Fix retry mechanism not sending body if first request fails before reading the body

admin.go

@@ -1,7 +1,6 @@
 package gapi
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 )
@@ -25,7 +24,7 @@ func (c *Client) CreateUser(user User) (int64, error) {
 		ID int64 `json:"id"`
 	}{}
 
-	err = c.request("POST", "/api/admin/users", nil, bytes.NewBuffer(data), &created)
+	err = c.request("POST", "/api/admin/users", nil, data, &created)
 	if err != nil {
 		return id, err
 	}
@@ -45,7 +44,7 @@ func (c *Client) UpdateUserPassword(id int64, password string) error {
 	if err != nil {
 		return err
 	}
-	return c.request("PUT", fmt.Sprintf("/api/admin/users/%d/password", id), nil, bytes.NewBuffer(data), nil)
+	return c.request("PUT", fmt.Sprintf("/api/admin/users/%d/password", id), nil, data, nil)
 }
 
 // UpdateUserPermissions sets a user's admin status.
@@ -55,7 +54,7 @@ func (c *Client) UpdateUserPermissions(id int64, isAdmin bool) error {
 	if err != nil {
 		return err
 	}
-	return c.request("PUT", fmt.Sprintf("/api/admin/users/%d/permissions", id), nil, bytes.NewBuffer(data), nil)
+	return c.request("PUT", fmt.Sprintf("/api/admin/users/%d/permissions", id), nil, data, nil)
 }
 
 // PauseAllAlerts pauses all Grafana alerts.
@@ -68,7 +67,7 @@ func (c *Client) PauseAllAlerts() (PauseAllAlertsResponse, error) {
 		return result, err
 	}
 
-	err = c.request("POST", "/api/admin/pause-all-alerts", nil, bytes.NewBuffer(data), &result)
+	err = c.request("POST", "/api/admin/pause-all-alerts", nil, data, &result)
 
 	return result, err
 }

alert.go

@@ -1,7 +1,6 @@
 package gapi
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"net/url"
@@ -68,7 +67,7 @@ func (c *Client) PauseAlert(id int64) (PauseAlertResponse, error) {
 		return result, err
 	}
 
-	err = c.request("POST", path, nil, bytes.NewBuffer(data), &result)
+	err = c.request("POST", path, nil, data, &result)
 	if err != nil {
 		return result, err
 	}

alerting_alert_rule.go

@@ -1,7 +1,6 @@
 package gapi
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"time"
@@ -93,7 +92,7 @@ func (c *Client) SetAlertRuleGroup(group RuleGroup) error {
 	}
 
 	uri := fmt.Sprintf("/api/v1/provisioning/folder/%s/rule-groups/%s", folderUID, name)
-	return c.request("PUT", uri, nil, bytes.NewBuffer(req), nil)
+	return c.request("PUT", uri, nil, req, nil)
 }
 
 // NewAlertRule creates a new alert rule and returns its UID.
@@ -104,7 +103,7 @@ func (c *Client) NewAlertRule(ar *AlertRule) (string, error) {
 		return "", err
 	}
 	result := AlertRule{}
-	err = c.request("POST", "/api/v1/provisioning/alert-rules", nil, bytes.NewBuffer(req), &result)
+	err = c.request("POST", "/api/v1/provisioning/alert-rules", nil, req, &result)
 	if err != nil {
 		return "", err
 	}
@@ -120,7 +119,7 @@ func (c *Client) UpdateAlertRule(ar *AlertRule) error {
 		return err
 	}
 
-	return c.request("PUT", uri, nil, bytes.NewBuffer(req), nil)
+	return c.request("PUT", uri, nil, req, nil)
 }
 
 // DeleteAlertRule deletes a alert rule, identified by the alert rule's UID.

alerting_contact_point.go

@@ -1,7 +1,6 @@
 package gapi
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"net/url"
@@ -62,7 +61,7 @@ func (c *Client) NewContactPoint(p *ContactPoint) (string, error) {
 	}
 	result := ContactPoint{}
 
-	err = c.request("POST", "/api/v1/provisioning/contact-points", nil, bytes.NewBuffer(req), &result)
+	err = c.request("POST", "/api/v1/provisioning/contact-points", nil, req, &result)
 	if err != nil {
 		return "", err
 	}
@@ -77,7 +76,7 @@ func (c *Client) UpdateContactPoint(p *ContactPoint) error {
 		return err
 	}
 
-	return c.request("PUT", uri, nil, bytes.NewBuffer(req), nil)
+	return c.request("PUT", uri, nil, req, nil)
 }
 
 // DeleteContactPoint deletes a contact point.

alerting_message_template.go

@@ -1,7 +1,6 @@
 package gapi
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 )
@@ -44,7 +43,7 @@ func (c *Client) SetMessageTemplate(name, content string) error {
 	}
 
 	uri := fmt.Sprintf("/api/v1/provisioning/templates/%s", name)
-	return c.request("PUT", uri, nil, bytes.NewBuffer(body), nil)
+	return c.request("PUT", uri, nil, body, nil)
 }
 
 // DeleteMessageTemplate deletes a message template.

alerting_mute_timing.go

@@ -1,7 +1,6 @@
 package gapi
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 )
@@ -65,7 +64,7 @@ func (c *Client) NewMuteTiming(mt *MuteTiming) error {
 		return err
 	}
 
-	return c.request("POST", "/api/v1/provisioning/mute-timings", nil, bytes.NewBuffer(req), nil)
+	return c.request("POST", "/api/v1/provisioning/mute-timings", nil, req, nil)
 }
 
 // UpdateMuteTiming updates a mute timing.
@@ -76,7 +75,7 @@ func (c *Client) UpdateMuteTiming(mt *MuteTiming) error {
 		return err
 	}
 
-	return c.request("PUT", uri, nil, bytes.NewBuffer(req), nil)
+	return c.request("PUT", uri, nil, req, nil)
 }
 
 // DeleteMutetiming deletes a mute timing.

alerting_notification_policy.go

@@ -1,7 +1,6 @@
 package gapi
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 )
@@ -116,7 +115,7 @@ func (c *Client) SetNotificationPolicyTree(np *NotificationPolicyTree) error {
 	if err != nil {
 		return err
 	}
-	return c.request("PUT", "/api/v1/provisioning/policies", nil, bytes.NewBuffer(req), nil)
+	return c.request("PUT", "/api/v1/provisioning/policies", nil, req, nil)
 }
 
 func (c *Client) ResetNotificationPolicyTree() error {

alertnotification.go

@@ -1,7 +1,6 @@
 package gapi
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 )
@@ -59,7 +58,7 @@ func (c *Client) NewAlertNotification(a *AlertNotification) (int64, error) {
 		ID int64 `json:"id"`
 	}{}
 
-	err = c.request("POST", "/api/alert-notifications", nil, bytes.NewBuffer(data), &result)
+	err = c.request("POST", "/api/alert-notifications", nil, data, &result)
 	if err != nil {
 		return 0, err
 	}
@@ -75,7 +74,7 @@ func (c *Client) UpdateAlertNotification(a *AlertNotification) error {
 	if err != nil {
 		return err
 	}
-	err = c.request("PUT", path, nil, bytes.NewBuffer(data), nil)
+	err = c.request("PUT", path, nil, data, nil)
 
 	return err
 }

annotation.go

@@ -1,7 +1,6 @@
 package gapi
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"net/url"
@@ -58,7 +57,7 @@ func (c *Client) NewAnnotation(a *Annotation) (int64, error) {
 		ID int64 `json:"id"`
 	}{}
 
-	err = c.request("POST", "/api/annotations", nil, bytes.NewBuffer(data), &result)
+	err = c.request("POST", "/api/annotations", nil, data, &result)
 	if err != nil {
 		return 0, err
 	}
@@ -77,7 +76,7 @@ func (c *Client) NewGraphiteAnnotation(gfa *GraphiteAnnotation) (int64, error) {
 		ID int64 `json:"id"`
 	}{}
 
-	err = c.request("POST", "/api/annotations/graphite", nil, bytes.NewBuffer(data), &result)
+	err = c.request("POST", "/api/annotations/graphite", nil, data, &result)
 	if err != nil {
 		return 0, err
 	}
@@ -97,7 +96,7 @@ func (c *Client) UpdateAnnotation(id int64, a *Annotation) (string, error) {
 		Message string `json:"message"`
 	}{}
 
-	err = c.request("PUT", path, nil, bytes.NewBuffer(data), &result)
+	err = c.request("PUT", path, nil, data, &result)
 	if err != nil {
 		return "", err
 	}
@@ -117,7 +116,7 @@ func (c *Client) PatchAnnotation(id int64, a *Annotation) (string, error) {
 		Message string `json:"message"`
 	}{}
 
-	err = c.request("PATCH", path, nil, bytes.NewBuffer(data), &result)
+	err = c.request("PATCH", path, nil, data, &result)
 	if err != nil {
 		return "", err
 	}
@@ -132,7 +131,7 @@ func (c *Client) DeleteAnnotation(id int64) (string, error) {
 		Message string `json:"message"`
 	}{}
 
-	err := c.request("DELETE", path, nil, bytes.NewBuffer(nil), &result)
+	err := c.request("DELETE", path, nil, nil, &result)
 	if err != nil {
 		return "", err
 	}
@@ -147,7 +146,7 @@ func (c *Client) DeleteAnnotationByRegionID(id int64) (string, error) {
 		Message string `json:"message"`
 	}{}
 
-	err := c.request("DELETE", path, nil, bytes.NewBuffer(nil), &result)
+	err := c.request("DELETE", path, nil, nil, &result)
 	if err != nil {
 		return "", err
 	}

api_key.go

@@ -1,7 +1,6 @@
 package gapi
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"net/url"
@@ -42,7 +41,7 @@ func (c *Client) CreateAPIKey(request CreateAPIKeyRequest) (CreateAPIKeyResponse
 		return response, err
 	}
 
-	err = c.request("POST", "/api/auth/keys", nil, bytes.NewBuffer(data), &response)
+	err = c.request("POST", "/api/auth/keys", nil, data, &response)
 	return response, err
 }
 

builtin_role_assignments.go

@@ -1,7 +1,6 @@
 package gapi
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 )
@@ -33,7 +32,7 @@ func (c *Client) NewBuiltInRoleAssignment(builtInRoleAssignment BuiltInRoleAssig
 
 	br := &BuiltInRoleAssignment{}
 
-	err = c.request("POST", baseURL, nil, bytes.NewBuffer(body), &br)
+	err = c.request("POST", baseURL, nil, body, &br)
 	if err != nil {
 		return nil, err
 	}
@@ -52,7 +51,7 @@ func (c *Client) DeleteBuiltInRoleAssignment(builtInRole BuiltInRoleAssignment)
 		"global": {fmt.Sprint(builtInRole.Global)},
 	}
 	url := fmt.Sprintf("%s/%s/roles/%s", baseURL, builtInRole.BuiltinRole, builtInRole.RoleUID)
-	err = c.request("DELETE", url, qp, bytes.NewBuffer(data), nil)
+	err = c.request("DELETE", url, qp, data, nil)
 
 	return err
 }

client.go

@@ -40,6 +40,8 @@ type Config struct {
 	OrgID int64
 	// NumRetries contains the number of attempted retries
 	NumRetries int
+	// RetryTimeout says how long to wait before retrying a request
+	RetryTimeout time.Duration
 }
 
 // New creates a new Grafana client.
@@ -71,35 +73,27 @@ func (c Client) WithOrgID(orgID int64) *Client {
 	return &c
 }
 
-func (c *Client) request(method, requestPath string, query url.Values, body io.Reader, responseStruct interface{}) error {
+func (c *Client) request(method, requestPath string, query url.Values, body []byte, responseStruct interface{}) error {
 	var (
 		req          *http.Request
 		resp         *http.Response
 		err          error
 		bodyContents []byte
 	)
 
-	// If we want to retry a request that sends data, we'll need to stash the request data in memory. Otherwise, we lose it since readers cannot be replayed.
-	var bodyBuffer bytes.Buffer
-	if c.config.NumRetries > 0 && body != nil {
-		body = io.TeeReader(body, &bodyBuffer)
-	}
-
 	// retry logic
 	for n := 0; n <= c.config.NumRetries; n++ {
-		// If it's not the first request, re-use the request body we stashed earlier.
-		if n > 0 {
-			body = bytes.NewReader(bodyBuffer.Bytes())
-		}
-
-		req, err = c.newRequest(method, requestPath, query, body)
+		req, err = c.newRequest(method, requestPath, query, bytes.NewReader(body))
 		if err != nil {
 			return err
 		}
 
 		// Wait a bit if that's not the first request
 		if n != 0 {
-			time.Sleep(time.Second * 5)
+			if c.config.RetryTimeout == 0 {
+				c.config.RetryTimeout = time.Second * 5
+			}
+			time.Sleep(c.config.RetryTimeout)
 		}
 
 		resp, err = c.client.Do(req)