Add xk6-redis as experimental redis js module

This commit imports the latest state of xk6-redis into k6's core as
an experimental module importable as "k6/experimental/redis".

With it comes a single direct dependency, the `redis/v8` library, and
two indirect dependencies implied by the former `xxhash`
and `go-rendezvous`.

This commit's essential files are:
* `js/modules/k6/experimental/redis`: the files composing the module
itself
* `js/initcontext.go`: exposes the module as `k6/experimental/redis`
* `samples/redis.go`: presents an example of the redis module in
action

The rest of the files are essentially go module and vendoring plumbing.

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/fatih/color v1.13.0
 	github.com/golang/protobuf v1.5.2
 	github.com/gorilla/websocket v1.5.0
+	github.com/grafana/xk6-redis v0.1.0
 	github.com/influxdata/influxdb1-client v0.0.0-20190402204710-8ff2fc3824fc
 	github.com/jhump/protoreflect v1.12.0
 	github.com/klauspost/compress v1.15.7
@@ -40,6 +41,12 @@ require (
 	gopkg.in/yaml.v3 v3.0.1
 )
 
+require (
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
+	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
+	github.com/go-redis/redis/v8 v8.11.5 // indirect
+)
+
 require (
 	github.com/andybalholm/cascadia v1.3.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
@@ -48,8 +55,6 @@ require (
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/mstoykov/envconfig v1.4.1-0.20220114105314-765c6d8c76f1
-	github.com/onsi/ginkgo v1.14.0 // indirect
-	github.com/onsi/gomega v1.10.1 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a // indirect
 	golang.org/x/text v0.3.7 // indirect

js/initcontext.go

@@ -51,6 +51,8 @@ import (
 	"go.k6.io/k6/lib"
 	"go.k6.io/k6/lib/fsext"
 	"go.k6.io/k6/loader"
+
+	"github.com/grafana/xk6-redis/redis"
 )
 
 type programWithSource struct {
@@ -370,17 +372,18 @@ func (i *InitContext) allowOnlyOpenedFiles() {
 
 func getInternalJSModules() map[string]interface{} {
 	return map[string]interface{}{
-		"k6":             k6.New(),
-		"k6/crypto":      crypto.New(),
-		"k6/crypto/x509": x509.New(),
-		"k6/data":        data.New(),
-		"k6/encoding":    encoding.New(),
-		"k6/execution":   execution.New(),
-		"k6/net/grpc":    grpc.New(),
-		"k6/html":        html.New(),
-		"k6/http":        http.New(),
-		"k6/metrics":     metrics.New(),
-		"k6/ws":          ws.New(),
+		"k6":                    k6.New(),
+		"k6/crypto":             crypto.New(),
+		"k6/crypto/x509":        x509.New(),
+		"k6/data":               data.New(),
+		"k6/encoding":           encoding.New(),
+		"k6/execution":          execution.New(),
+		"k6/experimental/redis": redis.New(),
+		"k6/net/grpc":           grpc.New(),
+		"k6/html":               html.New(),
+		"k6/http":               http.New(),
+		"k6/metrics":            metrics.New(),
+		"k6/ws":                 ws.New(),
 	}
 }
 

samples/redis.js

@@ -0,0 +1,96 @@
+import { check } from "k6";
+import http from "k6/http";
+import redis from "k6/experimental/redis";
+import exec from "k6/execution";
+import { textSummary } from "https://jslib.k6.io/k6-summary/0.0.1/index.js";
+
+export const options = {
+	scenarios: {
+		redisPerformance: {
+			executor: "shared-iterations",
+			vus: 10,
+			iterations: 200,
+			exec: "measureRedisPerformance",
+		},
+		usingRedisData: {
+			executor: "shared-iterations",
+			vus: 10,
+			iterations: 200,
+			exec: "measureUsingRedisData",
+		},
+	},
+};
+
+// Instantiate a new redis client
+const redisClient = new redis.Client({
+	addrs: __ENV.REDIS_ADDRS.split(",") || new Array("localhost:6379"), // in the form of "host:port", separated by commas
+	password: __ENV.REDIS_PASSWORD || "",
+});
+
+// Prepare an array of crocodile ids for later use
+// in the context of the measureUsingRedisData function.
+const crocodileIDs = new Array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9);
+
+export function measureRedisPerformance() {
+	// VUs are executed in a parallel fashion,
+	// thus, to ensure that parallel VUs are not
+	// modifying the same key at the same time,
+	// we use keys indexed by the VU id.
+	const key = `foo-${exec.vu.idInTest}`;
+
+	redisClient
+		.set(`foo-${exec.vu.idInTest}`, 1)
+		.then(() => redisClient.get(`foo-${exec.vu.idInTest}`))
+		.then((value) => redisClient.incrBy(`foo-${exec.vu.idInTest}`, value))
+		.then((_) => redisClient.del(`foo-${exec.vu.idInTest}`))
+		.then((_) => redisClient.exists(`foo-${exec.vu.idInTest}`))
+		.then((exists) => {
+			if (exists !== 0) {
+				throw new Error("foo should have been deleted");
+			}
+		});
+}
+
+export function setup() {
+	redisClient.sadd("crocodile_ids", ...crocodileIDs);
+}
+
+export function measureUsingRedisData() {
+	// Pick a random crocodile id from the dedicated redis set,
+	// we have filled in setup().
+	redisClient
+		.srandmember("crocodile_ids")
+		.then((randomID) => {
+			const url = `https://test-api.k6.io/public/crocodiles/${randomID}`;
+			const res = http.get(url);
+
+			check(res, {
+				"status is 200": (r) => r.status === 200,
+				"content-type is application/json": (r) =>
+					r.headers["content-type"] === "application/json",
+			});
+
+			return url;
+		})
+		.then((url) => redisClient.hincrby("k6_crocodile_fetched", url, 1));
+}
+
+export function teardown() {
+	redisClient.del("crocodile_ids");
+}
+
+export function handleSummary(data) {
+	redisClient
+		.hgetall("k6_crocodile_fetched")
+		.then((fetched) =>
+			Object.assign(data, { k6_crocodile_fetched: fetched })
+		)
+		.then((data) =>
+			redisClient.set(`k6_report_${Date.now()}`, JSON.stringify(data))
+		)
+		.then(() => redisClient.del("k6_crocodile_fetched"));
+
+	return {
+		stdout: textSummary(data, { indent: "  ", enableColors: true }),
+	};
+}