aboutsummaryrefslogtreecommitdiff
path: root/libpod/network/create.go
blob: c11904ecfee2e088748a72275e84b737fea9e565 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
package network

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"

	"github.com/containernetworking/cni/pkg/version"
	"github.com/containers/podman/v2/libpod"
	"github.com/containers/podman/v2/pkg/domain/entities"
	"github.com/containers/podman/v2/pkg/rootless"
	"github.com/containers/podman/v2/pkg/util"
	"github.com/pkg/errors"
)

// Create the CNI network
func Create(name string, options entities.NetworkCreateOptions, r *libpod.Runtime) (*entities.NetworkCreateReport, error) {
	var fileName string
	if err := isSupportedDriver(options.Driver); err != nil {
		return nil, err
	}
	config, err := r.GetConfig()
	if err != nil {
		return nil, err
	}
	// Acquire a lock for CNI
	l, err := acquireCNILock(filepath.Join(config.Engine.TmpDir, LockFileName))
	if err != nil {
		return nil, err
	}
	defer l.releaseCNILock()
	if len(options.MacVLAN) > 0 {
		fileName, err = createMacVLAN(r, name, options)
	} else {
		fileName, err = createBridge(r, name, options)
	}
	if err != nil {
		return nil, err
	}
	return &entities.NetworkCreateReport{Filename: fileName}, nil
}

// validateBridgeOptions validate the bridge networking options
func validateBridgeOptions(options entities.NetworkCreateOptions) error {
	subnet := &options.Subnet
	ipRange := &options.Range
	gateway := options.Gateway
	// if IPv6 is set an IPv6 subnet MUST be specified
	if options.IPv6 && ((subnet.IP == nil) || (subnet.IP != nil && !IsIPv6(subnet.IP))) {
		return errors.Errorf("ipv6 option requires an IPv6 --subnet to be provided")
	}
	// range and gateway depend on subnet
	if subnet.IP == nil && (ipRange.IP != nil || gateway != nil) {
		return errors.Errorf("every ip-range or gateway must have a corresponding subnet")
	}

	// if a range is given, we need to ensure it is "in" the network range.
	if ipRange.IP != nil {
		firstIP, err := FirstIPInSubnet(ipRange)
		if err != nil {
			return errors.Wrapf(err, "failed to get first IP address from ip-range")
		}
		lastIP, err := LastIPInSubnet(ipRange)
		if err != nil {
			return errors.Wrapf(err, "failed to get last IP address from ip-range")
		}
		if !subnet.Contains(firstIP) || !subnet.Contains(lastIP) {
			return errors.Errorf("the ip range %s does not fall within the subnet range %s", ipRange.String(), subnet.String())
		}
	}

	// if network is provided and if gateway is provided, make sure it is "in" network
	if gateway != nil && !subnet.Contains(gateway) {
		return errors.Errorf("gateway %s is not in valid for subnet %s", gateway.String(), subnet.String())
	}

	return nil

}

// createBridge creates a CNI network
func createBridge(r *libpod.Runtime, name string, options entities.NetworkCreateOptions) (string, error) {
	isGateway := true
	ipMasq := true
	runtimeConfig, err := r.GetConfig()
	if err != nil {
		return "", err
	}

	// validate options
	err = validateBridgeOptions(options)
	if err != nil {
		return "", err
	}

	// For compatibility with the docker implementation:
	// if IPv6 is enabled (it really means dual-stack) then an IPv6 subnet has to be provided, and one free network is allocated for IPv4
	// if IPv6 is not specified the subnet may be specified and can be either IPv4 or IPv6 (podman, unlike docker, allows IPv6 only networks)
	// If not subnet is specified an IPv4 subnet will be allocated
	subnet := &options.Subnet
	ipRange := &options.Range
	gateway := options.Gateway
	var ipamRanges [][]IPAMLocalHostRangeConf
	var routes []IPAMRoute
	if subnet.IP != nil {
		// if network is provided, does it conflict with existing CNI or live networks
		err = ValidateUserNetworkIsAvailable(runtimeConfig, subnet)
		if err != nil {
			return "", err
		}
		// obtain CNI subnet default route
		defaultRoute, err := NewIPAMDefaultRoute(IsIPv6(subnet.IP))
		if err != nil {
			return "", err
		}
		routes = append(routes, defaultRoute)
		// obtain CNI range
		ipamRange, err := NewIPAMLocalHostRange(subnet, ipRange, gateway)
		if err != nil {
			return "", err
		}
		ipamRanges = append(ipamRanges, ipamRange)
	}
	// if no network is provided or IPv6 flag used, figure out the IPv4 network
	if options.IPv6 || len(routes) == 0 {
		subnetV4, err := GetFreeNetwork(runtimeConfig)
		if err != nil {
			return "", err
		}
		// obtain IPv4 default route
		defaultRoute, err := NewIPAMDefaultRoute(false)
		if err != nil {
			return "", err
		}
		routes = append(routes, defaultRoute)
		// the CNI bridge plugin does not need to set
		// the range or gateway options explicitly
		ipamRange, err := NewIPAMLocalHostRange(subnetV4, nil, nil)
		if err != nil {
			return "", err
		}
		ipamRanges = append(ipamRanges, ipamRange)
	}

	// create CNI config
	ipamConfig, err := NewIPAMHostLocalConf(routes, ipamRanges)
	if err != nil {
		return "", err
	}

	if options.Internal {
		isGateway = false
		ipMasq = false
	}

	// obtain host bridge name
	bridgeDeviceName, err := GetFreeDeviceName(runtimeConfig)
	if err != nil {
		return "", err
	}

	if len(name) > 0 {
		netNames, err := GetNetworkNamesFromFileSystem(runtimeConfig)
		if err != nil {
			return "", err
		}
		if util.StringInSlice(name, netNames) {
			return "", errors.Errorf("the network name %s is already used", name)
		}
	} else {
		// If no name is given, we give the name of the bridge device
		name = bridgeDeviceName
	}

	// create CNI plugin configuration
	ncList := NewNcList(name, version.Current())
	var plugins []CNIPlugins
	// TODO need to iron out the role of isDefaultGW and IPMasq
	bridge := NewHostLocalBridge(bridgeDeviceName, isGateway, false, ipMasq, ipamConfig)
	plugins = append(plugins, bridge)
	plugins = append(plugins, NewPortMapPlugin())
	plugins = append(plugins, NewFirewallPlugin())
	// if we find the dnsname plugin or are rootless, we add configuration for it
	// the rootless-cni-infra container has the dnsname plugin always installed
	if (HasDNSNamePlugin(runtimeConfig.Network.CNIPluginDirs) || rootless.IsRootless()) && !options.DisableDNS {
		// Note: in the future we might like to allow for dynamic domain names
		plugins = append(plugins, NewDNSNamePlugin(DefaultPodmanDomainName))
	}
	ncList["plugins"] = plugins
	b, err := json.MarshalIndent(ncList, "", "   ")
	if err != nil {
		return "", err
	}
	if err := os.MkdirAll(GetCNIConfDir(runtimeConfig), 0755); err != nil {
		return "", err
	}
	cniPathName := filepath.Join(GetCNIConfDir(runtimeConfig), fmt.Sprintf("%s.conflist", name))
	err = ioutil.WriteFile(cniPathName, b, 0644)
	return cniPathName, err
}

func createMacVLAN(r *libpod.Runtime, name string, options entities.NetworkCreateOptions) (string, error) {
	var (
		plugins []CNIPlugins
	)
	liveNetNames, err := GetLiveNetworkNames()
	if err != nil {
		return "", err
	}

	config, err := r.GetConfig()
	if err != nil {
		return "", err
	}

	// Make sure the host-device exists
	if !util.StringInSlice(options.MacVLAN, liveNetNames) {
		return "", errors.Errorf("failed to find network interface %q", options.MacVLAN)
	}
	if len(name) > 0 {
		netNames, err := GetNetworkNamesFromFileSystem(config)
		if err != nil {
			return "", err
		}
		if util.StringInSlice(name, netNames) {
			return "", errors.Errorf("the network name %s is already used", name)
		}
	} else {
		name, err = GetFreeDeviceName(config)
		if err != nil {
			return "", err
		}
	}
	ncList := NewNcList(name, version.Current())
	macvlan := NewMacVLANPlugin(options.MacVLAN)
	plugins = append(plugins, macvlan)
	ncList["plugins"] = plugins
	b, err := json.MarshalIndent(ncList, "", "   ")
	if err != nil {
		return "", err
	}
	cniPathName := filepath.Join(GetCNIConfDir(config), fmt.Sprintf("%s.conflist", name))
	err = ioutil.WriteFile(cniPathName, b, 0644)
	return cniPathName, err
}