Make cache for generator predictable

This commit adds sorting of ZuulJobs entries so when cached
the produced output is always predictable and repeatable
across multiple calls to generator, no matter who, where
and when executes the code. This should allow us to include
small incremental changes in cache file when regenerating
the cache periodically for any upstream changes.

znoyder/generator.py

@@ -106,7 +106,7 @@ def fetch_osp_projects(branch: str, filters: dict) -> list:
 
 @cache('path', readable=True)
 def discover_upstream_jobs(path, templates, pipelines):
-    return finder.find_jobs(path, templates, pipelines)
+    return sorted(finder.find_jobs(path, templates, pipelines))
 
 
 def discover_jobs(project_name, osp_tag, directory,

znoyder/lib/cache.py

@@ -110,7 +110,7 @@ def save(self):
                 self._cache,
                 Dumper=NoAliasDumper,
                 default_flow_style=False,
-                sort_keys=False,
+                sort_keys=True,
                 width=math.inf,
             )
             file.write(data)

znoyder/lib/zuul.py

@@ -464,6 +464,12 @@ def __eq__(self, other) -> bool:
             and self.pipeline == other.pipeline
         )
 
+    def __lt__(self, other) -> bool:
+        if self.name == other.name:
+            return self.pipeline < other.pipeline
+
+        return self.name < other.name
+
     def really_equal(self, other) -> bool:
         return type(other) is type(self) and (
             self.name == other.name