kubernetes-the-hard-way/docs/02-compute-resources.md

# Provisioning Compute Resources

Note: You must have VirtualBox and Vagrant configured at this point

Download this github repository and cd into the vagrant folder

`github clone https://github.com/mmumshad/kubernetes-the-hard-way.git`

CD into vagrant directory

`cd kubernetes-the-hard-way\vagrant`

Run Vagrant up

`vagrant up`


This does the below:

- Deploys 5 VMs - 2 Master, 2 Worker and 1 Loadbalancer with the name 'kubernetes-ha-* '
    > This is the default settings. This can be changed at the top of the Vagrant file

- Set's IP addresses in the range 192.168.5

    | VM           |  VM Name               | Purpose       | IP           | Forwarded Port   |
    | ------------ | ---------------------- |:-------------:| ------------:| ----------------:|
    | master-1     | kubernetes-ha-master-1 | Master        | 192.168.5.11 |     2711         |
    | master-1     | kubernetes-ha-master-2 | Master        | 192.168.5.12 |     2712         |
    | worker-1     | kubernetes-ha-worker-1 | Worker        | 192.168.5.21 |     2730         |
    | worker-2     | kubernetes-ha-worker-2 | Worker        | 192.168.5.22 |     2721         |
    | loadbalancer | kubernetes-ha-lb       | LoadBalancer  | 192.168.5.30 |     2722         |

    > These are the default settings. These can be changed in the Vagrant file

- Add's a DNS entry to each of the nodes to access internet
    > DNS: 8.8.8.8

- Install's Docker on Master and Worker nodes
- Runs the below command on all nodes to allow for network forwarding in IP Tables.
  This is required for kubernetes networking to function correctly.
    > sysctl net.bridge.bridge-nf-call-iptables=1


## SSH to the nodes

There are two ways to SSH into the nodes:

### 1. SSH using Vagrant

  From the directory you ran the `vagrant up` command, run `vagrant ssh <vm>` for example `vagrant ssh master-1`.
  > Note: Use VM field from the above table and not the vm name itself.

### 2. SSH Using SSH Client Tools

Use your favourite SSH Terminal tool (putty).

Use the above IP addresses. Username and password based SSH is disabled by default.
Vagrant generates a private key for each of these VMs. It is placed under the .vagrant folder (in the directory you ran the `vagrant up` command from) at the below path for each VM:

**Private Key Path:** `.vagrant/machines/<machine name>/virtualbox/private_key`

**Username:** `vagrant`


## Verify Environment

- Ensure all VMs are up
- Ensure VMs are assigned the above IP addresses
- Ensure you can SSH into these VMs using the IP and private keys
- Ensure the VMs can ping each other
- Ensure the master and worker nodes have Docker installed on them. Version: 18.06
  > command `sudo docker version`

## Troubleshooting Tips

If any of the VMs failed to provision, or is not configured correct, delete the vm using the command:

`vagrant destroy <vm>`

Then reprovision. Only the missing VMs will be re-provisioned

`vagrant up`


Sometimes the delete does not delete the folder created for the vm and throws the below error.

VirtualBox error:

    VBoxManage.exe: error: Could not rename the directory 'D:\VirtualBox VMs\ubuntu-bionic-18.04-cloudimg-20190122_1552891552601_76806' to 'D:\VirtualBox VMs\kubernetes-ha-worker-2' to save the settings file (VERR_ALREADY_EXISTS)
    VBoxManage.exe: error: Details: code E_FAIL (0x80004005), component SessionMachine, interface IMachine, callee IUnknown
    VBoxManage.exe: error: Context: "SaveSettings()" at line 3105 of file VBoxManageModifyVM.cpp

In such cases delete the VM, then delete teh VM folder and then re-provision

`vagrant destroy <vm>`

`rmdir "<path-to-vm-folder>\kubernetes-ha-worker-2"`

`vagrant up`