add: kube-scheduler-simulator

f

.dockerignore

@@ -0,0 +1,2 @@
+web/*
+submodules/kubernetes/*

.gitignore

@@ -0,0 +1 @@
+bin/

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "submodules/kubernetes"]
+	path = submodules/kubernetes
+	url = [email protected]:kubernetes/kubernetes.git

.golangci.yml

@@ -0,0 +1,59 @@
+linters-settings:
+  gci:
+    local-prefixes: github.com/kubernetes-sigs/kube-scheduler-simulator
+  gocritic:
+    disabled-checks:
+      - appendAssign
+
+linters:
+  disable-all: true
+  enable:
+    - unused
+    - govet
+    - staticcheck
+    - typecheck
+    - varcheck
+    - errcheck
+    - gosimple
+    - asciicheck
+    - bodyclose
+    - cyclop
+    - dogsled
+    - durationcheck
+    - errorlint
+    - exportloopref
+    - forcetypeassert
+    - funlen
+    - gci
+    - gochecknoinits
+    - gocognit
+    - gocritic
+    - gocyclo
+    - godot
+    - goerr113
+    - gofmt
+    - gofumpt
+    - gosec
+    - ifshort
+    - makezero
+    - nakedret
+    - nestif
+    - nilerr
+    - nolintlint
+    - paralleltest
+    - predeclared
+    - revive
+    - rowserrcheck
+    - sqlclosecheck
+    - thelper
+    - unconvert
+    - unparam
+    - wastedassign
+
+issues:
+  exclude-rules:
+    - path: _test\.go
+      linters:
+        - funlen
+        - goerr113
+        - errcheck

CONTRIBUTING.md

@@ -6,11 +6,26 @@ _As contributors and maintainers of this project, and in the interest of fosteri
 
 ## Getting Started
 
-We have full documentation on how to get started contributing here:
+For the frontend, please see [README.md](./web/README.md) on ./web dir.
 
-<!---
-If your repo has certain guidelines for contribution, put them here ahead of the general k8s resources
--->
+The first step, you have to prepare tools with make.
+
+```bash
+make tools
+```
+
+Also, you can run lint, format and test with make.
+
+```bash
+# test
+make test
+# lint
+make lint
+# format
+make format
+```
+
+see [Makefile](Makefile) for more details.
 
 - [Contributor License Agreement](https://git.k8s.io/community/CLA.md) Kubernetes projects require that you sign a Contributor License Agreement (CLA) before we can accept your pull requests
 - [Kubernetes Contributor Guide](https://git.k8s.io/community/contributors/guide) - Main contributor documentation, or you can just jump directly to the [contributing section](https://git.k8s.io/community/contributors/guide#contributing)
@@ -19,13 +34,3 @@ If your repo has certain guidelines for contribution, put them here ahead of the
 ## Mentorship
 
 - [Mentoring Initiatives](https://git.k8s.io/community/mentoring) - We have a diverse set of mentorship programs available that are always looking for volunteers!
-
-<!---
-Custom Information - if you're copying this template for the first time you can add custom content here, for example:
-
-## Contact Information
-
-- [Slack channel](https://kubernetes.slack.com/messages/kubernetes-users) - Replace `kubernetes-users` with your slack channel string, this will send users directly to your channel. 
-- [Mailing list](URL)
-
--->

Dockerfile

@@ -0,0 +1,22 @@
+FROM golang:1.16.6 AS build-env
+
+ENV GOOS=linux
+ENV GOARCH=amd64
+ENV CGO_ENABLED=0
+ENV GO111MODULE=on
+
+WORKDIR /go/src/simulator-server
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN go build -v -o ./bin/simulator simulator.go
+
+FROM alpine:3.14.0
+
+COPY --from=build-env /go/src/simulator-server/bin/simulator /simulator
+RUN chmod a+x /simulator
+
+EXPOSE 1212
+CMD ["/simulator"]

Makefile

@@ -0,0 +1,55 @@
+.PHONY: tools
+tools:
+	cd ./tools; \
+	cat tools.go | grep "_" | awk -F'"' '{print $$2}' | xargs -tI % go install %
+
+.PHONY: generate
+generate:
+	go generate ./...
+
+.PHONY: lint
+lint:
+	golangci-lint run ./...
+
+.PHONY: format
+format:
+	golangci-lint run --fix ./...
+
+.PHONY: test
+test:
+	go test ./...
+
+.PHONY: build
+build:
+	go build -o ./bin/simulator ./simulator.go
+
+.PHONY: start
+serve: build
+	./hack/start_simulator.sh
+
+# re-generate openapi file for running api-server
+.PHONY: openapi
+openapi:
+	./hack/openapi.sh
+
+.PHONY: docker_build
+docker_build: docker_build_server docker_build_front
+
+.PHONY: docker_build_server
+docker_build_server:
+	docker build -t simulator-server .
+
+.PHONY: docker_build_front
+docker_build_front:
+	docker build -t simulator-frontend ./web/
+
+.PHONY: docker_up
+docker_up:
+	docker-compose up -d
+
+.PHONY: docker_build_and_up
+docker_build_and_up: docker_build docker_up
+
+.PHONY: docker_down
+docker_down:
+	docker-compose down

README.md

@@ -1,16 +1,86 @@
-# Kubernetes Template Project
+# Web-based Kubernetes scheduler simulator
 
-The Kubernetes Template Project is a template for starting new projects in the GitHub organizations owned by Kubernetes. All Kubernetes projects, at minimum, must have the following files:
+Hello world. Here is web-based Kubernetes scheduler simulator.
 
-- a `README.md` outlining the project goals, sponsoring sig, and community contact information
-- an `OWNERS` with the project leads listed as approvers ([docs on `OWNERS` files][owners])
-- a `CONTRIBUTING.md` outlining how to contribute to the project
-- an unmodified copy of `code-of-conduct.md` from this repo, which outlines community behavior and the consequences of breaking the code
-- a `LICENSE` which must be Apache 2.0 for code projects, or [Creative Commons 4.0] for documentation repositories, without any custom content
-- a `SECURITY_CONTACTS` with the contact points for the Product Security Team 
-  to reach out to for triaging and handling of incoming issues. They must agree to abide by the
-  [Embargo Policy](https://git.k8s.io/security/private-distributors-list.md#embargo-policy)
-  and will be removed and replaced if they violate that agreement.
+On the simulator, you can create/edit/delete these resources to simulate a cluster.
+
+- Nodes
+- Pods
+- Persistent Volumes
+- Persistent Volume Claims
+- Storage Classes
+
+![list resources](./docs/images/resources.png)
+
+You can create resources with yaml file as usual.
+
+![create node](./docs/images/create-node.png)
+
+And, after pods are scheduled, you can see the results of
+
+- Each Filter plugins
+- Each Score plugins
+- Final score (normalized and applied Plugin Weight)
+
+![result](./docs/images/result.jpg)
+
+You can configure the scheduler on the simulator through KubeSchedulerConfiguration.
+
+[Scheduler Configuration | Kubernetes](https://kubernetes.io/docs/reference/scheduling/config/)
+
+Note: changes to any fields other than `.profiles` are disabled on simulator, since they do not affect the results of the scheduling.
+
+![configure scheduler](./docs/images/schedulerconfiguration.jpg)
+
+## Background
+
+In real Kubernetes, we cannot know the results of scheduling in detail without reading the logs, which usually requires privileged access to the control plane.
+Therefore, we have developed a simulator for kube-scheduler -- you can try out the behavior of the scheduler with web UI while checking which plugin made what decision for which Node.
+
+It can be used to learn about the Kubernetes scheduler or to examine the detailed behavior of plugins, etc.
+
+## Getting started
+
+### Run with Docker
+
+We have [docker-compose.yml](./docker-compose.yml) to use the simulator easily.
+
+You can use it with the below command.
+
+```bash
+make docker_build_and_up
+```
+
+Then, you can access the simulator with http://localhost:3000
+
+### Run Locally
+
+You have to run frontend, server and etcd.
+
+#### Run simulator server and etcd
+
+To run this simulator's server, you have to install Go and etcd.
+
+You can install etcd with [kubernetes/kubernetes/hack/install-etcd.sh](https://github.com/kubernetes/kubernetes/blob/master/hack/install-etcd.sh).
+
+```bash
+make start
+```
+
+It starts etcd and simulator-server locally.
+
+#### Run simulator frontend
+
+To run the frontend, please see [README.md](./web/README.md) on ./web dir.
+
+## Contributing
+
+see [CONTRIBUTING.md](./CONTRIBUTING.md)
+
+### other docs
+
+- [how the simulator works](./docs/how-it-works.md)
+- [API Reference](./docs/api.md)
 
 ## Community, discussion, contribution, and support
 
@@ -26,4 +96,4 @@ You can reach the maintainers of this project at:
 Participation in the Kubernetes community is governed by the [Kubernetes Code of Conduct](code-of-conduct.md).
 
 [owners]: https://git.k8s.io/community/contributors/guide/owners.md
-[Creative Commons 4.0]: https://git.k8s.io/website/LICENSE
+[creative commons 4.0]: https://git.k8s.io/website/LICENSE

config/config.go

@@ -0,0 +1,75 @@
+package config
+
+import (
+	"errors"
+	"os"
+	"strconv"
+
+	"golang.org/x/xerrors"
+)
+
+// ErrEmptyEnv represents the required environment variable don't exist.
+var ErrEmptyEnv = errors.New("env is needed, but empty")
+
+// Config is configuration for simulator.
+type Config struct {
+	Port        int
+	EtcdURL     string
+	FrontendURL string
+}
+
+// NewConfig gets some settings from environment variables.
+func NewConfig() (*Config, error) {
+	port, err := getPort()
+	if err != nil {
+		return nil, xerrors.Errorf("get port: %w", err)
+	}
+
+	etcdurl, err := getEtcdURL()
+	if err != nil {
+		return nil, xerrors.Errorf("get etcd URL: %w", err)
+	}
+
+	frontendurl, err := getFrontendURL()
+	if err != nil {
+		return nil, xerrors.Errorf("get frontend URL: %w", err)
+	}
+
+	return &Config{
+		Port:        port,
+		EtcdURL:     etcdurl,
+		FrontendURL: frontendurl,
+	}, nil
+}
+
+// getPort gets Port from the environment variable named PORT.
+func getPort() (int, error) {
+	p := os.Getenv("PORT")
+	if p == "" {
+		return 0, xerrors.Errorf("get PORT from env: %w", ErrEmptyEnv)
+	}
+
+	port, err := strconv.Atoi(p)
+	if err != nil {
+		return 0, xerrors.Errorf("convert PORT of string to int: %w", err)
+	}
+	return port, nil
+}
+
+func getEtcdURL() (string, error) {
+	e := os.Getenv("KUBE_SCHEDULER_SIMULATOR_ETCD_URL")
+	if e == "" {
+		return "", xerrors.Errorf("get KUBE_SCHEDULER_SIMULATOR_ETCD_URL from env: %w", ErrEmptyEnv)
+	}
+
+	return e, nil
+}
+
+func getFrontendURL() (string, error) {
+	e := os.Getenv("FRONTEND_URL")
+	if e == "" {
+		return "", xerrors.Errorf("get FRONTEND_URL from env: %w", ErrEmptyEnv)
+	}
+
+	return e, nil
+}