I have set up Airflow with docker-compose as described here.
https://airflow.apache.org/docs/apache-airflow/stable/start/docker.html
And there is a airflow task that have to execute docker command like
BashOperator(
task_id='my',
bash_command="""
docker run ..............
""",
dag=dag,
)
This means Docker package required in the airflow docker image, but there is not.
So, I tried to build my own airflow image based docker installed image. like,
FROM apache/airflow:2.0.1 as airflow-image
SHELL ["/bin/bash", "-o", "pipefail", "-e", "-u", "-x", "-c"]
USER root
RUN apt-get update && apt-get --assume-yes install \
apt-transport-https \
ca-certificates \
curl \
gnupg \
lsb-release
RUN curl -fsSL https://download.docker.com/linux/debian/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
RUN echo $(lsb_release -cs)
RUN echo \
"deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/debian \
$(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
RUN apt-get update
RUN apt-get --assume-yes install docker-ce docker-ce-cli containerd.io
With an image of above Dockerfile, docker is installed like,
$ whereis docker
docker: /usr/bin/docker /usr/libexec/docker
$ whereis dockerd
dockerd: /usr/bin/dockerd
But I can not make docker daemon started so that task of airflow can execute docker run command.
After I see this ENTRYPOINT and tested several things,
https://github.com/apache/airflow/blob/master/Dockerfile#L535
ENTRYPOINT ["/usr/bin/dumb-init", "--", "/entrypoint"]
I wonder whether I can start docker daemon or not.
Any advice?
Can I make an docker image which is based airflow:2.0.1 and support docker commans?
If I understand you correctly you are trying to run a custom Docker image as a task in Airflow.
There is a DockerOperator available, see an example here.
I think what you tried to do is to host Docker inside of a Docker container. This is not necessary, since the Airflow Docker container should have access to Docker running on your machine.
So if you run Airflow 2.0 make sure to install this Python package apache-airflow-backport-providers-docker in your Airflow Docker container. And include this in your Python DAG file: from airflow.providers.docker.operators.docker import DockerOperator.
Then use the operator, something like this:
dockertask = DockerOperator(
task_id='docker_command',
image='centos:latest',
api_version='auto',
auto_remove=True,
command="/bin/sleep 30",
docker_url="unix://var/run/docker.sock",
network_mode="bridge"
)
Related
I have a Dockerfile that extends the Apache Airflow 2.5.1 base image. What I want to do is be able to use docker inside my airflow containers (i.e. docker-in-docker) for testing and evaluation purposes.
My docker-compose.yaml has the following mount:
volumes:
- /var/run/docker.sock:/var/run/docker.sock
My Dockerfile looks as follows:
FROM apache/airflow:2.5.1
USER root
RUN apt-get update && apt-get install -y ca-certificates curl gnupg lsb-release nano
RUN mkdir -p /etc/apt/keyrings
RUN curl -fsSL https://download.docker.com/linux/debian/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg
RUN echo \
"deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/debian \
$(lsb_release -cs) stable" | tee /etc/apt/sources.list.d/docker.list > /dev/null
RUN apt-get update
RUN apt-get install -y docker-ce docker-ce-cli containerd.io docker-compose-plugin
RUN groupadd -f docker
RUN usermod -a -G docker airflow
RUN service docker start
USER airflow
Basically:
Install docker.
Add the airflow user to the docker group.
Start the docker service.
Continue as airflow.
Unfortunately, this does not work. During RUN service docker start, I encounter the following error:
Step 11/12 : RUN service docker start
---> Running in 77e9b044bcea
mkdir: cannot create directory ‘cpuset’: Read-only file system
I have another Dockerfile for building a local jenkins image, which looks as follows:
FROM jenkins/jenkins:lts-jdk11
USER root
RUN apt-get update && apt-get install -y ca-certificates curl gnupg lsb-release nano
RUN mkdir -p /etc/apt/keyrings
RUN curl -fsSL https://download.docker.com/linux/debian/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg
RUN echo \
"deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/debian \
$(lsb_release -cs) stable" | tee /etc/apt/sources.list.d/docker.list > /dev/null
RUN apt-get update
RUN apt-get install -y docker-ce docker-ce-cli containerd.io docker-compose-plugin
RUN groupadd -f docker
RUN usermod -a -G docker jenkins
RUN service docker start
USER jenkins
I.e. it is exactly the same, except that I am using the jenkins user. Building this image works.
I have not set any extraneous permission on my /var/run/docker.sock:
$ ls -la /var/run/docker.sock
srw-rw---- 1 root docker 0 Jan 18 17:14 /var/run/docker.sock
My questions are:
Why does RUN service start docker not work when building my airflow image?
Why does the exact same command in my jenkins Dockerfile work?
I've tried most of the answers to similar questions, e.g. here and here, but they have unfortunately not helped.
I'd rather try to avoid the chmod 777 /var/run/docker.sock solution if at all possible, and it should be since my jenkins image can build correctly...
Just delete the RUN service start docker line.
The docker CLI tool needs to connect to a Docker daemon, which it normally does through the /var/run/docker.sock Unix socket file. Bind-mounting the socket into the container is enough to make the host's Docker daemon accessible; you do not need to separately start Docker in the container.
There are several issues with the RUN service ... line specifically. Docker has a kind of complex setup internally, and some of the things it does aren't normally allowed in a container; that's probably related to the "cannot create directory" error. In any case, a Docker image doesn't persist running processes, so if you were able to start Docker inside the build, it wouldn't still be running when the container eventually ran.
More conceptually, a container doesn't "run services", it is a wrapper around only a single process (and its children). Commands like service or systemctl often won't work the way you expect, and I'd generally avoid them in a Docker context.
Ive created a Dockerfile that is based off jenkins/jenkins:lts-jdk11
Im trying to install docker + docker compose so that jenkins will have access to this when i create my pipeline for CD/CI.
Here is my Dockerfile:
FROM jenkins/jenkins:lts-jdk11 AS jenkins
WORKDIR /home/jenkins
RUN chown -R 1000:1000 /var/jenkins_home
USER root
# Install aws cli version 2
RUN apt-get update && apt-get install -y unzip curl vim bash sudo
RUN curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"
RUN unzip awscliv2.zip
RUN ./aws/install
#Install docker cli command
RUN sudo apt-get update
RUN sudo apt install -y apt-transport-https ca-certificates curl gnupg lsb-release
RUN curl -fsSL https://download.docker.com/linux/debian/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
RUN echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/debian \
$(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
RUN sudo apt-get update
RUN sudo apt-get install -y docker-ce docker-ce-cli containerd.io
##Install docker compose
RUN mkdir -p /usr/local/lib/docker/cli-plugins
RUN curl -SL https://github.com/docker/compose/releases/download/v2.2.3/docker-compose-linux-x86_64 -o /usr/local/lib/docker/cli-plugins/docker-compose
RUN chmod +x /usr/local/lib/docker/cli-plugins/docker-compose
RUN sudo usermod -a -G docker jenkins
The docker commands work well within the container but as soon as i start to build an image it displays this error:
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
If i try to start the docker service with service docker start i get the following error:
mkdir: cannot create directory ‘cpuset’: Read-only file system
Im not sure how to solve this one.
TIA
container does not use an init system. The Docker service cannot be started because of this.
Am trying to create a self-hosted runner for Github actions on Kubernetes. As a first step was trying with the docker file as below:
FROM ubuntu:18.04
# set the github runner version
ARG RUNNER_VERSION="2.283.1"
# update the base packages and add a non-sudo user
RUN apt-get update -y && apt-get upgrade -y && useradd -m docker
RUN useradd -r -g docker nonroot
# install python and the packages the your code depends on along with jq so we can parse JSON
# add additional packages as necessary
RUN apt-get install -y curl jq build-essential libssl-dev apt-transport-https ca-certificates curl software-properties-common
# install docker
RUN curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add - \
&& add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu bionic stable" \
&& apt update \
&& apt-cache policy docker-ce \
&& apt install docker-ce -y
ENV TINI_VERSION v0.19.0
ADD https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini /tini
RUN chmod +x /tini
RUN usermod -aG docker nonroot
USER nonroot
# set the entrypoint to the start.sh script
ENTRYPOINT ["/tini", "--"]
CMD ["/bin/bash"]
After doing a build, I run the container with the below command:
docker run -v /var/run/docker.sock:/var/run/docker.sock -it srunner
When i try to pull image, I get the below error:
nonroot#0be0cdccb29b:/$ docker run hello-world
docker: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post "http://%2Fvar%2Frun%2Fdocker.sock/v1.24/containers/create": dial unix /var/run/docker.sock: connect: permission denied.
See 'docker run --help'.
nonroot#0be0cdccb29b:/$
Please advise if there is a possible way to run docker as non-root inside a docker container.
Instead of using sockets, there is also a way to connect to outer docker, from docker in container, over TCP.
Linux example:
Run ifconfig, it will print the docker's network interface that is created when you install docker on a host node. Its usually named docker0, note down the IP address of this interface.
Now, modify the /etc/docker/daemon.json and add thistcp://IP:2375 to the hosts section. Restart docker service.
Run containers with extra option: --add-host=host.docker.internal:host-gateway
Inside any such container, the address tcp://host.docker.internal:2375 now points to the outside docker engine.
Try adding your username to the docker group as suggested here.
Additionally, you should check your kernel compatibility.
I installed docker inside a container running on ubuntu:18.04 to run my nodejs app, I need docker installed inside this container because i need to dockerize an other small app
Her is my Dockerfile
FROM ubuntu:18.04
WORKDIR /app
COPY package*.json ./
# Install Nodejs
RUN apt-get update
RUN apt-get -y install curl wget dirmngr apt-transport-https lsb-release ca-certificates software-properties-common gnupg-agent
RUN curl -sL https://deb.nodesource.com/setup_12.x | bash -
RUN apt-get -y install nodejs
# Install Chromium
RUN wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add -
RUN sh -c 'echo "deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list'
RUN apt-get update
RUN apt-get install -y google-chrome-unstable fonts-ipafont-gothic fonts-wqy-zenhei fonts-thai-tlwg fonts-kacst \
--no-install-recommends
RUN rm -rf /var/lib/apt/lists/*
# Install Docker
RUN curl -fsSL https:/download.docker.com/linux/ubuntu/gpg | apt-key add -
RUN apt-key fingerprint 0EBFCD88
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
RUN npm install
COPY . .
CMD [ "npm", "start" ]
EXPOSE 3000
When the container is up, i docker exec -it app bash.
If i do a service docker start then ps ax, got this
PID TTY STAT TIME COMMAND
115 ? Z 0:00 [dockerd] <defunct>
What can i do to be able to use docker inside the container or is there a docker image not using apk but apt-get ? Because when i need to use it, i got this error :
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
First thing better to use one of the base images, either for node-image and install docker and for docker-image and installed node, instead of creating image from scratch. All you need
FROM node:buster
RUN apt-get update
RUN apt install docker.io -y
RUN docker --version
ENTRYPOINT nohup dockerd >/dev/null 2>&1 & sleep 10 && node /app/app.js
second thing, The error Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?, The reason is you are not starting the docker process in the Dockefile, and also running multiple processes in the container is not recommended, as if Docker process dies you will not know the status, you have to put one process in the background.
CMD nohup dockerd >/dev/null 2>&1 & sleep 10 && node /app/app.js
and run
docker run --privileged -it -p 8000:8000 -v /var/run/docker.sock:/var/run/docker.sock your_image
We are running a docker build agent inside a docker container.
It's based off debian jessie, and gets docker directly from docker as documented here.
The docker daemon runs fine the first time you start the container, but not the second time. (if you don't delete the container)
Dockerfile:
FROM debian:jessie
ARG DEBIAN_FRONTEND=noninteractive
RUN apt-get update \
&& apt-get -y install -q \
apt-transport-https \
ca-certificates \
software-properties-common \
curl \
&& curl -fsSL https://yum.dockerproject.org/gpg | apt-key add - \
&& add-apt-repository \
"deb https://apt.dockerproject.org/repo/ \
debian-$(lsb_release -cs) \
main" \
&& apt-get update \
&& apt-get install -y \
docker-engine
CMD []
docker-compose.yml:
services:
dockerTest:
container_name: dockerTest
privileged: true
image: tomeinc/intel-docker-node:latest
command: bash -c "service docker start && sleep 2 && docker ps"
To reproduce: build the Dockerfile with docker build -t test . and then use docker-compose up twice. The second time, docker-ps will fail with
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
Weirdly, if the container keeps running, you can manually start docker by running docker exec -it test /bin/bash and then executing service docker start and docker ps.
I'm not really sure how to approach debugging this, any suggestions are welcomed.
Turns out to be that docker thought that it and or containterd was still running(which it wasn't, but the PID files didn't get cleaned up)
Recommended starting approach to debugging issues: Look at the log files. I am shocked by this revelation.
Anyway adding rm /var/run/docker/libcontainerd/docker-containerd.pid /var/run/docker.pid to the start command before service docker start fixes it.