mirror of
https://github.com/marcel-dempers/docker-development-youtube-series.git
synced 2025-06-06 17:01:30 +00:00
updates k8s
This commit is contained in:
Marcel Dempers
parent
1cd21b939b
commit
7384d560d9
@ -2,6 +2,10 @@
|
||||
|
||||
This guide is aimed to fast-track your Kubernetes learning by focusing on a practical hands-on overview guide. </br>
|
||||
|
||||
When learning Kubernetes, you usually have an idea of some existing system you own and manage, or a website that you are building. </br>
|
||||
|
||||
The challenge is understanding which Kubernetes building blocks you need in order to run your workloads on Kubernetes </br>
|
||||
|
||||
<hr/>
|
||||
<b>The problem:</b> "I want to adopt Kubernetes" </br>
|
||||
<b>The problem:</b> "I have some common existing infrastructure"
|
||||
@ -10,11 +14,113 @@ This guide is aimed to fast-track your Kubernetes learning by focusing on a prac
|
||||
<b>Our focus:</b> Solving the problem by learning each building block
|
||||
in order to port our infrastructure to Kubernetes.
|
||||
|
||||
## Docker installation
|
||||
## Understanding Containers
|
||||
|
||||
Before even looking at Kubernetes, you need to have a general understanding of containers like `docker`.
|
||||
Your workloads need to fit in containers in order to be shipped on Kubernetes. </br>
|
||||
Containers also have a bunch of assumptions that you need to meet.
|
||||
|
||||
* Defining the container - `Dockerfile`
|
||||
* Serving traffic - Exposing ports
|
||||
* Configuration - mount config files & secrets or `env` variables
|
||||
* Data persistence - When a container is terminated, everything inside the container is gone
|
||||
* Container entrypoint - The main process that runs in the container. Your app
|
||||
|
||||
|
||||
### Docker installation
|
||||
|
||||
* Install Docker [here](https://docs.docker.com/get-docker/)
|
||||
* Let's take a look at [Wordpress on Docker Hub](https://hub.docker.com/_/wordpress)
|
||||
* Build our docker file
|
||||
|
||||
## Run Kubernetes
|
||||
## Create Network
|
||||
|
||||
```
|
||||
docker network create wordpress
|
||||
```
|
||||
|
||||
## Build & Test container images
|
||||
|
||||
### Wordpress example
|
||||
```
|
||||
cd kubernetes\tutorials\basics\
|
||||
|
||||
docker build -f dockerfiles/wordpress.dockerfile . -t aimvector/wordpress-example
|
||||
|
||||
```
|
||||
|
||||
* Run our Wordpress container
|
||||
|
||||
```
|
||||
docker run -it --rm -p 80:80 --net wordpress aimvector/wordpress-example
|
||||
```
|
||||
|
||||
The wordpress container will be visible on port 80 on `http://localhost/`
|
||||
|
||||
### MySQL example
|
||||
|
||||
* We need a database, let's take a look at [MySQL on Docker Hub](https://hub.docker.com/_/mysql)
|
||||
* Build our MySQl container image
|
||||
|
||||
```
|
||||
docker build -f dockerfiles/mysql.dockerfile . -t aimvector/mysql-example
|
||||
```
|
||||
|
||||
* How do we run our MySQL ?
|
||||
|
||||
We need to understand that databases require storage and state
|
||||
Just like installing software on a server, it will store its files in some
|
||||
directory. Mysql stores its files under `/var/lib/mysql`
|
||||
|
||||
* We need a volume mount
|
||||
|
||||
Let's see how to run this in docker
|
||||
|
||||
```
|
||||
mkdir data
|
||||
|
||||
docker run --rm -d `
|
||||
--name mysql `
|
||||
--net wordpress `
|
||||
-e MYSQL_DATABASE=exampledb `
|
||||
-e MYSQL_USER=exampleuser `
|
||||
-e MYSQL_PASSWORD=examplepassword `
|
||||
-e MYSQL_RANDOM_ROOT_PASSWORD=1 `
|
||||
-v ${PWD}/data:/var/lib/mysql `
|
||||
aimvector/mysql-example
|
||||
|
||||
# we can see the container with
|
||||
docker ps
|
||||
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
|
||||
92cde663a3f5 aimvector/mysql-example "docker-entrypoint.s…" 5 seconds ago Up 3 seconds 3306/tcp, 33060/tcp mysql
|
||||
|
||||
```
|
||||
|
||||
* Run Wordpress and connect it to MySQL
|
||||
|
||||
```
|
||||
docker run -d `
|
||||
--rm `
|
||||
-p 80:80 `
|
||||
--name wordpress `
|
||||
--net wordpress `
|
||||
-e WORDPRESS_DB_HOST=mysql `
|
||||
-e WORDPRESS_DB_USER=exampleuser `
|
||||
-e WORDPRESS_DB_PASSWORD=examplepassword `
|
||||
-e WORDPRESS_DB_NAME=exampledb `
|
||||
aimvector/wordpress-example
|
||||
```
|
||||
|
||||
### Clean up
|
||||
|
||||
```
|
||||
docker rm -f wordpress
|
||||
docker rm -f mysql
|
||||
docker network rm wordpress
|
||||
rm data
|
||||
```
|
||||
|
||||
## Run Kubernetes Locally
|
||||
|
||||
* Install `kubectl` to work with kubernetes
|
||||
|
||||
@ -27,7 +133,7 @@ You will want to head over to the [kind](https://kind.sigs.k8s.io/) site
|
||||
* Create a cluster
|
||||
|
||||
```
|
||||
kind create cluster
|
||||
kind create cluster --image kindest/node:v1.23.5
|
||||
```
|
||||
|
||||
## Namespaces
|
||||
@ -36,23 +142,23 @@ kind create cluster
|
||||
kubectl create namespace cms
|
||||
```
|
||||
|
||||
## Deployments
|
||||
|
||||
* Deployment [documentation](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/)
|
||||
|
||||
cd kubernetes\tutorial
|
||||
|
||||
```
|
||||
kubectl -n cms apply -f deploy.yaml
|
||||
kubectl -n cms get pods
|
||||
|
||||
kubectl -n cms port-forward <pod-name> 80
|
||||
```
|
||||
## Configmaps
|
||||
|
||||
[Environment Variables](https://kubernetes.io/docs/tasks/inject-data-application/define-environment-variable-container/) for pods
|
||||
|
||||
[How to use](https://kubernetes.io/docs/concepts/configuration/configmap/) configmaps
|
||||
|
||||
```
|
||||
kubectl -n cms create configmap mysql `
|
||||
--from-literal MYSQL_RANDOM_ROOT_PASSWORD=1
|
||||
|
||||
kubectl -n cms get configmaps
|
||||
```
|
||||
|
||||
## Secrets
|
||||
|
||||
[How to use](https://kubernetes.io/docs/concepts/configuration/secret/) secrets in pods
|
||||
|
||||
```
|
||||
kubectl -n cms create secret generic wordpress `
|
||||
--from-literal WORDPRESS_DB_HOST=mysql `
|
||||
@ -60,33 +166,80 @@ kubectl -n cms create secret generic wordpress `
|
||||
--from-literal WORDPRESS_DB_PASSWORD=examplepassword `
|
||||
--from-literal WORDPRESS_DB_NAME=exampledb
|
||||
|
||||
kubectl -n cms create secret generic mysql `
|
||||
--from-literal MYSQL_USER=exampleuser `
|
||||
--from-literal MYSQL_PASSWORD=examplepassword `
|
||||
--from-literal MYSQL_DATABASE=exampledb
|
||||
|
||||
|
||||
kubectl -n cms get secret
|
||||
|
||||
```
|
||||
[How to use](https://kubernetes.io/docs/concepts/configuration/secret/) secrets in pods
|
||||
|
||||
Apply changes to our deployment
|
||||
## Deployments
|
||||
|
||||
* Deployment [documentation](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/)
|
||||
|
||||
cd kubernetes\tutorials\basics
|
||||
|
||||
```
|
||||
kubectl -n cms apply -f deploy.yaml
|
||||
kubectl -n cms apply -f yaml/deploy.yaml
|
||||
kubectl -n cms get pods
|
||||
```
|
||||
|
||||
We can `port-forward` again, and notice an error connecting to the database because the database does not exist
|
||||
|
||||
# Statefulset
|
||||
|
||||
Statefulset [documentation](https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/)
|
||||
|
||||
# Storage Class
|
||||
|
||||
StorageClass [documentation](https://kubernetes.io/docs/concepts/storage/storage-classes/)
|
||||
|
||||
# Services
|
||||
|
||||
Services [documentation](https://kubernetes.io/docs/concepts/services-networking/service/)
|
||||
|
||||
# Storage Class
|
||||
|
||||
StorageClass [documentation](https://kubernetes.io/docs/concepts/storage/storage-classes/)
|
||||
|
||||
```
|
||||
kubectl get storageclass
|
||||
```
|
||||
|
||||
# Statefulset
|
||||
|
||||
Statefulset [documentation](https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/)
|
||||
|
||||
Let's deploy our `mysql` using what we learnt above:
|
||||
|
||||
```
|
||||
kubectl -n cms apply -f .\statefulset.yaml
|
||||
kubectl -n cms apply -f yaml/statefulset.yaml
|
||||
|
||||
kubectl -n cms get pods
|
||||
```
|
||||
|
||||
## Persistent Volumes
|
||||
|
||||
[Documentation](https://kubernetes.io/docs/concepts/storage/persistent-volumes/)
|
||||
|
||||
## Port Forwarding
|
||||
|
||||
We can access private service endpoints or pods using `port-forward` :
|
||||
|
||||
```
|
||||
kubectl -n cms get pods
|
||||
kubectl -n cms port-forward <pod-name> 80
|
||||
```
|
||||
|
||||
## Public Traffic
|
||||
|
||||
In order to make our site public, its common practise to expose web servers via </br>
|
||||
a proxy or API gateway. </br>
|
||||
In Kubernetes, an Ingress is used.
|
||||
|
||||
## Ingress
|
||||
|
||||
To use an ingress, we need an ingress controller
|
||||
|
||||
```
|
||||
kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.1.3/deploy/static/provider/cloud/deploy.yaml
|
||||
```
|
||||
|
||||
Create an Ingress
|
||||
|
||||
```
|
||||
kubectl -n cms apply -f yaml/ingress.yaml
|
||||
```
|
||||
|
||||
5
kubernetes/tutorials/basics/dockerfiles/mysql.dockerfile
Normal file
5
kubernetes/tutorials/basics/dockerfiles/mysql.dockerfile
Normal file
@ -0,0 +1,5 @@
|
||||
FROM mysql:5.7
|
||||
|
||||
# make any changes to MySQL installation
|
||||
|
||||
EXPOSE 3306
|
||||
@ -0,0 +1,5 @@
|
||||
FROM wordpress:5.9-apache
|
||||
|
||||
#COPY files , plugins, install extra stuff
|
||||
|
||||
EXPOSE 80
|
||||
@ -39,4 +39,4 @@ spec:
|
||||
valueFrom:
|
||||
secretKeyRef:
|
||||
name: wordpress
|
||||
key: WORDPRESS_DB_PASSWORD
|
||||
key: WORDPRESS_DB_NAME
|
||||
@ -38,20 +38,23 @@ spec:
|
||||
- name: MYSQL_DATABASE
|
||||
valueFrom:
|
||||
secretKeyRef:
|
||||
name: wordpress
|
||||
key: WORDPRESS_DB_PASSWORD
|
||||
name: mysql
|
||||
key: MYSQL_DATABASE
|
||||
- name: MYSQL_USER
|
||||
valueFrom:
|
||||
secretKeyRef:
|
||||
name: wordpress
|
||||
key: WORDPRESS_DB_USER
|
||||
name: mysql
|
||||
key: MYSQL_USER
|
||||
- name: MYSQL_PASSWORD
|
||||
valueFrom:
|
||||
secretKeyRef:
|
||||
name: wordpress
|
||||
key: WORDPRESS_DB_PASSWORD
|
||||
name: mysql
|
||||
key: MYSQL_PASSWORD
|
||||
- name: MYSQL_RANDOM_ROOT_PASSWORD
|
||||
value: "1"
|
||||
valueFrom:
|
||||
configMapKeyRef:
|
||||
name: mysql
|
||||
key: MYSQL_RANDOM_ROOT_PASSWORD
|
||||
volumeMounts:
|
||||
- name: db
|
||||
mountPath: /var/lib/mysql
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user