add pre-install hook, similar to post-install hook feature

docs/recipes.md

@@ -13,6 +13,7 @@ A recipe is comprised of the following yaml files in a directory:
 * `repo`: _optional_ custom spack package definitions.
 * `extra`: _optional_ additional meta data to copy to the meta data of the stack.
 * `post-install`: _optional_ a script to run after Spack has been executed to build the stack.
+* `pre-install`: _optional_ a script to run any packages have been built.
 
 ## Configuration
 
@@ -332,14 +333,14 @@ Post install scripts can be used to modify or extend an environment with operati
 The following steps are effectively run, where we assume that the recipe is in `$recipe` and the mount point is the default `/user-environment`:
 
 ```bash
-# copy the 
+# copy the post-install script to the mount point
 cp "$recipe"/post-install /user-environment
 chmod +x /user-environment/post-install
 
 # apply Jinja templates
 jinja -d env.json /user-environment/post-install > /user-environment/post-install
 
-# execute the script from inside the mount point
+# execute the script from the mount point
 cd /user-environment
 /user-environment/post-install
 ```
@@ -368,6 +369,15 @@ echo "export PATH=$gmx_path:$PATH" >> {{ env.mount }}/activate.sh
 !!! note
     The script does not have to be bash - it can be in any scripting language, such as Python or Perl, that is available on the target system.
 
+## Pre install configuration
+
+Similarly to the post-install hook, if a `pre-install` script is provided in the recipe, it will be run during the build process:
+
+* directly after the initial test that Spack has been installed correctly;
+* directly before the build cache is configured, or the first compiler environment is concretised.
+
+The pre-install script is copied, tempalted and executed similarly to the post-install hook (see above).
+
 ## Meta-Data
 
 Stackinator generates meta-data about the stack to the `extra` path of the installation path.

stackinator/builder.py

@@ -189,6 +189,7 @@ def generate(self, recipe):
                     cache=recipe.mirror,
                     modules=recipe.config["modules"],
                     post_install_hook=recipe.post_install_hook,
+                    pre_install_hook=recipe.pre_install_hook,
                     verbose=False,
                 )
             )
@@ -207,6 +208,15 @@ def generate(self, recipe):
         for f_etc in ["Make.inc", "bwrap-mutable-root.sh", "add-compiler-links.py"]:
             shutil.copy2(etc_path / f_etc, self.path / f_etc)
 
+
+        # used to configure both pre and post install hooks, if they are provided.
+        hook_env = {
+            "mount": recipe.mount,
+            "config": recipe.mount / "config",
+            "build": self.path,
+            "spack": self.path / "spack",
+        }
+
         # copy post install hook file, if provided
         post_hook = recipe.post_install_hook
         if post_hook is not None:
@@ -215,19 +225,29 @@ def generate(self, recipe):
                 loader=jinja2.FileSystemLoader(recipe.path)
             )
             post_hook_template = jinja_recipe_env.get_template("post-install")
-            hook_destination = store_path / "post-install-hook"
-
-            with hook_destination.open("w") as f:
-                hook_env = {
-                    "mount": recipe.mount,
-                    "config": recipe.mount / "config",
-                    "build": self.path,
-                    "spack": self.path / "spack",
-                }
+            post_hook_destination = store_path / "post-install-hook"
+
+            with post_hook_destination.open("w") as f:
                 f.write(post_hook_template.render(env=hook_env, verbose=False))
                 f.write("\n")
 
-            os.chmod(hook_destination, os.stat(hook_destination).st_mode | stat.S_IEXEC)
+            os.chmod(post_hook_destination, os.stat(post_hook_destination).st_mode | stat.S_IEXEC)
+
+        # copy pre install hook file, if provided
+        pre_hook = recipe.pre_install_hook
+        if pre_hook is not None:
+            self._logger.debug("installing pre-install-hook script")
+            jinja_recipe_env = jinja2.Environment(
+                loader=jinja2.FileSystemLoader(recipe.path)
+            )
+            pre_hook_template = jinja_recipe_env.get_template("pre-install")
+            pre_hook_destination = store_path / "pre-install-hook"
+
+            with pre_hook_destination.open("w") as f:
+                f.write(pre_hook_template.render(env=hook_env, verbose=False))
+                f.write("\n")
+
+            os.chmod(pre_hook_destination, os.stat(pre_hook_destination).st_mode | stat.S_IEXEC)
 
         # Generate the system configuration: the compilers, environments, etc.
         # that are defined for the target cluster.

stackinator/recipe.py

@@ -122,6 +122,12 @@ def __init__(self, args):
         else:
             self._logger.debug("no post install hook provided")
 
+        # optional pre install hook
+        if self.pre_install_hook is not None:
+            self._logger.debug(f"pre install hook {self.pre_install_hook}")
+        else:
+            self._logger.debug("no pre install hook provided")
+
     # Returns:
     #   Path: of the recipe extra path if it exists
     #   None: if there is no user-provided extra path in the recipe
@@ -142,6 +148,16 @@ def post_install_hook(self):
             return hook_path
         return None
 
+    # Returns:
+    #   Path: of the recipe pre install script if it was provided
+    #   None: if there is no user-provided pre install script
+    @property
+    def pre_install_hook(self):
+        hook_path = self.path / "pre-install"
+        if hook_path.exists() and hook_path.is_file():
+            return hook_path
+        return None
+
     # Returns a dictionary with the following fields
     #
     # root: /path/to/cache

stackinator/templates/Makefile

@@ -32,7 +32,11 @@ spack-setup: spack-version
 	$(SANDBOX) $(SPACK) spec zlib > /dev/null; \
 	printf "yup\n"
 
-mirror-setup: spack-setup
+pre-install: spack-setup
+	$(SANDBOX) $(STORE)/pre-install-hook
+
+mirror-setup: spack-setup{% if pre_install_hook %} pre-install{% endif %}
+
 	{% if cache %}
 	$(SANDBOX) $(SPACK) buildcache keys --install --trust
 	{% if cache.key %}

unittests/recipes/host-recipe/pre-install

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+echo "====================================="
+echo "=====      pre install hook     ====="
+
+mount_path={{ env.mount }}
+build_path={{ env.build }}
+echo RUNNING IN $mount_path with build path $build_path
+
+echo
+echo "=====   environment variabls    ====="
+printenv
+
+echo
+echo "=====   create \"config\" file {{ env.build }}/configxxx  ====="
+echo "$(date)" > "$build_path/configxxx"
+
+echo "====================================="