Merge ~sbparke/juju-lint/+git/juju-lint-1:bug/1915934-1 into juju-lint:master

[Steven Parker]

Added logic to parse multiple documents in exported bundle file for service overlays

Usage of saas service overlays and offers can lead to parsing errors as juju-lint is expecting a single yaml document within a juju export file.

This leads to BUG https://bugs.launchpad.net/juju-lint/+bug/1915934

applications:
  grafana:
    charm: cs:grafana-51
    channel: stable
    num_units: 1
    to:
    - 0
    options:
      install_method: snap
    bindings:
      "": oam-space
machines:
   0:
    constraints: tags=nagios spaces=oam-space
    series: bionic
--- # overlay.yaml <<-- starts new document
applications:
    grafana:
      offers:
       grafana:
         endpoints:
         - dashboards
         acl:
          admin: admin

leads to
yaml.composer.ComposerError: expected a single document in the stream
  in "<unicode string>", line 1, column 1:
    series: bionic
    ^
but found another document
  in "<unicode string>", line 627, column 1:
    --- # overlay.yaml
    ^

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

Change successfully merged at revision 003bbb91b8d7c48466faa98b833e66c97c7a333f

diff --git a/Makefile b/Makefile
index 917e96b..70a2762 100644
--- a/Makefile
+++ b/Makefile
@@ -10,3 +10,10 @@ deb-src:
 
 test:
 	tox -e unit
+
+build:
+	snapcraft --use-lxd --debug
+
+clean:
+	snapcraft clean --use-lxd
+
diff --git a/jujulint/lint.py b/jujulint/lint.py
index 6c425bd..a59d66a 100755
--- a/jujulint/lint.py
+++ b/jujulint/lint.py
@@ -969,16 +969,36 @@ class Linter:
                 if num_this_az < min_per_az:
                     self.model.az_unbalanced_apps[app_name] = [num_units, az_counter]
 
-    def lint_yaml_string(self, yaml):
+    # Juju now creates multiple documents within a single export-bundle file
+    #   This is to support offer overlays
+    #   This occurs with the format string "--- # overlay.yaml"
+    def get_main_bundle_doc(self, parsed_yaml_docs):
+        """Get main bundle document from yaml input that may contain mutiple documents."""
+        parsed_yaml = None
+
+        parsed_doc_list = list(parsed_yaml_docs)
+        for doc in parsed_doc_list:
+            offer_overlay = False
+            applications = doc["applications"]
+            for app in applications:
+                if "offers" in doc["applications"][app]:
+                    offer_overlay = True
+            if parsed_yaml is None or not offer_overlay:
+                parsed_yaml = doc
+        return(parsed_yaml)
+
+    def lint_yaml_string(self, yaml_string):
         """Lint provided YAML string."""
-        parsed_yaml = yaml.safe_load(yaml)
+        parsed_yaml_docs = yaml.safe_load_all(yaml_string)
+        parsed_yaml = self.get_main_bundle_doc(parsed_yaml_docs)
         return self.do_lint(parsed_yaml)
 
     def lint_yaml_file(self, filename):
         """Load and lint provided YAML file."""
         if filename:
             with open(filename, "r") as infile:
-                parsed_yaml = yaml.safe_load(infile.read())
+                parsed_yaml_docs = yaml.safe_load_all(infile.read())
+                parsed_yaml = self.get_main_bundle_doc(parsed_yaml_docs)
                 if parsed_yaml:
                     return self.do_lint(parsed_yaml)
         self.logger.fubar("Failed to parse YAML from file {}".format(filename))
diff --git a/tests/test_jujulint.py b/tests/test_jujulint.py
index d865c63..e67f8af 100644
--- a/tests/test_jujulint.py
+++ b/tests/test_jujulint.py
@@ -225,6 +225,43 @@ class TestLinter:
         assert errors[0]["id"] == "ops-charm-missing"
         assert errors[0]["charm"] == "telegraf"
 
+    def test_overlay_documents(self, linter, tmp_path):
+        """Test offer overlay format for saas cross model offers."""
+        # juju now exports two documents to exported files.
+        #  We need to ignore the overlay document and still parse the main yaml doc
+        yaml = """
+applications:
+  grafana:
+    charm: cs:grafana-51
+    channel: stable
+    num_units: 1
+    to:
+    - 0
+    options:
+      install_method: snap
+    bindings:
+      "": oam-space
+machines:
+   0:
+    constraints: tags=nagios spaces=oam-space
+    series: bionic
+--- # overlay.yaml
+applications:
+    grafana:
+      offers:
+       grafana:
+         endpoints:
+         - dashboards
+         acl:
+          admin: admin"""
+
+        linter.lint_yaml_string(yaml)
+
+        yaml_path = tmp_path / "bundle.yaml"
+        yaml_path.write_text(yaml)
+
+        linter.lint_yaml_file(yaml_path)
+
     def test_unrecognised_charm(self, linter, juju_status):
         """Test that unrecognised charms are detected."""
         # drop 'ubuntu' from the known charms