From 5e3a6f7ccbae5b5ed954238b0fb24f9bc5ec063e Mon Sep 17 00:00:00 2001
From: Dave Hall <skwashd@gmail.com>
Date: Fri, 1 Jun 2018 21:42:24 +1000
Subject: [PATCH] Fix GitHub teams for large orgs

Some large organisations have more than 100 teams. The current
implementation only checks the first 100 teams returned by the
API. This checks all teams the user is a member of.

Added support for GitHub's new nested team feature which means
inheritence works as designed. Again useful for large orgs.

Updated the limit from 200 to the [documented limit of
100](https://developer.github.com/v3/#pagination).
---
 providers/github.go      | 79 +++++++++++++++++++++++-----------------
 providers/github_test.go |  2 +-
 2 files changed, 47 insertions(+), 34 deletions(-)

diff --git a/providers/github.go b/providers/github.go
index 26526ce76..25247b20f 100644
--- a/providers/github.go
+++ b/providers/github.go
@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"net/url"
 	"path"
+	"regexp"
 	"strconv"
 	"strings"
 )
@@ -69,7 +70,7 @@ func (p *GitHubProvider) hasOrg(accessToken string) (bool, error) {
 	pn := 1
 	for {
 		params := url.Values{
-			"limit": {"200"},
+			"limit": {"100"},
 			"page":  {strconv.Itoa(pn)},
 		}
 
@@ -134,7 +135,7 @@ func (p *GitHubProvider) hasOrgAndTeam(accessToken string) (bool, error) {
 	}
 
 	params := url.Values{
-		"limit": {"200"},
+		"limit": {"100"},
 	}
 
 	endpoint := &url.URL{
@@ -143,45 +144,57 @@ func (p *GitHubProvider) hasOrgAndTeam(accessToken string) (bool, error) {
 		Path:     path.Join(p.ValidateURL.Path, "/user/teams"),
 		RawQuery: params.Encode(),
 	}
-	req, _ := http.NewRequest("GET", endpoint.String(), nil)
-	req.Header.Set("Accept", "application/vnd.github.v3+json")
-	req.Header.Set("Authorization", fmt.Sprintf("token %s", accessToken))
-	resp, err := http.DefaultClient.Do(req)
-	if err != nil {
-		return false, err
-	}
-
-	body, err := ioutil.ReadAll(resp.Body)
-	resp.Body.Close()
-	if err != nil {
-		return false, err
-	}
-	if resp.StatusCode != 200 {
-		return false, fmt.Errorf(
-			"got %d from %q %s", resp.StatusCode, endpoint.String(), body)
-	}
-
-	if err := json.Unmarshal(body, &teams); err != nil {
-		return false, fmt.Errorf("%s unmarshaling %s", err, body)
-	}
+	team_url := endpoint.String()
 
+	pattern := regexp.MustCompile(`<([^>]+)>; rel="next"`)
 	var hasOrg bool
 	presentOrgs := make(map[string]bool)
 	var presentTeams []string
-	for _, team := range teams {
-		presentOrgs[team.Org.Login] = true
-		if p.Org == team.Org.Login {
-			hasOrg = true
-			ts := strings.Split(p.Team, ",")
-			for _, t := range ts {
-				if t == team.Slug {
-					log.Printf("Found Github Organization:%q Team:%q (Name:%q)", team.Org.Login, team.Slug, team.Name)
-					return true, nil
+	for {
+		req, _ := http.NewRequest("GET", team_url, nil)
+		req.Header.Set("Accept", "application/vnd.github.hellcat-preview+json")
+		req.Header.Set("Authorization", fmt.Sprintf("token %s", accessToken))
+		resp, err := http.DefaultClient.Do(req)
+		if err != nil {
+			return false, err
+		}
+
+		body, err := ioutil.ReadAll(resp.Body)
+		resp.Body.Close()
+		if err != nil {
+			return false, err
+		}
+		if resp.StatusCode != 200 {
+			return false, fmt.Errorf(
+				"got %d from %q %s", resp.StatusCode, endpoint.String(), body)
+		}
+
+		if err := json.Unmarshal(body, &teams); err != nil {
+			return false, fmt.Errorf("%s unmarshaling %s", err, body)
+		}
+
+		for _, team := range teams {
+			presentOrgs[team.Org.Login] = true
+			if p.Org == team.Org.Login {
+				hasOrg = true
+				ts := strings.Split(p.Team, ",")
+				for _, t := range ts {
+					if t == team.Slug {
+						log.Printf("Found Github Organization:%q Team:%q (Name:%q)", team.Org.Login, team.Slug, team.Name)
+						return true, nil
+					}
 				}
+				presentTeams = append(presentTeams, team.Slug)
 			}
-			presentTeams = append(presentTeams, team.Slug)
 		}
+
+		matches := pattern.FindStringSubmatch(resp.Header["Link"][0])
+		if len(matches) == 0 {
+			break
+		}
+		team_url = matches[1]
 	}
+
 	if hasOrg {
 		log.Printf("Missing Team:%q from Org:%q in teams: %v", p.Team, p.Org, presentTeams)
 	} else {
diff --git a/providers/github_test.go b/providers/github_test.go
index 481018258..d1e4477fd 100644
--- a/providers/github_test.go
+++ b/providers/github_test.go
@@ -31,7 +31,7 @@ func testGitHubBackend(payload []string) *httptest.Server {
 	pathToQueryMap := map[string][]string{
 		"/user":        []string{""},
 		"/user/emails": []string{""},
-		"/user/orgs":   []string{"limit=200&page=1", "limit=200&page=2", "limit=200&page=3"},
+		"/user/orgs":   []string{"limit=100&page=1", "limit=100&page=2", "limit=100&page=3"},
 	}
 
 	return httptest.NewServer(http.HandlerFunc(