docker-container

I would like to understand the execution steps involved in building Docker Images using Dockerfile. Couple of questions I have listed down below. Please help me in understanding the build process. Dockerfile content #from base image FROM ubuntu:14.04 #author name MAINTAINER RAGHU #commands to run in the container RUN echo "hello Raghu" RUN sleep 10 RUN echo "TASK COMPLETED" Command used to build the image: docker build -t raghavendar/hands-on:2.0 . Sending build context to Docker daemon 20.04 MB Step 1 : FROM ubuntu:14.04 ---> b1719e1db756 Step 2 : MAINTAINER RAGHU ---> Running in 532ed79e6d55

I'm completely a newbie to docker. I tried to start a exited container like follows, I listed down all available containers using docker ps -a . It listed the following, I entered the following commands to start the container which is in the exited stage and enter into the terminal of that image. docker start 79b3fa70b51d docker exec -it 79b3fa70b51d \bin\sh It is throwing the following error. FATA[0000] Error response from daemon: Container 79b3fa70b51d is not running But when I start the container using docker start 79b3fa70b51d . It throws the container ID as output which is normal if it

I need to start multiple containers for the same image. If i create my compose file as shown below, it works fine. version: '2' services: app01: image: app app02: image: app app03: image: app app04: image: app app05: image: app Is there any easy way for me to mention the number of instances for the compose instead of copy and pasting multiple times? Updated answer (Oct 2017) As others mentioned, the docker API has changed. I'm updating my answer since it's the one most people will probably look at. docker-compose up -d --scale app=5 Unfortunately, we cannot specify this in a docker-compose.yml

As the title reads, I'm trying to assign more memory to my container. I'm using an image from docker hub called "aallam/tomcat-mysql" in case that's relevant. When I start it normally without any special flags, there's a memory limit of 2GB (even though I read that memory is unbounded if not set) Here are my docker stats CONTAINER CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS ba57d6c9e9d2 0.22% 145.6 MiB / 1.952 GiB 7.29% 508 B / 508 B 0 B / 6.91 MB 68 I tried setting memory explicitly like so but with same results docker run -d --memory=10g --memory-swap=-1 -e MYSQL_PASSWORD=password

When using Docker, we start with a base image. We boot it up, create changes and those changes are saved in layers forming another image. So eventually I have an image for my PostgreSQL instance and an image for my web application, changes to which keep on being persisted. So the question is: What is a container? Thomas Uhrig An instance of an image is called a container. You have an image, which is a set of layers as you describe. If you start this image, you have a running container of this image. You can have many running containers of the same image. You can see all your images with docker