Support conda/mamba install --copy

conda_lock/conda_lock.py

@@ -186,7 +186,11 @@ def do_validate_platform(lockfile: str) -> None:
 
 
 def do_conda_install(
-    conda: PathLike, prefix: str, name: str, file: pathlib.Path
+    conda: PathLike,
+    prefix: "str | None",
+    name: "str | None",
+    file: pathlib.Path,
+    copy: bool,
 ) -> None:
 
     _conda = partial(_invoke_conda, conda, prefix, name, check_call=True)
@@ -203,13 +207,18 @@ def do_conda_install(
     else:
         pip_requirements = []
 
+    env_prefix = ["env"] if kind == "env" and not is_micromamba(conda) else []
+    copy_arg = ["--copy"] if kind != "env" and copy else []
+    yes_arg = ["--yes"] if kind != "env" else []
+
     _conda(
         [
-            *(["env"] if kind == "env" and not is_micromamba(conda) else []),
+            *env_prefix,
             "create",
+            *copy_arg,
             "--file",
             str(file),
-            *([] if kind == "env" else ["--yes"]),
+            *yes_arg,
         ],
     )
 
@@ -1206,6 +1215,14 @@ def lock(
     default=False,
     help="don't attempt to use or install micromamba.",
 )
+@click.option(
+    "--copy",
+    is_flag=True,
+    help=(
+        "Install using `--copy` to prevent links. "
+        "This is useful for building containers"
+    ),
+)
 @click.option("-p", "--prefix", help="Full path to environment location (i.e. prefix).")
 @click.option("-n", "--name", help="Name of environment.")
 @click.option(
@@ -1247,6 +1264,7 @@ def install(
     conda: Optional[str],
     mamba: bool,
     micromamba: bool,
+    copy: bool,
     prefix: Optional[str],
     name: Optional[str],
     lock_file: pathlib.Path,
@@ -1269,7 +1287,9 @@ def install(
         yaml.safe_load(auth) if auth else read_json(auth_file) if auth_file else None
     )
     _conda_exe = determine_conda_executable(conda, mamba=mamba, micromamba=micromamba)
-    install_func = partial(do_conda_install, conda=_conda_exe, prefix=prefix, name=name)
+    install_func = partial(
+        do_conda_install, conda=_conda_exe, prefix=prefix, name=name, copy=copy
+    )
     if validate_platform and not lock_file.name.endswith(DEFAULT_LOCKFILE_NAME):
         lockfile_contents = read_file(lock_file)
         try:

conda_lock/invoke_conda.py

@@ -64,8 +64,8 @@ def determine_conda_executable(
 
 def _invoke_conda(
     conda: PathLike,
-    prefix: str,
-    name: str,
+    prefix: "str | None",
+    name: "str | None",
     command_args: Sequence[PathLike],
     post_args: Sequence[PathLike] = [],
     check_call: bool = False,
@@ -95,9 +95,11 @@ def _invoke_conda(
     if prefix:
         common_args.append("--prefix")
         common_args.append(prefix)
-    if name:
+    elif name:
         common_args.append("--name")
         common_args.append(name)
+    else:
+        raise ValueError("Neither prefix, nor name provided.")
     conda_flags = os.environ.get("CONDA_FLAGS")
     if conda_flags:
         common_args.extend(shlex.split(conda_flags))

docs/docker.md

@@ -4,6 +4,7 @@ In order to use conda-lock in a docker-style context you want to add the lockfil
 docker container.  This avoids the case where the `conda install xyz` statement is cached.
 
 Given a file tree like
+
 ```
   Dockerfile
   environment.yaml
@@ -15,24 +16,74 @@ You want a dockerfile that is structured something similar to this
 ```Dockerfile
 # Dockerfile
 
-# Build container
-FROM continuumio/miniconda:latest as conda
+# -----------------
+# Builder container
+# -----------------
+FROM continuumio/miniconda:latest as builder
 
-ADD conda-linux-64.lock /locks/conda-linux-64.lock
+COPY conda-linux-64.lock /locks/conda-linux-64.lock
 RUN conda create -p /opt/env --copy --file /locks/conda-linux-64.lock
 
+# -----------------
 # Primary container
+# -----------------
 FROM gcr.io/distroless/base-debian10
 # copy over the generated environment
-COPY --from=conda /opt/env /opt/env
+COPY --from=builder /opt/env /opt/env
+ENV PATH="/opt/env/bin:${PATH}"
 ```
 
-To get this to work nicely generate the platform specific lock run
+To get this to work nicely generate the platform specific lock run something
+like this in your shell
 
-```shell
+```bash
+# Update the lockfile
 conda lock --format explicit --platform linux-64
-docker build .
+# build the image
+docker build -t myimagename:mytag .
 ```
 
 This will ensure that your conda dependencies used in this docker container are
 always exactly reproducible.
+
+## conda-lock inside a build container
+
+You can also use conda-lock with a build-container style system if you make use of
+the `--copy` flag from `conda-lock install`
+
+```Dockerfile
+# -----------------
+# Builder container
+# -----------------
+FROM condaforge/mambaforge:4.14.0-0 as builder
+
+COPY environment.yml /docker/environment.yml
+
+RUN . /opt/conda/etc/profile.d/conda.sh && \
+    mamba create --name lock && \
+    conda activate lock && \
+    mamba env list && \
+    mamba install --yes pip conda-lock>=1.2.2 setuptools wheel && \
+    conda-lock lock \
+        --platform linux-64 \
+        --file /docker/environment.yml \
+        --kind lock \
+        --lockfile /docker/conda-lock.yml
+
+RUN . /opt/conda/etc/profile.d/conda.sh && \
+    conda activate lock && \
+    conda-lock install \
+        --mamba \
+        --copy \
+        --prefix /opt/env \
+        /docker/conda-lock.yml
+# optionally you can perfom some more cleanup on your conda install after this
+# to get a leaner conda environment
+
+# -----------------
+# Primary container
+# -----------------
+FROM gcr.io/distroless/base-debian10
+COPY --from=builder /opt/env /opt/env
+ENV PATH="/opt/env/bin:${PATH}"
+```