240 add skeleton fab script

CONTRIBUTORS.md

@@ -1,15 +1,17 @@
 # Contributors
-| GitHub user     | Real Name        | Affiliation | Date       |
-| --------------- | ---------------- | ----------- | ---------- |
-| andrewcoughtrie | Andrew Coughtrie | Met Office  | 2025.12.12 |
-| james-bruten-mo | James Bruten     | Met Office  | 2025-12-09 |
-| jedbakerMO      | Jed Baker        | Met Office  | 2025-12-29 |
-| jennyhickson    | Jenny Hickson    | Met Office  | 2025-12-10 |
-| mo-marqh        | Mark Hedley      | Met Office  | 2025-12-11 |
-| mike-hobson     | Mike Hobson      | Met Office  | 2025-12-17 |
-| MatthewHambley  | Matthew Hambley  | Met Office  | 2025-12-15 |
-| yaswant         | Yaswant Pradhan  | Met Office  | 2025-12-16 |
-| stevemullerworth | Steve Mullerworth | Met Office  | 2026-01-08 |
-| harry-shepherd  | Harry Shepherd   | Met Office  | 2026-01-08 |
-| EdHone          | Ed Hone          | Met Office  | 2026-01-09 |
-| tom-j-h         | Tom Hill         | Met Office  | 2026-01-19 |
+
+| GitHub user      | Real Name         | Affiliation           | Date       |
+| ---------------- | ----------------- | --------------------- | ---------- |
+| andrewcoughtrie  | Andrew Coughtrie  | Met Office            | 2025.12.12 |
+| james-bruten-mo  | James Bruten      | Met Office            | 2025-12-09 |
+| jedbakerMO       | Jed Baker         | Met Office            | 2025-12-29 |
+| jennyhickson     | Jenny Hickson     | Met Office            | 2025-12-10 |
+| mo-marqh         | Mark Hedley       | Met Office            | 2025-12-11 |
+| mike-hobson      | Mike Hobson       | Met Office            | 2025-12-17 |
+| MatthewHambley   | Matthew Hambley   | Met Office            | 2025-12-15 |
+| yaswant          | Yaswant Pradhan   | Met Office            | 2025-12-16 |
+| stevemullerworth | Steve Mullerworth | Met Office            | 2026-01-08 |
+| harry-shepherd   | Harry Shepherd    | Met Office            | 2026-01-08 |
+| EdHone           | Ed Hone           | Met Office            | 2026-01-09 |
+| tom-j-h          | Tom Hill          | Met Office            | 2026-01-19 |
+| hiker            | Joerg Henrichs    | Bureau of Meteorology | 2026-01-22 |

applications/skeleton/fab_skeleton.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+
+##############################################################################
+# (c) Crown copyright Met Office. All rights reserved.
+# The file LICENCE, distributed with this code, contains details of the terms
+# under which the code may be used.
+##############################################################################
+# Author: J. Henrichs, Bureau of Meteorology
+# Author: J. Lyu, Bureau of Meteorology
+
+"""
+A FAB build script for applications/skeleton. It relies on
+the LFRicBase class contained in the infrastructure directory.
+"""
+
+import logging
+from pathlib import Path
+import sys
+
+from fab.steps.grab.folder import grab_folder
+
+# We need to import the base class:
+sys.path.insert(0, str(Path(__file__).parents[2] / "infrastructure" /
+                       "build" / "fab"))
+
+from lfric_base import LFRicBase  # noqa: E402
+
+
+class FabSkeleton(LFRicBase):
+    """
+    A Fab-based build script for skeleton. It relies on the LFRicBase class
+    to implement the actual functionality, and only provides the required
+    source files.
+
+    :param name: The name of the application.
+    """
+
+    def __init__(self, name: str) -> None:
+        super().__init__(name=name)
+        # Store the root of this apps for later
+        this_file = Path(__file__).resolve()
+        self._this_root = this_file.parent
+
+    def grab_files_step(self) -> None:
+        """
+        Grabs the required source files and optimisation scripts.
+        """
+        super().grab_files_step()
+        dirs = ['applications/skeleton/source/']
+
+        # pylint: disable=redefined-builtin
+        for dir in dirs:
+            grab_folder(self.config, src=self.lfric_core_root / dir,
+                        dst_label='')
+
+        # Copy the optimisation scripts into a separate directory
+        grab_folder(self.config, src=self._this_root / "optimisation",
+                    dst_label='optimisation')
+
+    def get_rose_meta(self) -> Path:
+        """
+        :returns: the rose-meta.conf path.
+        """
+        return (self._this_root / 'rose-meta' / 'lfric-skeleton' / 'HEAD' /
+                'rose-meta.conf')
+
+
+# -----------------------------------------------------------------------------
+if __name__ == '__main__':
+
+    logger = logging.getLogger('fab')
+    logger.setLevel(logging.DEBUG)
+    fab_skeleton = FabSkeleton(name="skeleton")
+    fab_skeleton.build()

infrastructure/build/fab/README.md

@@ -0,0 +1,54 @@
+# LFRic Core Fab Build Scripts
+
+Make sure you have Fab version 2.0.1 or later installed (in addition to all
+LFRic core requirements of course).
+
+## Setting up Site- and Platform-specific Settings
+Site- and platform-specific settings are contained in 
+```$LFRIC_CORE/infrastructure/build/site-specific/${SITE}-${PLATFORM}```
+The default settings are in ```.../site-specific/default``` (and at this
+stage each other site-specific setup inherits the values set in the default,
+and then adds or modifies settings). The Fab build system provides various
+callbacks to the ```config.py``` file in the corresponding directory (details
+are in the [Fab documentation](https://metoffice.github.io/fab/fab_base/config.html).
+
+If there is no existing site-specific setup, it is recommended to copy an existing
+configuration file (e.g. from ```nci_gadi/config.py```). This act as a template
+to indicate where you can specify linker information, select a default compiler
+suite etc.
+
+The default setup contains compiler flags for Cray, GNU, Intel-classic (ifort),
+Intel-LLVM (ifx), and NVIDIA. For modularity's sake (and to keep the file length
+shorter), the default configuration will get the settings from the corresponding
+```setup_...py``` script. There is no need for a site to replicate this structure,
+existing ```config.py``` scripts show how this can be done.
+
+
+## Building the Skeleton Apps
+
+In order to build the skeleton apps, change into the directory
+```$LFRIC_CORE/applications/skeleton```,
+and use the following command:
+
+```
+./fab_skeleton.py --nprocs 4 --site nci --platform gadi  --suite intel-classic
+```
+Select an appropriate number of processes to run in parallel, and your site and platform.
+If you don't have a default compiler suite in your site-specific setup (or
+want to use a non-default suite), use the ``--suite`` option. Once the process is finished,
+you should have a binary in the directory
+```./fab-workspace/skeleton-full-debug-COMPILER``` (where ```COMPILER``` is the compiler
+used, e.g. ```mpif90-gfortran```).
+
+Using ```./fab_skeleton.py -h``` will show a help message with all supported command line
+options (and their default value). If a default value is listed using an environment
+variables (```(default: $SITE or 'default')```), the corresponding environment variable
+is used if no command line option has been specified.
+
+A different compilation profile can be specified using ```--profile``` option. Note
+that the available compilation profiles can vary from site to site (see
+[Fab documentation](https://metoffice.github.io/fab/fab_base/config.html) for details).
+
+If Fab has issues finding a compiler, you can use the Fab debug option
+```--available-compilers```, which will list all compilers and linkers Fab has
+identified as being available.

infrastructure/build/fab/configurator.py

@@ -0,0 +1,92 @@
+##############################################################################
+# (c) Crown copyright Met Office. All rights reserved.
+# The file LICENCE, distributed with this code, contains details of the terms
+# under which the code may be used.
+##############################################################################
+# Author J. Henrichs, Bureau of Meteorology
+# Author J. Lyu, Bureau of Meteorology
+
+"""
+This file defines the configurator script sequence for LFRic.
+"""
+
+import logging
+from pathlib import Path
+from typing import cast, Optional
+
+from fab.api import BuildConfig, find_source_files, Category
+from fab.tools.shell import Shell
+
+from rose_picker_tool import RosePicker
+
+logger = logging.getLogger('fab')
+
+
+def configurator(config: BuildConfig,
+                 lfric_core_source: Path,
+                 rose_meta_conf: Path,
+                 rose_picker: RosePicker,
+                 include_paths: Optional[list[Path]] = None,
+                 config_dir: Optional[Path] = None) -> None:
+    """
+    This method implements the LFRic configurator tool.
+
+    :param config: the Fab build config instance
+    :param lfric_core_source: the path to the LFRic core directory
+    :param rose_meta_conf: the path to the rose-meta configuration file
+    :param rose_picker: the rose picker tool
+    :param include_paths: additional include paths (each path will be added,
+        as well as the path with /'rose-meta')
+    :param config_dir: the directory for the generated configuration files
+    """
+
+    tools = lfric_core_source / 'infrastructure' / 'build' / 'tools'
+    config_dir = config_dir or config.build_output / 'configuration'
+    config_dir.mkdir(parents=True, exist_ok=True)
+
+    # rose picker
+    # -----------
+    # creates rose-meta.json and config_namelists.txt in
+    # gungho/build
+    logger.info('rose_picker')
+
+    include_dirs = [lfric_core_source, lfric_core_source / 'rose-meta']
+    if include_paths:
+        for path in include_paths:
+            include_dirs.extend([path, path / 'rose-meta'])
+
+    parameters = [rose_meta_conf, '-directory', config_dir]
+    for incl_dir in include_dirs:
+        parameters.extend(['-include_dirs', incl_dir])
+
+    rose_picker.execute(parameters=parameters)
+    rose_meta = config_dir / 'rose-meta.json'
+
+    shell = config.tool_box.get_tool(Category.SHELL)
+    shell = cast(Shell, shell)
+
+    # build_config_loaders
+    # --------------------
+    # builds a bunch of f90s from the json
+    logger.info('GenerateNamelist')
+    shell.exec(f"{tools / 'GenerateNamelist'} -verbose {rose_meta} "
+               f"-directory {config_dir}")
+
+    # create configuration_mod.f90 in source root
+    # -------------------------------------------
+    logger.info('GenerateLoader')
+    with open(config_dir / 'config_namelists.txt', encoding="utf8") as f_in:
+        names = [name.strip() for name in f_in.readlines()]
+
+    configuration_mod_fpath = config_dir / 'configuration_mod.f90'
+    shell.exec(f"{tools / 'GenerateLoader'} {configuration_mod_fpath} "
+               f"{' '.join(names)}")
+
+    # create feign_config_mod.f90 in source root
+    # ------------------------------------------
+    logger.info('GenerateFeigns')
+    feign_config_mod_fpath = config_dir / 'feign_config_mod.f90'
+    shell.exec(f"{tools / 'GenerateFeigns'} {rose_meta} "
+               f"-output {feign_config_mod_fpath}")
+
+    find_source_files(config, source_root=config_dir)