cmd-kola: add support for kola-blacklist.yaml

Rather than encoding the blacklist in three different places (the
fedora-coreos-config CI, the coreos-assembler CI, and the pipeline),
let's just teach `cosa kola` to auto-detect a `kola-blacklist.yaml` from
the src config and automatically blacklisting them when executing kola.

I proposed making this baked in kola itself with slightly different
semantics in: https://github.com/coreos/mantle/issues/1103

Though teaching this to cosa should still make things easier to maintain
for now at least.

src/cmd-kola

@@ -6,6 +6,7 @@ import json
 import os
 import sys
 import shutil
+import yaml
 
 cosa_dir = os.path.dirname(os.path.abspath(__file__))
 sys.path.insert(0, cosa_dir)
@@ -29,6 +30,17 @@ builddir = builds.get_build_dir(args.build)
 with open(os.path.join(builddir, "meta.json")) as f:
     buildmeta = json.load(f)
 
+# automatically add blacklisted tests specified in the src config
+blacklist_args = []
+blacklist_path = "src/config/kola-blacklist.yaml"
+if os.path.isfile(blacklist_path):
+    with open(blacklist_path) as f:
+        blacklist = yaml.safe_load(f)
+        for obj in blacklist:
+            print(f"⚠️  Skipping kola test pattern \"{obj['pattern']}\":")
+            print(f"⚠️  {obj['tracker']}")
+        blacklist_args += ['--blacklist-test', obj['pattern']]
+
 qemuimg = buildmeta['images'].get('qemu')
 if qemuimg is None:
     raise SystemExit(f"No qemu image in build: {args.build}")
@@ -60,6 +72,8 @@ outputdir = args.output_dir or "tmp/kola"
 kolaargs.extend(['--output-dir', outputdir])
 kolaargs.extend(args.subargs)
 
+kolaargs.extend(blacklist_args)
+
 # flush before exec; see https://docs.python.org/3.7/library/os.html#os.execvpe
 print(subprocess.list2cmdline(kolaargs), flush=True)
 env = dict(os.environ)