Background

When you have multiple credential of GitLab.com and you want to separate SSH keys used, there is no out-of-the-box / simple solution.

Your options are:

  1. Configure different host for each of your usage (e.g. change git host AND how you clone repositories), OR
  2. Override local git configs for each folder locally

This article assumes that you are using option 2, with addition of Terraform Modules on private repositories

Problem faced

When git configs are separated and Terraform needs to load modules from private repository, Terraform will perform ssh command, which will not use Overriden local git config

This will lead to terraform failing with an obscure error, and the root cause is failed authentication by git as it might not use the correct SSH key.

Solution

To prevent this issue, you need to add the following command before invoking terraform:

    export GIT_SSH_COMMAND='ssh -i /path/to/account/with/access'

For some unknown reason, local gitconfig which override settings would not work unless specified using GIT_SSH_COMMAND - using this command will ensure your terraform pulls from private git repo using correct credentials.

To make it easier, you can use the following alias on your .bashrc or .zshrc to wrap your terraform command with correct SSH key:

    alias terraform="GIT_SSH_COMMAND='ssh -i /path/to/account/with/access' terraform"