add url proxy (#109)

url/proxy/LICENSE

@@ -0,0 +1,104 @@
+# PolyForm Strict License 1.0.0
+
+<https://polyformproject.org/licenses/strict/1.0.0>
+
+## Acceptance
+
+In order to get any license under these terms, you must agree
+to them as both strict obligations and conditions to all
+your licenses.
+
+## Copyright License
+
+The licensor grants you a copyright license for the software
+to do everything you might do with the software that would
+otherwise infringe the licensor's copyright in it for any
+permitted purpose, other than distributing the software or
+making changes or new works based on the software.
+
+## Patent License
+
+The licensor grants you a patent license for the software that
+covers patent claims the licensor can license, or becomes able
+to license, that you would infringe by using the software.
+
+## Noncommercial Purposes
+
+Any noncommercial purpose is a permitted purpose.
+
+## Personal Uses
+
+Personal use for research, experiment, and testing for
+the benefit of public knowledge, personal study, private
+entertainment, hobby projects, amateur pursuits, or religious
+observance, without any anticipated commercial application,
+is use for a permitted purpose.
+
+## Noncommercial Organizations
+
+Use by any charitable organization, educational institution,
+public research organization, public safety or health
+organization, environmental protection organization,
+or government institution is use for a permitted purpose
+regardless of the source of funding or obligations resulting
+from the funding.
+
+## Fair Use
+
+You may have "fair use" rights for the software under the
+law. These terms do not limit them.
+
+## No Other Rights
+
+These terms do not allow you to sublicense or transfer any of
+your licenses to anyone else, or prevent the licensor from
+granting licenses to anyone else.  These terms do not imply
+any other licenses.
+
+## Patent Defense
+
+If you make any written claim that the software infringes or
+contributes to infringement of any patent, your patent license
+for the software granted under these terms ends immediately. If
+your company makes such a claim, your patent license ends
+immediately for work on behalf of your company.
+
+## Violations
+
+The first time you are notified in writing that you have
+violated any of these terms, or done anything with the software
+not covered by your licenses, your licenses can nonetheless
+continue if you come into full compliance with these terms,
+and take practical steps to correct past violations, within
+32 days of receiving notice.  Otherwise, all your licenses
+end immediately.
+
+## No Liability
+
+***As far as the law allows, the software comes as is, without
+any warranty or condition, and the licensor will not be liable
+to you for any damages arising out of these terms or the use
+or nature of the software, under any kind of legal claim.***
+
+## Definitions
+
+The **licensor** is the individual or entity offering these
+terms, and the **software** is the software the licensor makes
+available under these terms.
+
+**You** refers to the individual or entity agreeing to these
+terms.
+
+**Your company** is any legal entity, sole proprietorship,
+or other kind of organization that you work for, plus all
+organizations that have control over, are under the control of,
+or are under common control with that organization.  **Control**
+means ownership of substantially all the assets of an entity,
+or the power to direct its management and policies by vote,
+contract, or otherwise.  Control can be direct or indirect.
+
+**Your licenses** are all the licenses granted to you for the
+software under these terms.
+
+**Use** means anything you do with the software requiring one
+of your licenses.

url/proxy/README.md

@@ -0,0 +1,15 @@
+# URL Proxy
+
+The URL proxy provides the single entrypoint for m3o.one
+
+## Overview
+
+The [url](https://github.com/micro/services) service provides link shortening and sharing. The URL Proxy fronts those urls 
+as a single entrypoint at https://m3o.one. We don't serve directly because of time wasted on ssl certs, etc.
+
+## Usage
+
+- Assumes url is of format `https://m3o.one/u/AArfeZE`
+- Will call `https://api.m3o.com/url/proxy?shortURL=AArfeZE`
+- URL service should return `destinationURL=https://foobar.com/example`
+- Proxy will issue a 301 redirect

url/proxy/go.mod

@@ -0,0 +1,3 @@
+module github.com/micro/services/url/proxy
+
+go 1.15

url/proxy/main.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+func main() {
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		r.ParseForm()
+
+		// assuming /u/short-id
+		parts := strings.Split(r.URL.Path, "/")
+		if len(parts) < 3 {
+			return
+		}
+		// assuming its /u/ for url
+		if parts[1] != "u" {
+			return
+		}
+
+		// get the url id
+		//id := parts[2]
+
+		uri := url.URL{
+			Scheme: r.URL.Scheme,
+			Host:   r.URL.Host,
+			Path:   r.URL.Path,
+		}
+
+		// call the backend for the url
+		rsp, err := http.Get("https://api.m3o.com/url/proxy?shortURL=" + uri.String())
+		if err != nil {
+			http.Error(w, err.Error(), 500)
+			return
+		}
+		defer rsp.Body.Close()
+
+		if rsp.StatusCode != 200 {
+			http.Error(w, "unexpected error", 500)
+			return
+		}
+
+		result := map[string]interface{}{}
+
+		b, err := ioutil.ReadAll(rsp.Body)
+		if err != nil {
+			http.Error(w, err.Error(), 500)
+			return
+		}
+
+		if err := json.Unmarshal(b, &result); err != nil {
+			http.Error(w, err.Error(), 500)
+			return
+		}
+
+		// get the destination url
+		url, _ := result["destinationURL"].(string)
+		if len(url) == 0 {
+			return
+		}
+
+		// return the redirect url to caller
+		http.Redirect(w, r, url, 301)
+	})
+
+	http.ListenAndServe(":8080", nil)
+}