This error message is indicating that the Docker container is unable to find the “dotnet” executable file in its $PATH.
To resolve this issue, you may need to install the .NET Core runtime or SDK within your Docker image. You can do this by adding a command to your Dockerfile that installs .NET Core, such as:
RUN apt-get update && \
apt-get install -y --no-install-recommends \
curl \
gnupg \
&& curl https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > microsoft.asc.gpg \
&& mv microsoft.asc.gpg /etc/apt/trusted.gpg.d/ \
&& curl -o /etc/apt/sources.list.d/microsoft.list https://packages.microsoft.com/config/debian/10/prod.list \
&& apt-get update && apt-get install -y --no-install-recommends dotnet-sdk-3.1
This command will download and install the .NET Core SDK version 3.1 within your Docker image.
Once you have installed .NET Core, you should be able to run your application within the Docker container without encountering this error.
