Add support for enterprise repos to github plugin (#6194)

plugins/inputs/github/README.md

@@ -15,6 +15,9 @@ alternative method for collecting repository information.
   ## Github API access token.  Unauthenticated requests are limited to 60 per hour.
   # access_token = ""
 	
+  ## Github API enterprise url. Github Enterprise accounts must specify their base url.
+  # enterprise_base_url = ""
+
   ## Timeout for HTTP requests.
   # http_timeout = "5s"
 ```

plugins/inputs/github/github.go

@@ -20,6 +20,7 @@ import (
 type GitHub struct {
 	Repositories      []string          `toml:"repositories"`
 	AccessToken       string            `toml:"access_token"`
+	EnterpriseBaseURL string            `toml:"enterprise_base_url"`
 	HTTPTimeout       internal.Duration `toml:"http_timeout"`
 	githubClient      *github.Client
 
@@ -37,6 +38,9 @@ const sampleConfig = `
   ## Github API access token.  Unauthenticated requests are limited to 60 per hour.
   # access_token = ""
 	
+  ## Github API enterprise url. Github Enterprise accounts must specify their base url.
+  # enterprise_base_url = ""
+
   ## Timeout for HTTP requests.
   # http_timeout = "5s"
 `
@@ -71,9 +75,16 @@ func (g *GitHub) createGitHubClient(ctx context.Context) (*github.Client, error)
 
 		g.obfusticatedToken = g.AccessToken[0:4] + "..." + g.AccessToken[len(g.AccessToken)-3:]
 
-		return github.NewClient(oauthClient), nil
+		return g.newGithubClient(oauthClient)
 	}
 
+	return g.newGithubClient(httpClient)
+}
+
+func (g *GitHub) newGithubClient(httpClient *http.Client) (*github.Client, error) {
+	if g.EnterpriseBaseURL != "" {
+		return github.NewEnterpriseClient(g.EnterpriseBaseURL, "", httpClient)
+	}
 	return github.NewClient(httpClient), nil
 }
 

plugins/inputs/github/github_test.go

@@ -1,6 +1,7 @@
 package github
 
 import (
+	"net/http"
 	"reflect"
 	"testing"
 
@@ -8,6 +9,18 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func TestNewGithubClient(t *testing.T) {
+	httpClient := &http.Client{}
+	g := &GitHub{}
+	client, err := g.newGithubClient(httpClient)
+	require.Nil(t, err)
+	require.Contains(t, client.BaseURL.String(), "api.github.com")
+	g.EnterpriseBaseURL = "api.example.com/"
+	enterpriseClient, err := g.newGithubClient(httpClient)
+	require.Nil(t, err)
+	require.Contains(t, enterpriseClient.BaseURL.String(), "api.example.com")
+}
+
 func TestSplitRepositoryNameWithWorkingExample(t *testing.T) {
 	var validRepositoryNames = []struct {
 		fullName   string