feat: add cli - start server, list packages, purge packages

proxy/cache.go

@@ -0,0 +1,110 @@
+package proxy
+
+import (
+	"io/ioutil"
+	"net/http"
+	"strings"
+)
+
+// GetMetadata returns NPM response for a given package path
+func (proxy Proxy) GetMetadata(name string, originalPath 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 + name).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+originalPath, 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+name,
+			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(pkg), nil
+}
+
+// ListMetadata returns a list of all cached packages
+func (proxy Proxy) ListMetadata() ([]string, error) {
+	options, err := proxy.GetOptions()
+	if err != nil {
+		return nil, err
+	}
+
+	metadata, err := proxy.RedisClient.Keys(options.RedisPrefix + "*").Result()
+	if err != nil {
+		return nil, err
+	}
+
+	deprefixedMetadata := make([]string, 0)
+	for _, record := range metadata {
+		deprefixedMetadata = append(deprefixedMetadata, strings.Replace(record, options.RedisPrefix, "", 1))
+	}
+
+	return deprefixedMetadata, nil
+}
+
+// Purge deletes all cached packages
+func (proxy Proxy) PurgeMetadata() error {
+	options, err := proxy.GetOptions()
+	if err != nil {
+		return err
+	}
+
+	metadata, err := proxy.RedisClient.Keys(options.RedisPrefix + "*").Result()
+	if err != nil {
+		return err
+	}
+
+	for _, record := range metadata {
+		_, err := proxy.RedisClient.Del(record).Result()
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}