handle ratelimits for reading user groups

slack/resource_usergroup.go

@@ -2,10 +2,14 @@ package slack
 
 import (
 	"context"
+	"errors"
 	"fmt"
+	"math/rand"
 	"strings"
+	"time"
 
 	"github.com/hashicorp/terraform-plugin-sdk/v2/diag"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
 	"github.com/slack-go/slack"
 )
@@ -51,6 +55,10 @@ func resourceSlackUserGroup() *schema.Resource {
 				Optional: true,
 			},
 		},
+
+		Timeouts: &schema.ResourceTimeout{
+			Read: schema.DefaultTimeout(5 * time.Minute),
+		},
 	}
 }
 
@@ -109,10 +117,28 @@ func resourceSlackUserGroupCreate(ctx context.Context, d *schema.ResourceData, m
 func resourceSlackUserGroupRead(ctx context.Context, d *schema.ResourceData, m interface{}) diag.Diagnostics {
 	client := m.(*slack.Client)
 	id := d.Id()
-	var diags diag.Diagnostics
-	userGroups, err := client.GetUserGroupsContext(ctx, slack.GetUserGroupsOptionIncludeUsers(true))
+
+	var (
+		diags      diag.Diagnostics
+		userGroups []slack.UserGroup
+		backoff    = &Backoff{Base: time.Second, Cap: 15 * time.Second}
+	)
+	err := resource.RetryContext(ctx, d.Timeout(schema.TimeoutRead), func() *resource.RetryError {
+		var (
+			err   error
+			rlerr *slack.RateLimitedError
+		)
+		userGroups, err = client.GetUserGroupsContext(ctx, slack.GetUserGroupsOptionIncludeUsers(true))
+		if errors.As(err, &rlerr) {
+			backoff.Sleep(ctx)
+			return resource.RetryableError(err)
+		} else if err != nil {
+			return resource.NonRetryableError(fmt.Errorf("couldn't get usergroups: %w", err))
+		}
+		return nil
+	})
 	if err != nil {
-		return diag.FromErr(fmt.Errorf("couldn't get usergroups: %w", err))
+		return diag.FromErr(err)
 	}
 
 	for _, userGroup := range userGroups {
@@ -128,6 +154,29 @@ func resourceSlackUserGroupRead(ctx context.Context, d *schema.ResourceData, m i
 	return diags
 }
 
+type Backoff struct {
+	Attempt int
+	Base    time.Duration
+	Cap     time.Duration
+}
+
+func (b *Backoff) Sleep(ctx context.Context) {
+	b.Attempt++
+
+	wait := b.Base * (2 << b.Attempt)
+	if wait > b.Cap {
+		wait = b.Cap
+	}
+
+	wait = time.Duration(rand.Int63n(int64(wait)))
+
+	select {
+	case <-time.After(wait):
+	case <-ctx.Done():
+	}
+
+}
+
 func findUserGroupByName(ctx context.Context, name string, includeDisabled bool, m interface{}) (slack.UserGroup, error) {
 	client := m.(*slack.Client)
 	userGroups, err := client.GetUserGroupsContext(ctx, slack.GetUserGroupsOptionIncludeDisabled(includeDisabled), slack.GetUserGroupsOptionIncludeUsers(true))