This is my Dockerfile, which attempts to setup Nginx with Phusion Passenger, and then install Ruby.
# Build command: docker build --force-rm --tag="rails" .
# Run command: docker run -P -d rails
FROM ubuntu:14.04
ENV DEBIAN_FRONTEND noninteractive
# Install nginx and passenger
RUN sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 561F9B9CAC40B2F7
RUN sudo sudo apt-get install -yf apt-transport-https ca-certificates
RUN sudo echo 'deb https://oss-binaries.phusionpassenger.com/apt/passenger trusty main' > /etc/apt/sources.list.d/passenger.list
RUN sudo chown root: /etc/apt/sources.list.d/passenger.list
RUN sudo chmod 600 /etc/apt/sources.list.d/passenger.list
RUN sudo apt-get update
RUN sudo apt-get install -yf nginx-extras passenger
RUN sudo service nginx restart
# Install rbenv and ruby
RUN sudo apt-get install -yf git autoconf bison build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev libgdbm3 libgdbm-dev curl
RUN git clone https://github.com/sstephenson/rbenv.git ~/.rbenv
RUN git clone https://github.com/sstephenson/ruby-build.git ~/.rbenv/plugins/ruby-build
RUN echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
RUN echo 'eval "$(rbenv init -)"' >> ~/.bashrc
RUN /root/.rbenv/plugins/ruby-build/install.sh
ENV PATH /root/.rbenv/bin:$PATH
RUN rbenv install 2.1.5
RUN rbenv global 2.1.5
EXPOSE 80
Basically, I can build the image just fine, but I cannot start a container from this image.
This is my first time using docker, so I suspect that I need to use the CMD directive, but I have no idea what command should go there.
I appreciate any help to point out what is wrong with my Dockerfile.
The container is running successfully, its just exiting immediately as you don't specify any process to run. A container will only run as long as its main process. As you've run it in the background (the -d flag) it won't provide any output, which is a bit confusing.
For example:
$ docker run ubuntu echo "Hello World"
Hello World
The container ran the command and exited as expected.
$ docker run -d ubuntu echo "Hello World"
efd8f9980c1c9489f72a576575cf57ec3c2961e312b981ad13a2118914732036
The same thing as happened, but as we ran with -d, we got the id of the container back rather than the output. We can get the output using the logs command:
$ docker logs efd8f9980c1c9489f72a576575cf57ec3c2961e312b981ad13a2118914732036
Hello World
What you need to do is start your rails app, or whatever process you want the container to run when you launch the container. You can either do this from the docker run command or using CMD statement in the Dockerfile. Note that the main process must stay in the foreground - if it forks to the background the container will exit.
If you want to get a shell in a container, start it with -it e.g:
$ docker run -it ubuntu /bin/bash
To be honest, I think you'd be better served by using an official image e.g. https://registry.hub.docker.com/_/rails/.
You need to use ENTRYPOINT to start what you want, check the official documentation.
See what the logs says by issuing
docker logs rails
or, as
docker ps -an 1
should show the last id, with the command
docker logs this_id
Related
I want to use Kubeflow to check it out and see if it fits my projects. I want to deploy it locally as a development server so I can check it out, but I have Windows on my computer and Kubeflow only works on Linux. I'm not allowed to dual boot this computer, I could install a virtual machine, but I thought it would be easier to use docker, and oh boy was I wrong. So, the problem is, I want to install Kubernetes in a docker container, right now this is the Dockerfile I've written:
# Docker file with local deployment of Kubeflow
FROM ubuntu:18.04
ENV USER=Joao
ENV PASSWORD=Password
ENV WK_DIR=/home/${USER}
# Setup Ubuntu
RUN apt-get update -y
RUN apt-get install -y conntrack sudo wget
RUN useradd -rm -d /home/${USER} -s /bin/bash -g root -G sudo -u 1001 -p ${PASSWORD} ${USER}
WORKDIR ${WK_DIR}
# Installing Docker CE
RUN apt-get install -y apt-transport-https ca-certificates curl software-properties-common
RUN curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -
RUN add-apt-repository \
"deb [arch=amd64] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) \
stable"
RUN apt-get update -y
RUN apt-get install -y docker-ce docker-ce-cli containerd.io
# Installing Kubectl
RUN curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.15.0/bin/linux/amd64/kubectl
RUN chmod +x ./kubectl
RUN mv ./kubectl /usr/local/bin/kubectl
# Installing Minikube
RUN curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
RUN install minikube-linux-amd64 /usr/local/bin/minikube
ENV PATH="${PATH}:${WK_DIR}"
COPY start.sh start.sh
CMD sh start.sh
With this, just to make the deployment easier, I also have a docker-compose.yaml that looks like this:
services:
kf-local:
build: .
volumes:
- path/to/folder:/usr/kubeflow
privileged: true
And start.sh looks like this:
service docker start
minikube start \
--extra-config=apiserver.service-account-issuer=api \
--extra-config=apiserver.service-account-signing-key-file=/var/lib/minikube/certs/apiserver.key \
--extra-config=apiserver.service-account-api-audiences=api \
--driver=docker
The problem is, whenever I try running this I get the error:
X Exiting due to DRV_AS_ROOT: The "docker" driver should not be used with root privileges.
I've tried creating a user and running it from there also but then I'm not being able to run sudo, any idea how I could install Kubernetes on a Docker container?
As you thought you are right in case of using VM and that be easy to test it out.
Instead of setting up Kubernetes on docker you can use Linux base container for development testing.
There is linux container available name as LXC container. Docker is kind of application container while in simple words LXC is like VM for local development testing. you can install the stuff into rather than docker setting up application inside image.
read some details about lxc : https://medium.com/#harsh.manvar111/lxc-vs-docker-lxc-101-bd49db95933a
you can also run it on windows and try it out at : https://linuxcontainers.org/
If you have read the documentation of Kubeflow there is also one option multipass
Multipass creates a Linux virtual machine on Windows, Mac or Linux
systems. The VM contains a complete Ubuntu operating system which can
then be used to deploy Kubernetes and Kubeflow.
Learn more about Multipass : https://multipass.run/#install
Insufficient user permissions on the docker groups and minikube directory cause this error ("X Exiting due to DRV_AS_ROOT: The "docker" driver should not be used with root privileges.").
You can fix that error by adding your user to the docker group and setting permissions to the minikube profile directory (change the $USER with your username in the two commands below):
sudo usermod -aG docker $USER && newgrp docker
sudo chown -R $USER $HOME/.minikube; chmod -R u+wrx $HOME/.minikube
I have created a Dockerfile based on the description to create a rails application in Linux. Currently, I have two problems with the current setting:
First, I get the error or warning after every RUN command starting with the environment variable $shell. The error looks like this:
mesg: ttyname failed: Inappropriate ioctl for device
Second, my container stops directly after starting it with
docker run -d --name rails rails:test
My current docker file looks like this:
FROM ubuntu:18.04
RUN mkdir /usr/src/rails
WORKDIR /usr/src/rails
RUN apt-get update && apt-get install -y curl gnupg
RUN curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add -
RUN echo "deb https://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list
RUN apt-get update && apt install -y yarn
RUN curl -sSL https://get.rvm.io | bash
RUN useradd -G rvm rails
ENV shell /bin/bash -l -c
#RUN . /usr/local/rvm/scripts/rvm
RUN echo ". /etc/profile.d/rvm.sh" >> ~/.bashrc
RUN $shell "rvm requirements"
RUN $shell "rvm install ruby"
RUN echo "gem: --no-rdoc --no-ri" >> ~/.gemrc
RUN $shell "gem install rails"
RUN $shell "ruby -v" && $shell "rails -v"
USER rails
EXPOSE 3000
#CMD ["rails", "server", "-b", "0.0.0.0"]
CMD ["/bin/bash"]
The solution with the $shell variable I found on another website. Without the command /bin/bash -l -c the build process will fail. The command rvm or gem will be unknown. The mentioned command will be used as a wrapper around the real command inside the quotes. I do not really understand why this is necessary. If I create a docker container and execute the commands like they are in the Dockerfile, then everything works fine. Why it is not working as I execute the command inside of the Dockerfile script?
Since I use the wrapper command, everything works well, but I get this error or warning message mentioned above. The image will be made, so this is more like a minor problem. The main problem is, that my container doesn't start. If I type the command docker run -d rails:test the container will be exited directly after. I do not really understand why. Does anyone have some explanations?
I am attempting to build a simple app with Jenkins in a docker container. I have the following Dockerfile:
FROM ubuntu:trusty
# Install dependencies for Flask app.
RUN sudo apt-get update
RUN sudo apt-get install -y vim
RUN sudo apt-get install -y curl
RUN sudo apt-get install -y python3-pip
RUN pip3 install flask
# Install dependencies for Jenkins (Java).
# Install Java 1.8.
RUN sudo apt-get install -y python-software-properties debconf-utils
RUN sudo apt-get install -y software-properties-common
RUN sudo add-apt-repository -y ppa:webupd8team/java
RUN sudo apt-get update
RUN echo "oracle-java8-installer shared/accepted-oracle-license-v1-1 select true" | sudo debconf-set-selections
RUN sudo apt-get install -y oracle-java8-installer
# Install, start Jenkins.
RUN sudo apt-get install -y wget
RUN wget -q -O - https://pkg.jenkins.io/debian/jenkins-ci.org.key | apt-key add -
RUN echo deb http://pkg.jenkins-ci.org/debian binary/ > /etc/apt/sources.list.d/jenkins.list
RUN sudo apt-get update
RUN sudo apt-get install -y jenkins
RUN sudo /etc/init.d/jenkins start
COPY ./app /app
CMD ["python3","/app/main.py"]
I run this container with the following:
docker build -t jenkins_test .
docker run --name jenkins_test_container -tid -p 5000:5000 -p 8080:8080 jenkins_test:latest
I am able to start flask and install Jenkins, however, when running, Jenkins is not running. curl localhost:8080 is not successful.
In the log output, I am able to see:
Correct java version found
* Starting Jenkins Automation Server jenkins [ OK ]
However, it's still not running.
I can ssh into the container and manually run sudo /etc/init.d/jenkins start to start it, but I want it to start on docker run or docker build.
I have also tried putting sudo /etc/init.d/jenkins start in the CMD portion of the Docker file:
CMD python3 /app/main.py; sudo /etc/init.d/jenkins start
With this, I am able to curl Flask, but still not Jenkins.
How can I get Jenkins to start automatically?
You have some points that you need to be aware of:
No need to use sudo as the default user is root already.
In order to run multiple service in the same container you need to use any kind of service manager like Supervisord. Jenkins is not running because the CMD is the main entry point for your container so only flask should be running. Check the following link in order to know how to start multiple service in docker.
RUN will be executed only during the build process unlike CMD which will be executed each time you start a container from that image.
Combine all the RUN lines together as possible in order to minimize the build layers which lead to a smaller docker image.
Regarding the usage of this:
CMD python3 /app/main.py; sudo /etc/init.d/jenkins start
It does not work for you because this command python3 /app/main.py is not running as a background process so this command sudo /etc/init.d/jenkins start wont run until the previous command is done.
I was only able to get this to work by starting Jenkins in the CMD portion, but needed to start Jenkins before Flask since Flask would continuously run and the next command would never execute:
Did not work:
CMD python3 /app/main.py; sudo /etc/init.d/jenkins start
This did work:
CMD sudo /etc/init.d/jenkins start; python3 /app/main.py
EDIT:
I believe putting it in the RUN portion would not work because container would build but not save the any running services. I'm not sure if containers can be saved and loaded with running processes like that but I might be wrong. Would appreciate clarification if so.
It seems like a thing that should be in RUN so if anyone knows why that didn't work or some best practices, would also appreciate the info.
I m trying to start services(gunicorn, nginx) with my dockerfile but I got that error.
This is my dockerfile
FROM centos:centos7
RUN yum -y install epel-release
RUN yum -y --enablerepo=base clean metadata
RUN yum -y install nginx
RUN yum -y install python-pip
RUN pip install --upgrade pip
RUN yum -y install systemd;
RUN yum clean all;
COPY . /
RUN pip install --no-cache-dir -r requirements.txt
RUN ./manage.py makemigrations
RUN ./manage.py migrate
ENV container docker
RUN (cd /lib/systemd/system/sysinit.target.wants/; for i in *; do [ $i == \
systemd-tmpfiles-setup.service ] || rm -f $i; done); \
rm -f /lib/systemd/system/multi-user.target.wants/*;\
rm -f /etc/systemd/system/*.wants/*;\
rm -f /lib/systemd/system/local-fs.target.wants/*; \
rm -f /lib/systemd/system/sockets.target.wants/*udev*; \
rm -f /lib/systemd/system/sockets.target.wants/*initctl*; \
rm -f /lib/systemd/system/basic.target.wants/*;\
rm -f /lib/systemd/system/anaconda.target.wants/*;
#Gunicorn
RUN cp gunicorn_systemd /etc/systemd/system/gunicorn.service
RUN systemctl start gunicorn
RUN systemctl enable gunicorn
And this is my build command
docker build -t guni ./
Any help please ?
You are trying to interact with systemd in your build script:
RUN systemctl start gunicorn
There are a number of problems here. First, trying to "start" a service as part of the build process doesn't make any sense: you're building an image, not starting a container.
Secondly, you're trying to interact with systemd, but you're never starting systemd, and it is unlikely that you want to [1]. Since a docker container is typically a "single process" environment, you don't need any init-like process supervisor to start things for you. You just need to arrange to run the necessary command yourself.
Taking Apache httpd as an example, rather than running:
systemctl start httpd
You would run:
httpd -DFOREGROUND
This runs the webserver and ensures that it stays in the foreground (the Docker container will exit when the foreground process exits). You can surely do something similar with gunicorn.
Your container is also missing a CMD or ENTRYPOINT directive, so it's not going to do anything when you run it unless you provide an explicit command, and that's probably not the behavior you want.
[1] If you really think you need systemd, you would need to arrange to start it when the container starts (e.g, CMD /sbin/init), but systemd is not something that runs well in an unprivileged container environment. It's possible but I wouldn't recommend it.
I'm building a Docker image with this Dockerfile
FROM ubuntu:12.04
ENV DEBIAN_FRONTEND noninteractive
ENV PATH /usr/local/rvm/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
# update apt
RUN echo "deb http://archive.ubuntu.com/ubuntu precise main universe" > /etc/apt/sources.list
RUN apt-get update
RUN apt-get -y dist-upgrade
RUN apt-get install -y beanstalkd
RUN sed -i 's/\#START=yes/START=yes/g' /etc/default/beanstalkd
EXPOSE 11300
ENTRYPOINT service beanstalkd start
The image is successfully built and then I want to create an instance:
docker run -i -d -p 11300:11300 beanstalk /bin/bash
However, when I do docker ps -a, the instance has status Exit 0. I'm assuming that this means that the instance is not running. When I try to start it or attach to it, nothing seems to be happening.
So the question is why is the container not running?
Thanks, Michal
With service beanstalkd start you are starting the server, and then exiting. You will want to run the program directly - ENTRYPOINT /usr/local/bin/beanstalkd -l 0.0.0.0 -p 11300 -b .... (etc)