Backport of Integration test for ext-authz Envoy extension into release/1.16.x (#18003)

* backport of commit 6699b173136276c3b9d6bc7ed126d8f5dbd7c0a1

* resolve failed cherrypick

* remove extraneous changes to agent.go

---------

Co-authored-by: Chris Thain <chris.m.thain@gmail.com>

test/integration/consul-container/libs/cluster/agent.go

@@ -44,11 +44,11 @@ type Agent interface {
 type Config struct {
 	// NodeName is set for the consul agent name and container name
 	// Equivalent to the -node command-line flag.
-	// If empty, a randam name will be generated
+	// If empty, a random name will be generated
 	NodeName string
 	// NodeID is used to configure node_id in agent config file
 	// Equivalent to the -node-id command-line flag.
-	// If empty, a randam name will be generated
+	// If empty, a random name will be generated
 	NodeID string
 
 	// ExternalDataDir is data directory to copy consul data from, if set.
@@ -81,10 +81,7 @@ func (c *Config) DockerImage() string {
 func (c Config) Clone() Config {
 	c2 := c
 	if c.Cmd != nil {
-		c2.Cmd = make([]string, len(c.Cmd))
-		for i, v := range c.Cmd {
-			c2.Cmd[i] = v
-		}
+		copy(c2.Cmd, c.Cmd)
 	}
 	return c2
 }

test/integration/consul-container/test/envoy_extensions/ext_authz_test.go

@@ -0,0 +1,170 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package envoyextensions
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"github.com/testcontainers/testcontainers-go"
+
+	"github.com/hashicorp/consul/api"
+	"github.com/hashicorp/consul/sdk/testutil/retry"
+	libassert "github.com/hashicorp/consul/test/integration/consul-container/libs/assert"
+	libcluster "github.com/hashicorp/consul/test/integration/consul-container/libs/cluster"
+	libservice "github.com/hashicorp/consul/test/integration/consul-container/libs/service"
+	"github.com/hashicorp/consul/test/integration/consul-container/libs/topology"
+	"github.com/hashicorp/go-cleanhttp"
+)
+
+// TestExtAuthzLocal Summary
+// This test makes sure two services in the same datacenter have connectivity.
+// A simulated client (a direct HTTP call) talks to it's upstream proxy through the mesh.
+// The upstream (static-server) is configured with a `builtin/ext-authz` extension that
+// calls an OPA external authorization service to authorize incoming HTTP requests.
+// The external authorization service is deployed as a container on the local network.
+//
+// Steps:
+// - Create a single agent cluster.
+// - Create the example static-server and sidecar containers, then register them both with Consul
+// - Create an example static-client sidecar, then register both the service and sidecar with Consul
+// - Create an OPA external authorization container on the local network, this doesn't need to be registered with Consul.
+// - Configure the static-server service with a `builtin/ext-authz` EnvoyExtension targeting the OPA ext-authz service.
+// - Make sure a call to the client sidecar local bind port returns the expected response from the upstream static-server:
+//   - A call to `/allow` returns 200 OK.
+//   - A call to any other endpoint returns 403 Forbidden.
+func TestExtAuthzLocal(t *testing.T) {
+	t.Parallel()
+
+	cluster, _, _ := topology.NewCluster(t, &topology.ClusterConfig{
+		NumServers:                1,
+		NumClients:                1,
+		ApplyDefaultProxySettings: true,
+		BuildOpts: &libcluster.BuildOptions{
+			Datacenter:             "dc1",
+			InjectAutoEncryption:   true,
+			InjectGossipEncryption: true,
+		},
+	})
+
+	createLocalAuthzService(t, cluster)
+
+	clientService := createServices(t, cluster)
+	_, port := clientService.GetAddr()
+	_, adminPort := clientService.GetAdminAddr()
+
+	libassert.AssertUpstreamEndpointStatus(t, adminPort, "static-server.default", "HEALTHY", 1)
+	libassert.GetEnvoyListenerTCPFilters(t, adminPort)
+
+	libassert.AssertContainerState(t, clientService, "running")
+	libassert.AssertFortioName(t, fmt.Sprintf("http://localhost:%d", port), "static-server", "")
+
+	// Wire up the ext-authz envoy extension for the static-server
+	consul := cluster.APIClient(0)
+	defaults := api.ServiceConfigEntry{
+		Kind:     api.ServiceDefaults,
+		Name:     "static-server",
+		Protocol: "http",
+		EnvoyExtensions: []api.EnvoyExtension{{
+			Name: "builtin/ext-authz",
+			Arguments: map[string]any{
+				"Config": map[string]any{
+					"GrpcService": map[string]any{
+						"Target": map[string]any{"URI": "127.0.0.1:9191"},
+					},
+				},
+			},
+		}},
+	}
+	consul.ConfigEntries().Set(&defaults, nil)
+
+	// Make requests to the static-server. We expect that all requests are rejected with 403 Forbidden
+	// unless they are to the /allow path.
+	baseURL := fmt.Sprintf("http://localhost:%d", port)
+	doRequest(t, baseURL, http.StatusForbidden)
+	doRequest(t, baseURL+"/allow", http.StatusOK)
+}
+
+func createServices(t *testing.T, cluster *libcluster.Cluster) libservice.Service {
+	node := cluster.Agents[0]
+	client := node.GetClient()
+	// Create a service and proxy instance
+	serviceOpts := &libservice.ServiceOpts{
+		Name:     libservice.StaticServerServiceName,
+		ID:       "static-server",
+		HTTPPort: 8080,
+		GRPCPort: 8079,
+	}
+
+	// Create a service and proxy instance
+	_, _, err := libservice.CreateAndRegisterStaticServerAndSidecar(node, serviceOpts)
+	require.NoError(t, err)
+
+	libassert.CatalogServiceExists(t, client, "static-server-sidecar-proxy", nil)
+	libassert.CatalogServiceExists(t, client, libservice.StaticServerServiceName, nil)
+
+	// Create a client proxy instance with the server as an upstream
+	clientConnectProxy, err := libservice.CreateAndRegisterStaticClientSidecar(node, "", false, false)
+	require.NoError(t, err)
+
+	libassert.CatalogServiceExists(t, client, "static-client-sidecar-proxy", nil)
+
+	return clientConnectProxy
+}
+
+func createLocalAuthzService(t *testing.T, cluster *libcluster.Cluster) {
+	node := cluster.Agents[0]
+
+	cwd, err := os.Getwd()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	req := testcontainers.ContainerRequest{
+		Image:      "openpolicyagent/opa:0.53.0-envoy-3",
+		AutoRemove: true,
+		Name:       "ext-authz",
+		Env:        make(map[string]string),
+		Cmd: []string{
+			"run",
+			"--server",
+			"--addr=localhost:8181",
+			"--diagnostic-addr=0.0.0.0:8282",
+			"--set=plugins.envoy_ext_authz_grpc.addr=:9191",
+			"--set=plugins.envoy_ext_authz_grpc.path=envoy/authz/allow",
+			"--set=decision_logs.console=true",
+			"--set=status.console=true",
+			"--ignore=.*",
+			"/testdata/policies/policy.rego",
+		},
+		Mounts: []testcontainers.ContainerMount{{
+			Source: testcontainers.DockerBindMountSource{
+				HostPath: fmt.Sprintf("%s/testdata", cwd),
+			},
+			Target:   "/testdata",
+			ReadOnly: true,
+		}},
+	}
+
+	ctx := context.Background()
+
+	exposedPorts := []string{}
+	_, err = libcluster.LaunchContainerOnNode(ctx, node, req, exposedPorts)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func doRequest(t *testing.T, url string, expStatus int) {
+	retry.RunWith(&retry.Timer{Timeout: 5 * time.Second, Wait: time.Second}, t, func(r *retry.R) {
+		resp, err := cleanhttp.DefaultClient().Get(url)
+		require.NoError(r, err)
+		require.Equal(r, expStatus, resp.StatusCode)
+	})
+}

test/integration/consul-container/test/envoy_extensions/testdata/policies/policy.rego

@@ -0,0 +1,12 @@
+package envoy.authz
+
+import future.keywords
+
+import input.attributes.request.http as http_request
+
+default allow := false
+
+allow if {
+	http_request.method == "GET"
+	glob.match("/allow", ["/"], http_request.path)
+}