Receiving a Docker exec format error when you run the Docker? We can help you fix it. 

The Docker exec format error is a common error, and we fix the error by adding shebang in the entrypoint of the script.

At Bobcares, we get requests to fix docker exec format error, as a part of our Server Management Services.

Today, let’s have a look at how our Support Engineers fix this error.

Explore more about Docker

The docker container which allows OS level virtualization and is also known as containerization. The main benefits of the docker is to package applications in container and the container is portable to Linux or Windows operating system.

Docker container is a software stores up code and all its dependencies. So that the application runs fast and consistently good in quality and performance.

But, many times Docker container will end up with exec format error. Let’s see how our Support Engineers fix it.

Why does Docker show exec format error?

We see the below docker error when we launch the docker container.

Whenever our customers have such an error, our Support Engineers check the entrypoint in the Docker file.

A Docker file is the text document that use all the commands that a user could call on the command line to assemble an image.Also in Docker file we can write the instructions to build a Docker image.

The sign of this error is that the docker entrypoint script was missing a shebang. So to fix the error we add the shebang in the script.

How we fix the exec format error?

We fix this docker error by adding the shebang on the entrypoint of the script. The shebang is a special character sequence in a script file that specifies which program should be called to run the script.

The shebang is always on the first line of the script, and is composed of #! Characters. So the Shebang (#!/bin/bash) should be put on the first line of the script because the first bytes were checked by kernel. So we add the shebang in the script.

#!/bin/bash

The other method to fix the docker error is that we have to run the below command.

$ docker run -entrypoint="/bin/bash" -i test

This fixes the docker error.

[Need help in fixing Docker format error? – We’ll help you.]

Conclusion

In short, The Docker error occurs due to missing of the shebang in the script. The default entrypoint does not know how to run the script. Today, we saw how our Support Engineers fix this error for our customers by adding the shebang at the entrypoint of the script.