environment: add build-on and build-for architectures (#532)

Existing `CRAFT_TARGET_ARCH` and `CRAFT_ARCH_TRIPLET` refer to the
architecture we're building for. To align with the build-on/build-for
naming convention and to give users access to both architectures
when defining override scripts and environments, set new environment
variables as follows:
```
New environment variable 	Deprecated name
------------------------        ------------------
CRAFT_ARCH_BUILD_ON 	        n/a
CRAFT_ARCH_BUILD_FOR            CRAFT_TARGET_ARCH
CRAFT_ARCH_TRIPLET_BUILD_ON     n/a
CRAFT_ARCH_TRIPLET_BUILD_FOR    CRAFT_ARCH_TRIPLET
```
Signed-off-by: Claudio Matsuoka <claudio.matsuoka@canonical.com>

craft_parts/executor/environment.py

@@ -149,8 +149,14 @@ def _get_global_environment(info: ProjectInfo) -> Dict[str, str]:
     :return: A dictionary containing environment variables and values.
     """
     global_environment = {
+        # deprecated, use CRAFT_ARCH_TRIPLET_BUILD_{ON|FOR}
         "CRAFT_ARCH_TRIPLET": info.arch_triplet,
+        # deprecated, use CRAFT_ARCH_BUILD_FOR
         "CRAFT_TARGET_ARCH": info.target_arch,
+        "CRAFT_ARCH_BUILD_ON": info.arch_build_on,
+        "CRAFT_ARCH_BUILD_FOR": info.arch_build_for,
+        "CRAFT_ARCH_TRIPLET_BUILD_ON": info.arch_triplet_build_on,
+        "CRAFT_ARCH_TRIPLET_BUILD_FOR": info.arch_triplet_build_for,
         "CRAFT_PARALLEL_BUILD_COUNT": str(info.parallel_build_count),
         "CRAFT_PROJECT_DIR": str(info.project_dir),
     }
@@ -248,8 +254,10 @@ def _replace_attr(
 ) -> Union[List[str], Dict[str, str], str]:
     """Replace environment variables according to the replacements map."""
     if isinstance(attr, str):
-        for replacement, value in replacements.items():
-            attr = attr.replace(replacement, str(value))
+        for key, value in replacements.items():
+            if key in attr:
+                _warn_if_deprecated_key(key)
+                attr = attr.replace(key, str(value))
         return attr
 
     if isinstance(attr, (list, tuple)):
@@ -265,3 +273,12 @@ def _replace_attr(
         return result
 
     return attr
+
+
+def _warn_if_deprecated_key(key: str) -> None:
+    if key in ("$CRAFT_TARGET_ARCH", "${CRAFT_TARGET_ARCH}"):
+        logger.info("CRAFT_TARGET_ARCH is deprecated, use CRAFT_ARCH_BUILD_FOR")
+    elif key in ("$CRAFT_ARCH_TRIPLET", "${CRAFT_ARCH_TRIPLET}"):
+        logger.info(
+            "CRAFT_ARCH_TRIPLET is deprecated, use CRAFT_ARCH_TRIPLET_BUILD_{ON|FOR}"
+        )

craft_parts/infos.py

@@ -46,7 +46,7 @@ class ProjectVar(YamlModel):
     updated: bool = False
 
 
-# pylint: disable-next=too-many-instance-attributes
+# pylint: disable-next=too-many-instance-attributes,too-many-public-methods
 class ProjectInfo:
     """Project-level information containing project-specific fields.
 
@@ -132,6 +132,26 @@ def cache_dir(self) -> Path:
         """Return the directory used to store cached files."""
         return self._cache_dir
 
+    @property
+    def arch_build_on(self) -> str:
+        """The architecture we are building on."""
+        return self._host_machine["deb"]
+
+    @property
+    def arch_build_for(self) -> str:
+        """The architecture we are building for."""
+        return self._machine["deb"]
+
+    @property
+    def arch_triplet_build_on(self) -> str:
+        """The machine-vendor-os triplet for the platform we are building on."""
+        return self._host_machine["triplet"]
+
+    @property
+    def arch_triplet_build_for(self) -> str:
+        """The machine-vendor-os triplet for the platform we are building for."""
+        return self._machine["triplet"]
+
     @property
     def arch_triplet(self) -> str:
         """Return the machine-vendor-os platform triplet definition."""

tests/integration/executor/test_environment.py

@@ -84,7 +84,11 @@ def test_step_callback(new_dir, mocker, capfd, step):
     assert out == (
         textwrap.dedent(
             f"""\
+            CRAFT_ARCH_BUILD_FOR=arm64
+            CRAFT_ARCH_BUILD_ON=arm64
             CRAFT_ARCH_TRIPLET=aarch64-linux-gnu
+            CRAFT_ARCH_TRIPLET_BUILD_FOR=aarch64-linux-gnu
+            CRAFT_ARCH_TRIPLET_BUILD_ON=aarch64-linux-gnu
             CRAFT_PARALLEL_BUILD_COUNT=1
             CRAFT_PART_BUILD={new_dir}/parts/foo/build
             CRAFT_PART_BUILD_WORK={new_dir}/parts/foo/build
@@ -126,7 +130,11 @@ def test_prologue_callback(new_dir, capfd, mocker):
     assert out == (
         textwrap.dedent(
             f"""\
+            CRAFT_ARCH_BUILD_FOR=arm64
+            CRAFT_ARCH_BUILD_ON=arm64
             CRAFT_ARCH_TRIPLET=aarch64-linux-gnu
+            CRAFT_ARCH_TRIPLET_BUILD_FOR=aarch64-linux-gnu
+            CRAFT_ARCH_TRIPLET_BUILD_ON=aarch64-linux-gnu
             CRAFT_PARALLEL_BUILD_COUNT=1
             CRAFT_PART_BUILD={new_dir}/parts/foo/build
             CRAFT_PART_BUILD_WORK={new_dir}/parts/foo/build

tests/integration/executor/test_environment_overlay.py

@@ -103,7 +103,11 @@ def test_step_callback(new_dir, mocker, capfd, step):
     assert out == (
         textwrap.dedent(
             f"""\
+            CRAFT_ARCH_BUILD_FOR=arm64
+            CRAFT_ARCH_BUILD_ON=arm64
             CRAFT_ARCH_TRIPLET=aarch64-linux-gnu
+            CRAFT_ARCH_TRIPLET_BUILD_FOR=aarch64-linux-gnu
+            CRAFT_ARCH_TRIPLET_BUILD_ON=aarch64-linux-gnu
             CRAFT_OVERLAY={new_dir}/overlay/overlay
             CRAFT_PARALLEL_BUILD_COUNT=1
             CRAFT_PART_BUILD={new_dir}/parts/foo/build
@@ -146,7 +150,11 @@ def test_prologue_callback(new_dir, capfd, mocker):
     assert out == (
         textwrap.dedent(
             f"""\
+            CRAFT_ARCH_BUILD_FOR=arm64
+            CRAFT_ARCH_BUILD_ON=arm64
             CRAFT_ARCH_TRIPLET=aarch64-linux-gnu
+            CRAFT_ARCH_TRIPLET_BUILD_FOR=aarch64-linux-gnu
+            CRAFT_ARCH_TRIPLET_BUILD_ON=aarch64-linux-gnu
             CRAFT_OVERLAY={new_dir}/overlay/overlay
             CRAFT_PARALLEL_BUILD_COUNT=1
             CRAFT_PART_BUILD={new_dir}/parts/foo/build

tests/unit/executor/test_environment.py

@@ -14,6 +14,7 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import logging
 import textwrap
 from pathlib import Path
 from typing import Dict, List, Set
@@ -102,6 +103,10 @@ def test_generate_step_environment_build(new_dir):
         ## Part environment
         export CRAFT_ARCH_TRIPLET="aarch64-linux-gnu"
         export CRAFT_TARGET_ARCH="arm64"
+        export CRAFT_ARCH_BUILD_ON="amd64"
+        export CRAFT_ARCH_BUILD_FOR="arm64"
+        export CRAFT_ARCH_TRIPLET_BUILD_ON="x86_64-linux-gnu"
+        export CRAFT_ARCH_TRIPLET_BUILD_FOR="aarch64-linux-gnu"
         export CRAFT_PARALLEL_BUILD_COUNT="1"
         export CRAFT_PROJECT_DIR="{new_dir}"
         export CRAFT_STAGE="{new_dir}/stage"
@@ -150,6 +155,10 @@ def test_generate_step_environment_no_project_name(new_dir):
         ## Part environment
         export CRAFT_ARCH_TRIPLET="aarch64-linux-gnu"
         export CRAFT_TARGET_ARCH="arm64"
+        export CRAFT_ARCH_BUILD_ON="amd64"
+        export CRAFT_ARCH_BUILD_FOR="arm64"
+        export CRAFT_ARCH_TRIPLET_BUILD_ON="x86_64-linux-gnu"
+        export CRAFT_ARCH_TRIPLET_BUILD_FOR="aarch64-linux-gnu"
         export CRAFT_PARALLEL_BUILD_COUNT="1"
         export CRAFT_PROJECT_DIR="{new_dir}"
         export CRAFT_STAGE="{new_dir}/stage"
@@ -200,6 +209,10 @@ def test_generate_step_environment_no_build(new_dir, step):
         ## Part environment
         export CRAFT_ARCH_TRIPLET="aarch64-linux-gnu"
         export CRAFT_TARGET_ARCH="arm64"
+        export CRAFT_ARCH_BUILD_ON="amd64"
+        export CRAFT_ARCH_BUILD_FOR="arm64"
+        export CRAFT_ARCH_TRIPLET_BUILD_ON="x86_64-linux-gnu"
+        export CRAFT_ARCH_TRIPLET_BUILD_FOR="aarch64-linux-gnu"
         export CRAFT_PARALLEL_BUILD_COUNT="1"
         export CRAFT_PROJECT_DIR="{new_dir}"
         export CRAFT_STAGE="{new_dir}/stage"
@@ -249,6 +262,10 @@ def test_generate_step_environment_no_user_env(new_dir):
         ## Part environment
         export CRAFT_ARCH_TRIPLET="aarch64-linux-gnu"
         export CRAFT_TARGET_ARCH="arm64"
+        export CRAFT_ARCH_BUILD_ON="amd64"
+        export CRAFT_ARCH_BUILD_FOR="arm64"
+        export CRAFT_ARCH_TRIPLET_BUILD_ON="x86_64-linux-gnu"
+        export CRAFT_ARCH_TRIPLET_BUILD_FOR="aarch64-linux-gnu"
         export CRAFT_PARALLEL_BUILD_COUNT="1"
         export CRAFT_PROJECT_DIR="{new_dir}"
         export CRAFT_STAGE="{new_dir}/stage"
@@ -324,6 +341,34 @@ def test_expand_variables_skip(new_dir, partitions):
     }
 
 
+@pytest.mark.parametrize(
+    "name,value",
+    [
+        ("$CRAFT_TARGET_ARCH", "arm64"),
+        ("${CRAFT_TARGET_ARCH}", "arm64"),
+        ("$CRAFT_ARCH_TRIPLET", "aarch64-linux-gnu"),
+        ("${CRAFT_ARCH_TRIPLET}", "aarch64-linux-gnu"),
+    ],
+)
+def test_expand_variables_deprecated(new_dir, name, value, caplog):
+    info = ProjectInfo(
+        project_dirs=ProjectDirs(work_dir="/work"),
+        arch="aarch64",
+        application_name="xyz",
+        cache_dir=new_dir,
+        project_name="test-project",
+        work_dir="/work",
+    )
+
+    data = {"foo": name}
+    varname = name.strip("${}")
+
+    with caplog.at_level(logging.DEBUG):
+        environment.expand_environment(data, info=info)
+        assert data == {"foo": value}  # the variable is still expanded
+        assert f"{varname} is deprecated, use" in caplog.text  # but a warning is issued
+
+
 @pytest.mark.parametrize(
     "invalid_vars",
     [

tests/unit/executor/test_step_handler.py

@@ -177,6 +177,10 @@ def test_run_builtin_build(self, new_dir, partitions, mocker):
                 "## Part environment",
                 f'export CRAFT_ARCH_TRIPLET="{triplet}"',
                 f'export CRAFT_TARGET_ARCH="{deb}"',
+                f'export CRAFT_ARCH_BUILD_ON="{deb}"',
+                f'export CRAFT_ARCH_BUILD_FOR="{deb}"',
+                f'export CRAFT_ARCH_TRIPLET_BUILD_ON="{triplet}"',
+                f'export CRAFT_ARCH_TRIPLET_BUILD_FOR="{triplet}"',
                 'export CRAFT_PARALLEL_BUILD_COUNT="1"',
                 f'export CRAFT_PROJECT_DIR="{new_dir}"',
                 *partition_script_lines,

tests/unit/features/overlay/test_executor_environment.py

@@ -108,6 +108,10 @@ def test_generate_step_environment_build(new_dir, partitions):
         ## Part environment
         export CRAFT_ARCH_TRIPLET="aarch64-linux-gnu"
         export CRAFT_TARGET_ARCH="arm64"
+        export CRAFT_ARCH_BUILD_ON="amd64"
+        export CRAFT_ARCH_BUILD_FOR="arm64"
+        export CRAFT_ARCH_TRIPLET_BUILD_ON="x86_64-linux-gnu"
+        export CRAFT_ARCH_TRIPLET_BUILD_FOR="aarch64-linux-gnu"
         export CRAFT_PARALLEL_BUILD_COUNT="1"
         export CRAFT_PROJECT_DIR="{new_dir}"
         export CRAFT_OVERLAY="{new_dir}/overlay/overlay"
@@ -161,6 +165,10 @@ def test_generate_step_environment_no_project_name(new_dir, partitions):
         ## Part environment
         export CRAFT_ARCH_TRIPLET="aarch64-linux-gnu"
         export CRAFT_TARGET_ARCH="arm64"
+        export CRAFT_ARCH_BUILD_ON="amd64"
+        export CRAFT_ARCH_BUILD_FOR="arm64"
+        export CRAFT_ARCH_TRIPLET_BUILD_ON="x86_64-linux-gnu"
+        export CRAFT_ARCH_TRIPLET_BUILD_FOR="aarch64-linux-gnu"
         export CRAFT_PARALLEL_BUILD_COUNT="1"
         export CRAFT_PROJECT_DIR="{new_dir}"
         export CRAFT_OVERLAY="{new_dir}/overlay/overlay"
@@ -216,6 +224,10 @@ def test_generate_step_environment_no_build(new_dir, partitions, step):
         ## Part environment
         export CRAFT_ARCH_TRIPLET="aarch64-linux-gnu"
         export CRAFT_TARGET_ARCH="arm64"
+        export CRAFT_ARCH_BUILD_ON="amd64"
+        export CRAFT_ARCH_BUILD_FOR="arm64"
+        export CRAFT_ARCH_TRIPLET_BUILD_ON="x86_64-linux-gnu"
+        export CRAFT_ARCH_TRIPLET_BUILD_FOR="aarch64-linux-gnu"
         export CRAFT_PARALLEL_BUILD_COUNT="1"
         export CRAFT_PROJECT_DIR="{new_dir}"
         export CRAFT_OVERLAY="{new_dir}/overlay/overlay"
@@ -267,6 +279,10 @@ def test_generate_step_environment_no_user_env(new_dir, partitions):
         ## Part environment
         export CRAFT_ARCH_TRIPLET="aarch64-linux-gnu"
         export CRAFT_TARGET_ARCH="arm64"
+        export CRAFT_ARCH_BUILD_ON="amd64"
+        export CRAFT_ARCH_BUILD_FOR="arm64"
+        export CRAFT_ARCH_TRIPLET_BUILD_ON="x86_64-linux-gnu"
+        export CRAFT_ARCH_TRIPLET_BUILD_FOR="aarch64-linux-gnu"
         export CRAFT_PARALLEL_BUILD_COUNT="1"
         export CRAFT_PROJECT_DIR="{new_dir}"
         export CRAFT_OVERLAY="{new_dir}/overlay/overlay"