Introduction
The following steps are an example to create an own docker image on a local computer/server (not on login or calculation nodes) and upload to the Registry Server of Poblenou.
Before start building process you must know:
about the builder environment:
- Docker engine and root access on your builder machine.
- Shell scripting skills.
- Docker command line knowledge.
about Registry Server:
- You need a user to upload your image.
- Access to the private network of Remote Server registry.sb.upf.edu.
- Uploaded images can't be removed.
- Uploaded images can be updated
1) Create a directory to build the image
$ mkdir ubuntu-18.04 $ cd ubuntu-18.04/
1.1) Write a dockerfile with the settings
$ vi Dockerfile
FROM ubuntu:18.04
MAINTAINER John Brown "https://registry.sb.upf.edu"
LABEL authors="John Brown"
LABEL version="18.04"
LABEL description="Basic images with \
openssh-server nmap sudo telnet sssd installed."
RUN apt-get update
RUN apt-get install -y openssh-server nmap sudo telnet sssd
RUN mkdir /var/run/sshd
RUN echo 'root:xxxxxxxxxxxx' |chpasswd
RUN sed -ri 's/^#?PermitRootLogin\s+.*/PermitRootLogin yes/' /etc/ssh/sshd_config
RUN sed -ri 's/UsePAM yes/#UsePAM yes/g' /etc/ssh/sshd_config
RUN mkdir /root/.ssh
RUN apt-get clean && \
rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
EXPOSE 22
CMD ["/usr/sbin/sshd", "-D"]
It is essential to add "LABEL authors" with your name, surname and email address.
2) Build the image in a local docker-host
$ docker build . Sending build context to Docker daemon 2.048kB Step 1/12 : FROM ubuntu:18.04 18.04: Pulling from library/ubuntu a48c500ed24e: Pull complete 1e1de00ff7e1: Pull complete 0330ca45a200: Pull complete 471db38bcfbf: Pull complete 0b4aba487617: Pull complete Digest: sha256:c8c275751219dadad8fa56b3ac41ca6cb22219ff117ca98fe82b42f24e1ba64e Status: Downloaded newer image for ubuntu:18.04 ---> 452a96d81c30 Step 2/12 : MAINTAINER John Brown "https://registry.sb.upf.edu" ---> Running in 2fd5f8e83c17 Removing intermediate container 2fd5f8e83c17 ---> b984d50d740c Step 3/12 : RUN apt-get update ---> Running in 9c84731ef4ed ...
3) List and check the image
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
...
<none> <none> 401153215cb6 25 seconds ago 335MB
4) Rename the image
Change the RESEARCH_GROUP for the acronym of the research group you belong.
$ docker tag <IMAGE_ID> registry.sb.upf.edu/<research_group_acronym>/ubuntu:18.04
$ docker tag 401153215cb6 registry.sb.upf.edu/mygroup/ubuntu:18.04
Note: Use lowercase in research_group_acronym
5) List and check re-tagged image
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
...
registry.sb.upf.edu/mygroup/ubuntu 18.04 401153215cb6 About a minute ago 335MB
6) Provide credentials to establish a session with the corporate registry server
$ docker login registry.sb.upf.edu Username (): jbrown Password: Login Succeeded
7) Push the image
$ docker push registry.sb.upf.edu/mygroup/ubuntu:18.04 The push refers to repository [registry.sb.upf.edu/info/ubuntu] 68d59e996e14: Pushed b191e5e42292: Pushed dcb7bc3f07ca: Pushed ffc69fc3fb3e: Pushed 401b721534a1: Pushed a1355d87070f: Pushed b337788c3f94: Pushed a4d6cb1434aa: Pushed 059ad60bcacf: Pushed 8db5f072feec: Pushed 67885e448177: Pushed ec75999a0cb1: Pushed 65bdd50ee76a: Pushed 18.04: digest: sha256:54567b1dc80c7e463f9cada74da121dfd71590f0bf1256efc0f1a62e7dcf89e2 size: 3025
8. Check the image in a webbrowser
9. Convert Docker image to Singularity image
Finally, if we have uploaded a Docker image, it will be necessary to convert the file format (from OCI to SIF). You can do it directly from compute nodes:
$ cd /home/user/ $ singularity pull --docker-login docker://registry.sb.upf.edu/<research-group>/<image>Use your resarch user as Docker credentials.
