Allowing environment variables to be set in a spack.yaml (#47587)

This adds a new configuration section called `env_vars:` that can be set in an environment.

It looks very similar to the existing `environment:` section that can be added to `modules.yaml`,
but it is global for an entire spack environment. It's called `env_vars:` to deconflate it with spack
environments (the term was too overloaded).

The syntax looks like this:

```yaml
spack:
  specs:
    - cmake%gcc
  env_vars:
    set:
      ENVAR_SET_IN_ENV_LOAD: "True"
```

Any of our standard environment modifications can be added to the `env_vars` section, e.g.
`prepend_path:`, `unset:`, `append_path:`, etc.  Operations in `env_vars:` are performed
on `spack env activate` and undone on `spack env deactivate`.

lib/spack/spack/config.py

@@ -53,6 +53,7 @@
 import spack.schema.definitions
 import spack.schema.develop
 import spack.schema.env
+import spack.schema.env_vars
 import spack.schema.mirrors
 import spack.schema.modules
 import spack.schema.packages
@@ -70,6 +71,7 @@
     "compilers": spack.schema.compilers.schema,
     "concretizer": spack.schema.concretizer.schema,
     "definitions": spack.schema.definitions.schema,
+    "env_vars": spack.schema.env_vars.schema,
     "view": spack.schema.view.schema,
     "develop": spack.schema.develop.schema,
     "mirrors": spack.schema.mirrors.schema,

lib/spack/spack/environment/shell.py

@@ -10,6 +10,7 @@
 
 import spack.environment as ev
 import spack.repo
+import spack.schema.environment
 import spack.store
 from spack.util.environment import EnvironmentModifications
 
@@ -156,6 +157,11 @@ def activate(
     # MANPATH, PYTHONPATH, etc. All variables that end in PATH (case-sensitive)
     # become PATH variables.
     #
+
+    env_vars_yaml = env.manifest.configuration.get("env_vars", None)
+    if env_vars_yaml:
+        env_mods.extend(spack.schema.environment.parse(env_vars_yaml))
+
     try:
         if view and env.has_view(view):
             with spack.store.STORE.db.read_transaction():
@@ -189,6 +195,10 @@ def deactivate() -> EnvironmentModifications:
     if active is None:
         return env_mods
 
+    env_vars_yaml = active.manifest.configuration.get("env_vars", None)
+    if env_vars_yaml:
+        env_mods.extend(spack.schema.environment.parse(env_vars_yaml).reversed())
+
     active_view = os.getenv(ev.spack_env_view_var)
 
     if active_view and active.has_view(active_view):

lib/spack/spack/schema/env_vars.py

@@ -0,0 +1,22 @@
+# Copyright Spack Project Developers. See COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+"""Schema for env_vars.yaml configuration file.
+
+.. literalinclude:: _spack_root/lib/spack/spack/schema/env_vars.py
+   :lines: 15-
+"""
+from typing import Any, Dict
+
+import spack.schema.environment
+
+properties: Dict[str, Any] = {"env_vars": spack.schema.environment.definition}
+
+#: Full schema with metadata
+schema = {
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "Spack env_vars configuration file schema",
+    "type": "object",
+    "additionalProperties": False,
+    "properties": properties,
+}

lib/spack/spack/schema/merged.py

@@ -20,6 +20,7 @@
 import spack.schema.container
 import spack.schema.definitions
 import spack.schema.develop
+import spack.schema.env_vars
 import spack.schema.mirrors
 import spack.schema.modules
 import spack.schema.packages
@@ -38,6 +39,7 @@
     spack.schema.ci.properties,
     spack.schema.definitions.properties,
     spack.schema.develop.properties,
+    spack.schema.env_vars.properties,
     spack.schema.mirrors.properties,
     spack.schema.modules.properties,
     spack.schema.packages.properties,

lib/spack/spack/test/cmd/env.py

@@ -3023,6 +3023,35 @@ def test_stack_view_activate_from_default(
         assert "FOOBAR=mpileaks" in shell
 
 
+def test_envvar_set_in_activate(tmpdir, mock_fetch, mock_packages, mock_archive, install_mockery):
+    filename = str(tmpdir.join("spack.yaml"))
+    with open(filename, "w", encoding="utf-8") as f:
+        f.write(
+            """\
+spack:
+  specs:
+    - cmake%gcc
+  env_vars:
+    set:
+      ENVAR_SET_IN_ENV_LOAD: "True"
+"""
+        )
+    with tmpdir.as_cwd():
+        env("create", "test", "./spack.yaml")
+        with ev.read("test"):
+            install()
+
+        test_env = ev.read("test")
+        output = env("activate", "--sh", "test")
+
+        assert "ENVAR_SET_IN_ENV_LOAD=True" in output
+
+        with test_env:
+            with spack.util.environment.set_env(ENVAR_SET_IN_ENV_LOAD="True"):
+                output = env("deactivate", "--sh")
+                assert "unset ENVAR_SET_IN_ENV_LOAD" in output
+
+
 def test_stack_view_no_activate_without_default(
     installed_environment, template_combinatorial_env, tmp_path
 ):

share/spack/spack-completion.fish

@@ -1201,19 +1201,19 @@ complete -c spack -n '__fish_spack_using_command config' -l scope -r -d 'configu
 
 # spack config get
 set -g __fish_spack_optspecs_spack_config_get h/help
-complete -c spack -n '__fish_spack_using_command_pos 0 config get' -f -a 'bootstrap cdash ci compilers concretizer config definitions develop mirrors modules packages repos upstreams view'
+complete -c spack -n '__fish_spack_using_command_pos 0 config get' -f -a 'bootstrap cdash ci compilers concretizer config definitions develop env_vars mirrors modules packages repos upstreams view'
 complete -c spack -n '__fish_spack_using_command config get' -s h -l help -f -a help
 complete -c spack -n '__fish_spack_using_command config get' -s h -l help -d 'show this help message and exit'
 
 # spack config blame
 set -g __fish_spack_optspecs_spack_config_blame h/help
-complete -c spack -n '__fish_spack_using_command_pos 0 config blame' -f -a 'bootstrap cdash ci compilers concretizer config definitions develop mirrors modules packages repos upstreams view'
+complete -c spack -n '__fish_spack_using_command_pos 0 config blame' -f -a 'bootstrap cdash ci compilers concretizer config definitions develop env_vars mirrors modules packages repos upstreams view'
 complete -c spack -n '__fish_spack_using_command config blame' -s h -l help -f -a help
 complete -c spack -n '__fish_spack_using_command config blame' -s h -l help -d 'show this help message and exit'
 
 # spack config edit
 set -g __fish_spack_optspecs_spack_config_edit h/help print-file
-complete -c spack -n '__fish_spack_using_command_pos 0 config edit' -f -a 'bootstrap cdash ci compilers concretizer config definitions develop mirrors modules packages repos upstreams view'
+complete -c spack -n '__fish_spack_using_command_pos 0 config edit' -f -a 'bootstrap cdash ci compilers concretizer config definitions develop env_vars mirrors modules packages repos upstreams view'
 complete -c spack -n '__fish_spack_using_command config edit' -s h -l help -f -a help
 complete -c spack -n '__fish_spack_using_command config edit' -s h -l help -d 'show this help message and exit'
 complete -c spack -n '__fish_spack_using_command config edit' -l print-file -f -a print_file