Pushing Docker Images to a Docker Repository

The next logical step after creating a new image from an existing image is to share it with a select few of your friends, the whole world on Docker Hub, or other Docker registry that you have access to. To push an image to Docker Hub or any other Docker registry, you must have an account there.

This section shows you how to push a Docker image to Docker Hub. To learn how to create your own private Docker registry, check out How To Set Up a Private Docker Registry on Ubuntu 14.04.

To push your image, first log into Docker Hub.

docker login -u docker-registry-username

You’ll be prompted to authenticate using your Docker Hub password. If you specified the correct password, authentication should succeed. Continue reading “Pushing Docker Images to a Docker Repository” »

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Docker Commands

Working with Docker Images

Docker containers are built from Docker images. By default, Docker pulls these images from Docker Hub, a Docker registry managed by Docker, the company behind the Docker project. Anyone can host their Docker images on Docker Hub, so most applications and Linux distributions you’ll need will have images hosted there.

To check whether you can access and download images from Docker Hub, type:

docker run hello-world

The output will indicate that Docker in working correctly:

Output
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
1b930d010525: Pull complete
Digest: sha256:41a65640635299bab090f783209c1e3a3f11934cf7756b09cb2f1e02147c6ed8
Status: Downloaded newer image for hello-world:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.
...

Docker was initially unable to find the hello-world image locally, so it downloaded the image from Docker Hub, which is the default repository. Once the image downloaded, Docker created a container from the image and the application within the container executed, displaying the message. You can search for images available on Docker Hub by using the docker command with the search subcommand. For example, to search for the Ubuntu image, type: Continue reading “Docker Commands” »

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Install Docker on Debain 10

Installing Docker

The Docker installation package available in the official Debian repository may not be the latest version. To ensure we get the latest version, we’ll install Docker from the official Docker repository. To do that, we’ll add a new package source, add the GPG key from Docker to ensure the downloads are valid, and then install the package.

First, update your existing list of packages:

sudo apt update

Next, install a few prerequisite packages which let apt use packages over HTTPS:

sudo apt install apt-transport-https ca-certificates curl gnupg2 software-properties-common

Then add the GPG key for the official Docker repository to your system: Continue reading “Install Docker on Debain 10” »

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Install portainer on ubuntu 16 docker

Step 1 – Install Docker on Ubuntu 16.04 LTS
Before installing docker packages, please update the repository on your system and upgrade packages.

sudo apt update
sudo apt upgrade

Now install docker using the apt command below.

sudo apt install docker.io -y

After the installation is complete, start docker service and enable it to launch everytime at system boot.

systemctl start docker
systemctl enable docker

Docker installed on ubuntu 16.04 server, check it using the command below.

docker version

And you will get the docker version 1.x installed on the system.

Step 2 – Install and Configure Portainer
Portainer can be installed as a docker container and standalone without docker container. Continue reading “Install portainer on ubuntu 16 docker” »

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Sharing Volumes Between Containers

There are many situations where it is useful to share a Docker volume between containers, and several ways to accomplish this goal.

Sharing a Volume on the Host

If you create a volume on the host machine, it can be used by multiple different containers at once. This allows you to share data between containers and the host.

For this example we will create a directory on the host, and use that directory as a shared volume between two containers.

Begin by creating a directory to use as a Docker volume with the command:

sudo mkdir /webdata

Create a small test file in this directory with the command:

sudo echo "Hello from the host." >> /webdata/host-hello.txt

Next, launch a container named sql-database from the official PostgreSQL image, and map /webdata on the host to /data on the container with the command:

sudo docker run -it --name sql-database -v /webdata:/data postgres /bin/bash

Once you are at the new container’s command prompt verify that the shared volume is set up correctly with the command:

ls /data

You will see the host-hello.txt file which we created on the host. Let’s add a file to this shared volume with the command: Continue reading “Sharing Volumes Between Containers” »

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Install Discourse Forum with Nginx on Ubuntu 16.04

Step 1 – Install Docker on Ubuntu 16.04

The Discourse software is written in Ruby and Javascript, using PostgreSQL as the main database, and Redis as a cache and for transient data. We will install Discourse under the Docker container.
 
The installation process will be carried out on Ubuntu 16.04. So to begin with, install Docker using the command below.

wget -qO- https://get.docker.com/ | sh

 

After the installation is complete, check the docker service and make sure it’s already running on the system. Continue reading “Install Discourse Forum with Nginx on Ubuntu 16.04” »

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Install Netbox on Docker

The first thing to do is the installation of Docker. To do this, open a terminal window and issue the following commands:

Install Docker with the command: 

sudo apt-get install docker.io -y

Add your user to the docker group with the command: 

sudo usermod -aG docker $USER.

Log out and log back in to the server. Install docker-compose with the command: 

sudo curl -L "https://github.com/docker/compose/releases/download/1.24.1/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose

Change the permission of the docker-compose command with the command: 

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

Start the docker daemon with the command 

sudo systemctl start docker

Enable the docker daemon with the command 

sudo systemctl enable docker

To get Netbox Docker up and running run the following commands. There is a more complete Getting Started guide on our wiki which explains every step.

Create Direcotry:

mkdir /var/netbox
cd /var/netbox
git clone -b release https://github.com/netbox-community/netbox-docker.git
cd netbox-docker
tee docker-compose.override.yml <<EOF
version: '3.4'
services:
nginx:
ports:
- 8000:8080
EOF
docker-compose pull
docker-compose up (allow to run docker in the foregorund)
docker-compose up -d  (allow to run docker in the background)

The whole application will be available after a few minutes. Open the URL http://0.0.0.0:8000/ in a web-browser. You should see the Netbox homepage. In the top-right corner you can login. The default credentials are:

Username: admin
Password: admin
API Token: 0123456789abcdef0123456789abcdef01234567

How to access Netbox

It will take around two to five minutes before Netbox becomes available. During that time, issue the command:

echo "http://$(docker-compose port nginx 8080)/"

The above command will print out the exact port you should use to access Netbox. In my case the following output is printed:

http://0.0.0.0:8000/

Tips:

Before you deploy the container, you’ll want to edit the .env file and configure it to meet your needs. Issue the command:

nano env/netbox.env

In that file, you might want to change the line:

SUPERUSER_PASSWORD=admin

The above is the default password for the admin user. Change that to something unique and strong. Alter any other options you might want (such as SUPERUSER_EMAIL) and save the file. 

Src: 
https://www.techrepublic.com/article/how-to-deploy-the-netbox-network-documentationmanagement-tool-with-docker/
https://github.com/netbox-community/netbox-docker

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GoodReads: How to use Docker in a practical way (part 1 – Introduction)

Part 1: Introduction to the terminology

Preface

It is not an uncommon situation, for early adopters of newly introduced concepts and technologies, to be totally confused when these can fundamentally change the ways of developing and delivering services. Especially when everybody talks about something like Docker, and how awesome and game changing it is. This confusion happens when we try things early on and rushing straight to testing them without grasping the whole concept and background of this newly introduced technology.

This is why you may have abandoned the whole trend of Linux containers, or because you read some controversial article from yea sayers and naysayers. In this first part, of a series of articles, we will try our best to clear things up and put everything on the right perspective for any developer, sysadmins, Q/A engineers or even enthusiasts who just need the right inspiration to use Linux containers and solve their special IT problems.
We will start from the beginning, with some necessary description of the historical events and concepts and then I will showcase how we can start working with Docker containers. This way, you will be able to understand “what led to the creation of containers”, “what are the building blocks” and “how do they work”. Continue reading “GoodReads: How to use Docker in a practical way (part 1 – Introduction)” »

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