[v9] Regenerate host UUID of node if host_uuid is empty (#12222)

This change allows nodes to regenerate their UUID if the host_uuid file exists but is empty.

api/utils/slices_test.go

@@ -0,0 +1,57 @@
+/*
+Copyright 2022 Gravitational, Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package utils
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSliceContainsStr(t *testing.T) {
+	tests := []struct {
+		name         string
+		slice        []string
+		target       string
+		wantContains bool
+	}{
+		{name: "does contain", slice: []string{"two", "one"}, target: "one", wantContains: true},
+		{name: "does not contain", slice: []string{"two", "one"}, target: "five", wantContains: false},
+		{name: "empty slice", slice: nil, target: "one", wantContains: false},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			require.Equal(t, tc.wantContains, SliceContainsStr(tc.slice, tc.target))
+		})
+	}
+}
+
+func TestDeduplicate(t *testing.T) {
+	tests := []struct {
+		name         string
+		in, expected []string
+	}{
+		{name: "empty slice", in: []string{}, expected: []string{}},
+		{name: "slice with unique elements", in: []string{"a", "b"}, expected: []string{"a", "b"}},
+		{name: "slice with duplicate elements", in: []string{"a", "b", "b", "a", "c"}, expected: []string{"a", "b", "c"}},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			require.Equal(t, tc.expected, Deduplicate(tc.in))
+		})
+	}
+}

lib/service/service.go

@@ -677,7 +677,18 @@ func NewTeleport(cfg *Config) (*TeleportProcess, error) {
 		} else {
 			switch cfg.JoinMethod {
 			case types.JoinMethodToken, types.JoinMethodUnspecified, types.JoinMethodIAM:
-				cfg.HostUUID = uuid.New().String()
+				// Checking error instead of the usual uuid.New() in case uuid generation
+				// fails due to not enough randomness. It's been known to happen happen when
+				// Teleport starts very early in the node initialization cycle and /dev/urandom
+				// isn't ready yet.
+				rawID, err := uuid.NewRandom()
+				if err != nil {
+					return nil, trace.BadParameter("" +
+						"Teleport failed to generate host UUID. " +
+						"This may happen if randomness source is not fully initialized when the node is starting up. " +
+						"Please try restarting Teleport again.")
+				}
+				cfg.HostUUID = rawID.String()
 			case types.JoinMethodEC2:
 				cfg.HostUUID, err = utils.GetEC2NodeID()
 				if err != nil {

lib/utils/proxyjump_test.go

@@ -17,14 +17,16 @@ limitations under the License.
 package utils
 
 import (
-	"gopkg.in/check.v1"
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
-func (s *UtilsSuite) TestProxyJumpParsing(c *check.C) {
+func TestProxyJumpParsing(t *testing.T) {
 	type tc struct {
 		in  string
 		out []JumpHost
-		err error
 	}
 	testCases := []tc{
 		{
@@ -56,14 +58,11 @@ func (s *UtilsSuite) TestProxyJumpParsing(c *check.C) {
 			out: []JumpHost{{Username: "[email protected]", Addr: NetAddr{Addr: "[::1]:7777", AddrNetwork: "tcp"}}, {Username: "bob@localhost", Addr: NetAddr{Addr: "localhost", AddrNetwork: "tcp"}}},
 		},
 	}
-	for i, tc := range testCases {
-		comment := check.Commentf("Test case %v: %q", i, tc.in)
-		re, err := ParseProxyJump(tc.in)
-		if tc.err == nil {
-			c.Assert(err, check.IsNil, comment)
-			c.Assert(re, check.DeepEquals, tc.out)
-		} else {
-			c.Assert(err, check.FitsTypeOf, tc.err)
-		}
+	for _, tc := range testCases {
+		t.Run(fmt.Sprintf("%q", tc.in), func(t *testing.T) {
+			re, err := ParseProxyJump(tc.in)
+			require.NoError(t, err)
+			require.Equal(t, tc.out, re)
+		})
 	}
 }

lib/utils/utils.go

@@ -447,9 +447,13 @@ func ReadHostUUID(dataDir string) (string, error) {
 			//do not convert to system error as this loses the ability to compare that it is a permission error
 			return "", err
 		}
-		return "", trace.Wrap(err)
+		return "", trace.ConvertSystemError(err)
+	}
+	id := strings.TrimSpace(string(out))
+	if id == "" {
+		return "", trace.NotFound("host uuid is empty")
 	}
-	return strings.TrimSpace(string(out)), nil
+	return id, nil
 }
 
 // WriteHostUUID writes host UUID into a file
@@ -475,7 +479,18 @@ func ReadOrMakeHostUUID(dataDir string) (string, error) {
 	if !trace.IsNotFound(err) {
 		return "", trace.Wrap(err)
 	}
-	id = uuid.New().String()
+	// Checking error instead of the usual uuid.New() in case uuid generation
+	// fails due to not enough randomness. It's been known to happen happen when
+	// Teleport starts very early in the node initialization cycle and /dev/urandom
+	// isn't ready yet.
+	rawID, err := uuid.NewRandom()
+	if err != nil {
+		return "", trace.BadParameter("" +
+			"Teleport failed to generate host UUID. " +
+			"This may happen if randomness source is not fully initialized when the node is starting up. " +
+			"Please try restarting Teleport again.")
+	}
+	id = rawID.String()
 	if err = WriteHostUUID(dataDir, id); err != nil {
 		return "", trace.Wrap(err)
 	}