==================
Mirroring channels
==================

The conda configuration system has several keys that can be used to set up a mirrored context.

The default setup
=================

By default, ``conda`` can serve packages from two main locations:

- ``repo.anaconda.com``: this is where ``defaults`` points to by default.
  The default value has been marked for pending deprecation as of conda 24.9.0,
  but it is still the default for older versions. In conda 25.3.0, this default
  will be removed.

  This base location is hardcoded in the default value of ``default_channels``:
    - ``https://repo.anaconda.com/pkgs/main``
    - ``https://repo.anaconda.com/pkgs/r``
    - ``https://repo.anaconda.com/pkgs/msys2``
- ``conda.anaconda.org``: this is where conda clients look up community channels like ``conda-forge`` or ``bioconda``.
  This base location can be configured via ``channel_alias``.

So, when it comes to mirroring these channels, you have to account for those two locations.


Mirror ``defaults``
===================

Use ``default_channels`` to overwrite the :doc:`default configuration </configuration>`. For example:

.. code-block:: yaml

    default_channels:
        - https://my-mirror.com/pkgs/main
        - https://my-mirror.com/pkgs/r
        - https://my-mirror.com/pkgs/msys2


Mirror all community channels
=============================

Redefine ``channel_alias`` to point to your mirror. For example:

.. code-block:: yaml

    channel_alias: https://my-mirror.com

This will make ``conda`` look for all community channels at ``https://my-mirror.com/conda-forge``, ``https://my-mirror.com/bioconda``, etc.


Mirror only some community channels
===================================

If you want to mirror only some community channels, you must use ``custom_channels``.
This takes precedence over ``channel_alias``. For example:

.. code-block:: yaml

    custom_channels:
        conda-forge: https://my-mirror.com/conda-forge

With this configuration, conda-forge will be looked up at ``https://my-mirror.com/conda-forge``.
All other community channels will be looked up at ``https://conda.anaconda.org``.


.. note::

    Feel free to explore all the available options in :doc:`/configuration`.