Add capability to only mount EESSI

Author: ocaisa

.github/workflows/minimal-usage.yml

@@ -33,3 +33,18 @@ jobs:
         ls /cvmfs/software.eessi.io
         ls /cvmfs/dev.eessi.io
       shell: bash
+
+  test_mount_only:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+    - uses: ./
+    - name: Test EESSI not initialised
+      run: |
+        if [[ -v EESSI_VERSION ]]; then
+          echo "EESSI_VERSION should not be set as this indicates EESSI is initialised"
+          exit 1
+        fi
+        # Make sure CVMFS is mounted, and EESSI available
+        ls /cvmfs/software.eessi.io
+      shell: bash

action.yml

@@ -16,6 +16,10 @@ inputs:
     description: 'Use the EESSI module to initialise EESSI (rather than sourcing a bash script), valid values are true or false'
     required: false
     default: 'true'
+  mount_cvmfs_only:
+    description: 'Only mount CVMFS, do not initialise EESSI'
+    required: false
+    default: 'false'
   init_direnv:
     description: 'Enable direnv initialisation for the repository, valid values are true or false'
     required: false
@@ -34,13 +38,15 @@ runs:
       run: |
         if [ "$RUNNER_OS" == "Linux" ]; then
           echo 'unset BASH_ENV' >> $HOME/env_config.export
-          if [[ "${{ inputs.use_eessi_module }}" == "true" ]]; then
-            # Make the EESSI module sticky so that it persists in case `module purge` is used
-            # (while still allowing for a swap if needed)
-            echo "export EESSI_MODULE_STICKY=1" >> $HOME/env_config.export
-            echo "source /cvmfs/software.eessi.io/versions/$EESSI_STACK_VERSION/init/lmod/bash" >> $HOME/env_config.export
-          else
-            echo "source /cvmfs/software.eessi.io/versions/$EESSI_STACK_VERSION/init/bash" >> $HOME/env_config.export
+          if [[ "${{ inputs.mount_cvmfs_only }}" == "false" ]]; then
+            if [[ "${{ inputs.use_eessi_module }}" == "true" ]]; then
+              # Make the EESSI module sticky so that it persists in case `module purge` is used
+              # (while still allowing for a swap if needed)
+              echo "export EESSI_MODULE_STICKY=1" >> $HOME/env_config.export
+              echo "source /cvmfs/software.eessi.io/versions/$EESSI_STACK_VERSION/init/lmod/bash" >> $HOME/env_config.export
+            else
+              echo "source /cvmfs/software.eessi.io/versions/$EESSI_STACK_VERSION/init/bash" >> $HOME/env_config.export
+            fi
           fi
           # allow oversubscription for OpenMPI
           echo "export OMPI_MCA_rmaps_base_oversubscribe=1" >> $HOME/env_config.export