgmt
to other VMs. The command to use is ansible all -m ping.
Let us break this command down:
- all: the target nodes, all means all nodes in inventory.ini, we could also use a single node or node groups, such as app1 or app.
- -m: module
- ping: the module name. Ansible has a lot of modules, using Ansible is to use these modules to accomplish certain things. If you fail to find a certain module, you can always use the old good shell module.
Our first hello attempt fails. This is because the other
nodes do not know who mgmt is, we need to setup
the ssh trusty relationship between mgmt and other nodes.
Although this attempt fails, it puts infra,
app1, app2
into the known_hosts of mgmt,
another way to accomplish this is to ssh to these boxes
directly, and enter yes upon prompting.
To establish ssh trust, first create public and private keys using ssh-keygen -t rsa -b 2048. At prompting, simply hit enter. This will create keys in /home/vagrant/.ssh/id_rsa.pub and /home/vagrant/.ssh/id_rsa.
For the next step we can use Ansible to setup the trusty relationship. Create file ssh-addkey.yml:
---
- hosts: all
become: yes
become_method: sudo
gather_facts: no
tasks:
- name: install ssh key
authorized_key: user=vagrant
key="{{ lookup('file',
'/home/vagrant/.ssh/id_rsa.pub') }}"
state=present
This yml file is an ansible playbook, despite its format, it
follows similar structure as the above ansible command line:
- hosts: all: target at all nodes
- authorized_key: a module that sets up keys for user (here vagrant) for remote nodes, user, key, state are parameters for this module
Now run this playbook with command ansible-playbook
ssh-addkey.yml --ask-pass:
With --ask-pass, ansible will prompt you for
password, enter vagrant.
Now the trust relationship is setup. We can say hello again:
This time, it succeeds.
By the way, ansible will cache ssh connections for 10
seconds (configurable in ansible.cfg), you can check out the
connections:
So if you say hello again very soon, ansible will reuse the
existing ssh connections.
Yml format is very strict, in the beginning this always gets
on me (still does):
Indention must be lined up, and must be whitespaces. If you
use notepad++,
you can convert tab to whitespaces in settings/preferences:
Thanks for the information. The information you provided is very helpful for DevOps Training users.
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