allow output of conda recipes with pinned run_constraints

conda_lock/conda_lock.py

@@ -21,6 +21,7 @@
 from types import TracebackType
 from typing import Any, Optional, Union
 from urllib.parse import urlsplit
+import warnings
 
 import click
 import yaml
@@ -117,8 +118,10 @@
 KIND_EXPLICIT: Literal["explicit"] = "explicit"
 KIND_LOCK: Literal["lock"] = "lock"
 KIND_ENV: Literal["env"] = "env"
-TKindAll = Union[Literal["explicit"], Literal["lock"], Literal["env"]]
-TKindRendarable = Union[Literal["explicit"], Literal["lock"], Literal["env"]]
+KIND_RECIPE: Literal["recipe"] = "recipe"
+KINDS = [KIND_EXPLICIT, KIND_LOCK, KIND_ENV, KIND_RECIPE]
+TKindAll = Union[KIND_EXPLICIT, KIND_LOCK, KIND_ENV, KIND_RECIPE]
+TKindRendarable = Union[KIND_EXPLICIT, KIND_LOCK, KIND_ENV, KIND_RECIPE]
 
 
 DEFAULT_KINDS: list[Union[Literal["explicit"], Literal["lock"]]] = [
@@ -135,6 +138,7 @@
     KIND_EXPLICIT: "conda create --name YOURENV --file {lockfile}",
     KIND_ENV: "conda env create --name YOURENV --file {lockfile}",
     KIND_LOCK: "conda-lock install --name YOURENV {lockfile}",
+    KIND_RECIPE: "rattler build {lockfile}",
 }
 
 _implicit_cuda_message = """
@@ -497,6 +501,7 @@ def make_lock_files(  # noqa: C901
             filename_template=filename_template,
             extras=extras,
             check_input_hash=check_input_hash,
+            output_recipe=lock_spec.output_recipe,
         )
 
 
@@ -508,6 +513,7 @@ def do_render(
     extras: Optional[Set[str]] = None,
     check_input_hash: bool = False,
     override_platform: Optional[Sequence[str]] = None,
+    output_recipe: Optional[dict] = None,
 ) -> None:
     """Render the lock content for each platform in lockfile
 
@@ -527,6 +533,8 @@ def do_render(
         Do not re-render if specifications are unchanged
     override_platform :
         Generate only this subset of the platform files
+    output_recipe :
+        Additional content for rendering a rattler-build recipe
     """
     platforms = lockfile.metadata.platforms
     if override_platform is not None and len(override_platform) > 0:
@@ -583,11 +591,17 @@ def do_render(
                 extras=extras,
                 kind=kind,
                 platform=plat,
+                output_recipe=output_recipe,
             )
 
-            filename += KIND_FILE_EXT[kind]
-            with open(filename, "w") as fo:
-                fo.write("\n".join(lockfile_contents) + "\n")
+            if kind == "recipe":
+                filename = f"{output_recipe['name']}-{output_recipe['version']}-{output_recipe['build']['string']}-{plat}.yaml"
+                with open(filename, "w") as fo:
+                    fo.write("\n".join(lockfile_contents) + "\n")
+            else:
+                filename += KIND_FILE_EXT[kind]
+                with open(filename, "w") as fo:
+                    fo.write("\n".join(lockfile_contents) + "\n")
 
             print(
                 f" - Install lock using {'(see warning below)' if kind == 'env' else ''}:",
@@ -616,6 +630,7 @@ def render_lockfile_for_platform(  # noqa: C901
     kind: Union[Literal["env"], Literal["explicit"]],
     platform: str,
     suppress_warning_for_pip_and_explicit: bool = False,
+    output_recipe: Optional[dict] = None,
 ) -> list[str]:
     """
     Render lock content into a single-platform lockfile that can be installed
@@ -636,6 +651,8 @@ def render_lockfile_for_platform(  # noqa: C901
     suppress_warning_for_pip_and_explicit :
         When rendering internally for `conda-lock install`, we should suppress
         the warning about pip dependencies not being supported by all tools.
+    output_recipe :
+        Additional content for rendering a rattler-build recipe
     """
     lockfile_contents = [
         "# Generated by conda-lock.",
@@ -757,6 +774,29 @@ def sanitize_lockfile_line(line: str) -> str:
                 "newer unified lockfile format (i.e. removing the --kind=explicit "
                 "argument."
             )
+    elif kind == "recipe":
+        lockfile_contents = [
+            "package:",
+            f"  name: {output_recipe['name']}",
+            f"  version: {output_recipe['version']}",
+            f"build:",
+            f"  string: {output_recipe['build']['string']}",
+            "requirements:",
+            "  run_constraints:",
+        ]
+        lockfile.alphasort_inplace()
+
+        excludes = output_recipe.get("exclude_patterns", [])
+        exclude_pattern = None
+        if excludes:
+            exclude_pattern = re.compile("|".join([f".*{e}.*" for e in excludes if e]))
+        for p in conda_deps:
+            # exclude virtual packages
+            if not p.name.startswith("__") and exclude_pattern and not exclude_pattern.match(p.name):
+                lockfile_contents.append(f"    - {p.name} {p.version} {p.build}")
+
+        lockfile_contents.append("about:")
+        lockfile_contents.append(f"  summary: A pinning package for a {output_recipe['name']} environment, to be used as a set of constraints at build time for other recipes.")
     else:
         raise ValueError(f"Unrecognised lock kind {kind}.")
 
@@ -1289,9 +1329,9 @@ def main() -> None:
     "-k",
     "--kind",
     default=["lock"],
-    type=str,
+    type=click.Choice(KINDS),
     multiple=True,
-    help="Kind of lock file(s) to generate [should be one of 'lock', 'explicit', or 'env'].",
+    help=f"Kind of lock file(s) to generate.",
 )
 @click.option(
     "--filename-template",
@@ -1668,7 +1708,7 @@ def install(
     "-k",
     "--kind",
     default=["explicit"],
-    type=click.Choice(["explicit", "env"]),
+    type=click.Choice(KINDS),
     multiple=True,
     help="Kind of lock file(s) to generate.",
 )

conda_lock/conda_solver.py

@@ -98,7 +98,6 @@ def solve_conda(
         Channels to query
 
     """
-
     conda_specs = [
         _to_match_spec(dep.name, dep.version, dep.build, dep.conda_channel)
         for dep in specs.values()
@@ -140,6 +139,7 @@ def solve_conda(
         locked_dependency = LockedDependency(
             name=action["name"],
             version=action["version"],
+            build=action["build"],
             manager="conda",
             platform=platform,
             dependencies=dependencies,

conda_lock/lockfile/v1/models.py

@@ -114,6 +114,9 @@ def to_fetch_action(self) -> FetchAction:
                 f"Expected '{self.platform}' but URL '{self.url}' contains '{parsed_platform}'."
             )
         filename_with_extension = path.name  # e.g. "tzdata-2022g-h191b570_0.conda"
+        build = self.build or filename_with_extension.split("-")[-1].split(".")[0]
+        if not self.build:
+            self.build = build
 
         # base_url is everything up to the platform directory
         base_url_path = str(path.parent.parent)  # e.g. "/conda-forge"
@@ -135,6 +138,7 @@ def to_fetch_action(self) -> FetchAction:
             version=self.version,
             channel=channel_url,
             url=self.url,
+            build=build,
             fn=filename_with_extension,
             md5=self.hash.md5,
             sha256=self.hash.sha256,

conda_lock/models/dry_run_install.py

@@ -18,6 +18,7 @@ class FetchAction(TypedDict):
     timestamp: int
     url: str
     version: str
+    build: Optional[str]
 
 
 class LinkAction(TypedDict):

conda_lock/models/lock_spec.py

@@ -72,6 +72,7 @@ class LockSpecification(BaseModel):
     sources: list[pathlib.Path]
     pip_repositories: list[PipRepository] = Field(default_factory=list)
     allow_pypi_requests: bool = True
+    output_recipe: dict = {}
 
     @property
     def platforms(self) -> list[str]:

conda_lock/src_parser/__init__.py

@@ -141,4 +141,5 @@ def dep_has_category(d: Dependency, categories: Set[str]) -> bool:
         pip_repositories=pip_repositories,
         sources=aggregated_lock_spec.sources,
         allow_pypi_requests=aggregated_lock_spec.allow_pypi_requests,
+        output_recipe=aggregated_lock_spec.output_recipe,
     )

conda_lock/src_parser/aggregation.py

@@ -53,6 +53,12 @@ def aggregate_lock_specs(
         )
     except ValueError as e:
         raise ChannelAggregationError(*e.args)
+    try:
+        output_recipe = unify_output_recipe(
+            [lock_spec.output_recipe for lock_spec in lock_specs]
+        )
+    except ValueError as e:
+        raise ChannelAggregationError(*e.args)
 
     return LockSpecification(
         dependencies=dependencies,
@@ -64,6 +70,7 @@ def aggregate_lock_specs(
         allow_pypi_requests=all(
             lock_spec.allow_pypi_requests for lock_spec in lock_specs
         ),
+        output_recipe=output_recipe,
     )
 
 
@@ -107,3 +114,16 @@ def unify_package_sources(
                 f"{collection} is not an ordered subset at the end of {result}"
             )
     return result
+
+def unify_output_recipe(
+    collections: list[dict],
+) -> dict:
+    """Unify the output recipe from multiple lock specs.
+
+    The output recipe must be the same for all lock specs.
+    """
+    if not collections:
+        return {}
+    if not all(c == collections[0] for c in collections):
+        raise ValueError("Output recipe must be the same for all lock specs.")
+    return collections[0]

conda_lock/src_parser/environment_yaml.py

@@ -134,6 +134,7 @@ def parse_environment_file(
 
     # These extension fields are nonstandard
     category: str = env_yaml_data.get("category") or "main"
+    output_recipe: dict = env_yaml_data.get("output_recipe", {})
 
     # Parse with selectors for each target platform
     dep_map = {
@@ -148,4 +149,5 @@ def parse_environment_file(
         channels=channels,  # type: ignore
         pip_repositories=pip_repositories,  # type: ignore
         sources=[environment_file],
+        output_recipe=output_recipe,
     )