Allow to restrict servers that can join a given Serf Consul cluster. (#7628)

Based on work done in https://github.com/hashicorp/memberlist/pull/196
this allows to restrict the IP ranges that can join a given Serf cluster
and be a member of the cluster.

Restrictions on IPs can be done separatly using 2 new differents flags
and config options to restrict IPs for LAN and WAN Serf.
This commit is contained in:
Pierre Souchay 2020-05-20 11:31:19 +02:00 committed by GitHub
parent c985035aac
commit 3b548f0d77
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
9 changed files with 161 additions and 2 deletions

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@ -1177,6 +1177,8 @@ func (a *Agent) consulConfig() (*consul.Config, error) {
base.SerfLANConfig.MemberlistConfig.BindAddr = a.config.SerfBindAddrLAN.IP.String()
base.SerfLANConfig.MemberlistConfig.BindPort = a.config.SerfBindAddrLAN.Port
base.SerfLANConfig.MemberlistConfig.CIDRsAllowed = a.config.SerfAllowedCIDRsLAN
base.SerfWANConfig.MemberlistConfig.CIDRsAllowed = a.config.SerfAllowedCIDRsWAN
base.SerfLANConfig.MemberlistConfig.AdvertiseAddr = a.config.SerfAdvertiseAddrLAN.IP.String()
base.SerfLANConfig.MemberlistConfig.AdvertisePort = a.config.SerfAdvertiseAddrLAN.Port
base.SerfLANConfig.MemberlistConfig.GossipVerifyIncoming = a.config.EncryptVerifyIncoming

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@ -24,6 +24,7 @@ import (
"github.com/hashicorp/consul/types"
"github.com/hashicorp/go-multierror"
"github.com/hashicorp/go-sockaddr/template"
"github.com/hashicorp/memberlist"
"golang.org/x/time/rate"
)
@ -738,6 +739,15 @@ func (b *Builder) Build() (rt RuntimeConfig, err error) {
}
}
serfAllowedCIDRSLAN, err := memberlist.ParseCIDRs(c.SerfAllowedCIDRsLAN)
if err != nil {
return RuntimeConfig{}, fmt.Errorf("serf_lan_allowed_cidrs: %s", err)
}
serfAllowedCIDRSWAN, err := memberlist.ParseCIDRs(c.SerfAllowedCIDRsWAN)
if err != nil {
return RuntimeConfig{}, fmt.Errorf("serf_wan_allowed_cidrs: %s", err)
}
// ----------------------------------------------------------------
// build runtime config
//
@ -960,6 +970,8 @@ func (b *Builder) Build() (rt RuntimeConfig, err error) {
Segments: segments,
SerfAdvertiseAddrLAN: serfAdvertiseAddrLAN,
SerfAdvertiseAddrWAN: serfAdvertiseAddrWAN,
SerfAllowedCIDRsLAN: serfAllowedCIDRSLAN,
SerfAllowedCIDRsWAN: serfAllowedCIDRSWAN,
SerfBindAddrLAN: serfBindAddrLAN,
SerfBindAddrWAN: serfBindAddrWAN,
SerfPortLAN: serfPortLAN,

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@ -270,6 +270,8 @@ type Config struct {
RetryJoinMaxAttemptsLAN *int `json:"retry_max,omitempty" hcl:"retry_max" mapstructure:"retry_max"`
RetryJoinMaxAttemptsWAN *int `json:"retry_max_wan,omitempty" hcl:"retry_max_wan" mapstructure:"retry_max_wan"`
RetryJoinWAN []string `json:"retry_join_wan,omitempty" hcl:"retry_join_wan" mapstructure:"retry_join_wan"`
SerfAllowedCIDRsLAN []string `json:"serf_lan_allowed_cidrs,omitempty" hcl:"serf_lan_allowed_cidrs" mapstructure:"serf_lan_allowed_cidrs"`
SerfAllowedCIDRsWAN []string `json:"serf_wan_allowed_cidrs,omitempty" hcl:"serf_wan_allowed_cidrs" mapstructure:"serf_wan_allowed_cidrs"`
SerfBindAddrLAN *string `json:"serf_lan,omitempty" hcl:"serf_lan" mapstructure:"serf_lan"`
SerfBindAddrWAN *string `json:"serf_wan,omitempty" hcl:"serf_wan" mapstructure:"serf_wan"`
ServerMode *bool `json:"server,omitempty" hcl:"server" mapstructure:"server"`

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@ -105,6 +105,8 @@ func AddFlags(fs *flag.FlagSet, f *Flags) {
add(&f.Config.RetryJoinWAN, "retry-join-wan", "Address of an agent to join -wan at start time with retries enabled. Can be specified multiple times.")
add(&f.Config.RetryJoinMaxAttemptsLAN, "retry-max", "Maximum number of join attempts. Defaults to 0, which will retry indefinitely.")
add(&f.Config.RetryJoinMaxAttemptsWAN, "retry-max-wan", "Maximum number of join -wan attempts. Defaults to 0, which will retry indefinitely.")
add(&f.Config.SerfAllowedCIDRsLAN, "serf-lan-allowed-cidrs", "Networks (eg: 192.168.1.0/24) allowed for Serf LAN. Can be specified multiple times.")
add(&f.Config.SerfAllowedCIDRsWAN, "serf-wan-allowed-cidrs", "Networks (eg: 192.168.1.0/24) allowed for Serf WAN (other datacenters). Can be specified multiple times.")
add(&f.Config.SerfBindAddrLAN, "serf-lan-bind", "Address to bind Serf LAN listeners to.")
add(&f.Config.Ports.SerfLAN, "serf-lan-port", "Sets the Serf LAN port to listen on.")
add(&f.Config.SegmentName, "segment", "(Enterprise-only) Sets the network segment to join.")

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@ -1153,6 +1153,18 @@ type RuntimeConfig struct {
// hcl: bind_addr = string advertise_addr_wan = string ports { serf_wan = int }
SerfAdvertiseAddrWAN *net.TCPAddr
// SerfAllowedCIDRsLAN if set to a non-empty value, will restrict which networks
// are allowed to connect to Serf on the LAN.
// hcl: serf_lan_allowed_cidrs = []string
// flag: serf-lan-allowed-cidrs string (can be specified multiple times)
SerfAllowedCIDRsLAN []net.IPNet
// SerfAllowedCIDRsWAN if set to a non-empty value, will restrict which networks
// are allowed to connect to Serf on the WAN.
// hcl: serf_wan_allowed_cidrs = []string
// flag: serf-wan-allowed-cidrs string (can be specified multiple times)
SerfAllowedCIDRsWAN []net.IPNet
// SerfBindAddrLAN is the address to bind the Serf LAN TCP and UDP
// listeners to. The ip address is either the default bind address or the
// 'serf_lan' address which can be either an ip address or a go-sockaddr
@ -1794,6 +1806,14 @@ func sanitize(name string, v reflect.Value) reflect.Value {
case isArray(typ) || isSlice(typ):
ma := make([]interface{}, 0, v.Len())
if strings.HasPrefix(name, "SerfAllowedCIDRs") {
for i := 0; i < v.Len(); i++ {
addr := v.Index(i).Addr()
ip := addr.Interface().(*net.IPNet)
ma = append(ma, ip.String())
}
return reflect.ValueOf(ma)
}
for i := 0; i < v.Len(); i++ {
ma = append(ma, sanitize(fmt.Sprintf("%s[%d]", name, i), v.Index(i)).Interface())
}

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@ -1538,6 +1538,40 @@ func TestConfigFlagsAndEdgecases(t *testing.T) {
},
},
{
desc: "Serf Allowed CIDRS LAN, multiple values from flags",
args: []string{`-data-dir=` + dataDir, `-serf-lan-allowed-cidrs=127.0.0.0/4`, `-serf-lan-allowed-cidrs=192.168.0.0/24`},
json: []string{},
hcl: []string{},
patch: func(rt *RuntimeConfig) {
rt.DataDir = dataDir
rt.SerfAllowedCIDRsLAN = []net.IPNet{*(parseCIDR(t, "127.0.0.0/4")), *(parseCIDR(t, "192.168.0.0/24"))}
},
},
{
desc: "Serf Allowed CIDRS LAN/WAN, multiple values from HCL/JSON",
args: []string{`-data-dir=` + dataDir},
json: []string{`{"serf_lan_allowed_cidrs": ["127.0.0.0/4", "192.168.0.0/24"]}`,
`{"serf_wan_allowed_cidrs": ["10.228.85.46/25"]}`},
hcl: []string{`serf_lan_allowed_cidrs=["127.0.0.0/4", "192.168.0.0/24"]`,
`serf_wan_allowed_cidrs=["10.228.85.46/25"]`},
patch: func(rt *RuntimeConfig) {
rt.DataDir = dataDir
rt.SerfAllowedCIDRsLAN = []net.IPNet{*(parseCIDR(t, "127.0.0.0/4")), *(parseCIDR(t, "192.168.0.0/24"))}
rt.SerfAllowedCIDRsWAN = []net.IPNet{*(parseCIDR(t, "10.228.85.46/25"))}
},
},
{
desc: "Serf Allowed CIDRS WAN, multiple values from flags",
args: []string{`-data-dir=` + dataDir, `-serf-wan-allowed-cidrs=192.168.4.0/24`, `-serf-wan-allowed-cidrs=192.168.3.0/24`},
json: []string{},
hcl: []string{},
patch: func(rt *RuntimeConfig) {
rt.DataDir = dataDir
rt.SerfAllowedCIDRsWAN = []net.IPNet{*(parseCIDR(t, "192.168.4.0/24")), *(parseCIDR(t, "192.168.3.0/24"))}
},
},
// ------------------------------------------------------------
// validations
//
@ -6201,6 +6235,10 @@ func TestSanitize(t *testing.T) {
},
},
KVMaxValueSize: 1234567800000000,
SerfAllowedCIDRsLAN: []net.IPNet{
*parseCIDR(t, "192.168.1.0/24"),
*parseCIDR(t, "127.0.0.0/8"),
},
TxnMaxReqLen: 5678000000000000,
}
@ -6424,6 +6462,8 @@ func TestSanitize(t *testing.T) {
"Segments": [],
"SerfAdvertiseAddrLAN": "tcp://1.2.3.4:5678",
"SerfAdvertiseAddrWAN": "",
"SerfAllowedCIDRsLAN": ["192.168.1.0/24", "127.0.0.0/8"],
"SerfAllowedCIDRsWAN": [],
"SerfBindAddrLAN": "",
"SerfBindAddrWAN": "",
"SerfPortLAN": 0,

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@ -67,7 +67,7 @@ func testClientDC(t *testing.T, dc string) (string, *Client) {
})
}
func testClientWithConfig(t *testing.T, cb func(c *Config)) (string, *Client) {
func testClientWithConfigWithErr(t *testing.T, cb func(c *Config)) (string, *Client, error) {
dir, config := testClientConfig(t)
if cb != nil {
cb(config)
@ -91,6 +91,13 @@ func testClientWithConfig(t *testing.T, cb func(c *Config)) (string, *Client) {
client, err := NewClientLogger(config, logger, tlsConf)
if err != nil {
config.NotifyShutdown()
}
return dir, client, err
}
func testClientWithConfig(t *testing.T, cb func(c *Config)) (string, *Client) {
dir, client, err := testClientWithConfigWithErr(t, cb)
if err != nil {
t.Fatalf("err: %v", err)
}
return dir, client

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@ -13,6 +13,7 @@ import (
"github.com/google/tcpproxy"
"github.com/hashicorp/consul/agent/connect/ca"
"github.com/hashicorp/consul/ipaddr"
"github.com/hashicorp/memberlist"
"github.com/hashicorp/consul/agent/connect"
"github.com/hashicorp/consul/agent/metadata"
@ -28,6 +29,7 @@ import (
"github.com/hashicorp/go-uuid"
"golang.org/x/time/rate"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
@ -370,6 +372,68 @@ func TestServer_JoinLAN(t *testing.T) {
})
}
// TestServer_JoinLAN_SerfAllowedCIDRs test that IPs might be blocked
// with Serf.
// To run properly, this test requires to be able to bind and have access
// on 127.0.1.1 which is the case for most Linux machines and Windows,
// so Unit test will run in the CI.
// To run it on Mac OS, please run this commandd first, otherwise the
// test will be skipped: `sudo ifconfig lo0 alias 127.0.1.1 up`
func TestServer_JoinLAN_SerfAllowedCIDRs(t *testing.T) {
t.Parallel()
dir1, s1 := testServerWithConfig(t, func(c *Config) {
c.BootstrapExpect = 1
lan, err := memberlist.ParseCIDRs([]string{"127.0.0.1/32"})
assert.NoError(t, err)
c.SerfLANConfig.MemberlistConfig.CIDRsAllowed = lan
wan, err := memberlist.ParseCIDRs([]string{"127.0.0.0/24", "::1/128"})
assert.NoError(t, err)
c.SerfWANConfig.MemberlistConfig.CIDRsAllowed = wan
})
defer os.RemoveAll(dir1)
defer s1.Shutdown()
targetAddr := "127.0.1.1"
dir2, a2, err := testClientWithConfigWithErr(t, func(c *Config) {
c.SerfLANConfig.MemberlistConfig.BindAddr = targetAddr
})
defer os.RemoveAll(dir2)
if err != nil {
t.Skipf("Cannot bind on %s, to run on Mac OS: `sudo ifconfig lo0 alias 127.0.1.1 up`", targetAddr)
}
defer a2.Shutdown()
dir3, rs3 := testServerWithConfig(t, func(c *Config) {
c.BootstrapExpect = 1
c.Datacenter = "dc2"
})
defer os.RemoveAll(dir3)
defer rs3.Shutdown()
leaderAddr := joinAddrLAN(s1)
if _, err := a2.JoinLAN([]string{leaderAddr}); err != nil {
t.Fatalf("Expected no error, had: %#v", err)
}
// Try to join
joinWAN(t, rs3, s1)
retry.Run(t, func(r *retry.R) {
if got, want := len(s1.LANMembers()), 1; got != want {
// LAN is blocked, should be 1 only
r.Fatalf("got %d s1 LAN members want %d", got, want)
}
if got, want := len(a2.LANMembers()), 2; got != want {
// LAN is blocked a2 can see s1, but not s1
r.Fatalf("got %d a2 LAN members want %d", got, want)
}
if got, want := len(s1.WANMembers()), 2; got != want {
r.Fatalf("got %d s1 WAN members want %d", got, want)
}
if got, want := len(rs3.WANMembers()), 2; got != want {
r.Fatalf("got %d rs3 WAN members want %d", got, want)
}
})
}
func TestServer_LANReap(t *testing.T) {
t.Parallel()

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@ -445,10 +445,20 @@ The options below are all specified on the command-line.
more details. By default, this is an empty string, which is the default network
segment.
- `-serf-lan-allowed-cidrs` - The Serf LAN allowed CIDRs allow to accept incoming
connections for Serf only from several networks (mutiple values are supported).
Those networks are specified with CIDR notation (eg: 192.168.1.0/24).
This is available in Consul 1.8 and later.
- `-serf-lan-port` ((#\_serf_lan_port)) - the Serf LAN port to listen on.
This overrides the default Serf LAN port 8301. This is available in Consul 1.2.2
and later.
- `-serf-lan-allowed-cidrs` - he Serf LAN allowed CIDRs allow to accept incoming
connections for Serf only from several networks (mutiple values are supported).
Those networks are specified with CIDR notation (eg: 192.168.1.0/24).
This is available in Consul 1.8 and later.
- `-serf-wan-port` ((#\_serf_wan_port)) - the Serf WAN port to listen on.
This overrides the default Serf WAN port 8302. This is available in Consul 1.2.2
and later.