Work around MAAS 1.9.4 bug

Handle a JSON deserialisation error caused by the API version requiring login in MAAS 1.9.4 - this is fixed in 1.9.5, but we shouldn't break this for 1.9.4 users right now. MAAS bug: https://bugs.launchpad.net/maas/+bug/1583715 Fixes https://bugs.launchpad.net/juju/+bug/1680046
juju · Apr 6, 2017 · 5428ae9 · 5428ae9
1 parent eada3f3
commit 5428ae9
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diff --git a/controller.go b/controller.go
@@ -848,6 +848,14 @@ func indicatesUnsupportedVersion(err error) bool {
 		code := serverErr.StatusCode
 		return code == http.StatusNotFound || code == http.StatusGone
 	}
+	// Workaround for bug in MAAS 1.9.4 - instead of a 404 we get a
+	// redirect to the HTML login page, which doesn't parse as JSON.
+	// https://bugs.launchpad.net/maas/+bug/1583715
+	if syntaxErr, ok := errors.Cause(err).(*json.SyntaxError); ok {
+		logger.Criticalf("%#v", *syntaxErr)
+		message := "invalid character '<' looking for beginning of value"
+		return syntaxErr.Offset == 1 && syntaxErr.Error() == message
+	}
 	return false
 }
 

diff --git a/controller_test.go b/controller_test.go
@@ -219,6 +219,25 @@ func (s *controllerSuite) TestNewController404(c *gc.C) {
 	c.Assert(err, jc.Satisfies, IsUnsupportedVersionError)
 }
 
+func (s *controllerSuite) TestNewControllerWith194Bug(c *gc.C) {
+	// 1.9.4 has a bug where if you ask for /api/2.0/version/ without
+	// being logged in (rather than OAuth connection) it redirects you
+	// to the login page. This is fixed in 1.9.5, but we should work
+	// around it anyway. https://bugs.launchpad.net/maas/+bug/1583715
+	server := NewSimpleServer()
+	server.AddGetResponse("/api/2.0/users/?op=whoami", http.StatusOK, "the answer to all your prayers")
+	server.AddGetResponse("/api/2.0/version/", http.StatusOK, "<html><head>")
+	server.Start()
+	defer server.Close()
+
+	controller, err := NewController(ControllerArgs{
+		BaseURL: server.URL,
+		APIKey:  "fake:as:key",
+	})
+	c.Assert(controller, gc.IsNil)
+	c.Assert(err, jc.Satisfies, IsUnsupportedVersionError)
+}
+
 func (s *controllerSuite) TestBootResources(c *gc.C) {
 	controller := s.getController(c)
 	resources, err := controller.BootResources()