Throttling implementation

First implemented version

---------

Co-authored-by: Jose Manuel Cardona <josemanuel.cardona@softonic.com>
Co-authored-by: Alberto Gonzalez <alberto.gonzalez@softonic.com>
Co-authored-by: Juan Lotito <juan.lotito@softonic.com>

.gitignore

@@ -0,0 +1,18 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, build with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Never ignore gitkeep files
+!.gitignore
+
+# Ignoring generated files
+bin

.travis.yml

@@ -0,0 +1,16 @@
+dist: bionic
+
+language: go
+
+env: GO111MODULE=on GOFLAGS='-mod vendor'
+
+go:
+  - 1.13.x
+
+
+before_script:
+  - go install github.com/golangci/golangci-lint/cmd/golangci-lint
+
+script:
+  - make build
+  - golangci-lint run

CODEOWNERS

@@ -0,0 +1 @@
+* @joskfg @mindhells @paupm @lotykun @santinoncs

Dockerfile

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+FROM golang:1.23-bookworm AS build
+
+COPY ./ /go/src/github.com/softonic/hp-throttling
+
+RUN cd /go/src/github.com/softonic/hp-throttling && make build
+
+FROM scratch
+
+COPY --from=build /go/src/github.com/softonic/hp-throttling/bin/hp-throttling /
+
+ENTRYPOINT ["/hp-throttling", "-logtostderr"]

LICENSE

@@ -0,0 +1,13 @@
+Copyright 2019 Softonic International S.A.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

Makefile

@@ -0,0 +1,6 @@
+dep:
+	go mod download
+build: dep
+	CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -ldflags="-w -s" -o bin/hp-throttling pkg/main.go
+docker-build:
+	docker build -t softonic/hp-pass-middleware:dev .

README.md

@@ -1,29 +1,36 @@
-# HP Passthrough Middleware
+# HP throttling Middleware
 
-[Homing pigeon](https://github.com/softonic/homing-pigeon) middleware that just pass the data.
+[Homing pigeon](https://github.com/softonic/homing-pigeon) middleware that throttles messages to limit writes.
 
 ### Overview
 
-This dummy middleware can be used as base middleware to do your own implementations.
-
-### Requirements
-
-All the [Homing pigeon](https://github.com/softonic/homing-pigeon) middlewares must accept at least the next env vars.
-
-| Name       | Description                                | Example                                                                              |
-| ---------- | ------------------------------------------ | ------------------------------------------------------------------------------------ |
-| IN_SOCKET  | Socket where the data will be received     | `"/sockets/input.sock"`                                                              |
-| OUT_SOCKET | Socket to send data to the next middleware | `"passthrough:///unix:///sockets/input.sock"` or `""` if this is the last middleware |
+This middleware is a simple implementation of a throttling middleware. It will limit the number of messages per second that can be sent to the next middleware, allowing for
+burst usage.
 
 ### How it works
 
-The middleware receives a `github.com/softonic/homing-pigeon/middleware` message as request in the `IN_SOCKET`, so you can
-modify the input data to send it to the next middlewares. After the next middlewares are executed, it intercepts the response
-so it can be modified again before it is finally returned.
+The middleware uses the `rate` library of Go to implement throttling and burst functionality. This means that you can configure the number of messages allowed per second, as well as the ability to
+handle occasional bursts of traffic. The configuration is done according to the documentation provided by the [`rate` library](https://pkg.go.dev/golang.org/x/time/rate).
+
+- **Limit**: This defines the rate at which events are allowed. It's expressed in events per second. If you set a `Limit` of 5, you are allowing 5 events to occur per second. If the value is set to 0,
+  throttling is disabled.
 
-The main homing-pigeon package come with an `UnimplementedMiddleware` to allow you to implement just the middleware bussiness logic. If you need
-more control, you can implement your middleware from scratch. Take a look at `UnimplementedMiddleware` to know the basic implementation.
+- **Burst**: This is the maximum number of events that are allowed to burst beyond the `Limit` in a short period. Even if the rate is controlled by the `Limit`, a burst allows occasional bursts of
+  event traffic greater than the normal rate.
 
 ### Usage
 
-You just need to execute the binary or use docker to automatically run it. If you want to show some logging in the output, you can use the [kglog](https://github.com/kubernetes/klog) flags in the command.
+If you are using the [homing-pigeon-chart](https://github.com/softonic/homing-pigeon-chart/) Helm chart, you can enable the throttling middleware by setting the following values in the `values.yaml` file:
+
+```yaml
+requestMiddlewares:
+ - name: throttling
+   repository: softonic/hp-throttling
+   tag: latest
+   pullPolicy: IfNotPresent
+   env:
+   - name: THROTTLE_LIMIT
+     value: "100"
+   - name: THROTTLE_BURST
+     value: "100"
+```

docker-compose.yaml

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+version: '3.7'
+
+services:
+  hp-middleware-throttling:
+    volumes:
+      - ./sockets:/tmp
+    build:
+      context: .
+      dockerfile: Dockerfile
+    image: softonic/hp-throttling:0.1.0
+    entrypoint: ["/hp-throttling"]
+    environment:
+      IN_SOCKET: "/tmp/hp"
+      THROTTLE_LIMIT: "100"
+      THROTTLE_BURST: "100"

go.mod

@@ -0,0 +1,18 @@
+module github.com/softonic/hp-throttling
+
+require (
+	github.com/softonic/homing-pigeon v0.0.0-20191212144147-c9d6d0b55981
+	golang.org/x/time v0.0.0-20190308202827-9d24e82272b4
+	k8s.io/klog v1.0.0
+)
+
+require (
+	github.com/golang/protobuf v1.3.2 // indirect
+	golang.org/x/net v0.0.0-20191209160850-c0dbc17a3553 // indirect
+	golang.org/x/sys v0.0.0-20191210023423-ac6580df4449 // indirect
+	golang.org/x/text v0.3.2 // indirect
+	google.golang.org/genproto v0.0.0-20191206224255-0243a4be9c8f // indirect
+	google.golang.org/grpc v1.25.1 // indirect
+)
+
+go 1.23