failure enabling TLS in Docker distro of OAP server 8.1.0-es7

[pantovad]

Please answer these questions before submitting your issue.

• Why do you submit this issue?
• Question or discussion
• Bug
• Requirement
• Feature or performance improvement

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Question

• What do you want to know?

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Bug

• Which version of SkyWalking, OS and JRE?
  Docker OAP server 8.1.0-es7 (https://github.com/apache/skywalking-docker/tree/master/8/8.1.0/oap-es7)

• Which company or project?

• What happened?
  When enabling TLS on gRPC listener in OAP server it fails with errors missing required libraries.

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Requirement or improvement

• I managed to resolve the issue by using adoptopenjdk/openjdk11:alpine (instead of openjdk:8-jre-alpine) as base Java image for both base and OAP image.

[hanahmily]

it's because netty tc-native needs some dynamic libraries which apline doesn't contain. we should release a new base image to adopt to "jdk" instead of "jre".

Since OAP can work fine with jdk11, I prefer to use it as the new base image.
@wu-sheng @kezhenxu94 ^^

[wu-sheng]

Work for me. Please update the docker file in the main repo first.

[hanahmily]

Work for me. Please update the docker file in the main repo first.

main repo doesn't have this issue and uses the jdk based image all the time due to our development and debugging requirement.

[wu-sheng]

@innerpeacez I added this to the k8s release milestone for next version, in case we miss this in next time.

@hanahmily Do you plan to push the 8.1.0 images again for jdk binded?

@pantovad I will recommend you to re package first locally.

[kezhenxu94]

And now, when testing #5722 , I've also found that it(Kubernetes Java client) doesn't work well on openjdk:8-jdk (see kubernetes-client/java#1003 although it just happens in Minikube), thus I used openjdk:11-jdk for the tests, I suggest to upgrade the JDK version in the base image ASAP

[wu-sheng]

JDK11 as next TLS, make sense to me. Just feel strange, why JDK version matters