Unable to ssh in a multi-machine vagrant environment

Question

I created a three node multi-machine vagrant environment and am having issues ssh'ing from one vagrant vm to another.

Here is the Vagrantfile:

Vagrant.configure("2") do |config| 
  config.vm.box = "centos/7"

  config.vm.define "master" do |master|
    master.vm.hostname = "master.local" 
    master.vm.network "private_network", type: "dhcp"
  end 

  config.vm.define "node1" do |node1|
     node1.vm.hostname = "node1.local" 
     node1.vm.network "private_network", type: "dhcp" 
  end 

  config.vm.define "node2" do |node2|
    node2.vm.hostname = "node2.local" 
    node2.vm.network "private_network", type: "dhcp" 
  end  
end 

The hosts file (same on each node):

$ cat /etc/hosts
172.28.128.3    master.local    master
172.28.128.4    node1.local     node1
172.28.128.5    node2.local     node2

I can ping back and forth all day from any machine to the other but I cannot ssh from one vagrant vm to the other. The typical error message is (from node1 to master):

[vagrant@node1.local] $ ssh vagrant@172.28.128.3
Permission denied (publickey,gssapi-keyex,gssapi-with-mic) 

SSH is running and the port is open.

The firewall is not running.

I am sure this has to do with ssh keys. I readily admit I am not an expert.
What am I doing wrong here folks?

Answer 1

Following Vagrant file address this problem.

You can get all supporting key files along with this vagrant file at https://github.com/malyabee/IaaC/tree/master/ansible_lab

$commonscript = <<-SCRIPT
sudo yum update -y
sudo yum install python2 epel-release -y
sudo yum install -y ansible
sudo echo "192.168.22.10    ansiblecontroller.example.com ansiblecontroller" >> /etc/hosts
sudo echo "192.168.22.11   node01.example.com   node01" >> /etc/hosts
sudo echo "192.168.22.12   node02.example.com      node02" >> /etc/hosts
SCRIPT

$nodescript = <<-SCRIPT
cat /vagrant/ansible_lab.pub >> /home/vagrant/.ssh/authorized_keys
SCRIPT

$ansiblescript = <<-SCRIPT
sudo yum install ansible -y
sudo cp -r /vagrant/ansible_lab /home/vagrant/.ssh/id_rsa
sudo chmod 400  /home/vagrant/.ssh/id_rsa
sudo chown vagrant:vagrant /home/vagrant/.ssh/id_rsa
SCRIPT

Vagrant.configure("2") do |config|
  config.vm.provision "shell", inline: "echo Hello"

  config.vm.define "ansiblecontroller" do |ansiblecontroller|
    ansiblecontroller.vm.box = "centos/7"
    ansiblecontroller.vm.provider "virtualbox" do |v|
          v.memory = 512
          v.cpus = 1
       end
    ansiblecontroller.vm.network "private_network", ip: "192.168.22.10", virtualbox__intnet: "mynetwork01"
    ansiblecontroller.vm.hostname = "ansiblecontroller.example.com"
    # Installing required packages for ansible controller node
    ansiblecontroller.vm.provision "shell", inline: $commonscript
    ansiblecontroller.vm.provision "shell", inline: $ansiblescript
  end

  config.vm.define "node01" do |node01|
    node01.vm.box = "centos/7"
    node01.vm.provider "virtualbox" do |v|
          v.memory = 512
          v.cpus = 1
       end
    node01.vm.network "private_network", ip: "192.168.22.11", virtualbox__intnet: "mynetwork01"
    node01.vm.hostname = "node01.example.com"
    # Installing required packages for  node01
    node01.vm.provision "shell", inline: $commonscript
    node01.vm.provision "shell", inline: $nodescript
  end
  config.vm.define "node02" do |node02|
    node02.vm.box = "centos/7"
    node02.vm.provider "virtualbox" do |v|
          v.memory = 512
          v.cpus = 1
       end
    node02.vm.network "private_network", ip: "192.168.22.12", virtualbox__intnet: "mynetwork01"
    node02.vm.hostname = "node02.example.com"
    # Installing required packages for  node01
    node02.vm.provision "shell", inline: $commonscript
    node02.vm.provision "shell", inline: $nodescript
  end
end

Answer 2

According to the docs one should use:

vagrant ssh [name|id]

If there is a single node then use vagrant ssh and in case of multi-node define the name or id of the VM, e.g. vagrant ssh box1

If one would like to ssh between boxes then one could create an ssh key and provision the private key to each box and add the public key to authorized_keys file.

https://www.vagrantup.com/docs/provisioning/file.html

Vagrant.configure("2") do |config|
  # ... other configuration
config.vm.provision "file", source: "~/.gitconfig", destination: ".gitconfig"
end

Answer 3

Try this link. You need to either execute one of the following:

• ssh -i <pathto/private_key> <vagrant>@<ip>
• ssh -o PreferredAuthentications=password user@server-ip (if you haven’t disabled password based authentication)