How to install previous dotnet versions ( 3.1 ) on Linux ( Ubuntu )

Question

I'm using an Ubuntu based distribution and installed version 5.0.404 and 6.0.101 and now have to install the previous version 3.1 ( core ). After running

wget https://packages.microsoft.com/config/ubuntu/21.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb

I'm trying to figure out which commands to run to install the SDK and runtime. For the SDK I tried several versions e.g.

sudo apt-get update; \
  sudo apt-get install -y apt-transport-https && \
  sudo apt-get update && \
  sudo apt-get install -y dotnet-sdk-3.1

or

sudo apt-get update; \
  sudo apt-get install -y apt-transport-https && \
  sudo apt-get update && \
  sudo apt-get install -y aspnetcore-sdk-3.1

but it couldn't locate the package. Does someone know the correct package name for .Net Core 3.1.x ?

Answer 1

I use macOS instead of linux, but:

#download the latest version of the Microsoft install package
wget https://packages.microsoft.com/config/ubuntu/21.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb

#install the package
 sudo dpkg -i packages-microsoft-prod.deb

#delete the download
 rm packages-microsoft-prod.deb

apt-get is an alternative package installer to dpkg.

sudo apt-get update; \
  sudo apt-get install -y apt-transport-https && \
  sudo apt-get update && \
  sudo apt-get install -y dotnet-sdk-6.0

line 1 updates apt-get to the latest version
line 2 install https support for apt-get
line 3 run apt-get update again
line 4 fetch and install dotnet-sdk-6.0

to install the 3.1 sdk you would need to know the package name. if you look at the 3.1 install instructions, they use apt rather than apt-get

sudo apt install dotnet-sdk-3.1

if you don't have apt, just download the tar file and extract t the correct folder.

DOTNET_FILE=dotnet-sdk-6.0.100-linux-x64.tar.gz
export DOTNET_ROOT=$(pwd)/.dotnet

mkdir -p "$DOTNET_ROOT" && tar zxf "$DOTNET_FILE" -C "$DOTNET_ROOT"

export PATH=$PATH:$DOTNET_ROOT

use the correct tar file name.

Answer 2

you probably have to use an earlier package source

wget https://packages.microsoft.com/config/ubuntu/20.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb 

but as you have already installed net 6, I'd do a manual install from the download tar

https://dotnet.microsoft.com/en-us/download/dotnet/3.1