diff --git a/kubernetes/tutorials/basics/README.md b/kubernetes/tutorials/basics/README.md index e943d50..285271f 100644 --- a/kubernetes/tutorials/basics/README.md +++ b/kubernetes/tutorials/basics/README.md @@ -2,6 +2,10 @@ This guide is aimed to fast-track your Kubernetes learning by focusing on a practical hands-on overview guide.
+When learning Kubernetes, you usually have an idea of some existing system you own and manage, or a website that you are building.
+ +The challenge is understanding which Kubernetes building blocks you need in order to run your workloads on Kubernetes
+
The problem: "I want to adopt Kubernetes"
The problem: "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 Our focus: 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.
+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 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 80 +``` + +## Public Traffic + +In order to make our site public, its common practise to expose web servers via
+a proxy or API gateway.
+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 ``` diff --git a/kubernetes/tutorials/basics/dockerfiles/mysql.dockerfile b/kubernetes/tutorials/basics/dockerfiles/mysql.dockerfile new file mode 100644 index 0000000..53d0d5d --- /dev/null +++ b/kubernetes/tutorials/basics/dockerfiles/mysql.dockerfile @@ -0,0 +1,5 @@ +FROM mysql:5.7 + +# make any changes to MySQL installation + +EXPOSE 3306 \ No newline at end of file diff --git a/kubernetes/tutorials/basics/dockerfiles/wordpress.dockerfile b/kubernetes/tutorials/basics/dockerfiles/wordpress.dockerfile new file mode 100644 index 0000000..42accc8 --- /dev/null +++ b/kubernetes/tutorials/basics/dockerfiles/wordpress.dockerfile @@ -0,0 +1,5 @@ +FROM wordpress:5.9-apache + +#COPY files , plugins, install extra stuff + +EXPOSE 80 \ No newline at end of file diff --git a/kubernetes/tutorials/basics/yaml/deploy.yaml b/kubernetes/tutorials/basics/yaml/deploy.yaml index da0992b..74ffc3e 100644 --- a/kubernetes/tutorials/basics/yaml/deploy.yaml +++ b/kubernetes/tutorials/basics/yaml/deploy.yaml @@ -39,4 +39,4 @@ spec: valueFrom: secretKeyRef: name: wordpress - key: WORDPRESS_DB_PASSWORD \ No newline at end of file + key: WORDPRESS_DB_NAME \ No newline at end of file diff --git a/kubernetes/tutorials/basics/yaml/statefulset.yaml b/kubernetes/tutorials/basics/yaml/statefulset.yaml index 28eebc2..b80c23e 100644 --- a/kubernetes/tutorials/basics/yaml/statefulset.yaml +++ b/kubernetes/tutorials/basics/yaml/statefulset.yaml @@ -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