commit 4dad509dc62e36484a9eae11e11ca37e9dfac353
Author:  Ilya Atamas <stackdumper@gmail.com>
Date:   Tue Apr 16 15:05:21 2019 +0300

    feat: initial commit

diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..b6f8530
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,4 @@
+*
+!*.go
+!go.mod
+!go.sum
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b0e6fe8
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,18 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Build
+build/
+
+# APFS cache
+.DS_Store
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..ca9025a
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,27 @@
+# === BUILD STAGE === #
+FROM golang:1.12-alpine as build
+
+ARG ACCESS_TOKEN
+
+RUN apk add --no-cache git
+
+WORKDIR /srv/app
+ENV CGO_ENABLED=0 GOOS=linux GOARCH=amd64
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN go test -v ./...
+RUN go build -ldflags="-w -s" -o build
+
+# === RUN STAGE === #
+FROM scratch as run
+
+WORKDIR /srv/app
+COPY --from=build /srv/app/build /srv/app/build
+
+ENV LISTEN_ADDRESS 0.0.0.0:8080
+ENV GIN_MODE release
+
+CMD ["/srv/app/build"]
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..d3bed69
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,11 @@
+.PHONY: run
+run:
+	go run main.go
+
+.PHONY: build
+build:
+	CGO_ENABLED=0 go build -ldflags="-w -s" -o build/router
+
+.PHONY: test
+test:
+	go test ./...
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..c6a1a28
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,10 @@
+module github.com/emeralt/npm-cache-proxy
+
+go 1.12
+
+require (
+	github.com/gin-contrib/zap v0.0.0-20190405225521-7c4b822813e7
+	github.com/gin-gonic/gin v1.3.0
+	github.com/go-redis/redis v6.15.2+incompatible
+	go.uber.org/zap v1.9.1
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..dbbf477
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,36 @@
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/gin-contrib/sse v0.0.0-20170109093832-22d885f9ecc7 h1:AzN37oI0cOS+cougNAV9szl6CVoj2RYwzS3DpUQNtlY=
+github.com/gin-contrib/sse v0.0.0-20170109093832-22d885f9ecc7/go.mod h1:VJ0WA2NBN22VlZ2dKZQPAPnyWw5XTlK1KymzLKsr59s=
+github.com/gin-contrib/zap v0.0.0-20190405225521-7c4b822813e7 h1:v6rNWmMnVDBVMc1pUUSCTobu2p4BukiPMwoj0pLqBhA=
+github.com/gin-contrib/zap v0.0.0-20190405225521-7c4b822813e7/go.mod h1:pQKeeey3PeRN2SbZe1jWiIkTJkylO9hL1K0Hf4Wbtt4=
+github.com/gin-gonic/gin v1.3.0 h1:kCmZyPklC0gVdL728E6Aj20uYBJV93nj/TkwBTKhFbs=
+github.com/gin-gonic/gin v1.3.0/go.mod h1:7cKuhb5qV2ggCFctp2fJQ+ErvciLZrIeoOSOm6mUr7Y=
+github.com/go-redis/redis v6.15.2+incompatible h1:9SpNVG76gr6InJGxoZ6IuuxaCOQwDAhzyXg+Bs+0Sb4=
+github.com/go-redis/redis v6.15.2+incompatible/go.mod h1:NAIEuMOZ/fxfXJIrKDQDz8wamY7mA7PouImQ2Jvg6kA=
+github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/json-iterator/go v1.1.5/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
+github.com/mattn/go-isatty v0.0.4 h1:bnP0vzxcAdeI1zdubAl5PjU6zsERjGZb7raWodagDYs=
+github.com/mattn/go-isatty v0.0.4/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
+github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
+github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
+github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/ugorji/go/codec v0.0.0-20181209151446-772ced7fd4c2 h1:EICbibRW4JNKMcY+LsWmuwob+CRS1BmdRdjphAm9mH4=
+github.com/ugorji/go/codec v0.0.0-20181209151446-772ced7fd4c2/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
+go.uber.org/atomic v1.3.2 h1:2Oa65PReHzfn29GpvgsYwloV9AVFHPDk8tYxt2c2tr4=
+go.uber.org/atomic v1.3.2/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
+go.uber.org/multierr v1.1.0 h1:HoEmRHQPVSqub6w2z2d2EOVs2fjyFRGyofhKuyDq0QI=
+go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
+go.uber.org/zap v1.9.1 h1:XCJQEf3W6eZaVwhRBof6ImoYGJSITeKWsyeh3HFu/5o=
+go.uber.org/zap v1.9.1/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
+golang.org/x/net v0.0.0-20181220203305-927f97764cc3/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20181221143128-b4a75ba826a6/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/go-playground/assert.v1 v1.2.1/go.mod h1:9RXL0bg/zibRAgZUYszZSwO/z8Y/a8bDuhia5mkpMnE=
+gopkg.in/go-playground/validator.v8 v8.18.2 h1:lFB4DoMU6B626w8ny76MV7VX6W2VHct2GVOI3xgiMrQ=
+gopkg.in/go-playground/validator.v8 v8.18.2/go.mod h1:RX2a/7Ha8BgOhfk7j780h4/u/RRjR0eouCJSH80/M2Y=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..40f7358
--- /dev/null
+++ b/main.go
@@ -0,0 +1,34 @@
+package main
+
+import (
+	"net/http"
+	"time"
+
+	npmproxy "github.com/emeralt/npm-cache-proxy/proxy"
+	"github.com/go-redis/redis"
+)
+
+func getOptions() (npmproxy.Options, error) {
+	return npmproxy.Options{
+		RedisPrefix:        "",
+		RedisExpireTimeout: 1 * time.Hour,
+
+		UpstreamAddress:     "http://registry.npmjs.org",
+		ReplaceAddress:      "https://registry.npmjs.org",
+		StaticServerAddress: "http://localhost:8080",
+	}, nil
+}
+
+func main() {
+	proxy := npmproxy.Proxy{
+		RedisClient: redis.NewClient(&redis.Options{}),
+		HttpClient: &http.Client{
+			Transport: http.DefaultTransport,
+		},
+		GetOptions: getOptions,
+	}
+
+	proxy.Server(npmproxy.ServerOptions{
+		ListenAddress: "localhost:8080",
+	}).ListenAndServe()
+}
diff --git a/proxy/main.go b/proxy/main.go
new file mode 100644
index 0000000..78a7493
--- /dev/null
+++ b/proxy/main.go
@@ -0,0 +1,24 @@
+package proxy
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/go-redis/redis"
+)
+
+type Proxy struct {
+	RedisClient *redis.Client
+	HttpClient  *http.Client
+
+	GetOptions func() (Options, error)
+}
+
+type Options struct {
+	RedisPrefix        string
+	RedisExpireTimeout time.Duration
+
+	UpstreamAddress     string
+	ReplaceAddress      string
+	StaticServerAddress string
+}
diff --git a/proxy/metadata.go b/proxy/metadata.go
new file mode 100644
index 0000000..3a76a18
--- /dev/null
+++ b/proxy/metadata.go
@@ -0,0 +1,68 @@
+package proxy
+
+import (
+	"io/ioutil"
+	"net/http"
+	"strings"
+)
+
+// GetMetadata returns NPM response for a given package path
+func (proxy Proxy) GetMetadata(path string, header http.Header) ([]byte, error) {
+	options, err := proxy.GetOptions()
+	if err != nil {
+		return nil, err
+	}
+
+	// get package from redis
+	pkg, err := proxy.RedisClient.Get(options.RedisPrefix + path).Result()
+
+	// either package doesn't exist or there's some other problem
+	if err != nil {
+
+		// check if error is caused by nonexistend package
+		// if no, return error
+		if err.Error() != "redis: nil" {
+			return nil, err
+		}
+
+		// error is caused by nonexistent package
+		// fetch package
+		req, err := http.NewRequest("GET", options.UpstreamAddress+path, nil)
+
+		// inherit headers from request
+		req.Header = header
+		if err != nil {
+			return nil, err
+		}
+
+		res, err := proxy.HttpClient.Do(req)
+		if err != nil {
+			return nil, err
+		}
+
+		defer res.Body.Close()
+		body, err := ioutil.ReadAll(res.Body)
+		if err != nil {
+			return nil, err
+		}
+
+		// convert body to string
+		pkg = string(body)
+
+		// save to redis
+		_, err = proxy.RedisClient.Set(
+			options.RedisPrefix+path,
+			pkg,
+			options.RedisExpireTimeout,
+		).Result()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	// replace tarball urls
+	// FIXME: unmarshall and replace only necessary fields
+	convertedPkg := strings.ReplaceAll(string(pkg), options.ReplaceAddress, options.StaticServerAddress)
+
+	return []byte(convertedPkg), nil
+}
diff --git a/proxy/server.go b/proxy/server.go
new file mode 100644
index 0000000..89306b1
--- /dev/null
+++ b/proxy/server.go
@@ -0,0 +1,65 @@
+package proxy
+
+import (
+	"net/http"
+	"strings"
+	"time"
+
+	ginzap "github.com/gin-contrib/zap"
+	gin "github.com/gin-gonic/gin"
+	zap "go.uber.org/zap"
+)
+
+type ServerOptions struct {
+	ListenAddress string
+}
+
+func (proxy Proxy) Server(options ServerOptions) *http.Server {
+	router := gin.New()
+
+	logger, _ := zap.NewProduction()
+	router.Use(ginzap.Ginzap(logger, time.RFC3339, true))
+
+	router.GET("/:scope/:name", proxy.GetPackageHandler)
+	router.GET("/:scope", proxy.GetPackageHandler)
+	router.NoRoute(proxy.NoRouteHandler)
+
+	return &http.Server{
+		Handler: router,
+		Addr:    options.ListenAddress,
+	}
+}
+
+func (proxy Proxy) GetPackageHandler(c *gin.Context) {
+	key := c.Request.URL.Path
+
+	pkg, err := proxy.GetMetadata(key, c.Request.Header)
+
+	if err != nil {
+		c.AbortWithError(500, err)
+	} else {
+		c.Data(200, "application/json", pkg)
+	}
+}
+
+func (proxy Proxy) NoRouteHandler(c *gin.Context) {
+	if strings.Contains(c.Request.URL.Path, ".tgz") {
+		proxy.GetPackageHandler(c)
+	} else if c.Request.URL.Path == "/" {
+		_, err := proxy.RedisClient.Ping().Result()
+
+		if err != nil {
+			c.AbortWithStatusJSON(503, err)
+		} else {
+			c.AbortWithStatusJSON(200, gin.H{"ok": true})
+		}
+	} else {
+		options, err := proxy.GetOptions()
+
+		if err != nil {
+			c.AbortWithStatusJSON(500, err)
+		} else {
+			c.Redirect(http.StatusTemporaryRedirect, options.UpstreamAddress+c.Request.URL.Path)
+		}
+	}
+}
diff --git a/readme.md b/readme.md
new file mode 100644
index 0000000..619ceb8
--- /dev/null
+++ b/readme.md
@@ -0,0 +1,10 @@
+# npm-cache-proxy
+
+## Installation
+...
+
+## Configuration
+...
+
+## Programmatic usage
+...