Optimize HTTP client used for GitHub (#689)

* Optimize HTTP client used for GitHub

Use a single instance with tweaked defaults across all the invocations. Plus use newer API of `go-github` (including google/go-github#3011 fix).

Previously a default client was used which doesn't have nor request timeout nor idle connection timeout. This resulted in poor `p99` performance since sometimes connections were hanging blocking others to access `github.com`.

* Renamed to `defaultGitHubClient`

go.mod

@@ -25,7 +25,6 @@ require (
 	github.com/go-git/go-git/v5 v5.6.1
 	github.com/go-test/deep v1.1.0
 	github.com/golang/protobuf v1.5.3
-	github.com/google/go-github/v53 v53.0.0
 	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510
 	github.com/google/uuid v1.3.1
 	github.com/grpc-ecosystem/go-grpc-middleware v1.4.0
@@ -58,7 +57,7 @@ require (
 	github.com/yudai/pp v2.0.1+incompatible // indirect
 	go.starlark.net v0.0.0-20230302034142-4b1e35fe2254
 	golang.org/x/crypto v0.18.0
-	golang.org/x/oauth2 v0.13.0
+	golang.org/x/oauth2 v0.13.0 // indirect
 	golang.org/x/sys v0.16.0
 	golang.org/x/text v0.14.0
 	google.golang.org/appengine v1.6.8 // indirect
@@ -71,6 +70,7 @@ require (
 require (
 	github.com/IGLOU-EU/go-wildcard v1.0.3
 	github.com/goccy/go-yaml v1.11.0
+	github.com/google/go-github/v59 v59.0.0
 	github.com/puzpuzpuz/xsync/v3 v3.0.2
 	github.com/samber/lo v1.38.1
 	github.com/shirou/gopsutil/v3 v3.23.7

go.sum

@@ -276,8 +276,8 @@ github.com/google/go-cmp v0.5.8/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeN
 github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
-github.com/google/go-github/v53 v53.0.0 h1:T1RyHbSnpHYnoF0ZYKiIPSgPtuJ8G6vgc0MKodXsQDQ=
-github.com/google/go-github/v53 v53.0.0/go.mod h1:XhFRObz+m/l+UCm9b7KSIC3lT3NWSXGt7mOsAWEloao=
+github.com/google/go-github/v59 v59.0.0 h1:7h6bgpF5as0YQLLkEiVqpgtJqjimMYhBkD4jT5aN3VA=
+github.com/google/go-github/v59 v59.0.0/go.mod h1:rJU4R0rQHFVFDOkqGWxfLNo6vEk4dv40oDjhV/gH6wM=
 github.com/google/go-querystring v1.1.0 h1:AnCroh3fv4ZBgVIf1Iwtovgjaw/GiKJo8M8yD/fhyJ8=
 github.com/google/go-querystring v1.1.0/go.mod h1:Kcdr2DB4koayq7X8pmAG4sNG59So17icRSOU623lUBU=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=

pkg/larker/fs/github/github.go

@@ -6,17 +6,26 @@ import (
 	"errors"
 	"fmt"
 	"github.com/cirruslabs/cirrus-cli/pkg/larker/fs"
-	"github.com/google/go-github/v53/github"
+	"github.com/google/go-github/v59/github"
 	lru "github.com/hashicorp/golang-lru"
-	"golang.org/x/oauth2"
 	"net/http"
 	"os"
 	"path"
 	"syscall"
+	"time"
 )
 
 var ErrAPI = errors.New("failed to communicate with the GitHub API")
 
+var defaultGitHubClient = github.NewClient(&http.Client{
+	Transport: &http.Transport{
+		MaxIdleConns:        1024,
+		MaxIdleConnsPerHost: 1024,        // default is 2 which is too small and we mostly access the same host
+		IdleConnTimeout:     time.Minute, // let's put something big but not infinite like the default
+	},
+	Timeout: 11 * time.Second, // GitHub has a 10-second timeout for API requests
+})
+
 type GitHub struct {
 	token     string
 	owner     string
@@ -119,17 +128,12 @@ func (gh *GitHub) Join(elem ...string) string {
 	return path.Join(elem...)
 }
 
-func (gh *GitHub) client(ctx context.Context) *github.Client {
-	var client *http.Client
-
+func (gh *GitHub) client() *github.Client {
 	if gh.token != "" {
-		tokenSource := oauth2.StaticTokenSource(&oauth2.Token{
-			AccessToken: gh.token,
-		})
-		client = oauth2.NewClient(ctx, tokenSource)
+		return defaultGitHubClient.WithAuthToken(gh.token)
 	}
 
-	return github.NewClient(client)
+	return defaultGitHubClient
 }
 
 func (gh *GitHub) getContentsWrapper(
@@ -143,7 +147,7 @@ func (gh *GitHub) getContentsWrapper(
 
 	gh.apiCallCount++
 
-	fileContent, directoryContent, resp, err := gh.client(ctx).Repositories.GetContents(ctx, gh.owner, gh.repo, path,
+	fileContent, directoryContent, resp, err := gh.client().Repositories.GetContents(ctx, gh.owner, gh.repo, path,
 		&github.RepositoryContentGetOptions{
 			Ref: gh.reference,
 		},