### Writing controllers

Istio provides a few helper libraries to get started writing a controller. While these libraries help, there are still a lot of subtleties in correctly writing (and testing!) a controller properly.

				assert.NoError(t, err)
			}
			verifyExecTestOutput(t, DebugCommand(ctx), c)
		})
	}
}

func verifyExecTestOutput(t *testing.T, cmd *cobra.Command, c execTestCase) {
	t.Helper()

	var out bytes.Buffer
	cmd.SetArgs(c.args)
	cmd.SilenceUsage = true
	cmd.SetOut(&out)
	cmd.SetErr(&out)

	fErr := cmd.Execute()
	output := out.String()

	t.Helper()
	path := mustGetPath(t, obj, "webhooks")
	by, err := json.Marshal(path)
	if err != nil {
		t.Fatal(err)
	}
	var mwh []v1.MutatingWebhook
	if err := json.Unmarshal(by, &mwh); err != nil {
		t.Fatal(err)
	}
	return mwh
}

func getWebhooks(t *testing.T, setFlags string, webhookName string) []v1.MutatingWebhook {
	t.Helper()

   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its
   contributors may be used to endorse or promote products derived from
   this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

		tf.UnstructuredClient = &fake.RESTClient{
			NegotiatedSerializer: resource.UnstructuredPlusDefaultContentConfig().NegotiatedSerializer,
			Resp: &http.Response{
				StatusCode: http.StatusOK,
				Header:     cmdtesting.DefaultHeader(),
				Body: cmdtesting.ObjBody(codec,
					cmdtesting.NewInternalType("", "", "foo")),
			},
		}
		return tf
	}

// SelfSubjectReview contains the user information that the kube-apiserver has about the user making this request.
// When using impersonation, users will receive the user info of the user being impersonated.  If impersonation or
// request header authentication is used, any extra keys will have their case ignored and returned as lowercase.
message SelfSubjectReview {
  // Standard object's metadata.

  // For example: the master will return an internal IP CIDR only, if the client reaches the server using an internal IP.
  // Server looks at X-Forwarded-For header or X-Real-Ip header or request.RemoteAddr (in that order) to get the client IP.
  // +optional
  repeated ServerAddressByClientCIDR serverAddressByClientCIDRs = 4;
}

  // Requests will be matched against the Host field in the following way:
  // 1. If Host is precise, the request matches this rule if the http host header is equal to Host.
  // 2. If Host is a wildcard, then the request matches this rule if the http host header
  // is to equal to the suffix (removing the first label) of the wildcard rule.
  // +optional
  optional string host = 1;