Convert Docker container to Singularity with a little assistance from our experts. Read on to find out how. 

At Bobcares, we offer solutions for every query, big and small, as a part of our Docker Hosting Support Services.

Let’s take a look at how our Docker Support Team is ready to help customers convert Docker container to Singularity.

How to convert Docker container to Singularity

SingularityCE runs complex applications on HPC clusters in a portable, simple way that is also reproducible. If you are looking for a way to ensure your Docker images run on an HPC cluster that supports Singularity, you have come to the right place. Our Support Team is here to help you convert your Docker Container to Singularity.

Furthermore, Singularity offers pull, build as well as other general commands to work with Docker images. If these do not meet our requirements, we can always turn to docker2singularity as seen here:

$ docker run quay.io/singularity/docker2singularity

docker2singularity [-m "/mount_point1 /mount_point2"] [options] docker_image_name

The options available include:

• Image format:
  • squashfs
  • sandbox
  • ext3
• –folder or -f
• –option or -o
• –writable or -w
• –name or -n
• –mount or -m
• –help or -h

Additionally, we can convert from Docker to Singularity easily by creating a special Docker image that can tap into the host docker daemon and carry out the conversion. For instance:

docker run \  -v /var/run/docker.sock:/var/run/docker.sock   -v

D:\host\path\where\to\output\singularity\image:/output   --privileged -t --rm   filo/docker2singularity   ubuntu:14.04

Here, we have to replace D:\host\path\where\to\output\singularity\image with the path filesystem where we want to create the Singularity image. In addition, replace ubuntu:14.04 with the Docker image name we want to convert.

However, even after the above process, one of our customers came across the following error while using docker2singularty:

docker: Error response from daemon: client is newer than server

In this scenario, our Support Team recommends checking the docker version via the docker info command and using the corresponding version of docker2singularity. Furthermore, 1.10, 1.11, 1.2, and 1.13 are currently supported.

[Need assistance with a different issue? We are available 24/7.]

Conclusion

In a nutshell, our skilled Docker Support Engineers at Bobcares demonstrated how to convert Docker container to Singularity.