Containerizing applications

• Generally we run serverside components in the containers such as web servers, databases, webstores etc…
• Monolith vs Microservices
  

Lets bring up a Website in a container

• HTML Refer Here download link
• steps

mkdir website
cd website
wget https://www.free-css.com/assets/files/free-css-templates/download/page296/little-fashion.zip
unzip little-fashion.zip
mv 2127_little_fashion/ fashion/
# move this folder to html location in webserver 2127_little_fashion
# mv 2127_little_fashion /var/www/html/fashion/

• Webservers:
  • apache: /usr/local/apache2/htdocs/
  • nginx: default directory /usr/share/nginx/html
• Create a file called as Dockerfile
• Now add the following

FROM nginx:1.27
COPY fashion/ /usr/share/nginx/html/fashion/

• Now to build the docker image lets use docker build command

docker image build -t fashion:1.0 .

* Now lets view the images

• Now lets build the container with this image

docker container run -d --name web1 -P fashion:1.0

* Note: use this instruction docker container run -d --name web2 -p 80:80 fashion:1.0

Dockerfile

• Dockerfile contains instructions to build the image
• basic syntax

<INSTRUCTION 1> <arguments>
<INSTRUCTION 2> <arguments>
..
<INSTRUCTION n> <arguments>

• Dockerfile Reference

Necessary instructions

FROM

• This instruction is used to select base image. official docs

FROM nginx

FROM nginx:1.27

• Platforms
• docker image building by default chooses the platform of host
• docker has given an additional command called buildx to support cross platforms and multiplatforms
• Best Practices:
  • Always use a image with tag in FROM

ADD COPY

• ADD
• COPY
• ADD instruction can copy the file or folder into docker image from host or remote sources (https)
• COPY instruction can copy file or folder into docker image from host
• Exercise: Try building a docker image for carvilla with the following base image
  • nginx
  • httpd