chore: add apptainer descrtipion

Author: timurbazhirov

lang/en/docs/jobs-cli/batch-scripts/apptainer.md

@@ -0,0 +1,57 @@
+# Apptainer and Environment Modules
+
+On the new platform, environment modules integrate with Apptainer to provide consistent, containerized runtimes for HPC applications. When you `module load` an application, the module system:
+
+- Resolves and loads required dependencies (e.g., `gcc`, `mpi`)
+- Sets per-application environment variables (e.g., `$EXEC_CMD_VASP`, `$EXEC_CMD_QE`)
+- Updates a convenience variable `$EXEC_CMD` to the most recently loaded application's command
+- Maintains `$EXEC_CMDS` as a colon-separated list of loaded application exec variables (e.g., `EXEC_CMD_VASP:EXEC_CMD_QE`)
+
+## Example session
+
+```bash
+>>>> module load espresso/6.3-gcc-openmpi-openblas
+The module gcc/11.2.0 is loaded
+The module mpi/ompi-4.1.1 is loaded
+The module espresso/6.3-gcc-openmpi-openblas is loaded
+
+Loading espresso/6.3-gcc-openmpi-openblas
+  Loading requirement: gcc/11.2.0 mpi/ompi-4.1.1
+
+>>>> echo $EXEC_CMD
+apptainer exec --bind /export,/scratch,/dropbox,/cluster-001-share \
+  /export/compute/software/applications/espresso/6.3-gcc-openmpi-openblas/image.sif
+
+>>>> echo $EXEC_CMDS
+EXEC_CMD_QE
+
+>>>> echo $EXEC_CMD_QE
+apptainer exec --bind /export,/scratch,/dropbox,/cluster-001-share \
+  /export/compute/software/applications/espresso/6.3-gcc-openmpi-openblas/image.sif
+
+>>>> module load vasp/5.4.4-gcc-openmpi-openblas-fftw-scalapack
+The module vasp/5.4.4-gcc-openmpi-openblas-fftw-scalapack is loaded
+
+>>>> echo $EXEC_CMDS
+EXEC_CMD_VASP:EXEC_CMD_QE
+
+>>>> echo $EXEC_CMD
+apptainer exec --bind /export,/scratch,/dropbox,/cluster-001-share \
+  /export/compute/software/applications/vasp/5.4.4-gcc-openmpi-openblas-fftw-scalapack/image.sif
+
+>>>> echo $EXEC_CMD_VASP
+apptainer exec --bind /export,/scratch,/dropbox,/cluster-001-share \
+  /export/compute/software/applications/vasp/5.4.4-gcc-openmpi-openblas-fftw-scalapack/image.sif
+```
+
+Notes:
+- The Apptainer command binds common platform directories into the container (e.g., `/export`, `/scratch`, `/dropbox`, and the cluster share such as `/cluster-001-share`).
+- `$EXEC_CMD` always points to the last loaded application's container exec command.
+- Use per-app variables (e.g., `$EXEC_CMD_VASP`, `$EXEC_CMD_QE`) when you need to be explicit in job scripts.
+
+## Using in job scripts
+
+See:
+- [Jobs via Command Line](../overview.md)
+- [Batch Scripts > General Structure](general-structure.md)
+- [Batch Scripts > Sample Scripts](sample-scripts.md)

lang/en/docs/jobs-cli/overview.md

@@ -14,6 +14,10 @@ We describe the accounting aspects of Job submission via CLI, such as specifying
 
 The actions pertaining to Jobs submission and execution under the CLI are reviewed [in this section](actions/overview.md) of the documentation. Other general actions concerning the CLI, such as the loading of modules, the compilation of new applications or the creation of new python environments, are described [separately](../cli/actions/overview.md).
 
+## Apptainer and Environment Modules
+
+For the new platform, CLI workflows use Apptainer-backed modules that set `$EXEC_CMD` variables for containerized execution. See: [Apptainer and Environment Modules](batch-scripts/apptainer.md)
+
 ## [Tutorials](../tutorials/jobs-cli/overview.md)
 
 We provide tutorials guiding the user through the complete procedure for submitting jobs via CLI, and subsequently retrieving the corresponding results under the [Web Interface](../ui/overview.md) of our platform. These tutorials are introduced [here](../tutorials/jobs-cli/overview.md).

lang/en/docs/migrating-to-new-platform.md

@@ -76,6 +76,16 @@ You can sign in to the new platform with the same credentials you use for the cu
 4. Contact us for assistance with bulk data migration and best practices
 5. Validate your workflows on the new clusters (e.g., `cluster-001`, `cluster-002`, `cluster-003`, `cluster-101`)
 
+## CLI and Environment Modules with Apptainer
+
+See examples of module loading, `$EXEC_CMD`, and containerized execution in: [Apptainer and Environment Modules](jobs-cli/batch-scripts/apptainer.md)
+
+### Using in job scripts
+
+As below:
+
+```
+
 ## Contact and Support
 
 - For migration help (data movement, cluster selection, workflow updates), contact your Mat3ra representative or reach us via Support Widget in the platform header or `[email protected]`.

mkdocs.yml

@@ -628,6 +628,7 @@ nav:
             - General Structure:                        jobs-cli/batch-scripts/general-structure.md
             - Directives:                               jobs-cli/batch-scripts/directives.md
             - Working Directory:                        jobs-cli/batch-scripts/directories.md
+            - Apptainer & Environment Modules:          jobs-cli/batch-scripts/apptainer.md
             - Sample Scripts:                           jobs-cli/batch-scripts/sample-scripts.md
         - Actions:
             - Overview:                                 jobs-cli/actions/overview.md