AIT SAD 2022

# Workshop: Nginx

WARNING

  • Please prepare one folder for this Workshop

# Step 1: Create files

index.html

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <h1>Hi Hello SAD Class</h1>
</body>

</html>
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

Dockerfile

FROM nginx:stable-alpine

COPY ./index.html /usr/share/nginx/html

CMD ["nginx", "-g", "daemon off;"]
1
2
3
4
5
  • COPY: copy files from host to Image

# Step 2: From Dockerfile to create Docker Image

docker build . -t my-web:v1
1

# Step 3: Run Docker Container from your Image

  • check your Image
docker image ls
1

output

REPOSITORY                 TAG             IMAGE ID       CREATED         SIZE
my-web                     v1              9a6a38822c69   7 minutes ago   23.2MB
1
2
  • run
docker run -d -p 80:80  my-web:v1
1

# Step 4: Stop and remove container

docker container stop {container_id}
docker container rm {container_id}
1
2

or

docker stop {container_id}
docker rm {container_id}
1
2

or

docker container rm {container_id} -f
1

or

docker rm {container_id} -f
1
  • find the container id
docker ps
1

or

docker container ls
1

output

CONTAINER ID   IMAGE                      COMMAND                  CREATED              STATUS              PORTS                    NAMES
084e8bd8e49d   my-web:v1                  "/docker-entrypoint.…"   About a minute ago   Up About a minute   0.0.0.0:80->80/tcp       clever_lalande
1
2
docker rm 084 -f
1
  • PS. you can use the short id.

# Step 5-0: Discussion

  • Next, we will proof if the container changes the state (ex. add more files, file changing or something which makes your container isn't same as original Image) and you might remove it (docker rm). Then, you create the container again (docker run). What you have changed before would be gone too.
  • In another word, it looks like you have VM. You have code in it. You have data. Then, you delete it. If you create a new VM, you would get new VM. However, please keep it in your mind, container isn't VM. Container is a process.

# Step 5: Create a new Container

docker run -d -p 80:80  my-web:v1
1

# Step 6: Go inside Container

# Discussion

Dockerize an SSH service (opens new window)

Running sshd inside a container is discouraged, however, it might be still useful for certain use cases such as port forwarding.

See https://github.com/linuxserver/docker-openssh-server for an example of Dockerized SSH service.

  • Basically, we don't need to use ssh to go inside Docker container. What we can do is Run a shell command to our container.
docker exec -it {container_id/NAME} {command}
1
  • docker exec (opens new window)
  • -it for interactive shell
  • There are many shell commands. For example, bash, sh, zsh, and more depend on Base Image.
  • nginx container does not have bash but it has sh
  1. find ID
docker ps
1

output

CONTAINER ID   IMAGE                      COMMAND                  CREATED          STATUS          PORTS                    NAMES
19c5def99721   my-web:v1                  "/docker-entrypoint.…"   11 minutes ago   Up 11 minutes   0.0.0.0:80->80/tcp       keen_wiles
1
2
  1. run shell command
docker exec -it 19c sh
1

output

/ # |
1
  • Now, we are in nginx container.
  1. make some states change (we will add some files)
echo HelloSADClass > hello.txt
ls
1
2

output



 

bin                   docker-entrypoint.sh  home                  mnt                   root                  srv                   usr
dev                   etc                   lib                   opt                   run                   sys                   var
docker-entrypoint.d   hello.txt             media                 proc                  sbin                  tmp
1
2
3
  • saw hello.txt
  1. exit from this container
exit
1

# Step 7: remove old container and create a new one.

  1. rm and run
docker rm 19c -f
docker run -d -p 80:80  my-web:v1 
docker ps
1
2
3

output

CONTAINER ID   IMAGE                      COMMAND                  CREATED          STATUS          PORTS                    NAMES
c20808a474ac   my-web:v1                  "/docker-entrypoint.…"   4 seconds ago    Up 2 seconds    0.0.0.0:80->80/tcp       jolly_colden
1
2
  • new ID new Container
  1. make sure that hello.txt is not here
docker exec -it c20 sh
1
ls
1

output

bin                   docker-entrypoint.sh  lib                   opt                   run                   sys                   var
dev                   etc                   media                 proc                  sbin                  tmp
docker-entrypoint.d   home                  mnt                   root                  srv                   usr
1
2
3
  1. exit from container
exit
1
  1. rm container and finish this lab
docker rm c20 -f
1