feat: implement initial functionality

.github/workflows/release.yml

@@ -0,0 +1,85 @@
+name: release
+
+on:
+  workflow_dispatch:
+  push:
+    tags:
+      - "v*"
+
+jobs:
+  release-backend:
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+
+      - name: setup go dependencies
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.22"
+
+      - name: setup quemu
+        uses: docker/setup-qemu-action@v3
+
+      - name: setup docker buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: login to docker hub
+        uses: docker/login-action@v2
+        with:
+          username: ${{ secrets.FLASHBOTS_DOCKERHUB_USERNAME }}
+          password: ${{ secrets.FLASHBOTS_DOCKERHUB_TOKEN }}
+
+      - name: login to ghcr
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: build and publish backend release
+        uses: goreleaser/goreleaser-action@v5
+        with:
+          args: release --clean
+          distribution: goreleaser
+          workdir: ./backend
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+  release-frontend:
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+
+      - name: setup go dependencies
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.22"
+
+      - name: setup quemu
+        uses: docker/setup-qemu-action@v3
+
+      - name: setup docker buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: login to docker hub
+        uses: docker/login-action@v2
+        with:
+          username: ${{ secrets.FLASHBOTS_DOCKERHUB_USERNAME }}
+          password: ${{ secrets.FLASHBOTS_DOCKERHUB_TOKEN }}
+
+      - name: login to ghcr
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: build and publish frontend release
+        uses: docker/build-push-action@v5
+        with:
+          context: ./frontend
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: flashbots/eth-faucet-frontend:${{ github.ref_name }},ghcr.io/flashbots/eth-faucet-frontend:${{ github.ref_name }}

.gitignore

@@ -2,6 +2,7 @@
 
 .idea
 .vscode
+*.code-workspace
 
 # temporary files
 

LICENSE

@@ -0,0 +1,20 @@
+Copyright (c) 2024 Flashbots
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Makefile

@@ -0,0 +1,22 @@
+VERSION := $(shell git describe --tags --always --dirty="-dev" --match "v*.*.*" || echo "development" )
+VERSION := $(VERSION:v%=%)
+
+.PHONY: build-backend
+build-backend:
+	@cd ./backend && CGO_ENABLED=0 go build \
+			-ldflags "-X main.version=${VERSION}" \
+			-o ./bin/eth-faucet \
+		github.com/flashbots/eth-faucet/cmd
+
+.PHONY: release-backend
+release-backend:
+	@cd ./backend && goreleaser release --snapshot --clean
+
+.PHONY: build-frontend
+build-frontend:
+	@cd ./frontend && yarn install && yarn build
+
+.PHONY: docker-compose
+docker-compose:
+	@docker compose down --remove-orphans
+	@docker compose up --build

backend/.dockerignore

@@ -0,0 +1 @@
+!include: .gitignore

backend/.gitignore

@@ -0,0 +1,4 @@
+/dist
+
+/bin/*
+!/bin/.gitkeep

backend/.golangci.yml

@@ -0,0 +1,21 @@
+run:
+  timeout: 5m
+  skip-dirs:
+    - .github
+    - web
+
+linters-settings:
+  misspell:
+    locale: US
+
+linters:
+  disable-all: true
+  enable:
+    - gosimple
+    - govet
+    - ineffassign
+    - goconst
+    - goimports
+    - revive
+    - unconvert
+    - unused

backend/.goreleaser.yml

@@ -0,0 +1,56 @@
+env:
+  - CGO_ENABLED=0
+
+builds:
+  - main: ./cmd
+    ldflags:
+      - -s
+      - -w
+      - -X main.version={{ .Version }}
+    targets:
+      - linux_amd64
+      - linux_arm64
+
+archives:
+  - id: zip
+    format: zip
+    name_template: "{{ .ProjectName }}_{{ .Os }}_{{ .Arch }}"
+    files:
+      - none*
+
+checksum:
+  name_template: 'checksums.txt'
+
+release:
+  prerelease: auto
+
+dockers:
+  - dockerfile: Dockerfile.goreleaser
+    goarch: amd64
+    goos: linux
+    use: buildx
+    build_flag_templates:
+      - --platform=linux/amd64
+    image_templates:
+      - "flashbots/eth-faucet-backend:{{ .Tag }}-amd64"
+      - "ghcr.io/flashbots/eth-faucet-backend:{{ .Tag }}-amd64"
+
+  - dockerfile: Dockerfile.goreleaser
+    goarch: arm64
+    goos: linux
+    use: buildx
+    build_flag_templates:
+      - --platform=linux/arm64
+    image_templates:
+      - "flashbots/eth-faucet-backend:{{ .Tag }}-arm64"
+      - "ghcr.io/flashbots/eth-faucet-backend:{{ .Tag }}-arm64"
+
+docker_manifests:
+  - name_template: "flashbots/eth-faucet-backend:{{ .Tag }}"
+    image_templates:
+      - "flashbots/eth-faucet-backend:{{ .Tag }}-amd64"
+      - "flashbots/eth-faucet-backend:{{ .Tag }}-arm64"
+  - name_template: "ghcr.io/flashbots/eth-faucet-backend:{{ .Tag }}"
+    image_templates:
+      - "ghcr.io/flashbots/eth-faucet-backend:{{ .Tag }}-amd64"
+      - "ghcr.io/flashbots/eth-faucet-backend:{{ .Tag }}-arm64"

backend/Dockerfile

@@ -0,0 +1,26 @@
+# stage: build ---------------------------------------------------------
+
+FROM golang:1.22-alpine as build
+
+RUN apk add --no-cache gcc musl-dev linux-headers
+
+WORKDIR /go/src/github.com/flashbots/eth-faucet
+
+COPY go.* ./
+RUN go mod download
+
+COPY . .
+
+RUN go build -o bin/eth-faucet -ldflags "-s -w" github.com/flashbots/eth-faucet/cmd
+
+# stage: run -----------------------------------------------------------
+
+FROM alpine
+
+RUN apk add --no-cache ca-certificates
+
+WORKDIR /app
+
+COPY --from=build /go/src/github.com/flashbots/eth-faucet/bin/eth-faucet ./eth-faucet
+
+ENTRYPOINT ["/app/eth-faucet"]

backend/Dockerfile.goreleaser

@@ -0,0 +1,9 @@
+# stage: run
+
+FROM gcr.io/distroless/static-debian12 as runner
+
+WORKDIR /app
+
+COPY eth-faucet ./
+
+ENTRYPOINT [ "./eth-faucet" ]

backend/backoff/backoff.go

@@ -0,0 +1,102 @@
+package backoff
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"slices"
+	"time"
+
+	"github.com/flashbots/eth-faucet/logutils"
+	"github.com/google/uuid"
+	"go.uber.org/zap"
+)
+
+var (
+	ErrBackoffContextError                 = errors.New("context error")
+	ErrBackoffDownstreamOperationCancelled = errors.New("downstream canceled the operation")
+	ErrBackoffFunctionalError              = errors.New("functional error")
+	ErrBackoffNonRetryableError            = errors.New("non-retryable error")
+	ErrBackoffTotalTimeoutExpired          = errors.New("total timeout expired")
+)
+
+func Backoff(
+	ctx context.Context,
+	params *Parameters,
+	payload func(ctx context.Context) error,
+) error {
+	params = WithDefaults(params)
+	deadline := time.Now().Add(params.TotalTimeout)
+
+	l := logutils.LoggerFromContext(ctx)
+	if l != nil {
+		l = l.With(zap.String(
+			"operation_uuid", uuid.Must(uuid.NewUUID()).String(),
+		))
+		ctx = logutils.ContextWithLogger(ctx, l)
+	}
+
+	errs := make([]error, 0)
+	attempt := 1
+	timeout := params.BaseTimeout
+
+	for time.Now().Before(deadline) {
+		start := time.Now()
+		if l != nil {
+			l.Debug("Running backoff-wrapped operation...",
+				zap.Duration("timeout", timeout),
+				zap.Int("attempt", attempt),
+			)
+		}
+
+		if timeout > params.MaximumTimeout {
+			timeout = params.MaximumTimeout
+		}
+		_ctx, cancel := context.WithTimeout(ctx, timeout)
+		defer cancel()
+
+		err := payload(_ctx)
+		ctxErr := _ctx.Err()
+
+		switch {
+		case err == nil && ctxErr == nil:
+			// happy path
+			return nil
+		case err != nil:
+			// error during execution
+			errs = append(errs, err)
+
+			// operation encountered non-retryable error
+			if !IsRetryable(err) {
+				slices.Reverse(errs)
+				return fmt.Errorf("%w: attempt %d: error log:\n%w",
+					ErrBackoffNonRetryableError, attempt,
+					errors.Join(errs...),
+				)
+			}
+		case ctxErr != nil:
+			// no execution error, but something wrong with context
+			errs = append(errs, ctxErr)
+
+			// downstream canceled the operation
+			if errors.Is(ctxErr, context.Canceled) {
+				slices.Reverse(errs)
+				return fmt.Errorf("%w: attempt %d: error log:\n%w",
+					ErrBackoffDownstreamOperationCancelled, attempt,
+					errors.Join(errs...),
+				)
+			}
+		}
+
+		time.Sleep(timeout - time.Since(start))
+
+		timeout = time.Duration(params.Multiplier * float64(timeout))
+		attempt++
+	}
+
+	slices.Reverse(errs)
+	return fmt.Errorf("%w: error log:\n%w",
+		ErrBackoffTotalTimeoutExpired,
+		errors.Join(errs...),
+	)
+}