How to Install, Run and Delete Applications Inside Docker Containers - Part 2

Following the previous Docker article, this tutorial will discuss how to save a Docker container into a new image, remove a container, and run an Nginx web server inside a container.

How To Run and Save a Docker Container

1. In this example, we will run and save an Ubuntu-based Docker container where the Nginx server will be installed. But before committing any changes to a container, first start the container with the below commands which updates and installs Nginx daemon into Ubuntu image:

# docker run ubuntu bash -c "apt-get -y update" 
# docker run ubuntu bash -c "apt-get -y install nginx" 

Install Nginx on Ubuntu Docker Container
Install Nginx on Ubuntu Docker Container

If you get error ‘E: Unable to locate package nginx‘, then you need to connect to a container with interactive CLI and install nginx as shown.

# docker run -it ubuntu bash
# apt install nginx
# exit

2. Next, after Nginx package is installed, issue the command docker ps -l to get the ID or name of the running container.

# docker ps -l

Find Docker Container ID Name
Find Docker Container ID Name

And apply changes by running the below command:

# docker commit 5976e4ae287c ubuntu-nginx

Here, 5976e4ae287c represents the container ID and ubuntu-nginx represents the name of the new image that has been saved with committed changes.

In order to view if the new image has been successfully created just run docker images command and a listing of all saved images will be shown.

# docker images

Docker Container Changes
Docker Container Changes

Chances are that the installation process inside the container finishes fast which leads to a non-running container (container is stopped). In this case the docker ps command won’t show any output because no container is running.

In order to be able to still get the container’s id run docker ps -a | head -3 to output the most recent containers and identify the container based on the command issued to create the container and the exited status.

#centos #docker #nginx #redhat #virtualization #centos tips #docker tips #nginx tips #rhel tips #virtualization

What is GEEK

Buddha Community

How to Install, Run and Delete Applications Inside Docker Containers - Part 2

How to Install, Run and Delete Applications Inside Docker Containers - Part 2

Following the previous Docker article, this tutorial will discuss how to save a Docker container into a new image, remove a container, and run an Nginx web server inside a container.

How To Run and Save a Docker Container

1. In this example, we will run and save an Ubuntu-based Docker container where the Nginx server will be installed. But before committing any changes to a container, first start the container with the below commands which updates and installs Nginx daemon into Ubuntu image:

# docker run ubuntu bash -c "apt-get -y update" 
# docker run ubuntu bash -c "apt-get -y install nginx" 

Install Nginx on Ubuntu Docker Container
Install Nginx on Ubuntu Docker Container

If you get error ‘E: Unable to locate package nginx‘, then you need to connect to a container with interactive CLI and install nginx as shown.

# docker run -it ubuntu bash
# apt install nginx
# exit

2. Next, after Nginx package is installed, issue the command docker ps -l to get the ID or name of the running container.

# docker ps -l

Find Docker Container ID Name
Find Docker Container ID Name

And apply changes by running the below command:

# docker commit 5976e4ae287c ubuntu-nginx

Here, 5976e4ae287c represents the container ID and ubuntu-nginx represents the name of the new image that has been saved with committed changes.

In order to view if the new image has been successfully created just run docker images command and a listing of all saved images will be shown.

# docker images

Docker Container Changes
Docker Container Changes

Chances are that the installation process inside the container finishes fast which leads to a non-running container (container is stopped). In this case the docker ps command won’t show any output because no container is running.

In order to be able to still get the container’s id run docker ps -a | head -3 to output the most recent containers and identify the container based on the command issued to create the container and the exited status.

#centos #docker #nginx #redhat #virtualization #centos tips #docker tips #nginx tips #rhel tips #virtualization

Iliana  Welch

Iliana Welch

1597368540

Docker Tutorial for Beginners 8 - Build and Run C++ Applications in a Docker Container

Docker is an open platform that allows use package, develop, run, and ship software applications in different environments using containers.
In this course We will learn How to Write Dockerfiles, Working with the Docker Toolbox, How to Work with the Docker Machine, How to Use Docker Compose to fire up multiple containers, How to Work with Docker Kinematic, Push images to Docker Hub, Pull images from a Docker Registery, Push stacks of servers to Docker Hub.
How to install Docker on Mac.

#docker tutorial #c++ #docker container #docker #docker hub #devopstools

Christa  Stehr

Christa Stehr

1602964260

50+ Useful Kubernetes Tools for 2020 - Part 2

Introduction

Last year, we provided a list of Kubernetes tools that proved so popular we have decided to curate another list of some useful additions for working with the platform—among which are many tools that we personally use here at Caylent. Check out the original tools list here in case you missed it.

According to a recent survey done by Stackrox, the dominance Kubernetes enjoys in the market continues to be reinforced, with 86% of respondents using it for container orchestration.

(State of Kubernetes and Container Security, 2020)

And as you can see below, more and more companies are jumping into containerization for their apps. If you’re among them, here are some tools to aid you going forward as Kubernetes continues its rapid growth.

(State of Kubernetes and Container Security, 2020)

#blog #tools #amazon elastic kubernetes service #application security #aws kms #botkube #caylent #cli #container monitoring #container orchestration tools #container security #containers #continuous delivery #continuous deployment #continuous integration #contour #developers #development #developments #draft #eksctl #firewall #gcp #github #harbor #helm #helm charts #helm-2to3 #helm-aws-secret-plugin #helm-docs #helm-operator-get-started #helm-secrets #iam #json #k-rail #k3s #k3sup #k8s #keel.sh #keycloak #kiali #kiam #klum #knative #krew #ksniff #kube #kube-prod-runtime #kube-ps1 #kube-scan #kube-state-metrics #kube2iam #kubeapps #kubebuilder #kubeconfig #kubectl #kubectl-aws-secrets #kubefwd #kubernetes #kubernetes command line tool #kubernetes configuration #kubernetes deployment #kubernetes in development #kubernetes in production #kubernetes ingress #kubernetes interfaces #kubernetes monitoring #kubernetes networking #kubernetes observability #kubernetes plugins #kubernetes secrets #kubernetes security #kubernetes security best practices #kubernetes security vendors #kubernetes service discovery #kubernetic #kubesec #kubeterminal #kubeval #kudo #kuma #microsoft azure key vault #mozilla sops #octant #octarine #open source #palo alto kubernetes security #permission-manager #pgp #rafay #rakess #rancher #rook #secrets operations #serverless function #service mesh #shell-operator #snyk #snyk container #sonobuoy #strongdm #tcpdump #tenkai #testing #tigera #tilt #vert.x #wireshark #yaml

Mikel  Okuneva

Mikel Okuneva

1602317778

Ever Wondered Why We Use Containers In DevOps?

At some point we’ve all said the words, “But it works on my machine.” It usually happens during testing or when you’re trying to get a new project set up. Sometimes it happens when you pull down changes from an updated branch.

Every machine has different underlying states depending on the operating system, other installed programs, and permissions. Getting a project to run locally could take hours or even days because of weird system issues.

The worst part is that this can also happen in production. If the server is configured differently than what you’re running locally, your changes might not work as you expect and cause problems for users. There’s a way around all of these common issues using containers.

What is a container

A container is a piece of software that packages code and its dependencies so that the application can run in any computing environment. They basically create a little unit that you can put on any operating system and reliably and consistently run the application. You don’t have to worry about any of those underlying system issues creeping in later.

Although containers were already used in Linux for years, they became more popular in recent years. Most of the time when people are talking about containers, they’re referring to Docker containers. These containers are built from images that include all of the dependencies needed to run an application.

When you think of containers, virtual machines might also come to mind. They are very similar, but the big difference is that containers virtualize the operating system instead of the hardware. That’s what makes them so easy to run on all of the operating systems consistently.

What containers have to do with DevOps

Since we know how odd happenings occur when you move code from one computing environment to another, this is also a common issue with moving code to the different environments in our DevOps process. You don’t want to have to deal with system differences between staging and production. That would require more work than it should.

Once you have an artifact built, you should be able to use it in any environment from local to production. That’s the reason we use containers in DevOps. It’s also invaluable when you’re working with microservices. Docker containers used with something like Kubernetes will make it easier for you to handle larger systems with more moving pieces.

#devops #containers #containers-devops #devops-containers #devops-tools #devops-docker #docker #docker-image

Hudson  Kunde

Hudson Kunde

1596367440

What to do if a Docker container immediately exits

If you run a container using docker run and it immediately exits and every time you press the Start button in Docker Desktop it exits again, there is a problem.

The way to figure out what is wrong is to run docker logs, adding the name of the container at the end:

You can also click the Container name in Docker Desktop, and it will show a list of logs:

#docker #container #docker desktop #docker run