Merge pull request #499 from jacksmith15/feat/464/support-v2-lockfile…

…s-with-any-name

Detect lockfile type based on contents rather than filename

README.md

@@ -75,9 +75,7 @@ and update operations. You can supply a different filename with e.g.
 conda-lock --lockfile superspecial.conda-lock.yml
 ```
 
-The extension `.conda-lock.yml` will be added if not present. Rendered
-environment files (env or explicit) must end with `.lock` and will be named as
-`"conda-{platform}.lock"` by default.
+Rendered `explicit` and `env` lockfiles will be named as `"conda-{platform}.lock"` and `"conda-{platform}.lock.yml` respectively by default.
 
 If you want to override that call conda-lock as follows.
 ```bash
@@ -89,7 +87,7 @@ conda-lock -k explicit --filename-template "specific-{platform}.conda.lock"
 Conda-lock will build a spec list from several files if requested.
 
 ```bash
-conda-lock -f base.yml -f specific.yml -p linux-64 --filename-template "specific-{platform}.lock"
+conda-lock -f base.yml -f specific.yml -p linux-64 -k explicit --filename-template "specific-{platform}.lock"
 ````
 
 In this case all dependencies are combined, and the ordered union of all `channels` is used as the final

conda_lock/conda_lock.py

@@ -36,6 +36,7 @@
 import yaml
 
 from ensureconda.api import ensureconda
+from ensureconda.resolve import platform_subdir
 from typing_extensions import Literal
 
 from conda_lock.click_helpers import OrderedGroup
@@ -54,7 +55,11 @@
     determine_conda_executable,
     is_micromamba,
 )
-from conda_lock.lockfile import parse_conda_lock_file, write_conda_lock_file
+from conda_lock.lockfile import (
+    UnknownLockfileVersion,
+    parse_conda_lock_file,
+    write_conda_lock_file,
+)
 from conda_lock.lockfile.v2prelim.models import (
     GitMeta,
     InputMeta,
@@ -139,6 +144,10 @@
 """
 
 
+class UnknownLockfileKind(ValueError):
+    pass
+
+
 def _extract_platform(line: str) -> Optional[str]:
     search = PLATFORM_PATTERN.search(line)
     if search:
@@ -932,13 +941,11 @@ def _render_lockfile_for_install(
         Optional dependency groups to include in output
 
     """
-
-    if not filename.name.endswith(DEFAULT_LOCKFILE_NAME):
+    kind = _detect_lockfile_kind(pathlib.Path(filename))
+    if kind in ("explicit", "env"):
         yield filename
         return
 
-    from ensureconda.resolve import platform_subdir
-
     lock_content = parse_conda_lock_file(pathlib.Path(filename))
 
     platform = platform_subdir()
@@ -984,6 +991,25 @@ def _render_lockfile_for_install(
         yield path
 
 
+def _detect_lockfile_kind(path: pathlib.Path) -> TKindAll:
+    content = path.read_text(encoding="utf-8")
+    if "@EXPLICIT" in {line.strip() for line in content.splitlines()}:
+        return "explicit"
+    try:
+        lockfile = yaml.safe_load(content)
+        if {"channels", "dependencies"} <= set(lockfile):
+            return "env"
+        if "version" in lockfile:
+            # Version validation is handled by `lockfile.parse_conda_lock_file`
+            return "lock"
+        raise UnknownLockfileKind(f"Could not detect the kind of lockfile at {path}")
+    except yaml.YAMLError:
+        raise UnknownLockfileKind(
+            f"Could not detect the kind of lockfile at {path}. Note that explicit "
+            "lockfiles must contain the line '@EXPLICIT'."
+        )
+
+
 def run_lock(
     environment_files: List[pathlib.Path],
     *,

conda_lock/lockfile/__init__.py

@@ -17,6 +17,14 @@
 from conda_lock.models.lock_spec import Dependency
 
 
+class MissingLockfileVersion(ValueError):
+    pass
+
+
+class UnknownLockfileVersion(ValueError):
+    pass
+
+
 def _seperator_munge_get(
     d: Mapping[str, Union[List[LockedDependency], LockedDependency]], key: str
 ) -> Union[List[LockedDependency], LockedDependency]:
@@ -135,8 +143,10 @@ def parse_conda_lock_file(path: pathlib.Path) -> Lockfile:
     version = content.pop("version", None)
     if version == 1:
         return lockfile_v1_to_v2(LockfileV1.parse_obj(content))
+    elif version is None:
+        raise MissingLockfileVersion(f"{path} is missing a version")
     else:
-        raise ValueError(f"{path} has unknown version {version}")
+        raise UnknownLockfileVersion(f"{path} has unknown version {version}")
 
 
 def write_conda_lock_file(