Add support for mirrored channels (#1008)

Co-authored-by: Marco Esters <mesters@anaconda.com>
Co-authored-by: jaimergp <jaimergp@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 4 people

CONSTRUCT.md

@@ -81,6 +81,27 @@ channels_remap:
 
 At least one channel must be supplied, either in `channels` or `channels_remap`.
 
+### `mirrored_channels`
+
+A mapping of channels to their mirror URLs. Each channel maps to a list of
+mirror URLs that will be used as fallbacks. The mirrored channels will be
+included in the `.condarc` file of the installer.
+
+Requires `mamba` to be listed in the `base` environment, and `write_condarc`
+to be `True`.
+
+Example use:
+
+```yaml
+mirrored_channels:
+  conda-forge:
+    - "https://conda.anaconda.org/conda-forge"
+    - "https://conda.anaconda.org/conda-forge-mirror"
+  defaults:
+    - "https://repo.anaconda.com/pkgs/main"
+    - "https://repo.anaconda.com/pkgs/main-mirror"
+```
+
 ### `specs`
 
 A list of package specifications; e.g. `python 2.7*`, `pyzmq` or `numpy >=1.8`.

constructor/_schema.py

@@ -247,6 +247,27 @@ class ConstructorConfiguration(BaseModel):
 
     At least one channel must be supplied, either in `channels` or `channels_remap`.
     """
+    mirrored_channels: dict[NonEmptyStr, list[NonEmptyStr]] = {}
+    """
+    A mapping of channels to their mirror URLs. Each channel maps to a list of
+    mirror URLs that will be used as fallbacks. The mirrored channels will be
+    included in the `.condarc` file of the installer.
+
+    Requires `mamba` to be listed in the `base` environment, and `write_condarc`
+    to be `True`.
+
+    Example use:
+
+    ```yaml
+    mirrored_channels:
+      conda-forge:
+        - "https://conda.anaconda.org/conda-forge"
+        - "https://conda.anaconda.org/conda-forge-mirror"
+      defaults:
+        - "https://repo.anaconda.com/pkgs/main"
+        - "https://repo.anaconda.com/pkgs/main-mirror"
+    ```
+    """
     specs: list[NonEmptyStr] | NonEmptyStr = []
     """
     A list of package specifications; e.g. `python 2.7*`, `pyzmq` or `numpy >=1.8`.

constructor/data/construct.schema.json

@@ -871,6 +871,22 @@
       "description": "A list of packages with menu items to be installed. The packages must have necessary metadata in `Menu/<package name>.json`. By default, all menu items found in the installation will be created; supplying this list allows a subset to be selected instead. If an empty list is supplied, no shortcuts will be created.\nIf all environments (`extra_envs` included) set `menu_packages` to an empty list, no UI options about shortcuts will be offered to the user.\nNote: This option is not fully implemented when `micromamba` is used as the `--conda-exe` binary. The only accepted value is an empty list (`[]`).",
       "title": "Menu Packages"
     },
+    "mirrored_channels": {
+      "additionalProperties": {
+        "items": {
+          "minLength": 1,
+          "type": "string"
+        },
+        "type": "array"
+      },
+      "default": {},
+      "description": "A mapping of channels to their mirror URLs. Each channel maps to a list of mirror URLs that will be used as fallbacks. The mirrored channels will be included in the `.condarc` file of the installer.\nRequires `mamba` to be listed in the `base` environment, and `write_condarc` to be `True`.\nExample use:\n```yaml\nmirrored_channels:\n  conda-forge:\n    - \"https://conda.anaconda.org/conda-forge\"\n    - \"https://conda.anaconda.org/conda-forge-mirror\"\n  defaults:\n    - \"https://repo.anaconda.com/pkgs/main\"\n    - \"https://repo.anaconda.com/pkgs/main-mirror\"\n```",
+      "propertyNames": {
+        "minLength": 1
+      },
+      "title": "Mirrored Channels",
+      "type": "object"
+    },
     "name": {
       "description": "Name of the installer. Names may be composed of letters, numbers, underscores, dashes, and periods, but must not begin or end with a dash or period.",
       "minLength": 1,

constructor/utils.py

@@ -130,14 +130,19 @@ def if_repl(match):
 
 
 def add_condarc(info):
+    from .conda_interface import MatchSpec  # prevent circular import
+
     condarc = info.get("condarc")
     if condarc is None:
         # The legacy approach
         write_condarc = info.get("write_condarc")
         default_channels = info.get("conda_default_channels")
         channel_alias = info.get("conda_channel_alias")
         channels = info.get("channels")
-        if not (write_condarc and (default_channels or channels or channel_alias)):
+        mirrored_channels = info.get("mirrored_channels")
+        if not (
+            write_condarc and (default_channels or channels or channel_alias or mirrored_channels)
+        ):
             return
         condarc = {}
         if default_channels:
@@ -146,6 +151,14 @@ def add_condarc(info):
             condarc["channels"] = channels
         if channel_alias:
             condarc["channel_alias"] = channel_alias
+        if mirrored_channels:
+            if "mamba" in {MatchSpec(spec).name for spec in info.get("specs", ())}:
+                condarc["mirrored_channels"] = mirrored_channels
+            else:
+                logger.warning(
+                    "The 'mirrored_channels' key is only supported by mamba. "
+                    "It will not be included in the installer."
+                )
     if isinstance(condarc, dict):
         condarc = yaml_to_string(condarc)
     yield "# ----- add condarc"

docs/source/construct-yaml.md

@@ -81,6 +81,27 @@ channels_remap:
 
 At least one channel must be supplied, either in `channels` or `channels_remap`.
 
+### `mirrored_channels`
+
+A mapping of channels to their mirror URLs. Each channel maps to a list of
+mirror URLs that will be used as fallbacks. The mirrored channels will be
+included in the `.condarc` file of the installer.
+
+Requires `mamba` to be listed in the `base` environment, and `write_condarc`
+to be `True`.
+
+Example use:
+
+```yaml
+mirrored_channels:
+  conda-forge:
+    - "https://conda.anaconda.org/conda-forge"
+    - "https://conda.anaconda.org/conda-forge-mirror"
+  defaults:
+    - "https://repo.anaconda.com/pkgs/main"
+    - "https://repo.anaconda.com/pkgs/main-mirror"
+```
+
 ### `specs`
 
 A list of package specifications; e.g. `python 2.7*`, `pyzmq` or `numpy >=1.8`.

examples/mirrored_channels/construct.yaml

@@ -0,0 +1,20 @@
+# yaml-language-server: $schema=../../constructor/data/construct.schema.json
+"$schema": "../../constructor/data/construct.schema.json"
+
+name: Mirrors
+version: X
+
+channels:
+  - conda-forge
+
+mirrored_channels:
+  conda-forge:
+    - "https://conda.anaconda.org/conda-forge"
+    - "https://conda.anaconda.org/mirror1"
+    - "https://conda.anaconda.org/mirror2"
+
+write_condarc: True
+
+specs:
+  - python
+  - mamba

news/1008-mirrored-channels-schema

@@ -0,0 +1,19 @@
+### Enhancements
+
+* Add support for `mirrored_channels` in `construct.yaml`. These mirrored channels are included in the resulting `.condarc` file if one is created. (#1008)
+
+### Bug fixes
+
+* <news item>
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>

tests/requirements.txt

@@ -2,3 +2,4 @@ pytest
 pytest-cov
 coverage
 jinja2
+ruamel.yaml

tests/test_examples.py

@@ -19,6 +19,7 @@
 from conda.base.context import context
 from conda.core.prefix_data import PrefixData
 from conda.models.version import VersionOrder as Version
+from ruamel.yaml import YAML
 
 from constructor.utils import StandaloneExe, identify_conda_exe
 
@@ -473,6 +474,31 @@ def test_example_extra_files(tmp_path, request):
         _run_installer(input_path, installer, install_dir, request=request)
 
 
+def test_example_mirrored_channels(tmp_path, request):
+    input_path = _example_path("mirrored_channels")
+    for installer, install_dir in create_installer(input_path, tmp_path):
+        _run_installer(input_path, installer, install_dir, request=request, uninstall=False)
+
+        expected_condarc = {
+            "channels": ["conda-forge"],
+            "mirrored_channels": {
+                "conda-forge": [
+                    "https://conda.anaconda.org/conda-forge",
+                    "https://conda.anaconda.org/mirror1",
+                    "https://conda.anaconda.org/mirror2",
+                ]
+            },
+        }
+
+        condarc_file = install_dir / ".condarc"
+        assert condarc_file.exists()
+
+        with open(condarc_file) as file:
+            condarc_data = YAML().load(file)
+
+        assert condarc_data == expected_condarc
+
+
 @pytest.mark.xfail(
     (
         CONDA_EXE == StandaloneExe.CONDA