e2e: add group-switch scenario using a short tunnel-cache TTL

StartProxy now accepts env overrides so a test can set a short
NB_PROXY_TUNNEL_CACHE_TTL and observe authorization changes propagate in
seconds instead of the 5-minute default.

Add TestGuardrailGroupSwitchTakesEffectAfterTTL: a client starts in group A
(allowed modelA) with a second policy granting group B modelB. After moving the
peer A -> B via the API, once the short tunnel-cache TTL expires the proxy
re-validates, the guardrail decision flips (modelB served, modelA denied), and
the cross-group deny is enforced by management's per-policy/group check.

e2e/agentnetwork/guardrail_groupswitch_test.go

@@ -0,0 +1,205 @@
+//go:build e2e
+
+package agentnetwork
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/e2e/harness"
+	"github.com/netbirdio/netbird/shared/management/http/api"
+)
+
+// TestGuardrailGroupSwitchTakesEffectAfterTTL proves that moving a peer between
+// groups flips its model-allowlist decision once the proxy's tunnel-peer cache
+// expires. The peer's groups reach the guardrail via ValidateTunnelPeer, which
+// the proxy caches; the switch is invisible until that cache expires. The proxy
+// runs with a short NB_PROXY_TUNNEL_CACHE_TTL so the flip happens in seconds
+// instead of the 5-minute default.
+//
+// Setup: one catch-all provider declaring modelA + modelB; polA (grpA -> allow
+// modelA) and polB (grpB -> allow modelB). The client starts in grpA. modelA is
+// served and modelB denied; after switching the client grpA -> grpB, modelB is
+// served and modelA denied. The cross-group deny comes from management's
+// per-policy/group CheckLLMPolicyLimits (the proxy backstop carries the union).
+func TestGuardrailGroupSwitchTakesEffectAfterTTL(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Minute)
+	defer cancel()
+
+	const (
+		modelA = "e2e-model-a"
+		modelB = "e2e-model-b"
+		// Short tunnel-cache TTL so a group switch propagates in seconds.
+		// Exercises the NB_PROXY_TUNNEL_CACHE_TTL override.
+		cacheTTL = 3 * time.Second
+	)
+
+	vllm, err := harness.StartVLLM(ctx, srv)
+	require.NoError(t, err, "start mock upstream")
+	t.Cleanup(func() { _ = vllm.Terminate(context.Background()) })
+
+	grpA, err := srv.API().Groups.Create(ctx, api.PostApiGroupsJSONRequestBody{Name: "e2e-gswitch-a"})
+	require.NoError(t, err, "create group A")
+	t.Cleanup(func() { _ = srv.API().Groups.Delete(context.Background(), grpA.Id) })
+
+	grpB, err := srv.API().Groups.Create(ctx, api.PostApiGroupsJSONRequestBody{Name: "e2e-gswitch-b"})
+	require.NoError(t, err, "create group B")
+	t.Cleanup(func() { _ = srv.API().Groups.Delete(context.Background(), grpB.Id) })
+
+	ephemeral := false
+	sk, err := srv.API().SetupKeys.Create(ctx, api.PostApiSetupKeysJSONRequestBody{
+		Name:       "e2e-gswitch-client",
+		Type:       "reusable",
+		ExpiresIn:  86400,
+		UsageLimit: 0,
+		AutoGroups: []string{grpA.Id}, // client starts in group A
+		Ephemeral:  &ephemeral,
+	})
+	require.NoError(t, err, "mint setup key")
+	require.NotEmpty(t, sk.Key, "setup key plaintext")
+
+	staticKey := "static-e2e-token"
+	prov, err := srv.CreateProvider(ctx, api.AgentNetworkProviderRequest{
+		Name:        "gswitch",
+		ProviderId:  "openai_api",
+		UpstreamUrl: vllm.URL,
+		ApiKey:      &staticKey,
+		Enabled:     ptr(true),
+		Models: &[]api.AgentNetworkProviderModel{
+			{Id: modelA, InputPer1k: 0.001, OutputPer1k: 0.001},
+			{Id: modelB, InputPer1k: 0.001, OutputPer1k: 0.001},
+		},
+		BootstrapCluster: ptr(harness.AgentNetworkCluster),
+	})
+	require.NoError(t, err, "create provider")
+	t.Cleanup(func() { _ = srv.DeleteProvider(context.Background(), prov.Id) })
+
+	mkGuard := func(name, model string) api.AgentNetworkGuardrail {
+		var gr api.AgentNetworkGuardrailRequest
+		gr.Name = name
+		gr.Checks.ModelAllowlist.Enabled = true
+		gr.Checks.ModelAllowlist.Models = []string{model}
+		g, gerr := srv.CreateGuardrail(ctx, gr)
+		require.NoError(t, gerr, "create guardrail %s", name)
+		t.Cleanup(func() { _ = srv.DeleteGuardrail(context.Background(), g.Id) })
+		return g
+	}
+	gA := mkGuard("e2e-gswitch-a", modelA)
+	gB := mkGuard("e2e-gswitch-b", modelB)
+
+	enabled := true
+	polA, err := srv.CreatePolicy(ctx, api.AgentNetworkPolicyRequest{
+		Name:                   "e2e-gswitch-a",
+		Enabled:                &enabled,
+		SourceGroups:           []string{grpA.Id},
+		DestinationProviderIds: []string{prov.Id},
+		GuardrailIds:           &[]string{gA.Id},
+	})
+	require.NoError(t, err, "create policy A")
+	t.Cleanup(func() { _ = srv.DeletePolicy(context.Background(), polA.Id) })
+
+	polB, err := srv.CreatePolicy(ctx, api.AgentNetworkPolicyRequest{
+		Name:                   "e2e-gswitch-b",
+		Enabled:                &enabled,
+		SourceGroups:           []string{grpB.Id},
+		DestinationProviderIds: []string{prov.Id},
+		GuardrailIds:           &[]string{gB.Id},
+	})
+	require.NoError(t, err, "create policy B")
+	t.Cleanup(func() { _ = srv.DeletePolicy(context.Background(), polB.Id) })
+
+	settings, err := srv.GetSettings(ctx)
+	require.NoError(t, err, "read settings")
+	require.NotEmpty(t, settings.Endpoint, "endpoint must be assigned")
+
+	proxyToken, err := srv.CreateProxyTokenCLI(ctx, "e2e-gswitch-proxy")
+	require.NoError(t, err, "mint proxy token")
+	px, err := harness.StartProxy(ctx, srv, proxyToken, map[string]string{
+		"NB_PROXY_TUNNEL_CACHE_TTL": cacheTTL.String(),
+	})
+	require.NoError(t, err, "start proxy")
+	t.Cleanup(func() { _ = px.Terminate(context.Background()) })
+
+	cl, err := harness.StartClient(ctx, srv, sk.Key)
+	require.NoError(t, err, "start client")
+	t.Cleanup(func() { _ = cl.Terminate(context.Background()) })
+
+	require.NoError(t, cl.WaitConnected(ctx, 90*time.Second), "client must connect to management")
+	proxyIP, err := cl.ResolveProxyIP(ctx, settings.Endpoint)
+	require.NoError(t, err, "resolve endpoint to proxy IP")
+	if err := cl.WaitProxyPeer(ctx, 180*time.Second); err != nil {
+		t.Fatalf("client did not see the proxy peer: %v\n=== proxy logs ===\n%s", err, px.Logs(context.Background()))
+	}
+
+	send := func(model string) (int, string) {
+		code, body, cerr := cl.Chat(ctx, settings.Endpoint, proxyIP, harness.WireChat, model, "Reply with exactly: pong", "")
+		require.NoError(t, cerr, "request must reach the proxy")
+		return code, body
+	}
+	sendUntil := func(model string, want int, timeout time.Duration) (int, string) {
+		var code int
+		var body string
+		deadline := time.Now().Add(timeout)
+		for time.Now().Before(deadline) {
+			code, body = send(model)
+			if code == want {
+				return code, body
+			}
+			time.Sleep(2 * time.Second)
+		}
+		return code, body
+	}
+
+	// Phase 1 — client is in group A: modelA served, modelB denied.
+	code, body := sendUntil(modelA, 200, 90*time.Second)
+	assert.Equal(t, 200, code,
+		"group-A model must be served while the client is in group A; body: %s\n=== proxy logs ===\n%s", body, px.Logs(context.Background()))
+	code, body = send(modelB)
+	assert.Equal(t, 403, code,
+		"group-B model must be denied while the client is in group A; body: %s", body)
+	assert.Contains(t, body, "llm_policy.model_blocked")
+
+	// Switch the client peer from group A to group B.
+	peerID := clientPeerInGroup(t, ctx, grpA.Id)
+	_, err = srv.API().Groups.Update(ctx, grpB.Id, api.PutApiGroupsGroupIdJSONRequestBody{
+		Name:  grpB.Name,
+		Peers: &[]string{peerID},
+	})
+	require.NoError(t, err, "add peer to group B")
+	_, err = srv.API().Groups.Update(ctx, grpA.Id, api.PutApiGroupsGroupIdJSONRequestBody{
+		Name:  grpA.Name,
+		Peers: &[]string{},
+	})
+	require.NoError(t, err, "remove peer from group A")
+
+	// Phase 2 — after the short TTL expires the proxy re-validates the peer,
+	// sees group B, and the decision flips. Poll to absorb TTL + re-validation.
+	code, body = sendUntil(modelB, 200, 60*time.Second)
+	assert.Equal(t, 200, code,
+		"after the group switch + TTL, the group-B model must be served; body: %s\n=== proxy logs ===\n%s", body, px.Logs(context.Background()))
+	code, body = send(modelA)
+	assert.Equal(t, 403, code,
+		"after the switch, the old group-A model must be denied; body: %s", body)
+	assert.Contains(t, body, "llm_policy.model_blocked")
+}
+
+// clientPeerInGroup returns the id of the single peer that is a member of the
+// given group — the test client. The proxy peer is never added to test groups.
+func clientPeerInGroup(t *testing.T, ctx context.Context, groupID string) string {
+	t.Helper()
+	peers, err := srv.API().Peers.List(ctx)
+	require.NoError(t, err, "list peers")
+	for _, p := range peers {
+		for _, g := range p.Groups {
+			if g.Id == groupID {
+				return p.Id
+			}
+		}
+	}
+	t.Fatalf("no peer found in group %s", groupID)
+	return ""
+}

e2e/harness/proxy.go

@@ -38,7 +38,11 @@ type Proxy struct {
 // network, registered via the given account proxy token and serving the
 // AgentNetworkCluster over a self-signed wildcard cert. It does not wait for
 // peer connectivity — callers poll management for the proxy peer.
-func StartProxy(ctx context.Context, c *Combined, proxyToken string) (*Proxy, error) {
+// StartProxy launches the reverse-proxy container. Optional envOverrides are
+// merged into the container environment after the defaults, so callers can set
+// or override any NB_PROXY_* var (e.g. NB_PROXY_TUNNEL_CACHE_TTL for tests that
+// need a short authorization-cache window).
+func StartProxy(ctx context.Context, c *Combined, proxyToken string, envOverrides ...map[string]string) (*Proxy, error) {
 	root, err := repoRoot()
 	if err != nil {
 		return nil, err
@@ -93,6 +97,12 @@ func StartProxy(ctx context.Context, c *Combined, proxyToken string) (*Proxy, er
 		WaitingFor: wait.ForLog("Initial mapping sync complete").WithStartupTimeout(90 * time.Second),
 	}
 
+	for _, ov := range envOverrides {
+		for k, v := range ov {
+			req.Env[k] = v
+		}
+	}
+
 	ctr, err := testcontainers.GenericContainer(ctx, testcontainers.GenericContainerRequest{
 		ContainerRequest: req,
 		Started:          true,