Pod to Pod communication using VirtualService

Jonas_Jasas · January 8, 2021, 2:59pm

Hello,

how to set up Kubernetes cluster pod to pod HTTP communication using VirtualService with the retry feature and locality balancing?

If I use VirtualService through Gateway: Pod -> Kubernetes service -> Istio Gateway -> Virtual service then for some reason locality balancing feature is not working.

nick_tetrate · January 8, 2021, 6:10pm

Do you have outlier detection enabled?

tenaki · January 13, 2021, 9:49pm

I must admit, this aspect is lacking in the istio documentation. It took ages for me to realise that I can actually use virtual services internally, and even then, I’ve got similar questions about how to leverage the different benefits, what it means for application development, etc etc.

Could the documentation be updated to provide more examples?

Thank you

nick_tetrate · January 14, 2021, 4:40pm

what kind of documentation in particular do you feel is lacking?

most of the Istio functionality is tested in integration tests so thats probably the best place to look.

github.com

istio/istio/blob/4d31d423e5f699f86084c85ad7f86c4ac7468d6d/tests/integration/pilot/locality_test.go

// +build integ
// Copyright Istio Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package pilot

import (
	"bytes"
	"fmt"

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Jonas_Jasas · January 19, 2021, 12:44pm

It is important to mention that when sidecars are injected Kubernetes services are no longer used and there is no use from the topologyKeys in service declaration. There always should be DestinationRule created for Istio locality start to work.
Am I right?

nick_tetrate · January 19, 2021, 2:41pm

its pretty clear in the documentation i posted

Jonas_Jasas · January 19, 2021, 3:08pm

But it didn’t say that Kubernetes native service Locality feature isn’t working. For the beginner that would save some time.