GitHub Actions workflow tweaks.

- Temporarily allow the E2E test to be triggered by an issue comment so that minor issues with migrating it from the rpki-deploy repo can be resolved without unnecessary commits just to trigger the build.
- Debug print the current working directory to find out why the build was unable to find the Dockerfile.
- Be explicit about the paths to use.

.github/workflows/main.yml

@@ -1,6 +1,6 @@
 name: E2E Test
 
-on: [push, pull_request]
+on: [push, pull_reques, issue_comment]
 
 jobs:
   krill_e2e_test:
@@ -23,20 +23,23 @@ jobs:
     # to leverage an existing Cargo cache and thus speed up deployment.
     - name: Install modified Dockerfile into Krill checkout
       run: |
-        cp terraform/krill-e2e-test/lib/docker/krill/Dockerfile ${GITHUB_WORKSPACE}/../krill/Dockerfile
-        
+        cp ${GITHUB_WORKSPACE}/../repki-deploy/terraform/krill-e2e-test/lib/docker/krill/Dockerfile ${GITHUB_WORKSPACE}/../krill/Dockerfile
+
     - name: Install Terraform
       uses: marocchino/setup-terraform@v1
       with:
         version: "0.12.13"
 
+    - name: Debug print cwd
+      run: pwd
+
     - name: Install Terraform plugins
       run: |
         mkdir -p $HOME/.terraform.d/plugins/
-        cp terraform/plugins/terraform-provider-dockermachine $HOME/.terraform.d/plugins/
+        cp ${GITHUB_WORKSPACE}/../repki-deploy/terraform/plugins/terraform-provider-dockermachine $HOME/.terraform.d/plugins/
 
     - name: Decrypt SSH key
-      working-directory: terraform/krill-e2e-test
+      working-directory: ${GITHUB_WORKSPACE}/../repki-deploy/terraform/krill-e2e-test
       run: |
         ./decrypt-ssh-key.sh
         ls -la $HOME/secrets/
@@ -46,7 +49,7 @@ jobs:
     # Don't lock the state file, otherwise if the user cancels the build via the
     # GitHub Actions UI the terraform destroy cleanup step will fail.
     - name: Deploy
-      working-directory: terraform/krill-e2e-test/run_on_do
+      working-directory: ${GITHUB_WORKSPACE}/../repki-deploy/terraform/krill-e2e-test/run_on_do
       timeout-minutes: 30
       run: |
         terraform init
@@ -59,7 +62,7 @@ jobs:
         TF_VAR_size: s-8vcpu-32gb
 
     - name: Run tests
-      working-directory: terraform/krill-e2e-test/run_on_do
+      working-directory: ${GITHUB_WORKSPACE}/../repki-deploy/terraform/krill-e2e-test/run_on_do
       run: terraform apply -auto-approve -var "ssh_key_path=$HOME/secrets/ssh_key" -var "krill_build_path=${GITHUB_WORKSPACE}/../krill"
       env:
         # Don't embed env var references in env var definitions here, instead
@@ -69,7 +72,7 @@ jobs:
 
     - name: Undeploy
       if: always()
-      working-directory: terraform/krill-e2e-test/run_on_do
+      working-directory: ${GITHUB_WORKSPACE}/../repki-deploy/terraform/krill-e2e-test/run_on_do
       run: terraform destroy -auto-approve -var "ssh_key_path=$HOME/secrets/ssh_key" -var "krill_build_path=${GITHUB_WORKSPACE}/../krill"
       env:
         # Don't embed env var references in env var definitions here, instead