Merge pull request #31 from statuspal/me/spl-679-ensure-terraform-provider-complies-with-api-rate-limits

feat: add http request throttling

Author: messutied

go.mod

@@ -11,6 +11,7 @@ require (
 	github.com/hashicorp/terraform-plugin-go v0.25.0
 	github.com/hashicorp/terraform-plugin-log v0.9.0
 	github.com/hashicorp/terraform-plugin-testing v1.11.0
+	golang.org/x/time v0.8.0
 )
 
 require (

go.sum

@@ -255,6 +255,8 @@ golang.org/x/text v0.3.8/go.mod h1:E6s5w1FMmriuDzIBO73fBruAKo1PCIq6d2Q6DHfQ8WQ=
 golang.org/x/text v0.4.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
 golang.org/x/text v0.20.0 h1:gK/Kv2otX8gz+wn7Rmb3vT96ZwuoxnQlY+HlJVj7Qug=
 golang.org/x/text v0.20.0/go.mod h1:D4IsuqiFMhST5bX19pQ9ikHC2GsaKyk/oF+pn3ducp4=
+golang.org/x/time v0.8.0 h1:9i3RxcPv3PZnitoVGMPDKZSq1xW1gK1Xy3ArNOGZfEg=
+golang.org/x/time v0.8.0/go.mod h1:3BpzKBy/shNhVucY/MWOyx10tF3SFh9QdLuxbVysPQM=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=

internal/client/client.go

@@ -6,6 +6,8 @@ import (
 	"net/http"
 	"os"
 	"time"
+
+	"golang.org/x/time/rate"
 )
 
 // Client struct.
@@ -15,6 +17,15 @@ type Client struct {
 	ApiKey     string
 }
 
+// RateLimit defines a limit of requests per second.
+const RateLimit = 10
+
+// BurstLimit defines a value of request that can be bursted.
+const BurstLimit = 10
+
+// RateLimiter defines the rate limit with a burst for the requests.
+var RateLimiter = rate.NewLimiter(BurstLimit, BurstLimit)
+
 // NewClient function.
 func NewClient(api_key *string, region *string, test_url *string) (*Client, error) {
 	env := os.Getenv("TF_ENV")
@@ -47,6 +58,12 @@ func NewClient(api_key *string, region *string, test_url *string) (*Client, erro
 }
 
 func (c *Client) doRequest(req *http.Request) (*[]byte, error) {
+	if !RateLimiter.Allow() {
+		if err := RateLimiter.Wait(req.Context()); err != nil {
+			return nil, fmt.Errorf("failed to wait the time required by rate limiter: %w", err)
+		}
+	}
+
 	req.Header.Set("Accept", "application/json")
 	req.Header.Set("Content-Type", "application/json")
 	req.Header.Set("Authorization", c.ApiKey)

internal/client/client_test.go

@@ -0,0 +1,44 @@
+package statuspal
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+func TestClient_doRequest_rate_limit(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	}))
+	defer server.Close()
+
+	client := &Client{
+		HostURL:    server.URL,
+		HTTPClient: server.Client(),
+		ApiKey:     "test",
+	}
+
+	start := time.Now()
+	var requestsCount uint
+
+	// NOTE: Executes the request 100 times to have enough register to validate the request per second.
+	for i := 0; i < 100; i++ {
+		req, _ := http.NewRequest(http.MethodGet, client.HostURL, nil)
+		if _, err := client.doRequest(req.WithContext(context.Background())); err != nil {
+			t.Errorf("Request error at iteration %d: %v", i, err)
+		}
+
+		requestsCount += 1
+	}
+
+	requestsTime := time.Since(start).Round(time.Duration(RateLimiter.Limit()) * time.Second)
+
+	requestPerSecond := requestsCount / uint(requestsTime.Seconds())
+	if requestPerSecond != uint(RateLimiter.Burst()) {
+		t.Fatal("Requests rate doesn't meet the request rate required")
+	}
+
+	t.Logf("All requests executed within the rate limit of %d per second", requestPerSecond)
+}