From 2ed1d64a00f767ab711a82c0606d42b0e5820217 Mon Sep 17 00:00:00 2001
From: Lars Erik Wik <lars.erik.wik@northern.tech>
Date: Wed, 12 Aug 2026 18:22:17 +0200
Subject: [PATCH] Added --label to build by Jenkins build label

The build-in-container.py script already knows how a Jenkins label maps
to a platform. Hence, an option to build based on a label makes it so
that a Jenkins job does not also have to know this mapping.

With this change, adding a platform will only require editing
platforms.json and labels.txt.

Signed-off-by: Lars Erik Wik <lars.erik.wik@northern.tech>
---
 build-in-container.md |  3 +++
 build-in-container.py | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/build-in-container.md b/build-in-container.md
index e32a770c4..eac915d9d 100644
--- a/build-in-container.md
+++ b/build-in-container.md
@@ -11,6 +11,9 @@ only Docker and Python 3 on the host.
 
 # Build a nova hub release package for Debian 12
 ./build-in-container.py --platform debian-12 --project nova --role hub --build-type RELEASE
+
+# Alternatively, use Jenkins labels (see build-scripts/labels.txt)
+./build-in-container.py --label PACKAGES_HUB_x86_64_linux_debian_12 --project nova --build-type RELEASE
 ```
 
 In the examples above, we run the script from inside `buildscripts/` (with
diff --git a/build-in-container.py b/build-in-container.py
index c5e8523c9..c5ef6d77f 100755
--- a/build-in-container.py
+++ b/build-in-container.py
@@ -386,6 +386,21 @@ def cache_label(platform_name, role, arch):
     return f"PACKAGES{hub}_{arch_token}_linux_{label_os}"
 
 
+def platform_role_arch(label):
+    """Return the (platform, role, arch) that cache_label() turns into label.
+
+    Found by trying every combination rather than by parsing the label. That
+    keeps cache_label() the only place that knows how a label is spelled, so the
+    two cannot drift apart.
+    """
+    for platform_name, platform_config in get_config().items():
+        for role in ("agent", "hub"):
+            for arch in platform_architectures(platform_config):
+                if cache_label(platform_name, role, arch) == label:
+                    return platform_name, role, arch
+    return None
+
+
 def run_container(args, image_tag, source_dir, script_dir, label):
     """Run the build inside a Docker container."""
     # Keep the packages in a directory of their own, so that building several
@@ -493,6 +508,12 @@ def parse_args():
         choices=list(get_config().keys()),
         help="Target platform",
     )
+    parser.add_argument(
+        "--label",
+        help="Build what this Jenkins build label names, e.g. "
+        "PACKAGES_HUB_x86_64_linux_debian_12. Sets --platform, --role and "
+        "--arch, so it replaces all three. See build-scripts/labels.txt.",
+    )
     parser.add_argument(
         "--project",
         choices=["community", "nova"],
@@ -593,6 +614,17 @@ def parse_args():
         # --platform is optional for these modes; updates all if omitted
         return args
 
+    if args.label:
+        if args.tarballs:
+            parser.error("--label and --tarballs build different things")
+        if args.platform or args.role or args.arch:
+            parser.error("--label already sets --platform, --role and --arch")
+        found = platform_role_arch(args.label)
+        if not found:
+            parser.error(f"no platform builds {args.label}")
+        args.platform, args.role, args.arch = found
+        log.info(f"{args.label}: {args.platform} {args.role} {args.arch}")
+
     if args.tarballs:
         # The tarballs are built from core and masterfiles alone, in an image of
         # their own, so the platform, project and role are not choices here. The