Hi! Awesome idea. Seeing this being viable in a platform like Apache OpenWhisk would be great too. I keep hearing customers asking about lightweight containers to run Camel context. :)
+++1 Zanini On Fri, Jul 13, 2018 at 5:31 AM, Antonin Stefanutti <anto...@stefanutti.fr> wrote: > Hi Nicola, > > I love the idea. > > I just wonder whether YAML/JSON is an expressive enough format in the long > term. But as you’ve mentioned, starting simple would enable experimenting > some very interesting / promising optimisations. So it seems worth taking > that path, instead of trying to embed a complex DSL or the existing XML DSL > into the CRD. > > Definitely +1 > > > On 13 Jul 2018, at 01:30, Nicola Ferraro <ni.ferr...@gmail.com> wrote: > > > > Hi Cameleers, > > it's now passed some time since I started thinking about a new project > that > > we can begin here at Apache Camel, and I'd like to have your opinion. > > > > We've already been targeting cloud-native applications with Camel, > > especially on top of Kubernetes, that is becoming "the standard" cloud > > platform. But writing a Camel integration and running it on Kubernetes > > requires some effort: choosing the base platform (spring-boot, karaf, > > simple main?), adding health checks (actuator?), packaging a docker image > > and creating the Kubernetes resources (fabric8-maven-plugin, helm?), > > publishing the image on a docker registry, then finally deploying the > > resources on a Kubernetes cluster. > > > > The resulting integration container is then far from being optimal from a > > resource consumption point of view: it is likely that a Camel Spring-Boot > > application will require at least 200MB of RAM and also some CPU shares > > because of polling threads used by many components. > > > > In case people use a CI/CD pipeline, it will take also a long time to get > > from a code update to having a Kubernetes POD up and running. > > Apart from compilation and image push/pull time, also startup time is > often > > ~10 seconds for Camel + Spring-Boot in a container with standard limits > on > > resources, making it difficult to propose this combination for > "serverless > > integration" (this term is becoming increasingly more popular). > > > > So, my proposal is to start to investigate a "more cloud-native" approach > > to integration: *making Camel integrations first-class citizens in > > Kubernetes, and making them super fast and lightweight.* > > > > We can base the project on Kubernetes Custom Resource Definitions (CRD) > > <https://kubernetes.io/docs/concepts/extend-kubernetes/ > api-extension/custom-resources/>, > > for example a Integration CRD and have a Kubernetes "operator" > > <https://coreos.com/operators/> taking care of: > > - Optimizing the integration that we want to run > > - Packaging in a container > > - Running it on Kubernetes > > - Managing its entire lifecycle > > > > A Kubernetes-native integration may look like: > > > > ------------------- > > kind: "Integration" > > apiVersion: "camel.apache.org/v1alpha1" > > metadata: > > name: "example" > > spec: > > replicas: 1 > > routes: > > - id: timer > > route: > > - type: endpoint > > uri: timer:tick > > - type: endpoint > > uri: log:info > > ------------------- > > > > For those who are not familiar with Kubernetes resources, this kind of > > YAML/JSON resource definitions are really common. > > The example route is embedded in the Kubernetes resource declaration and > > follows a basic "flow DSL". We may start from a basic one and evolve it > as > > new requirements arrive from the community. > > > > I've made a very simple (but working) POC here: > > https://github.com/nicolaferraro/integration-operator. > > > > This idea of a "Cloud-Native Camel" on Kubernetes (project codename can > be " > > *Kamel*", if you like it :D), will be an enabler for a lot of nice > features. > > > > For example, we can propose "Kamel" as "ideal" platform for "serverless > > integration" (I see many people reinventing the wheel out there): the > > operator can reduce resource consumption of a single integration by > > optimizing the runtime and also pause/resume integrations when they are > not > > used, that is the basic idea behind "serverless" (e.g. think to > > HTTP-triggered integrations, but not only). > > Focusing on serverless will bring more emphasis on push-based > notifications > > (webhooks, cloud events <https://cloudevents.io/>), that are rarely > used in > > Camel components, that prefer a poll based approach being it simpler to > use > > in classic deployments, but not so good in the cloud, where more > resources > > become higher direct costs for the users. > > > > The presence of the simplified DSL enables also experimenting on > "*reduced* > > subsets of Camel" implemented in languages other than Java, for example > one > > language that has a reactive approach on thread scheduling and a really > low > > memory footprint, like Go. > > > > But apart from this kind of experiments (that are valid IMO), the "Kamel" > > optimizer will have free room to choose the right platform for the > > integration that the user wants to run, including, in the future, doing > AOT > > compilation using Graal/VM (less memory, faster startup) if the features > > (components) used in the integration are supporting it (maybe we can add > > AOT compilation in the roadmap for Camel 3). > > A silly optimization: integrations starting from "timer:..." may be > > scheduled directly with Kubernetes CronJobs, so they will consume > resources > > only when actually running. > > > > Being the final integrations lightweight and being the DSL > > language-independent, we may see a increased adoption of Camel also as > > agile integration layer for not-only-java applications (both "cloud" and > > "serverless" applications). > > > > I'm the first one that would like to work on a project ilke this. I've > > worked on many Kubernetes/Openshift based applications and frameworks in > > the past years, also on operators and CRDs, and I think this way of > > redesigning integrations has a lot of potential. > > > > Integrations will not be necessarily limited to the simplified DSL, but > we > > can add extension points for scripting and even custom libraries > (although > > limiting the freedom of the optimizer). > > > > The most important thing: it may become a great project, since it's > driven > > by a great community. > > > > So, what do you think? Is it crazy enough? > > > > Nicola > >
