Merge commit from fork

Instead of casting lease ID to uint32, fix the TTL() function
to use etcd time-to-live API for determining TTL. Add configurable
min-lease-ttl and max-lease-ttl options to prevent extreme TTL
values. By default, lease records now go through bounds checking
with 30s to 1d as the min/max.

Added unit tests for validation and docs.

Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>

plugin/etcd/setup_test.go

@@ -66,6 +66,31 @@ func TestSetupEtcd(t *testing.T) {
 		}
 			`, true, "skydns", []string{"http://localhost:2379"}, "Wrong argument count", "", "",
 		},
+		// with custom min-lease-ttl
+		{
+			`etcd {
+			endpoint http://localhost:2379
+			min-lease-ttl 60
+		}
+			`, false, "skydns", []string{"http://localhost:2379"}, "", "", "",
+		},
+		// with custom max-lease-ttl
+		{
+			`etcd {
+			endpoint http://localhost:2379
+			max-lease-ttl 1h
+		}
+			`, false, "skydns", []string{"http://localhost:2379"}, "", "", "",
+		},
+		// with both custom min-lease-ttl and max-lease-ttl
+		{
+			`etcd {
+			endpoint http://localhost:2379
+			min-lease-ttl 120
+			max-lease-ttl 7200
+		}
+			`, false, "skydns", []string{"http://localhost:2379"}, "", "", "",
+		},
 	}
 
 	for i, test := range tests {
@@ -113,6 +138,84 @@ func TestSetupEtcd(t *testing.T) {
 					t.Errorf("Etcd password not correctly set for input %s. Expected: '%+v', actual: '%+v'", test.input, test.password, etcd.Client.Password)
 				}
 			}
+
+			// Check TTL configuration for specific test cases
+			if strings.Contains(test.input, "min-lease-ttl 60") {
+				if etcd.MinLeaseTTL != 60 {
+					t.Errorf("MinLeaseTTL not set correctly for input %s. Expected: 60, actual: %d", test.input, etcd.MinLeaseTTL)
+				}
+			}
+			if strings.Contains(test.input, "max-lease-ttl 1h") {
+				if etcd.MaxLeaseTTL != 3600 {
+					t.Errorf("MaxLeaseTTL not set correctly for input %s. Expected: 3600, actual: %d", test.input, etcd.MaxLeaseTTL)
+				}
+			}
+			if strings.Contains(test.input, "min-lease-ttl 120") && strings.Contains(test.input, "max-lease-ttl 7200") {
+				if etcd.MinLeaseTTL != 120 {
+					t.Errorf("MinLeaseTTL not set correctly for input %s. Expected: 120, actual: %d", test.input, etcd.MinLeaseTTL)
+				}
+				if etcd.MaxLeaseTTL != 7200 {
+					t.Errorf("MaxLeaseTTL not set correctly for input %s. Expected: 7200, actual: %d", test.input, etcd.MaxLeaseTTL)
+				}
+			}
 		}
 	}
 }
+
+func TestParseTTL(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected uint32
+		hasError bool
+		desc     string
+	}{
+		// Plain numbers (assumed to be seconds)
+		{"30", 30, false, "plain number should be treated as seconds"},
+		{"300", 300, false, "plain number should be treated as seconds"},
+
+		// Explicit seconds
+		{"30s", 30, false, "explicit seconds"},
+		{"90s", 90, false, "explicit seconds"},
+
+		// Minutes
+		{"5m", 300, false, "5 minutes"},
+		{"1m", 60, false, "1 minute"},
+
+		// Hours
+		{"1h", 3600, false, "1 hour"},
+		{"2h", 7200, false, "2 hours"},
+
+		// Complex durations (Go's ParseDuration supports this)
+		{"2h30m", 9000, false, "2 hours 30 minutes"},
+		{"1h30m45s", 5445, false, "1 hour 30 minutes 45 seconds"},
+
+		// Edge cases
+		{"0", 0, false, "zero should be allowed"},
+		{"0s", 0, false, "zero seconds should be allowed"},
+		{"", 0, false, "empty string should return 0"},
+
+		// Error cases
+		{"-30s", 0, true, "negative duration should error"},
+		{"abc", 0, true, "invalid format should error"},
+		{"1y", 0, true, "unsupported unit should error"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.desc, func(t *testing.T) {
+			result, err := parseTTL(tt.input)
+
+			if tt.hasError {
+				if err == nil {
+					t.Errorf("parseTTL(%q) expected error but got none", tt.input)
+				}
+			} else {
+				if err != nil {
+					t.Errorf("parseTTL(%q) unexpected error: %v", tt.input, err)
+				}
+				if result != tt.expected {
+					t.Errorf("parseTTL(%q) = %d, expected %d", tt.input, result, tt.expected)
+				}
+			}
+		})
+	}
+}