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152
docs/03-compute-resources.md
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@@ -1,46 +1,107 @@
# Provisioning Compute Resources
Kubernetes requires a set of machines to host the Kubernetes control plane and the worker nodes where containers are ultimately run. In this lab you will provision the machines required for setting up a Kubernetes cluster.
Kubernetes requires a set of machines to host the Kubernetes control plane and
the worker nodes where containers are ultimately run. In this lab you will
provision the machines required for setting up a Kubernetes cluster.
## Machine Database
This tutorial will leverage a text file, which will serve as a machine database, to store the various machine attributes that will be used when setting up the Kubernetes control plane and worker nodes. The following schema represents entries in the machine database, one entry per line:
This tutorial will leverage a text file, which will serve as a machine database,
to store the various machine attributes that will be used when setting up the
Kubernetes control plane and worker nodes. The following schema represents
entries in the machine database, one entry per line:
```text
IPV4_ADDRESS FQDN HOSTNAME POD_SUBNET
```
Each of the columns corresponds to a machine IP address `IPV4_ADDRESS`, fully qualified domain name `FQDN`, host name `HOSTNAME`, and the IP subnet `POD_SUBNET`. Kubernetes assigns one IP address per `pod` and the `POD_SUBNET` represents the unique IP address range assigned to each machine in the cluster for doing so.
Each of the columns corresponds to a machine IP address `IPV4_ADDRESS`, fully
qualified domain name `FQDN`, host name `HOSTNAME`, and the IP subnet
`POD_SUBNET`. Kubernetes assigns one IP address per `pod` and the `POD_SUBNET`
represents the unique IP address range assigned to each machine in the cluster
for doing so.
Here is an example machine database similar to the one used when creating this tutorial. Notice the IP addresses have been masked out. Your machines can be assigned any IP address as long as each machine is reachable from each other and the `jumpbox`.
Here is an example machine database similar to the one used when creating this
tutorial. Notice the IP addresses have been masked out. Your machines can be
assigned any IP address as long as each machine is reachable from each other
and the `jumpbox`.
```bash
cat machines.txt
```
```text
XXX.XXX.XXX.XXX server.kubernetes.local server
XXX.XXX.XXX.XXX node-0.kubernetes.local node-0 10.200.0.0/24
XXX.XXX.XXX.XXX node-1.kubernetes.local node-1 10.200.1.0/24
XXX.XXX.XXX.XXX controlplane.kubernetes.local controlplane
XXX.XXX.XXX.XXX node01.kubernetes.local node01 10.200.0.0/24
XXX.XXX.XXX.XXX node02.kubernetes.local node02 10.200.1.0/24
```
Now it's your turn to create a `machines.txt` file with the details for the three machines you will be using to create your Kubernetes cluster. Use the example machine database from above and add the details for your machines.
Now it's your turn to create a `machines.txt` file with the details for the
three machines you will be using to create your Kubernetes cluster. Use the
example machine database from above and add the details for your machines.
## Enable root Login
Initially the root account will be locked on all machines. You will need to
manually unlock the root account on each virtual machine.
You'll need to repeat these steps on each machine.
Login to the machine with the `vagrant` user:
`vagrant ssh@jumpbox`
Now set a password for the root account:
```shell
sudo passwd root
```
NOTE: You can choose password **vagrant** to keep it the same as the vagrant
user, and there will be only 1 password to remember.
You'll need to unlock the password of the named account. This option re-enables
a password by changing the password back to its previous value. In this case
it should be set to the password we just assigned.
```shell
sudo passwd -u root
```
Test that it works by running and entering the password you set:
```shell
su
```
## Configuring SSH Access
SSH will be used to configure the machines in the cluster. Verify that you have `root` SSH access to each machine listed in your machine database. You may need to enable root SSH access on each node by updating the sshd_config file and restarting the SSH server.
SSH will be used to configure the machines in the cluster. Verify that you have
`root` SSH access to each machine listed in your machine database. You may need
to enable root SSH access on each node by updating the sshd_config file and
restarting the SSH server.
### Enable root SSH Access
If `root` SSH access is enabled for each of your machines you can skip this section.
If `root` SSH access is enabled for each of your machines you can skip this
section.
By default, a new `debian` install disables SSH access for the `root` user. This is done for security reasons as the `root` user has total administrative control of unix-like systems. If a weak password is used on a machine connected to the internet, well, let's just say it's only a matter of time before your machine belongs to someone else. As mentioned earlier, we are going to enable `root` access over SSH in order to streamline the steps in this tutorial. Security is a tradeoff, and in this case, we are optimizing for convenience. Log on to each machine via SSH using your user account, then switch to the `root` user using the `su` command:
By default, a new install may disable SSH access for the `root` user. This is
done for security reasons as the `root` user has total administrative control
of unix-like systems. If a weak password is used on a machine connected to the
internet, well, let's just say it's only a matter of time before your machine
belongs to someone else. As mentioned earlier, we are going to enable `root`
access over SSH in order to streamline the steps in this tutorial. Security is
a tradeoff, and in this case, we are optimizing for convenience. Log on to each
machine via SSH using your user account, then switch to the `root` user using
the `su` command:
```bash
su - root
```
Edit the `/etc/ssh/sshd_config` SSH daemon configuration file and set the `PermitRootLogin` option to `yes`:
Edit the `/etc/ssh/sshd_config` SSH daemon configuration file and set the
`PermitRootLogin` option to `yes`:
```bash
sed -i \
@@ -56,7 +117,10 @@ systemctl restart sshd
### Generate and Distribute SSH Keys
In this section you will generate and distribute an SSH keypair to the `server`, `node-0`, and `node-1`, machines, which will be used to run commands on those machines throughout this tutorial. Run the following commands from the `jumpbox` machine.
In this section you will generate and distribute an SSH keypair to the
`controlplane`, `node01`, and `node02` machines, which will be used to run
commands on those machines throughout this tutorial. Run the following commands
from the `jumpbox` machine.
Generate a new SSH key:
@@ -90,16 +154,23 @@ done < machines.txt
```
```text
server
node-0
node-1
controlplane
node01
node02
```
## Hostnames
In this section you will assign hostnames to the `server`, `node-0`, and `node-1` machines. The hostname will be used when executing commands from the `jumpbox` to each machine. The hostname also plays a major role within the cluster. Instead of Kubernetes clients using an IP address to issue commands to the Kubernetes API server, those clients will use the `server` hostname instead. Hostnames are also used by each worker machine, `node-0` and `node-1` when registering with a given Kubernetes cluster.
In this section you will assign hostnames to the `controlplane`, `node01`,
and `node02` machines. The hostname will be used when executing commands from
the `jumpbox` to each machine. The hostname also plays a major role within the
cluster. Instead of Kubernetes clients using an IP address to issue commands to
the Kubernetes API server, those clients will use the `controlplane` hostname
instead. Hostnames are also used by each worker machine, `node01` and `node02`
when registering with a given Kubernetes cluster.
To configure the hostname for each machine, run the following commands on the `jumpbox`.
To configure the hostname for each machine, run the following commands on the
`jumpbox`.
Set the hostname on each machine listed in the `machines.txt` file:
@@ -121,14 +192,14 @@ done < machines.txt
```
```text
server.kubernetes.local
node-0.kubernetes.local
node-1.kubernetes.local
controlplane.kubernetes.local
node01.kubernetes.local
node02.kubernetes.local
```
## Host Lookup Table
In this section you will generate a `hosts` file which will be appended to `/etc/hosts` file on the `jumpbox` and to the `/etc/hosts` files on all three cluster members used for this tutorial. This will allow each machine to be reachable using a hostname such as `server`, `node-0`, or `node-1`.
In this section you will generate a `hosts` file which will be appended to `/etc/hosts` file on the `jumpbox` and to the `/etc/hosts` files on all three cluster members used for this tutorial. This will allow each machine to be reachable using a hostname such as `controlplane`, `node01`, or `node02`.
Create a new `hosts` file and add a header to identify the machines being added:
@@ -137,7 +208,8 @@ echo "" > hosts
echo "# Kubernetes The Hard Way" >> hosts
```
Generate a host entry for each machine in the `machines.txt` file and append it to the `hosts` file:
Generate a host entry for each machine in the `machines.txt` file and append it
to the `hosts` file:
```bash
while read IP FQDN HOST SUBNET; do
@@ -155,14 +227,15 @@ cat hosts
```text
# Kubernetes The Hard Way
XXX.XXX.XXX.XXX server.kubernetes.local server
XXX.XXX.XXX.XXX node-0.kubernetes.local node-0
XXX.XXX.XXX.XXX node-1.kubernetes.local node-1
XXX.XXX.XXX.XXX controlplane.kubernetes.local server
XXX.XXX.XXX.XXX node01.kubernetes.local node01
XXX.XXX.XXX.XXX node02.kubernetes.local node02
```
## Adding `/etc/hosts` Entries To A Local Machine
In this section you will append the DNS entries from the `hosts` file to the local `/etc/hosts` file on your `jumpbox` machine.
In this section you will append the DNS entries from the `hosts` file to the
local `/etc/hosts` file on your `jumpbox` machine.
Append the DNS entries from `hosts` to `/etc/hosts`:
@@ -186,28 +259,30 @@ ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
# Kubernetes The Hard Way
XXX.XXX.XXX.XXX server.kubernetes.local server
XXX.XXX.XXX.XXX node-0.kubernetes.local node-0
XXX.XXX.XXX.XXX node-1.kubernetes.local node-1
XXX.XXX.XXX.XXX controlplane.kubernetes.local server
XXX.XXX.XXX.XXX node01.kubernetes.local node01
XXX.XXX.XXX.XXX node02.kubernetes.local node02
```
At this point you should be able to SSH to each machine listed in the `machines.txt` file using a hostname.
At this point you should be able to SSH to each machine listed in the
`machines.txt` file using a hostname.
```bash
for host in server node-0 node-1
for host in controlplane node01 node02
do ssh root@${host} hostname
done
```
```text
server
node-0
node-1
controlplane
node01
node02
```
## Adding `/etc/hosts` Entries To The Remote Machines
In this section you will append the host entries from `hosts` to `/etc/hosts` on each machine listed in the `machines.txt` text file.
In this section you will append the host entries from `hosts` to `/etc/hosts`
on each machine listed in the `machines.txt` text file.
Copy the `hosts` file to each machine and append the contents to `/etc/hosts`:
@@ -219,6 +294,9 @@ while read IP FQDN HOST SUBNET; do
done < machines.txt
```
At this point, hostnames can be used when connecting to machines from your `jumpbox` machine, or any of the three machines in the Kubernetes cluster. Instead of using IP addresses you can now connect to machines using a hostname such as `server`, `node-0`, or `node-1`.
At this point, hostnames can be used when connecting to machines from your
`jumpbox` machine, or any of the three machines in the Kubernetes cluster.
Instead of using IP addresses you can now connect to machines using a hostname
such as `controlplane`, `node01`, or `node02`.
Next: [Provisioning a CA and Generating TLS Certificates](04-certificate-authority.md)

10
docs/04-certificate-authority.md
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@@ -42,7 +42,7 @@ Generate the certificates and private keys:
```bash
certs=(
"admin" "node-0" "node-1"
"admin" "node01" "node02"
"kube-proxy" "kube-scheduler"
"kube-controller-manager"
"kube-api-server"
@@ -77,10 +77,10 @@ ls -1 *.crt *.key *.csr
In this section you will copy the various certificates to every machine at a path where each Kubernetes component will search for its certificate pair. In a real-world environment these certificates should be treated like a set of sensitive secrets as they are used as credentials by the Kubernetes components to authenticate to each other.
Copy the appropriate certificates and private keys to the `node-0` and `node-1` machines:
Copy the appropriate certificates and private keys to the `node01` and `node02` machines:
```bash
for host in node-0 node-1; do
for host in node01 node02; do
ssh root@${host} mkdir /var/lib/kubelet/
scp ca.crt root@${host}:/var/lib/kubelet/
@@ -93,12 +93,12 @@ for host in node-0 node-1; do
done
```
Copy the appropriate certificates and private keys to the `server` machine:
Copy the appropriate certificates and private keys to the `controlplane` machine:
```bash
scp \
ca.key ca.crt \
kube-api-server.key kube-api-server.crt \
kube-api-controlplane.key kube-api-controlplane.crt \
service-accounts.key service-accounts.crt \
root@server:~/
```

12
docs/05-kubernetes-configuration-files.md
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@@ -12,10 +12,10 @@ When generating kubeconfig files for Kubelets the client certificate matching th
> The following commands must be run in the same directory used to generate the SSL certificates during the [Generating TLS Certificates](04-certificate-authority.md) lab.
Generate a kubeconfig file for the `node-0` and `node-1` worker nodes:
Generate a kubeconfig file for the `node01` and `node02` worker nodes:
```bash
for host in node-0 node-1; do
for host in node01 node02; do
kubectl config set-cluster kubernetes-the-hard-way \
--certificate-authority=ca.crt \
--embed-certs=true \
@@ -41,8 +41,8 @@ done
Results:
```text
node-0.kubeconfig
node-1.kubeconfig
node01.kubeconfig
node02.kubeconfig
```
### The kube-proxy Kubernetes Configuration File
@@ -184,10 +184,10 @@ admin.kubeconfig
## Distribute the Kubernetes Configuration Files
Copy the `kubelet` and `kube-proxy` kubeconfig files to the `node-0` and `node-1` machines:
Copy the `kubelet` and `kube-proxy` kubeconfig files to the `node01` and `node02` machines:
```bash
for host in node-0 node-1; do
for host in node01 node02; do
ssh root@${host} "mkdir -p /var/lib/{kube-proxy,kubelet}"
scp kube-proxy.kubeconfig \

16
docs/09-bootstrapping-kubernetes-workers.md
View File

@@ -9,7 +9,7 @@ The commands in this section must be run from the `jumpbox`.
Copy the Kubernetes binaries and systemd unit files to each worker instance:
```bash
for HOST in node-0 node-1; do
for HOST in node01 node02; do
SUBNET=$(grep ${HOST} machines.txt | cut -d " " -f 4)
sed "s|SUBNET|$SUBNET|g" \
configs/10-bridge.conf > 10-bridge.conf
@@ -23,7 +23,7 @@ done
```
```bash
for HOST in node-0 node-1; do
for HOST in node01 node02; do
scp \
downloads/worker/* \
downloads/client/kubectl \
@@ -38,17 +38,17 @@ done
```
```bash
for HOST in node-0 node-1; do
for HOST in node01 node02; do
scp \
downloads/cni-plugins/* \
root@${HOST}:~/cni-plugins/
done
```
The commands in the next section must be run on each worker instance: `node-0`, `node-1`. Login to the worker instance using the `ssh` command. Example:
The commands in the next section must be run on each worker instance: `node01`, `node02`. Login to the worker instance using the `ssh` command. Example:
```bash
ssh root@node-0
ssh root@node01
```
## Provisioning a Kubernetes Worker Node
@@ -184,7 +184,7 @@ systemctl is-active kubelet
active
```
Be sure to complete the steps in this section on each worker node, `node-0` and `node-1`, before moving on to the next section.
Be sure to complete the steps in this section on each worker node, `node01` and `node02`, before moving on to the next section.
## Verification
@@ -200,8 +200,8 @@ ssh root@server \
```
NAME STATUS ROLES AGE VERSION
node-0 Ready <none> 1m v1.32.3
node-1 Ready <none> 10s v1.32.3
node01 Ready <none> 1m v1.32.3
node02 Ready <none> 10s v1.32.3
```
Next: [Configuring kubectl for Remote Access](10-configuring-kubectl.md)

4
docs/10-configuring-kubectl.md
View File

@@ -74,8 +74,8 @@ kubectl get nodes
```
NAME STATUS ROLES AGE VERSION
node-0 Ready <none> 10m v1.32.3
node-1 Ready <none> 10m v1.32.3
node01 Ready <none> 10m v1.32.3
node02 Ready <none> 10m v1.32.3
```
Next: [Provisioning Pod Network Routes](11-pod-network-routes.md)

16
docs/11-pod-network-routes.md
View File

@@ -15,10 +15,10 @@ Print the internal IP address and Pod CIDR range for each worker instance:
```bash
{
SERVER_IP=$(grep server machines.txt | cut -d " " -f 1)
NODE_0_IP=$(grep node-0 machines.txt | cut -d " " -f 1)
NODE_0_SUBNET=$(grep node-0 machines.txt | cut -d " " -f 4)
NODE_1_IP=$(grep node-1 machines.txt | cut -d " " -f 1)
NODE_1_SUBNET=$(grep node-1 machines.txt | cut -d " " -f 4)
NODE_0_IP=$(grep node01 machines.txt | cut -d " " -f 1)
NODE_0_SUBNET=$(grep node01 machines.txt | cut -d " " -f 4)
NODE_1_IP=$(grep node02 machines.txt | cut -d " " -f 1)
NODE_1_SUBNET=$(grep node02 machines.txt | cut -d " " -f 4)
}
```
@@ -30,13 +30,13 @@ EOF
```
```bash
ssh root@node-0 <<EOF
ssh root@node01 <<EOF
ip route add ${NODE_1_SUBNET} via ${NODE_1_IP}
EOF
```
```bash
ssh root@node-1 <<EOF
ssh root@node02 <<EOF
ip route add ${NODE_0_SUBNET} via ${NODE_0_IP}
EOF
```
@@ -55,7 +55,7 @@ XXX.XXX.XXX.0/24 dev ens160 proto kernel scope link src XXX.XXX.XXX.XXX
```
```bash
ssh root@node-0 ip route
ssh root@node01 ip route
```
```text
@@ -65,7 +65,7 @@ XXX.XXX.XXX.0/24 dev ens160 proto kernel scope link src XXX.XXX.XXX.XXX
```
```bash
ssh root@node-1 ip route
ssh root@node02 ip route
```
```text