Just a quick meta comment concerning one PR vs. two PRs vs. multiple PRs: I
would recommend to split the changes up in as many PRs as possible. In my
experience, a large uber PR usually won't be reviewed as thoroughly because
of the sheer size. Moreover, the reviewing usually takes much longer. Of
course, this only makes sense if the change can be split in multiple parts.
Cheers,
Till
On Tue, Feb 25, 2020 at 5:39 AM Canbin Zheng <felixzhen...@gmail.com> wrote:
> Thanks, Yang Wang and tison,
>
> Since we have reached a consensus on the decorator design evolution and the
> parameters parser, and after an offline discussion with tison and Yang
> Wang, we have agreed on attaching one PR instead of two to avoid repeated
> code adapting and reviewing.
>
> Thanks for all the feedback.
>
> tison <wander4...@gmail.com> 于2020年2月24日周一 下午10:14写道：
>
> > Thank Canbin for starting the discussion and thanks for participating so
> > far.
> >
> > I agree that we can start with the "Parameters Parser" part and actually
> > split it into a
> > self-contained issue.
> >
> > Best,
> > tison.
> >
> >
> > Yang Wang <danrtsey...@gmail.com> 于2020年2月24日周一 下午8:38写道：
> >
> >> It seems that we could benefit a lot from the "Parameters Parser". Let's
> >> start to
> >> add the dedicated jobmanager/taskmanager config parser classes.
> >>
> >>
> >> Best,
> >> Yang
> >>
> >> Canbin Zheng <felixzhen...@gmail.com> 于2020年2月24日周一 上午10:39写道：
> >>
> >>> Hi, Yang Wang,
> >>>
> >>> Thanks for the feedback.
> >>>
> >>> > Parameters Parser
> >>>
> >>> I can think of many benefits of the dedicated parameter
> >>> parsing/verifying tools, here is some of them:
> >>> 1. Reuse the parameters parsing and verifying code.
> >>> 2. Ensure consistent handling logic for the same setting.
> >>> 3. Simplify some of the method's signature because we can avoid
> defining
> >>> too many unnecessary input parameters.
> >>>
> >>> > BTW, the fabric8 kubernetes-client and Kubernetes api server already
> >>> has
> >>> the parameters check before starting to create the resources. I think
> >>> the exceptions
> >>> are usually meaning and enough for the users to get the root cause.
> >>>
> >>> 1. On the one hand, there are gaps between the declarative model used
> by
> >>> Kubernetes and the configuration model used by Flink. Indeed, the
> >>> Kubernetes client/server helps check the Kubernetes side parameters and
> >>> throw exceptions in case of failures; however, the exception messages
> are
> >>> not always easily understood from the perspective of Flink users.
> >>> Independent of the solutions, what we should make sure is that the
> >>> exception information in the Flink configuration model is meaningful
> enough
> >>> for the Flink users.
> >>> 2. On the other hand, some prechecking is beneficial in some scenarios
> >>> since we can avoid useless effort on Kubernetes resource creation in
> case
> >>> of failures leading to clean up all the created resources.
> >>>
> >>>
> >>> Regards,
> >>> Canbin Zheng
> >>>
> >>> Yang Wang <danrtsey...@gmail.com> 于2020年2月23日周日 下午10:37写道：
> >>>
> >>>> > The new introduced decorator
> >>>> After some offline discussion with Canbin and tison, i totally
> >>>> understand
> >>>> the evolved decorator design. Each decorator will be self-contained
> and
> >>>> is responsible for just one thing. Currently, if we want to mount a
> new
> >>>> config
> >>>> file to jobmanager/taskmanager, then both `ConfigMapDecorator`,
> >>>> `JobManagerDecorator`, `TaskManagerDecorator` needs to be updated.
> >>>> It is not convenient for the new contributors to do this. In the new
> >>>> design,
> >>>> by leveraging the accompanying kubernetes resources in decorator, we
> >>>> could finish the creating and mounting config map in one decorator.
> >>>>
> >>>> Since now we just have a basic implementation for native Kubernetes
> >>>> integration and lots of features need to be developed. And many users
> >>>> want to participate in and contribute to the integration. So i agree
> to
> >>>> refactor
> >>>> the current decorator implementation and make it easier for the new
> >>>> contributor.
> >>>>
> >>>> For the detailed divergences(naming, etc.), i think we could discuss
> in
> >>>> the PR.
> >>>>
> >>>> > Parameters Parser
> >>>> Currently, the decorator directly use Flink configuration to get the
> >>>> parameters
> >>>> to build the Kubernetes resource. It is straightforward, however we
> >>>> could not
> >>>> have a unified parameters check. So i am not sure whether you will
> >>>> introduce
> >>>> a tool to check the parameters or just simply have our own basic
> check.
> >>>>
> >>>> BTW, the fabric8 kubernetes-client and Kubernetes api server already
> has
> >>>> the parameters check before starting to create the resources. I think
> >>>> the exceptions
> >>>> are usually meaning and enough for the users to get the root cause.
> >>>>
> >>>>
> >>>>
> >>>> Best,
> >>>> Yang
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> felixzheng zheng <felixzhen...@gmail.com> 于2020年2月22日周六 上午10:54写道：
> >>>>
> >>>>> Great thanks for the quick feedback Till. You are right; it is not a
> >>>>> fundamentally different approach compared to
> >>>>> what we have right now, all the Kubernetes resources created are the
> >>>>> same,
> >>>>> we aim to evolve the existing decorator approach so that,
> >>>>> 1. the decorators are monadic and smaller in size and functionality.
> >>>>> 2. the new decorator design allows reusing the decorators between the
> >>>>> client and the cluster as much as possible.
> >>>>> 3. all the decorators are independent with each other, and they could
> >>>>> have
> >>>>> arbitrary order in the chain, they share the same APIs and follow a
> >>>>> unified
> >>>>> orchestrator architecture so that new developers could quickly
> >>>>> understand
> >>>>> what should be done to introduce a new feature.
> >>>>>
> >>>>> Besides that, the new approach allows us adding tests for every
> >>>>> decorator
> >>>>> alone instead of doing a final test of all the decorators in the
> >>>>> Fabric8ClientTest.java.
> >>>>>
> >>>>> Cheers,
> >>>>> Canbin Zheng
> >>>>>
> >>>>> Till Rohrmann <trohrm...@apache.org> 于2020年2月22日周六 上午12:28写道：
> >>>>>
> >>>>> > Thanks for starting this discussion Canbin. If I understand your
> >>>>> proposal
> >>>>> > correctly, then you would like to evolve the existing decorator
> >>>>> approach so
> >>>>> > that decorators are monadic and smaller in size and functionality.
> >>>>> The
> >>>>> > latter aspect will allow to reuse them between the client and the
> >>>>> cluster.
> >>>>> > Just to make sure, it is not a fundamentally different approach
> >>>>> compared to
> >>>>> > what we have right now, is it?
> >>>>> >
> >>>>> > If this is the case, then I think it makes sense to reuse code as
> >>>>> much as
> >>>>> > possible and to create small code units which are easier to test.
> >>>>> >
> >>>>> > Cheers,
> >>>>> > Till
> >>>>> >
> >>>>> > On Fri, Feb 21, 2020 at 4:41 PM felixzheng zheng <
> >>>>> felixzhen...@gmail.com>
> >>>>> > wrote:
> >>>>> >
> >>>>> > > Thanks for the feedback @Yang Wang. I would like to discuss some
> >>>>> of the
> >>>>> > > details in depth about why I am confused about the existing
> design.
> >>>>> > >
> >>>>> > > Question 1: How do we mount a configuration file?
> >>>>> > >
> >>>>> > > For the existing design,
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > We need several classes to finish it:
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > InitializerDecorator
> >>>>> > > 2.
> >>>>> > >
> >>>>> > > OwnerReferenceDecorator
> >>>>> > > 3.
> >>>>> > >
> >>>>> > > ConfigMapDecorator
> >>>>> > > 4.
> >>>>> > >
> >>>>> > > KubernetesUtils: providing the getConfigMapVolume method to
> >>>>> share
> >>>>> > for
> >>>>> > > the FlinkMasterDeploymentDecorator and the
> >>>>> TaskManagerPodDecorator.
> >>>>> > > 5.
> >>>>> > >
> >>>>> > > FlinkMasterDeploymentDecorator: mounts the ConfigMap
> volume.
> >>>>> > > 6.
> >>>>> > >
> >>>>> > > TaskManagerPodDecorator: mounts the ConfigMap volume.
> >>>>> > > 7.
> >>>>> > >
> >>>>> > > If in the future, someone would like to introduce an init
> >>>>> > Container,
> >>>>> > > the InitContainerDecorator has to mount the ConfigMap
> volume
> >>>>> too.
> >>>>> > >
> >>>>> > >
> >>>>> > > I am confused about the current solution to mounting a
> >>>>> configuration
> >>>>> > file:
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > Actually, we do not need so many Decorators for mounting a
> file.
> >>>>> > > 2.
> >>>>> > >
> >>>>> > > If we would like to mount a new file, we have no choice but to
> >>>>> repeat
> >>>>> > > the same tedious and scattered routine.
> >>>>> > > 3.
> >>>>> > >
> >>>>> > > There’s no easy way to test the file mounting functionality
> >>>>> alone; we
> >>>>> > > have to construct the ConfigMap, the Deployment or the
> >>>>> TaskManagerPod
> >>>>> > > first
> >>>>> > > and then do a final test.
> >>>>> > >
> >>>>> > >
> >>>>> > > The reason why it is so complex to mount a configuration file is
> >>>>> that we
> >>>>> > > don’t fully consider the internal connections among those
> >>>>> resources in
> >>>>> > the
> >>>>> > > existing design.
> >>>>> > >
> >>>>> > > The new abstraction we proposed could solve such a kind of
> >>>>> problem, the
> >>>>> > new
> >>>>> > > Decorator object is as follows:
> >>>>> > >
> >>>>> > > public interface KubernetesStepDecorator {
> >>>>> > >
> >>>>> > > /**
> >>>>> > >
> >>>>> > > * Apply transformations to the given FlinkPod in accordance
> >>>>> with this
> >>>>> > > feature. This can include adding
> >>>>> > >
> >>>>> > > * labels/annotations, mounting volumes, and setting startup
> >>>>> command or
> >>>>> > > parameters, etc.
> >>>>> > >
> >>>>> > > */
> >>>>> > >
> >>>>> > > FlinkPod decorateFlinkPod(FlinkPod flinkPod);
> >>>>> > >
> >>>>> > > /**
> >>>>> > >
> >>>>> > > * Build the accompanying Kubernetes resources that should be
> >>>>> > introduced
> >>>>> > > to support this feature. This could
> >>>>> > >
> >>>>> > > * only applicable to the client-side submission process.
> >>>>> > >
> >>>>> > > */
> >>>>> > >
> >>>>> > > List<HasMetadata> buildAccompanyingKubernetesResources() throws
> >>>>> > > IOException;
> >>>>> > >
> >>>>> > > }
> >>>>> > >
> >>>>> > > The FlinkPod is a composition of the Pod, the main Container, the
> >>>>> init
> >>>>> > > Container, and the sidecar Container.
> >>>>> > >
> >>>>> > > Next, we introduce a KubernetesStepDecorator implementation, the
> >>>>> method
> >>>>> > of
> >>>>> > > buildAccompanyingKubernetesResources creates the corresponding
> >>>>> ConfigMap,
> >>>>> > > and the method of decorateFlinkPod configures the Volume for the
> >>>>> Pod and
> >>>>> > > all the Containers.
> >>>>> > >
> >>>>> > > So, for the scenario of mounting a configuration file, the
> >>>>> advantages of
> >>>>> > > this new architecture are as follows:
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > One dedicated KubernetesStepDecorator implementation is enough
> >>>>> to
> >>>>> > finish
> >>>>> > > all the mounting work, meanwhile, this class would be shared
> >>>>> between
> >>>>> > the
> >>>>> > > client-side and the master-side. Besides that, the number of
> >>>>> lines of
> >>>>> > > code
> >>>>> > > in that class will not exceed 300 lines which facilitate code
> >>>>> > > readability
> >>>>> > > and maintenance.
> >>>>> > > 2.
> >>>>> > >
> >>>>> > > Testing becomes an easy thing now, as we can add a dedicated
> >>>>> test
> >>>>> > class
> >>>>> > > for only this class, the test would never rely on the
> >>>>> construction of
> >>>>> > > other
> >>>>> > > components such as the Deployment.
> >>>>> > > 3.
> >>>>> > >
> >>>>> > > It’s quite convenient to mount a new configuration file via
> the
> >>>>> newly
> >>>>> > > dedicated KubernetesStepDecorator implementation.
> >>>>> > >
> >>>>> > >
> >>>>> > > Question 2: How do we construct the Pod?
> >>>>> > >
> >>>>> > > For the existing design,
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > The FlinkMasterDeploymentDecorator is responsible for building
> >>>>> the
> >>>>> > > Deployment and configuring the Pod and the Containers, while
> the
> >>>>> > > TaskManagerPodDecorator is responsible for building the
> >>>>> TaskManager
> >>>>> > Pod.
> >>>>> > > Take FlinkMasterDeploymentDecorator as an example, let’s see
> >>>>> what it
> >>>>> > has
> >>>>> > > done.
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > Configure the main Container, including the name, command,
> >>>>> args,
> >>>>> > > image, image pull policy, resource requirements, ports, all
> >>>>> kinds
> >>>>> > of
> >>>>> > > environment variables, all kinds of volume mounts, etc.
> >>>>> > > 2.
> >>>>> > >
> >>>>> > > Configure the Pod, including service account, all kinds of
> >>>>> volumes,
> >>>>> > > and attach all kinds of Container, including the main
> >>>>> Container,
> >>>>> > the
> >>>>> > > init
> >>>>> > > Container, and the sidecar Container.
> >>>>> > > 3.
> >>>>> > >
> >>>>> > > Configure the Deployment.
> >>>>> > >
> >>>>> > >
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > The InitializerDecorator and the OwnerReferenceDecorator have
> >>>>> basic
> >>>>> > > logic so that the most complex work is completed in the
> >>>>> > > FlinkMasterDeploymentDecorator and the
> TaskManagerPodDecorator.
> >>>>> With
> >>>>> > the
> >>>>> > > introduction of new features for the Pod, such as customized
> >>>>> volume
> >>>>> > > mounts,
> >>>>> > > Hadoop configuration support, Kerberized HDFS support, secret
> >>>>> mounts,
> >>>>> > > Python support, etc. the construction process could become far
> >>>>> more
> >>>>> > > complicated, and the functionality of a single class could
> >>>>> explode,
> >>>>> > > which
> >>>>> > > hurts code readability, writability, and testability. Besides
> >>>>> that,
> >>>>> > both
> >>>>> > > the client-side and the master-side shares much of the Pod
> >>>>> > construction
> >>>>> > > logic.
> >>>>> > >
> >>>>> > >
> >>>>> > > So the problems are as follows:
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > We don’t have a consistent abstraction that is applicable to
> >>>>> both the
> >>>>> > > client-side and the master-side for Pod construction
> (including
> >>>>> the
> >>>>> > > Containers) so that we have to share some of the code via tool
> >>>>> classes
> >>>>> > > which is a trick solution, however, we can’t share most of the
> >>>>> code as
> >>>>> > > much
> >>>>> > > as possible.
> >>>>> > > 2.
> >>>>> > >
> >>>>> > > We don’t have a step-by-step orchestrator architecture to help
> >>>>> the Pod
> >>>>> > > construction.
> >>>>> > >
> >>>>> > >
> >>>>> > > For the proposed design,
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > The problems above are all solved: we have a consistent
> >>>>> abstraction
> >>>>> > that
> >>>>> > > leads to a monadic-step orchestrator architecture to construct
> >>>>> the Pod
> >>>>> > > step
> >>>>> > > by step. One step is responsible for exactly one thing,
> >>>>> following that
> >>>>> > > is
> >>>>> > > the fact that every step is well testable, because each unit
> >>>>> can be
> >>>>> > > considerably small, and the number of branches to test in any
> >>>>> given
> >>>>> > > step is
> >>>>> > > limited. Moreover, much of the step could be shared between
> the
> >>>>> > > client-side
> >>>>> > > and the master-side, such as configuration files mount, etc.
> >>>>> > >
> >>>>> > >
> >>>>> > > Question 3: Could all the resources share the same orchestrator
> >>>>> > > architecture?
> >>>>> > >
> >>>>> > > For the existing design,
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > We don’t have a unified orchestrator architecture for the
> >>>>> construction
> >>>>> > > of all the Kubernetes resources, therefore, we need a
> Decorator
> >>>>> chain
> >>>>> > > for
> >>>>> > > every Kubernetes resource.
> >>>>> > >
> >>>>> > >
> >>>>> > > For the proposed design,
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > Following Question 1 ~ 2 and the design doc[1], we have
> >>>>> introduced a
> >>>>> > > monadic-step orchestrator architecture to construct the Pod
> and
> >>>>> all
> >>>>> > the
> >>>>> > > Containers. Besides that, this architecture also works for the
> >>>>> other
> >>>>> > > resources, such as the Services and the ConfigMaps. For
> >>>>> example, if we
> >>>>> > > need
> >>>>> > > a new Service or a ConfigMap, just introduce a new step.
> >>>>> > >
> >>>>> > >
> >>>>> > >
> >>>>> > > Question 4: How do we introduce the InitContainer or the side-car
> >>>>> > > Container?
> >>>>> > >
> >>>>> > > For the existing design,
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > Both the client-side and the master-side introduce some new
> >>>>> > Decorators,
> >>>>> > >
> >>>>> > > the client-side chain could be:
> >>>>> > >
> >>>>> > > InitializerDecorator -> OwnerReferenceDecorator ->
> >>>>> > > FlinkMasterDeploymentDecorator -> InitContainerDecorator ->
> >>>>> > > SidecarDecorator -> etc
> >>>>> > >
> >>>>> > > -
> >>>>> > >
> >>>>> > > and the master-side could be:
> >>>>> > >
> >>>>> > > InitializerDecorator -> OwnerReferenceDecorator ->
> >>>>> > TaskManagerPodDecorator
> >>>>> > > -> InitContainerDecorator -> SidecarDecorator -> etc
> >>>>> > >
> >>>>> > > As we can see, the FlinkMasterDeploymentDecorator or the
> >>>>> > > TaskManagerPodDecorator is designed for the Pod construction,
> >>>>> including
> >>>>> > the
> >>>>> > > Containers, so we don’t need to treat the init Container and the
> >>>>> sidecar
> >>>>> > > Container as special cases different from the main Container by
> >>>>> > introducing
> >>>>> > > a dedicated Decorator for every one of them. Such kind of trick
> >>>>> solution
> >>>>> > > confuses me, maybe to the other developers.
> >>>>> > >
> >>>>> > > For the proposed design,
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > Following Question 1 ~ 4 and the design doc [1], the central
> >>>>> premise
> >>>>> > of
> >>>>> > > the proposed orchestrator architecture is that the Pod, the
> main
> >>>>> > > Container,
> >>>>> > > the init Container, the sidecar Container, the Services, and
> the
> >>>>> > > ConfigMaps
> >>>>> > > all sit on an equal footing. For every one of the Pod, the
> main
> >>>>> > > Container,
> >>>>> > > the init Container and the sidecar Container, people could
> >>>>> introduce
> >>>>> > any
> >>>>> > > number of steps to finish its construction; we attach all the
> >>>>> > > Containers to
> >>>>> > > the Pod in the Builder tool classes after the orchestrator
> >>>>> > architecture
> >>>>> > > constructs them.
> >>>>> > >
> >>>>> > >
> >>>>> > > Question 5: What is the relation between the Decorators?
> >>>>> > >
> >>>>> > > For the existing design,
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > The Decorators are not independent; most of them have a strict
> >>>>> order
> >>>>> > in
> >>>>> > > the chain.
> >>>>> > > 2.
> >>>>> > >
> >>>>> > > The Decorators do not share common APIs in essence, as their
> >>>>> input
> >>>>> > type
> >>>>> > > could be different so that we can’t finish the construction
> of a
> >>>>> > > Kubernetes
> >>>>> > > resource such as the Deployment and the TaskManager Pod
> through
> >>>>> a
> >>>>> > > one-time
> >>>>> > > traversal, there are boxing and unboxing overheads among some
> >>>>> of the
> >>>>> > > neighboring Decorators.
> >>>>> > >
> >>>>> > >
> >>>>> > > For the proposed design,
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > The steps are completely independent so that they could have
> >>>>> arbitrary
> >>>>> > > order in the chain; The only rule is that the Hadoop
> >>>>> configuration
> >>>>> > > Decorator should be the last node in the chain.
> >>>>> > > 2.
> >>>>> > >
> >>>>> > > All the steps share common APIs, with the same input type of
> >>>>> all the
> >>>>> > > methods, so we can construct a Kubernetes resource via a
> >>>>> one-time
> >>>>> > > traversal.
> >>>>> > >
> >>>>> > >
> >>>>> > > Question 6: What is the number of Decorators chains?
> >>>>> > >
> >>>>> > > For the existing design,
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > People have to introduce a new chain once they introduce a new
> >>>>> > > Kubernetes resource. For example, a new ConfigMap Decorator
> >>>>> chain for
> >>>>> > > mounting a new configuration file. At this moment, we already
> >>>>> have
> >>>>> > five
> >>>>> > > Decorator chains.
> >>>>> > >
> >>>>> > >
> >>>>> > > For the proposed design,
> >>>>> > >
> >>>>> > > 1.
> >>>>> > >
> >>>>> > > There are always two chains, one is for constructing all the
> >>>>> > Kubernetes
> >>>>> > > resources on the client-side, including the JobManager Pod,
> the
> >>>>> > > Containers,
> >>>>> > > the ConfigMap(s), and the Services(s); the other one is for
> >>>>> > constructing
> >>>>> > > the TaskManager Pod and the Containers.
> >>>>> > >
> >>>>> > >
> >>>>> > >
> >>>>> > >
> >>>>> > >
> >>>>> > >
> >>>>> > >
> >>>>> > > Yang Wang <danrtsey...@gmail.com> 于2020年2月21日周五 下午2:05写道：
> >>>>> > >
> >>>>> > > > Hi Canbing,
> >>>>> > > >
> >>>>> > > >
> >>>>> > > > Thanks a lot for sharing your thoughts to improve the Flink on
> >>>>> K8s
> >>>>> > native
> >>>>> > > > integration.
> >>>>> > > > Frankly speaking, your discussion title confuses me and i am
> >>>>> wondering
> >>>>> > > > whether you
> >>>>> > > > want to refactor the whole design. However, after i dive into
> the
> >>>>> > details
> >>>>> > > > and the provided
> >>>>> > > > document, i realize that mostly you want to improve the
> >>>>> implementation.
> >>>>> > > >
> >>>>> > > >
> >>>>> > > > Regarding your two main points.
> >>>>> > > >
> >>>>> > > > >> Introduce a unified monadic-step based orchestrator
> >>>>> architecture
> >>>>> > that
> >>>>> > > > has a better,
> >>>>> > > > cleaner and consistent abstraction for the Kubernetes resources
> >>>>> > > > construction process,
> >>>>> > > > both applicable to the client side and the master side.
> >>>>> > > >
> >>>>> > > > When i introduce the decorator for the K8s in Flink, there is
> >>>>> always a
> >>>>> > > > guideline in my mind
> >>>>> > > > that it should be easy for extension and adding new features.
> >>>>> Just as
> >>>>> > you
> >>>>> > > > say, we have lots
> >>>>> > > > of functions to support and the K8s is also evolving very fast.
> >>>>> The
> >>>>> > > current
> >>>>> > > > `ConfigMapDecorator`,
> >>>>> > > > `FlinkMasterDeploymentDecorator`, `TaskManagerPodDecorator` is
> a
> >>>>> basic
> >>>>> > > > implementation with
> >>>>> > > > some prerequisite parameters. Of course we could chain more
> >>>>> decorators
> >>>>> > to
> >>>>> > > > construct the K8s
> >>>>> > > > resources. For example, InitializerDecorator ->
> >>>>> OwnerReferenceDecorator
> >>>>> > > ->
> >>>>> > > > FlinkMasterDeploymentDecorator -> InitContainerDecorator ->
> >>>>> > > > SidecarDecorator -> etc.
> >>>>> > > >
> >>>>> > > > I am little sceptical about splitting every parameter into a
> >>>>> single
> >>>>> > > > decorator. Since it does
> >>>>> > > > not take too much benefits. But i agree with moving some common
> >>>>> > > parameters
> >>>>> > > > into separate
> >>>>> > > > decorators(e.g. volume mount). Also introducing the `~Builder`
> >>>>> class
> >>>>> > and
> >>>>> > > > spinning off the chaining
> >>>>> > > > decorator calls from `Fabric8FlinkKubeClient` make sense to me.
> >>>>> > > >
> >>>>> > > >
> >>>>> > > >
> >>>>> > > > >> Add some dedicated tools for centrally parsing, verifying,
> and
> >>>>> > > managing
> >>>>> > > > the Kubernetes parameters.
> >>>>> > > >
> >>>>> > > > Currently, we always get the parameters directly from Flink
> >>>>> > > configuration(
> >>>>> > > > e.g.
> >>>>> > `flinkConfig.getString(KubernetesConfigOptions.CONTAINER_IMAGE)`).
> I
> >>>>> > > > think it could be improved
> >>>>> > > > by introducing some dedicated conf parser classes. It is a good
> >>>>> idea.
> >>>>> > > >
> >>>>> > > >
> >>>>> > > > Best,
> >>>>> > > > Yang
> >>>>> > > >
> >>>>> > > >
> >>>>> > > >
> >>>>> > > >
> >>>>> > > > felixzheng zheng <felixzhen...@gmail.com> 于2020年2月21日周五
> >>>>> 上午9:31写道：
> >>>>> > > >
> >>>>> > > > > Hi everyone,
> >>>>> > > > >
> >>>>> > > > > I would like to kick off a discussion on refactoring the
> >>>>> existing
> >>>>> > > > > Kubernetes resources construction architecture design.
> >>>>> > > > >
> >>>>> > > > > I created a design document [1] that clarifies our motivation
> >>>>> to do
> >>>>> > > this
> >>>>> > > > > and some improvement proposals for the new design.
> >>>>> > > > >
> >>>>> > > > > Briefly, we would like to
> >>>>> > > > > 1. Introduce a unified monadic-step based orchestrator
> >>>>> architecture
> >>>>> > > that
> >>>>> > > > > has a better, cleaner and consistent abstraction for the
> >>>>> Kubernetes
> >>>>> > > > > resources construction process, both applicable to the client
> >>>>> side
> >>>>> > and
> >>>>> > > > the
> >>>>> > > > > master side.
> >>>>> > > > > 2. Add some dedicated tools for centrally parsing, verifying,
> >>>>> and
> >>>>> > > > managing
> >>>>> > > > > the Kubernetes parameters.
> >>>>> > > > >
> >>>>> > > > > It would be great to start the efforts before adding big
> >>>>> features for
> >>>>> > > the
> >>>>> > > > > native Kubernetes submodule, and Tison and I plan to work
> >>>>> together
> >>>>> > for
> >>>>> > > > this
> >>>>> > > > > issue.
> >>>>> > > > >
> >>>>> > > > > Please let me know your thoughts.
> >>>>> > > > >
> >>>>> > > > > Regards,
> >>>>> > > > > Canbin Zheng
> >>>>> > > > >
> >>>>> > > > > [1]
> >>>>> > > > >
> >>>>> > > > >
> >>>>> > > >
> >>>>> > >
> >>>>> >
> >>>>>
> https://docs.google.com/document/d/1dFBjqho8IRyNWxKVhFnTf0qGCsgp72aKON4wUdHY5Pg/edit?usp=sharing
> >>>>> > > > > [2] https://issues.apache.org/jira/browse/FLINK-16194
> >>>>> > > > >
> >>>>> > > >
> >>>>> > >
> >>>>> >
> >>>>>
> >>>>
>
