Freeze enviornment with conda-lock

approximately one million times faster than running a full install

installation time should be faster, too, as there is no solve

Author: minrk

repo2docker/buildpacks/conda/environment.yml

@@ -1,3 +1,5 @@
+channels:
+  - conda-forge
 dependencies:
   - python=3.7
   - ipywidgets==7.6.3

repo2docker/buildpacks/conda/freeze.py

@@ -2,7 +2,7 @@
 """
 Freeze the conda environment.yml
 
-It runs the freeze in a continuumio/miniconda3 image to ensure portability
+Using conda-lock
 
 Usage:
 
@@ -19,12 +19,6 @@
 from ruamel.yaml import YAML
 
 
-DOCKER_IMAGE = "condaforge/mambaforge:4.9.2-5"
-# set mamba and/or conda versions
-# if needed to differ from what's in the image
-MAMBA_VERSION = ""
-CONDA_VERSION = ""
-
 HERE = pathlib.Path(os.path.dirname(os.path.abspath(__file__)))
 
 ENV_FILE = HERE / "environment.yml"
@@ -36,13 +30,12 @@
 yaml = YAML(typ="rt")
 
 
-def freeze(env_file, frozen_file):
+def freeze(env_file, frozen_file, platform="linux-64"):
     """Freeze a conda environment.yml
 
-    By running in docker:
+    By running
 
-        mamba env create
-        mamba env export
+        conda-lock --mamba --platform=linux-64 -f environment.yml
 
     Result will be stored in frozen_file
     """
@@ -58,43 +51,32 @@ def freeze(env_file, frozen_file):
                 return
     print(f"Freezing {env_file} -> {frozen_file}")
 
+    # FIXME: conda-lock 0.8 requires {platform} in template
+    # https://github.com/conda-incubator/conda-lock/pull/78
+    frozen_template = str(frozen_dest) + ".{platform}"
+    frozen_tempfile = pathlib.Path(frozen_template.format(platform=platform))
+
+    check_call(
+        [
+            "conda-lock",
+            # FIXME: adopt micromamba after ordering is fixed
+            # https://github.com/conda-incubator/conda-lock/issues/79
+            "--mamba",
+            f"--platform={platform}",
+            f"--filename-template={frozen_template}",
+            f"--file={env_file}",
+        ]
+    )
+
     with frozen_dest.open("w") as f:
         f.write(
             f"# AUTO GENERATED FROM {env_file.relative_to(HERE)}, DO NOT MANUALLY MODIFY\n"
         )
         f.write(f"# Frozen on {datetime.utcnow():%Y-%m-%d %H:%M:%S UTC}\n")
+        with frozen_tempfile.open() as temp:
+            f.write(temp.read())
 
-    check_call(
-        [
-            "docker",
-            "run",
-            "--rm",
-            "-v" f"{HERE}:/r2d",
-            "-it",
-            DOCKER_IMAGE,
-            "sh",
-            "-c",
-            "; ".join(
-                [
-                    "set -ex",
-                    "conda config --set channel_priority strict",
-                    "conda config --add channels conda-forge",
-                    f"mamba install -yq -S mamba={MAMBA_VERSION}"
-                    if MAMBA_VERSION
-                    else "true",
-                    f"mamba install -yq -S conda={CONDA_VERSION}"
-                    if CONDA_VERSION
-                    else "true",
-                    "conda config --system --set auto_update_conda false",
-                    f"mamba env create -v -f /r2d/{env_file.relative_to(HERE)} -n r2d",
-                    # add conda-forge broken channel as lowest priority in case
-                    # any of our frozen packages are marked as broken after freezing
-                    "conda config --append channels conda-forge/label/broken",
-                    f"mamba env export -n r2d >> /r2d/{frozen_file.relative_to(HERE)}",
-                ]
-            ),
-        ]
-    )
+    os.remove(frozen_tempfile)
 
 
 def set_python(py_env_file, py):