Added initial Spack overview and link important docs

Author: MdHassanPappu

docs/environment/spack.md

@@ -6,17 +6,102 @@
 
 ## Introduction to Spack
 
+<p style="text-align: justify;"> Spack is an open-source package manager designed for installing, building, and managing scientific software across a wide range of systems—from personal laptops to the world’s largest supercomputers. It supports multiple versions, compilers, and configurations of packages, all coexisting without conflict. Spack is especially popular in high-performance computing (HPC) environments due to its non-destructive installations, flexible dependency resolution, and robust support for complex software stacks. </p>
 
-A brief introduction to Spack will be added here.
+### Why spack ? 
+
+<p style="text-align: justify;">Spack simplifies the software installation process in scientific computing. It uses a concise <code>spec</code> syntax to let users define versions, compilers, build options, and dependencies in a readable format. Package recipes in Spack are written in pure Python, allowing contributors to manage many builds with a single file. With over 8,500 official packages available, Spack offers great flexibility—and it's not limited to pre-existing packages. Users can create custom ( e.g. <code>package.py</code> ) files for software not yet available in the Spack pre-defined packages. <a href="https://spack.readthedocs.io/en/latest/" target="_blank">[1]</a> </p>
+
+### Key Features of Spack
+<ul style="text-align: justify;"> 
+
+<li><strong>Multiple Versions & Configurations:</strong> Easily install multiple versions of the same software with different compilers or build options.</li> 
+
+<li><strong>Custom Dependencies:</strong> Flexibly control dependencies, even choosing between alternative implementations.</li> 
+
+<li><strong>Non-destructive Installs:</strong> New installations do not interfere with existing packages.</li> 
+
+<li><strong>Package Coexistence:</strong> Different builds of the same software can live side by side.</li>
+
+ <li><strong>Easy Package Creation:</strong> Write simple ( e.g. <code>package.py</code> ) files in Python to add new software to Spack.</li> 
+ 
+ <li><strong>Virtual Environments:</strong> Create isolated environments for experiments or projects.</li> 
+ 
+ </ul>
+
+
+### Key Resources
+
+Below are essential resources including its official documentation, usage guides, packaging tutorials, and community links:
+
+=== "Important Resources"
+
+    -  <a href="https://spack.readthedocs.io/en/latest/" target="_blank">**Official Documentation**</a>  
+
+    -  <a href="https://spack-tutorial.readthedocs.io/en/latest/" target="_blank">**Spack Tutorial**</a>  
+
+    - <a href="https://packages.spack.io/" target="_blank"> **Package Index**  </a> 
+
+    -  <a href="https://spack.readthedocs.io/en/latest/package_fundamentals.html" target="_blank">**Package Fundamentals**</a>   
+
+    - <a href="https://spack.readthedocs.io/en/latest/environments.html" target="_blank">**Spack Environments**</a>  
+
+    - <a href="https://cache.spack.io/" target="_blank"> **Spack Build Cache** </a>  
+
+
+=== "Additional Resources"
+
+    - <a href="https://spack.readthedocs.io/en/latest/configuration.html" target="_blank">**Spack Configuration file **</a>  
+
+    -  <a href="https://spack.readthedocs.io/en/latest/packaging_guide.html" target="_blank">**Advance Packaging Guide**</a> 
+
+    - <a href="https://spack.readthedocs.io/en/latest/build_settings.html" target="_blank">**Concretization Settings**</a>  
+
+
+    - <a href="https://github.com/spack/spack/discussions" target="_blank">**Spack Community & Discussions**</a>  
+
+???+ tabs "Spack Resources"
+
+    === "Important Resources"
+
+        -  <a href="https://spack.readthedocs.io/en/latest/" target="_blank">**Official Documentation**</a>  
+
+        -  <a href="https://spack-tutorial.readthedocs.io/en/latest/" target="_blank">**Spack Tutorial**</a>  
+
+
+        -  <a href="https://spack.readthedocs.io/en/latest/package_fundamentals.html" target="_blank">**Package Fundamentals**</a>  
+
+        - <a href="https://packages.spack.io/" target="_blank"> **Package Index**  </a>  
+
+        - <a href="https://spack.readthedocs.io/en/latest/environments.html" target="_blank">**Spack Environments**</a>  
+
+        
+        - <a href="https://cache.spack.io/" target="_blank"> **Spack Build Cache** </a>  
+
+
+    === "Additional Resources"
+
+        - <a href="https://spack.readthedocs.io/en/latest/configuration.html" target="_blank">**Spack Configuration file **</a>  
+
+        -  <a href="https://spack.readthedocs.io/en/latest/packaging_guide.html" target="_blank">**Advance Packaging Guide**</a>  
+
+        - <a href="https://spack.readthedocs.io/en/latest/build_settings.html" target="_blank">**Concretization Settings**</a>  
+
+        - <a href="https://github.com/spack/spack/discussions" target="_blank">**Spack Community & Discussions**</a>  
+
+
+
+
+
+## Setting up Spack.
 
-## Setting up Spack
 
 !!! note
     The guide is also applicable to other HPC clusters where users need to manage components such as MPI libraries, compilers, and other software through the `module` system.
 
 
 ### Connection to a compute node
-
+For all tests and compilation with Spack, it is essential to run on a **compute node**, not in the login/access node. Here's an example of how to allocate an [interactive session](../jobs/interactive.md) in **Aion cluster**.
 
 ```{.sh .copy}
 si -N 1 -n 16 -c 1 -t 0-02:00:00 # on iris: -C broadwell or -C skylake
@@ -57,24 +142,106 @@ si -N 1 -n 16 -c 1 -t 0-02:00:00 # on iris: -C broadwell or -C skylake
 
 ### Clone & Setup Spack
 
-Clone and setup spack in `$HOME`  - it has better much better performance for 
-small files than `$SCRATCH`
+Cloning and setting up Spack in  `$HOME` directory is recommended, as it provides significantly better performance for handling small files compared to `$SCRATCH`.
+To clone the Spack Repository: 
 
 ``` { .sh .copy }
 cd $HOME
 git clone --depth=2 https://github.com/spack/spack.git
 cd spack
 ```
-To make Spack available in your shell session, source its environment setup script:
+To make Spack available in the shell session, source its environment setup script:
 
 ``` { .sh .copy }
 source $HOME/spack/share/spack/setup-env.sh
 ```
 For convenience, this line can be added to the .`bashrc` file to make Spack automatically available in every new shell session.
 
+??? note "Test some basic functionality"
+
+    Once Spack is sourced, the installation can be verified and basic functionality explored using the following commands:
+
+    **Check Spack Version:**
+    ```sh
+    # Displays the currently installed version of Spack
+    spack --version 
+    ```
+    **Search for Available Packages:**
+    ```sh
+    # Lists all available packages in Spack
+    spack list
+    ```
+
+    **Search for a specific one:**
+    ```sh
+    # Shows all packages whose names contain "cmake"
+    spack list cmake
+    ```
+
+    **Find Installed Packages:**
+    ```sh
+    # Lists all currently installed packages
+    spack find
+    ```
+    !!! note 
+
+        If Spack was just installed, this list will likely be empty. Installed packages will appear here after the first successful build.
+        
+    For more details : 
+    
+      - <a href="https://spack-tutorial.readthedocs.io/en/latest/tutorial_basics.html#" target="_blank">**Spack Basic Tutorial.**</a>  
+
+### Useful Spack Commands.
+
+
+The following tables summarizes the basic commands for managing software packages with Spack, from searching and installation to managing the software environment.
+
+| Spack Command                | Description                                                  |
+|------------------------------|--------------------------------------------------------------|
+|`spack list`|	Lists all available packages. |
+|`spack list <package>` |	Searches for packages matching the name or keyword.|
+|` spack info <package>` | displays detailed information about that package|
+| `spack install <package>`    | Installs a new package on the cluster.                       |
+| `spack uninstall <package>`  | Removes an installed package from the cluster.               |
+| `spack load <package>`       | Makes a package ready for use in the current session.        |
+| `spack unload <package>`     | Removes a package from the current session's environment.    |
+| `spack versions <package>`   | Shows all available versions of a package for installation on the cluster. |
+| `spack help` |	Displays general help and available subcommands. |
+| `spack help <subcommand>` |	Shows help for a specific subcommand. |
+|`spack config get`|	Shows current Spack configuration settings |
+|`spack compiler find	`| Detects and registers available compilers on the system |
+|`spack dependencies <package>`|	Lists dependencies of a package |
+
+??? info "Further Reference"
+    For a comprehensive list of commands and advanced usage options, refer to the official Spack documentation:<a href="https://spack.readthedocs.io/en/latest/command_index.html" target="_blank"><strong>Spack Command Index</strong></a>
+
+
+### Spack Environments
+
+A Spack environment is a powerful feature that allows users to manage sets of software packages, dependencies, and configurations in an isolated and reproducible way. 
+
+Below is a list of commonly used Spack environment commands:
+
+| Spack Command                      | Description                                                  |
+|-----------------------------------|--------------------------------------------------------------|
+| `spack env status`                | Displays the currently active Spack environment.             |
+| `spack env list`                  | Lists all existing Spack environments.                       |
+| `spack env create <env_name>`     | Creates a new Spack environment with the specified name.     |
+| `spack env activate <env_name>`   | Activates the specified Spack environment.                   |
+| `spack env deactivate`            | Deactivates the currently active environment.                |
+|`spack concretize`|	Prepares a full dependency spec for an environment or package before install |
+| `spack install --add <package>`   | Installs a package into the currently active environment.    |
+
+
+??? info "Further Reference"
+    For more technical details, see the official Spack documentation:<a href="https://spack.readthedocs.io/en/latest/environments.html" target="_blank"><strong>Spack Environments</strong></a>
+
+
+
 ### Define System-Provided Packages
 
-`packages.yaml` A spack configuration file used to tell Spack what tools and versions already exist on the cluster, so Spack can use those instead of building everything again.Create a packages.yaml file under: `$HOME/.spack/packages.yaml` 
+Spack allows users to control how software is built using the`packages.yaml` configuration file. This enables users to choose preferred implementations for virtual dependencies (like MPI or BLAS/LAPACK), choose particular compilers, and even configure Spack to use external installed software that are already available on the system while avoiding the need to rebuild everything from source.<a href="https://spack.readthedocs.io/en/latest/packages_yaml.html#package-settings-packages-yaml" target="_blank">[2]</a> </p>Create a `packages.yaml` file under: `$HOME/.spack/packages.yaml` 
+
 
 ``` { .sh .copy }
 touch $HOME/.spack/packages.yaml

mkdocs.yml

@@ -418,7 +418,9 @@ markdown_extensions:
       social_url_shorthand: true
   - pymdownx.snippets:
       base_path: snippets
-  - pymdownx.tabbed
+        
+  - pymdownx.tabbed:
+      alternate_style: true
   - pymdownx.smartsymbols
   # code blocks with syntax highlighting, graphs
   - pymdownx.superfences