Add lock plugin

conda-store-server/conda_store_server/plugins/__init__.py

@@ -2,4 +2,9 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
-BUILTIN_PLUGINS = []
+from conda_store_server.plugins.lock import conda_lock
+
+
+BUILTIN_PLUGINS = [
+    conda_lock.CondaLock
+]

conda-store-server/conda_store_server/plugins/lock/__init__.py

@@ -0,0 +1,3 @@
+# Copyright (c) conda-store development team. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.

conda-store-server/conda_store_server/plugins/lock/conda_lock.py

@@ -0,0 +1,85 @@
+# Copyright (c) conda-store development team. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+import json
+import os
+import pathlib
+import typing
+
+import yaml
+
+from conda_lock.conda_lock import run_lock
+
+from conda_store_server._internal import conda_utils, schema
+from conda_store_server.plugins import hookspec
+from conda_store_server.plugins.plugin_context import PluginContext
+
+
+class CondaLock():
+    @classmethod
+    def name(cls):
+        return "lock-conda_lock"
+
+    def __init__(self, conda_flags="--strict-channel-priority", conda_command="mamba", *kwargs):
+        self.conda_command = conda_command
+        self.conda_flags = conda_flags
+
+    @hookspec.hookimpl
+    def lock_environment(
+        self,
+        context: PluginContext,
+        spec: schema.CondaSpecification, 
+        platforms: typing.List[str] = [conda_utils.conda_platform()],
+    ) -> str:
+        context.log.info("lock_environment entrypoint for conda-lock")
+
+        environment_filename = pathlib.Path.cwd() / "environment.yaml"
+        lockfile_filename = pathlib.Path.cwd() / "conda-lock.yaml"
+
+        with environment_filename.open("w") as f:
+            json.dump(spec.dict(), f)
+
+        context.log.info(
+            "Note that the output of `conda config --show` displayed below only reflects "
+            "settings in the conda configuration file, which might be overridden by "
+            "variables required to be set by conda-store via the environment. Overridden "
+            f"settings: CONDA_FLAGS={self.conda_flags}"
+        )
+
+        # The info command can be used with either mamba or conda
+        context.run_command([self.conda_command, "info"])
+        # The config command is not supported by mamba
+        context.run_command(["conda", "config", "--show"])
+        context.run_command(["conda", "config", "--show-sources"])
+
+        # conda-lock ignores variables defined in the specification, so this code
+        # gets the value of CONDA_OVERRIDE_CUDA and passes it to conda-lock via
+        # the with_cuda parameter, see:
+        # https://github.com/conda-incubator/conda-store/issues/719
+        # https://docs.conda.io/projects/conda/en/latest/user-guide/tasks/manage-virtual.html#overriding-detected-packages
+        # TODO: Support all variables once upstream fixes are made to conda-lock,
+        # see the discussion in issue 719.
+        if spec.variables is not None:
+            cuda_version = spec.variables.get("CONDA_OVERRIDE_CUDA")
+        else:
+            cuda_version = None
+
+        # CONDA_FLAGS is used by conda-lock in conda_solver.solve_specs_for_arch
+        try:
+            conda_flags_name = "CONDA_FLAGS"
+            print(f"{conda_flags_name}={self.conda_flags}")
+            os.environ[conda_flags_name] = self.conda_flags
+
+            run_lock(
+                environment_files=[environment_filename],
+                platforms=platforms,
+                lockfile_path=lockfile_filename,
+                conda_exe=self.conda_command,
+                with_cuda=cuda_version,
+            )
+        finally:
+            os.environ.pop(conda_flags_name, None)
+
+        with lockfile_filename.open() as f:
+            return yaml.safe_load(f)