Terraform has now been open-source and forked with the OpenTofu project. The ‘tofu’ binary is a drop-in replacement for terraform, and this article will show you how to install on Debian/Ubuntu.
After installation, we will then use the Debian/Ubuntu Alternatives concept to supersede existing calls to ‘terraform’ to instead invoke ‘tofu’.
Setup OpenTofu apt repository
As described in the official docs, first add the OpenTofu GPG key
sudo install -m 0755 -d /etc/apt/keyrings curl -fsSL https://get.opentofu.org/opentofu.gpg | sudo tee /etc/apt/keyrings/opentofu.gpg >/dev/null curl -fsSL https://packages.opentofu.org/opentofu/tofu/gpgkey | sudo gpg --no-tty --batch --dearmor -o /etc/apt/keyrings/opentofu-repo.gpg >/dev/null sudo chmod a+r /etc/apt/keyrings/opentofu.gpg /etc/apt/keyrings/opentofu-repo.gpg
Then add OpenTofu to the apt source list, referencing the gpg key just downloaded.
echo \ "deb [signed-by=/etc/apt/keyrings/opentofu.gpg,/etc/apt/keyrings/opentofu-repo.gpg] https://packages.opentofu.org/opentofu/tofu/any/ any main deb-src [signed-by=/etc/apt/keyrings/opentofu.gpg,/etc/apt/keyrings/opentofu-repo.gpg] https://packages.opentofu.org/opentofu/tofu/any/ any main" | \ sudo tee /etc/apt/sources.list.d/opentofu.list > /dev/null sudo chmod a+r /etc/apt/sources.list.d/opentofu.list
Install OpenTofu
Now you can install the ‘tofu’ apt package, just like any other apt package.
sudo apt-get update sudo apt-get install -y tofu
Validate installation
$ which tofu /usr/bin/tofu $ tofu --version
Create Debian/Ubuntu alternative to supersede terraform binary
In order to route any invocation of ‘terraform’ to use ‘tofu’ instead, we can use Debian/Ubuntu Alternatives.
# are any alternatives for 'terraform' already defined?
sudo update-alternatives --query terraform
# if regular file exists at alternative location, then delete it
[ -L /usr/local/bin/terraform ] || { echo "deleting regular file to make room for alternative";sudo rm /usr/local/bin/terraform; }
# set high priority 80 to invoking tofu
sudo update-alternatives --install /usr/local/bin/terraform terraform /usr/bin/tofu 80
# now call to 'terraform' should invoke opentofu 'tofu'
$ terraform --version
OpenTofu v1.8.1
on linux_amd64
+ provider registry.opentofu.org/hashicorp/local v2.5.1
REFERENCES
Setup OpenTofu apt repository for Ubuntu