Add skywalking satellite support

[mrproliu]

• Support using satellite as a gateway
• upgrade E2E as infra-e2e

[wu-sheng]

We should add description about user should set service address to satellite instead of oap, right?

[mrproliu]

been added, please take a look.

[hanahmily]

Some nits of manifests.

[kezhenxu94]

Others LGTM

[wu-sheng]

Once recent optimization are done, we should add document about how to set up load balancer in the main doc, and provide it(next release) as activated component in the showcase.
Please submit an issue to track for doc and showcase.

[kezhenxu94]

Once recent optimization are done, we should add document about how to set up load balancer in the main doc, and provide it(next release) as activated component in the showcase.
Please submit an issue to track for doc and showcase.

Just a reminder, satellite is not mandatory so we won't make all agent services connect to it in showcase, as we have 2 Java services (gateway and songs) we can make one of them send data to satellite and leave all others as is.

[wu-sheng]

Once recent optimization are done, we should add document about how to set up load balancer in the main doc, and provide it(next release) as activated component in the showcase.
Please submit an issue to track for doc and showcase.

Just a reminder, satellite is not mandatory so we won't make all agent services connect to it in showcase, as we have 2 Java services (gateway and songs) we can make one of them send data to satellite and leave all others as is.

With time, more and more verification, could come from the product env(end users), if all are good, I would like to put it as recommended. In all these days perf testing and load balance testing, connection based load balance has very clear disadvantage, but most proxies are only supporting this way.
Users complained many times, now, we have the solution.
So, once we confirm Satellite is good, it should be some kind of mandatory(recommended as it is better to have). Does this make sense to you?

[kezhenxu94]

Once recent optimization are done, we should add document about how to set up load balancer in the main doc, and provide it(next release) as activated component in the showcase.

Please submit an issue to track for doc and showcase.

Just a reminder, satellite is not mandatory so we won't make all agent services connect to it in showcase, as we have 2 Java services (gateway and songs) we can make one of them send data to satellite and leave all others as is.

With time, more and more verification, could come from the product, if all are good, I would like to put it as recommended. In all these days perf testing and local balance testing, connection based load balance has very clear disadvantage, but most proxies are only supporting this way.

Users complained many times, now, we have the solution.

So, once we confirm Satellite is good, it should be some kind of mandatory(recommended as it is better to have). Does this make sense to you?

We could recommend, but showcase repo serves as a demonstration that will be referenced by all users, we should have examples without Satellite, unless we say officially SkyWalking cannot work without Satellite, which is obviously not the case.

I know Satellite can work with or without Kubernetes but for traditional deployments I don't believe users will deploy another Satellite process along with their application process, in this case they will ask for non-Satellite solution. That's why I want to keep agents without Satellite in showcase.

[wu-sheng]

If you are concern about this, I would prefer not deploy satellite in showcase.
The reason I asked about this, is users will face this load balance issue from day one when they go to product env deployment. Even Java agent provide random-based client-side load balancing, AFAIK, it doesn't work perfectly.

If you set the principle of deploying XYZ in showcase as tech level mandatory, then let's leave satellite out of it. It is definitely not.

Half through satellite, and half using direct link, are really not a good showcase at all. It just increases the confusion, I am afraid.

[kezhenxu94]

If you set the principle of deploying XYZ in showcase as tech level mandatory,

Hey that's not what I mean, we have agent services and agentless services and agent is not mandatory tech in SkyWalking but we deploy them still. (I just want to cover more general scenarios that users have). Let's find another way to add Satellite into showcase. Now we have many feature flags that users can choose to deploy a subset of features of SkyWalking(though we enable all features by default), let's add another feature flag satellite that deploys Satellite and makes all agents and ALS connect to it, and enable this feature by default (on demo.skywalking.a.o), but users can have a chance to remove satellite feature and make agent connect to OAP directly. WDYT?

[wu-sheng]

I don't want showcase becomes another challenge to new users. Features related are complex enough so far.
Let's keep satellite out for now.

[wu-sheng]

Let's continue discussion on that new created issue if needed.
This is not a block for this pull request.

[hanahmily]

LGTM, thanks a lot.