hack: split some functions so that the original call is less sprawling

Split up the function setting up the docker buildx or podman build
commands so that the higher level function is shorter overall.

Best viewed with git diff -w

Signed-off-by: John Mulligan <[email protected]>

Author: phlogistonjohn

hack/build-image

@@ -204,64 +204,72 @@ def container_engine(cli):
     return _DISCOVERED_CONTAINER_ENGINES[0]
 
 
-def container_build(cli, target):
-    """Construct and execute a command to build the target container image."""
+def _buildx_build_tasks(cli, target):
     eng = container_engine(cli)
     tasks = []
+    args = [eng, "buildx"]
+
+    # Docker's default builder only supports the host architecture.
+    # Therefore, we need to create a new builder to support other
+    # architectures, and we must ensure we start with a fresh builder
+    # that does not contain any images from previous builds.
+    tasks.append({"cmd": args + ["rm", target.flat_name()], "check": False})
+    tasks.append(
+        {
+            "cmd": args + ["create", f"--name={target.flat_name()}"],
+            "check": True,
+        }
+    )
 
-    # For docker cross-builds we need to use buildx
-    if "docker" in eng and target.arch != host_arch():
-        args = [eng, "buildx"]
-
-        # Docker's default builder only supports the host architecture.
-        # Therefore, we need to create a new builder to support other
-        # architectures, and we must ensure we start with a fresh builder
-        # that does not contain any images from previous builds.
-        tasks.append(
-            {"cmd": args + ["rm", target.flat_name()], "check": False}
-        )
-        tasks.append(
-            {
-                "cmd": args + ["create", f"--name={target.flat_name()}"],
-                "check": True,
-            }
-        )
+    tasks.append(
+        {
+            "cmd": args
+            + [
+                "build",
+                f"--builder={target.flat_name()}",
+                f"--platform=linux/{target.arch}",
+                "--load",
+            ]
+            + create_common_container_engine_args(cli, target),
+            "check": True,
+        }
+    )
 
-        tasks.append(
-            {
-                "cmd": args
-                + [
-                    "build",
-                    f"--builder={target.flat_name()}",
-                    f"--platform=linux/{target.arch}",
-                    "--load",
-                ]
-                + create_common_container_engine_args(cli, target),
-                "check": True,
-            }
-        )
+    tasks.append({"cmd": args + ["rm", target.flat_name()], "check": True})
+    return tasks
 
-        tasks.append(
-            {"cmd": args + ["rm", target.flat_name()], "check": True}
-        )
+
+def _common_build_tasks(cli, target):
+    # podman/common build tasks
+    eng = container_engine(cli)
+    tasks = []
+    args = [eng, "build"]
+    if target.arch != host_arch() or FORCE_ARCH_FLAG:
+        # We've noticed a few small quirks when using podman with the
+        # --arch option. The main issue is that building the client image
+        # works but then the toolbox image fails because it somehow doesn't
+        # see the image we just built as usable. This doesn't happen when
+        # --arch is not provided. So if the target arch and the host_arch
+        # are the same, skip passing the extra argument.
+        args += [f"--arch={target.arch}"]
+
+    tasks.append(
+        {
+            "cmd": args + create_common_container_engine_args(cli, target),
+            "check": True,
+        }
+    )
+    return tasks
+
+
+def container_build(cli, target):
+    """Construct and execute a command to build the target container image."""
+    eng = container_engine(cli)
+    # For docker cross-builds we need to use buildx
+    if "docker" in eng and target.arch != host_arch():
+        tasks = _buildx_build_tasks(cli, target)
     else:
-        args = [eng, "build"]
-        if target.arch != host_arch() or FORCE_ARCH_FLAG:
-            # We've noticed a few small quirks when using podman with the
-            # --arch option. The main issue is that building the client image
-            # works but then the toolbox image fails because it somehow doesn't
-            # see the image we just built as usable. This doesn't happen when
-            # --arch is not provided. So if the target arch and the host_arch
-            # are the same, skip passing the extra argument.
-            args += [f"--arch={target.arch}"]
-
-        tasks.append(
-            {
-                "cmd": args
-                + create_common_container_engine_args(cli, target),
-                "check": True,
-            }
-        )
+        tasks = _common_build_tasks(cli, target)
 
     for task in tasks:
         run(cli, **task)