From aaf61ce9fc79dbcf19bade91db4e4426dba65b26 Mon Sep 17 00:00:00 2001
From: Christian Kellner <christian@kellner.me>
Date: Tue, 8 Dec 2020 18:13:33 +0100
Subject: [PATCH] formats: extract manifest loading into module

Extract the code that loads a pipeline from a pipeline description,
i.e. a manifest, into a new module inside a new 'formats' package.
The idea is to have different descriptions, i.e. different formats,
for the same internal representation. This allows changing the
internal representation, i.e. data structures, but still having the
same external description.
Later a new description might be added that better matches the new
internal representation.
---
 osbuild/__init__.py         |  4 ++--
 osbuild/formats/__init__.py |  3 +++
 osbuild/formats/v1.py       | 32 ++++++++++++++++++++++++++++++++
 osbuild/pipeline.py         | 29 -----------------------------
 4 files changed, 37 insertions(+), 31 deletions(-)
 create mode 100644 osbuild/formats/__init__.py
 create mode 100644 osbuild/formats/v1.py

diff --git a/osbuild/__init__.py b/osbuild/__init__.py
index fed324ef..50fc83c1 100644
--- a/osbuild/__init__.py
+++ b/osbuild/__init__.py
@@ -8,8 +8,8 @@ The utility module `osbuild.util` provides access to common functionality
 independent of osbuild but used across the osbuild codebase.
 """
 
-
-from .pipeline import Assembler, load, load_build, Pipeline, Stage
+from .formats.v1 import load, load_build
+from .pipeline import Assembler, Pipeline, Stage
 
 
 __all__ = [
diff --git a/osbuild/formats/__init__.py b/osbuild/formats/__init__.py
new file mode 100644
index 00000000..8eeb5e19
--- /dev/null
+++ b/osbuild/formats/__init__.py
@@ -0,0 +1,3 @@
+"""
+Concrete representation of manifest descriptions
+"""
diff --git a/osbuild/formats/v1.py b/osbuild/formats/v1.py
new file mode 100644
index 00000000..ce7fd6b9
--- /dev/null
+++ b/osbuild/formats/v1.py
@@ -0,0 +1,32 @@
+# Version 1 of the manifest description
+
+from ..pipeline import Pipeline, detect_host_runner
+
+
+def load_build(description, sources_options):
+    pipeline = description.get("pipeline")
+    if pipeline:
+        build_pipeline = load(pipeline, sources_options)
+    else:
+        build_pipeline = None
+
+    return build_pipeline, description["runner"]
+
+
+def load(description, sources_options):
+    build = description.get("build")
+    if build:
+        build_pipeline, runner = load_build(build, sources_options)
+    else:
+        build_pipeline, runner = None, detect_host_runner()
+
+    pipeline = Pipeline(runner, build_pipeline)
+
+    for s in description.get("stages", []):
+        pipeline.add_stage(s["name"], sources_options, s.get("options", {}))
+
+    a = description.get("assembler")
+    if a:
+        pipeline.set_assembler(a["name"], a.get("options", {}))
+
+    return pipeline
diff --git a/osbuild/pipeline.py b/osbuild/pipeline.py
index 9773fc1b..87fdd47e 100644
--- a/osbuild/pipeline.py
+++ b/osbuild/pipeline.py
@@ -363,32 +363,3 @@ def detect_host_runner():
     """Use os-release(5) to detect the runner for the host"""
     osname = osrelease.describe_os(*osrelease.DEFAULT_PATHS)
     return "org.osbuild." + osname
-
-
-def load_build(description, sources_options):
-    pipeline = description.get("pipeline")
-    if pipeline:
-        build_pipeline = load(pipeline, sources_options)
-    else:
-        build_pipeline = None
-
-    return build_pipeline, description["runner"]
-
-
-def load(description, sources_options):
-    build = description.get("build")
-    if build:
-        build_pipeline, runner = load_build(build, sources_options)
-    else:
-        build_pipeline, runner = None, detect_host_runner()
-
-    pipeline = Pipeline(runner, build_pipeline)
-
-    for s in description.get("stages", []):
-        pipeline.add_stage(s["name"], sources_options, s.get("options", {}))
-
-    a = description.get("assembler")
-    if a:
-        pipeline.set_assembler(a["name"], a.get("options", {}))
-
-    return pipeline