Adding ssh key to --on?

[commandodev]

I've got this:

 - uses: cachix/install-nix-action@v27
        with:
          github_access_token: ${{ secrets.GITHUB_TOKEN }}
          extra-nix-config: |
            builders = ssh://${{ vars.NIX_BUILDER }} x86_64-linux ${{ env.SSH_LOCATION }} 0 0
            builders-use-substitutes = true
      - uses: DeterminateSystems/flake-checker-action@main
      - name: Install Cachix and Omnix
        run: "nix profile install --accept-flake-config github:juspay/omnix nixpkgs#cachix"
      - name: Authenticate Cachix
        run: "cachix authtoken ${{ secrets.CACHIX_AUTH_TOKEN }} && cachix use ${{ vars.CACHE_NAME }}"
      - name: Build all flake outputs and push to Cachix
        run: "om ci run --on ssh://${{ vars.NIX_BUILDER }} | cachix push ${{ vars.CACHE_NAME }}"

But my remote builder need an SSH key. How do I add that?

[srid]

By the way, when using om ci run --on, you do not need to configure extra-nix-config (or change Nix configuration at all).

Just configure your machine so that ssh ${{ vars.NIX_BUILDER}} succeeds. i.e., add the CI machine's pubic key to the target's ~/.ssh/authorized_keys.