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https://github.com/weaponsforge/nodeapp

Basic nodejs webapp for Docker testing.
https://github.com/weaponsforge/nodeapp

devops docker

Last synced: 8 months ago
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Basic nodejs webapp for Docker testing.

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README 

          
## Information



The following notes describe how to install **docker** on CentOS 8 running on a VM (Virtual Box), which can be optional. It also discusses how to dockerize a nodejs webapp.



## Content



- [Prerequisites](#prerequisites)

- [Docker Installation](#docker-installation)

- [Docker Post Installation](#post-installation)

- [Install Docker Compose (Optional)](#install-docker-compose-optional)

- [Dockerize a NodeJS Web App](#dockerize-a-nodejs-web-app)

- [Run a NodeJS Web App Inside a Docker Container](#run-a-nodejs-web-app-inside-a-docker-container)

- [Common Docker Commands](#common-docker-commands)

	- [Images](#images)

	- [Containers](#containers)

- [References](#references)



## Prerequisites



> See the related tutorials on [**Virtual Box - CentOS 8**](https://trello.com/c/yj4wPomj) for more information on setting up CentOS on VirtualBox.



1. (Optional) Virtual Box 6.14

2. CentOS 8.1



## Docker Installation



1. Update your system.  

`sudo dnf update -y`

2. Add Docker CE yum repository using dnf command.  

`sudo dnf config-manager --add-repo=https://download.docker.com/linux/centos/docker-ce.repo`

3. Build cache for Docker yum repository.  

`sudo dnf makecache`

4. Docker CE requires containerd.io-1.2.2-3 (or later) package, which is blocked in CentOS 8. Therefore, we have to use an earlier version of containerd.io package. Install docker-ce with an earlier version of containerd.io using following command.  

`sudo dnf -y install --nobest docker-ce --alowerasing`

5. Enable and start Docker service.  

`systemctl enable --now docker.service`

6. Check status of Docker service.  

`systemctl status docker.service`

7. Check Docker version.  

`docker version`

8. Verify that docker runs.  

`docker run hello-world`

9. View the list of docker containers.  

`docker container ls -a`

10. Stop and remove a docker container.

   - Get its `CONTAINER ID/s` from step #8.

   - Run: `docker container rm   ...`



## Docker Post Installation



1. Add your user to the docker group.  



		sudo usermod -aG docker $USER

		id $USER



2. Disable firewalld on CentOS 8  

`sudo systemctl disable firewalld`

3. Reboot system.  

`sudo shutdown -r now`

4. Test: Pull the Alpine Linux image from Docker Hub.  



		docker search alpine --filter is-official=true

		docker pull alpine



4. List the locally available docker images.  

`docker images`

5. Create and run a container using Alpine Linux image.  



		docker run -it --rm alpine /bin/sh

		apk update



## Install Docker Compose (Optional)



1. Download and install the latest **docker-compose** from Github. Refer to the list of latest releases [here](https://github.com/docker/compose/releases).



		sudo curl -L https://github.com/docker/compose/releases/download/1.25.1-rc1/docker-compose-`uname -s`-`uname -m` -o /usr/local/bin/docker-compose



2. Grant execute permissions to **docker-compose**.  

`chmod +x /usr/local/bin/docker-compose`

3. Check **docker-compose** version.  

`docker-compose version`



## Dockerize a NodeJS Web App



1. Create a basic express nodejs app. For reference, use the [**nodeapp**](https://github.com/weaponsforge/nodeapp) repository. The demo project has a folder structure as follows:  



		[+] nodeapp

		  [+] app

		     [+] public

		         [-] index.html

		     [-] server.js

		  [-] Dockerfile

		  [-] .dockerignore

		  [-] package.json

		  [-] package-lock.json



2. Create a `Dockerfile` file inside the project repository with the following content.  



		FROM node:12

		# app directory

		WORKDIR /usr/src/app

		# Install dependencies

		COPY package*.json ./

		RUN npm install

		# Bundle app source

		COPY ./app ./app

		EXPOSE 3000

		CMD ["node", "app/server.js"]



3. Create a `.dockerignore` file inside the project repository with the following content.  



		node_modules

		npm-debug.log



## Run a NodeJS Web App Inside a Docker Container



1. Clone this git repository, or create a working [nodejs web app directory set-up for Docker](#dockerize-a-nodejs-web-app).  

`git clone https://github.com/weaponsforge/nodeapp.git`

2. **cd** into the directory.  

`cd nodeapp`

3. Build the docker image locally.  

`docker build -t nodeapp .`

4. Confirm that the image is listed by docker.  

`docker images`

5. Run the image in detached mode using any of the (2) options. The 1st one is the most recommended option. 

   - The following command maps the app's src directory from the host to the container's WORKDIR. This allows editing of the app's source files without needing to rebuild the nodeapp image.  



			# docker run -it -v :/

			# APP_ROOT_DIR=project's root dir on the HOST machine, i.e. /home/ubuntu/nodeapp

			# CONTAINER_WORKDIR=WORKDIR defined in the Dockerfile, where the app's source codes will be deployed in the container

			docker run -it -v $(pwd):/usr/src/app -p 49160:3000 -d nodeapp



	- The following command makes the container's local port **3000** accessible to the host machine as port **49160**.  

`docker run -p 49160:3000 -d nodeapp`

6. Print the output of your app.

   - Get the container id: `docker ps`

   - Print the app output: `docker logs `

7. Go inside the running container from another terminal.  

`docker exec -it  /bin/bash`

8. Verify the port mapping from inside the container (3000) to your machine's port (49160).  

`docker ps`

9. Test if the app can be called outside using **curl**, or load the website from a web browser.  

`curl -i localhost:49160`

10. Stop the running container/s.

	- (stop 1) `docker container stop `

	- (stop all) `docker container stop $(docker container ls -aq)`

11. Remove a container. Note: The container should first be stopped before it is removed. 

	- `docker container rm `

	- `docker container rm   ...`



## Common Docker Commands



### `Images`



- **show the list of all installed docker images**  

`docker images`

- **delete docker image/s**  

`docker image rm   ...`



### `Containers`



- **show the list, status and CONTAINER ID of all installed docker containers**  

`docker container ls -a`  

- **show the list of active running containers**  

`docker ps`

- **create and run a docker container for an app** (with reference to a nodejs web app)  

`docker run -it -v $(pwd):/usr/src/app -p 49160:3000 -d nodeapp`

- **create and run a docker container for most apps**  

	- NOTE: Appropriate Dockerfile is required.

	- `docker run `

- **stop a running container**

	- get the target container's CONTAINER ID

	- `docker container stop `

- **stop all running containers**  

`docker container stop $(docker container ls -aq)`

- **remove a docker container**

	- first, stop the target container from running

	- `docker container rm `

- **remove all docker containers**

	- first, stop the target containers from running

	- get the target containers' CONTAINER ID's

	- `docker container rm   ...)`



## References



[[1]](https://www.alibabacloud.com/blog/how-to-install-docker-ce-and-docker-compose-on-centos-8_595741) - install docker ce and docker-compose on centos 8  

[[2]](https://phoenixnap.com/kb/how-to-install-docker-on-centos-8) - install docker on centos 8  

[[3]](https://docs.docker.com/engine/install/centos/) - official docker installation on centos  

[[4]](https://github.com/nodejs/docker-node/blob/master/docs/BestPractices.md) - docker and nodejs best practices  

[[5]](https://hub.docker.com/_/node/) - nodejs official docker images  

[[6]](https://trello.com/c/7WiCI60n) - trello notes



@weaponsforge  

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