In a previous article we described how to create a pre-configured virtual machine image using packer to be used in vagrant later on, here we will learn how to run multi-server environment using vagrant which will be used in future tutorials to test them and create development environments on developers’ machines before they are deployed to production servers.
We will assume vagrant is up and running if not please read my previous article to install it if you are using Ubuntu or Debian but if you are using windows you can download the installer from here and start using it after installation.
When vagrant is initialized in a directory it creates a file called
Vagrantfile, this file
describes the servers we are going to create, use this command for initialization.
vagrant init ubuntu/bionic64
After removing comments we get these three lines in the file
Vagrant.configure("2") do |config| config.vm.box = "ubuntu/bionic64" end
The first line defines the configuration section which uses version 2 of the configuration language, the second line defines the box (image) used to create the VM that is “ubuntu/bionic64” which comes pre-installed with Ubuntu 18.04 Server and the last line terminates configuration.
To run this environment just execute
And vagrant will use Virtual Box to create a new VM from the “ubuntu/bionic64” and configures it to be accessible over SSh using this command
If you want to connect using your own SSH client then just execute this command
And vagrant will print the configuration which must be used to connect to the VM using SSH client
An example output is
Host default HostName 127.0.0.1 User vagrant Port 2222 UserKnownHostsFile /dev/null StrictHostKeyChecking no PasswordAuthentication no IdentityFile /home/mouhsen/Linux/VMs/MultiServer/.vagrant/machines/default/virtualbox/private_key IdentitiesOnly yes LogLevel FATAL
To connect using SSH client use this command
ssh email@example.com -p2222 -i /home/mouhsen/Linux/VMs/MultiServer/.vagrant/machines/default/virtualbox/private_key
Okay now we created a single VM using vagrant let us move to the next section and create two VMs using vagrant and connect to both of them
Multi VM with vagrant
To create more than one VM using vagrant we have to modify the Vagrantfile we just created, remove the second line and replace it with these lines
config.vm.define "vm1" do |vm1| vm1.vm.box = "ubuntu/bionic64" end config.vm.define "vm2" do |vm2| vm2.vm.box = "ubuntu/bionic64" end
Now execute this command to run the servers
This will create two VMs one is called “vm1” and the other “vm2” to connect to any of them use this command
vagrant ssh vm1 # to connect to VM1
The configuration is simple just add more lines to create more VMs, each VM can have its own and different configuration such as a different box, different IP address and different specs, in the next section we will see how to customize the VM.
In the previous section we created three identical VMs each one had the same network (default NAT), the same box and same CPU and RAM, in this section we will customize each one of these parameters.
Let us start by changing the box for each VM, we previously saw how to choose a box for the VM, just change the value for the required option, as follows
vm2.vm.box = "ubuntu/xenial64"
This will use Ubuntu 16.04 for the second VM, to give each VM a unique private IP use this option
vm1.vm.network "private_network", ip: "192.168.22.11"
This will give the first VM an IP address “192.168.22.11” which can be used to connect to the VM and reach any port inside it, this is useful if you want to connect to multiple services inside the VM using an IP address, however if you only have a web server on port 80 you can use forwarded port as follows
vm1.vm.network "forwarded_port", guest: 80, host: 8080
After adding this you can connect to port 80 inside the VM using port 8080 on the host machine.
To change the RAM and CPU for the VM use this option
vm2.vm.provider "virtualbox" do |vb| vb.memory = "1024" vb.cpus = 4 end
Here we are giving 1GB of RAM for the VM
vm2 and 4 CPUs
To apply changes you need to reload the environment as follows
After each VM is created we can ask vagrant to execute a script inside the VM to configure it for example it can install some software setup some directories or users etc…
To run a script once the VM has booted use this section
vm1.vm.provision "shell", inline: <<-SHELL apt update apt install -y mysql-server SHELL
You can put any shell commands in there, here we chose to install mysql-server package on the first VM we can do what ever we want, this can be used later to configure the VM as we want.
To run the provision script after the VM booted and we included the script after that use this command
To shutdown the VMs use this command
To delete them use
Destroy means completely delete the VM and its hard disk.
Here we learned more about vagrant and how it can be used to run multiple VMs, this will help us in future articles to create VMs and test software on them also we will learn how to run a development environment for a web project using it.
I hope you find the content useful for any comments or questions you can contact me on my email address firstname.lastname@example.org
Stay tuned for more articles. :) :)