constants: update skylab package pin from a constant CIPD instance ID to a label which can be moved between instances.

This also moves the skylab package version to a newer one. No side effect on cbuildbot code, since the skylab CLI input and output is unaffected.

BUG=chromium:1137410
TEST=local runs with skylab CLI to confirm that the newer version runs all commands used by CI builders

Change-Id: I6a558a9c91f25967cc6f2c1d0d54f8c4cb62e33f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2616518
Tested-by: Jared Loucks <jaredloucks@google.com>
Reviewed-by: Sean Abraham <seanabraham@chromium.org>
Reviewed-by: Dhanya Ganesh <dhanyaganesh@chromium.org>
Reviewed-by: LaMont Jones <lamontjones@chromium.org>
diff --git a/.gitignore b/.gitignore
index 5aeab11..8c5859e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,3 +30,6 @@
 # Obsolete
 /virtualenv/
 /.venv/
+
+# Intellij files.
+*.iml
\ No newline at end of file
diff --git a/lib/cipd.py b/lib/cipd.py
index f68a155..ee69286 100644
--- a/lib/cipd.py
+++ b/lib/cipd.py
@@ -169,14 +169,14 @@
 
 
 @memoize.Memoize
-def InstallPackage(cipd_path, package, instance_id, destination,
+def InstallPackage(cipd_path, package, version, destination,
                    service_account_json=None):
   """Installs a package at a given destination using cipd.
 
   Args:
     cipd_path: The path to a cipd executable. GetCIPDFromCache can give this.
     package: A package name.
-    instance_id: The version of the package to install.
+    version: The CIPD version of the package to install (can be instance ID or a ref).
     destination: The folder to install the package under.
     service_account_json: The path of the service account credentials.
 
@@ -190,7 +190,7 @@
     service_account_flag = ['-service-account-json', service_account_json]
 
   with tempfile.NamedTemporaryFile() as f:
-    f.write(('%s %s' % (package, instance_id)).encode('utf-8'))
+    f.write(('%s %s' % (package, version)).encode('utf-8'))
     f.flush()
 
     cros_build_lib.run(
diff --git a/lib/constants.py b/lib/constants.py
index 00e9aea..6743e30 100644
--- a/lib/constants.py
+++ b/lib/constants.py
@@ -638,10 +638,9 @@
 
 # The cipd package for skylab tool
 CIPD_SKYLAB_PACKAGE = 'chromiumos/infra/skylab/linux-amd64'
-# crbug.com/1108489: The skylab tool CIPD package is pinned to a specific
-# version to avoid uncontrolled tool release and so that the tool is effectively
-# branched with cbuildbot.
-CIPD_SKYLAB_INSTANCE_ID = 'rfAczIAWe-S_ySaRTGXRHxo1aN_4oNzUIoD9-w886cYC'
+# The skylab tool CIPD package is pinned to a specific tag to avoid uncontrolled
+# tool release.
+CIPD_SKYLAB_INSTANCE_ID = 'cbuildbot-prod'
 
 # HWTest result statuses
 HWTEST_STATUS_PASS = 'pass'