Merge pull request #26457 from aboch/auto

Add fallback to resolveSystemAddr() in linux
This commit is contained in:
Brian Goff 2016-09-09 20:46:29 -04:00 committed by GitHub
commit ebae43efc2
3 changed files with 111 additions and 93 deletions

View File

@ -149,6 +149,101 @@ func resolveInterfaceAddr(specifiedInterface string) (net.IP, error) {
return interfaceAddr6, nil
}
func (c *Cluster) resolveSystemAddrViaSubnetCheck() (net.IP, error) {
// Use the system's only IP address, or fail if there are
// multiple addresses to choose from. Skip interfaces which
// are managed by docker via subnet check.
interfaces, err := net.Interfaces()
if err != nil {
return nil, err
}
var systemAddr net.IP
var systemInterface string
// List Docker-managed subnets
v4Subnets := c.config.NetworkSubnetsProvider.V4Subnets()
v6Subnets := c.config.NetworkSubnetsProvider.V6Subnets()
ifaceLoop:
for _, intf := range interfaces {
// Skip inactive interfaces and loopback interfaces
if (intf.Flags&net.FlagUp == 0) || (intf.Flags&net.FlagLoopback) != 0 {
continue
}
addrs, err := intf.Addrs()
if err != nil {
continue
}
var interfaceAddr4, interfaceAddr6 net.IP
for _, addr := range addrs {
ipAddr, ok := addr.(*net.IPNet)
// Skip loopback and link-local addresses
if !ok || !ipAddr.IP.IsGlobalUnicast() {
continue
}
if ipAddr.IP.To4() != nil {
// IPv4
// Ignore addresses in subnets that are managed by Docker.
for _, subnet := range v4Subnets {
if subnet.Contains(ipAddr.IP) {
continue ifaceLoop
}
}
if interfaceAddr4 != nil {
return nil, errMultipleIPs(intf.Name, intf.Name, interfaceAddr4, ipAddr.IP)
}
interfaceAddr4 = ipAddr.IP
} else {
// IPv6
// Ignore addresses in subnets that are managed by Docker.
for _, subnet := range v6Subnets {
if subnet.Contains(ipAddr.IP) {
continue ifaceLoop
}
}
if interfaceAddr6 != nil {
return nil, errMultipleIPs(intf.Name, intf.Name, interfaceAddr6, ipAddr.IP)
}
interfaceAddr6 = ipAddr.IP
}
}
// In the case that this interface has exactly one IPv4 address
// and exactly one IPv6 address, favor IPv4 over IPv6.
if interfaceAddr4 != nil {
if systemAddr != nil {
return nil, errMultipleIPs(systemInterface, intf.Name, systemAddr, interfaceAddr4)
}
systemAddr = interfaceAddr4
systemInterface = intf.Name
} else if interfaceAddr6 != nil {
if systemAddr != nil {
return nil, errMultipleIPs(systemInterface, intf.Name, systemAddr, interfaceAddr6)
}
systemAddr = interfaceAddr6
systemInterface = intf.Name
}
}
if systemAddr == nil {
return nil, errNoIP
}
return systemAddr, nil
}
func listSystemIPs() []net.IP {
interfaces, err := net.Interfaces()
if err != nil {

View File

@ -16,8 +16,11 @@ func (c *Cluster) resolveSystemAddr() (net.IP, error) {
return nil, err
}
var systemAddr net.IP
var systemInterface string
var (
systemAddr net.IP
systemInterface string
deviceFound bool
)
for _, intf := range interfaces {
// Skip non device or inactive interfaces
@ -40,6 +43,9 @@ func (c *Cluster) resolveSystemAddr() (net.IP, error) {
continue
}
// At least one non-loopback device is found and it is administratively up
deviceFound = true
if ipAddr.To4() != nil {
if interfaceAddr4 != nil {
return nil, errMultipleIPs(intf.Attrs().Name, intf.Attrs().Name, interfaceAddr4, ipAddr)
@ -71,6 +77,13 @@ func (c *Cluster) resolveSystemAddr() (net.IP, error) {
}
if systemAddr == nil {
if !deviceFound {
// If no non-loopback device type interface is found,
// fall back to the regular auto-detection mechanism.
// This is to cover the case where docker is running
// inside a container (eths are in fact veths).
return c.resolveSystemAddrViaSubnetCheck()
}
return nil, errNoIP
}

View File

@ -5,95 +5,5 @@ package cluster
import "net"
func (c *Cluster) resolveSystemAddr() (net.IP, error) {
// Use the system's only IP address, or fail if there are
// multiple addresses to choose from.
interfaces, err := net.Interfaces()
if err != nil {
return nil, err
}
var systemAddr net.IP
var systemInterface string
// List Docker-managed subnets
v4Subnets := c.config.NetworkSubnetsProvider.V4Subnets()
v6Subnets := c.config.NetworkSubnetsProvider.V6Subnets()
ifaceLoop:
for _, intf := range interfaces {
// Skip inactive interfaces and loopback interfaces
if (intf.Flags&net.FlagUp == 0) || (intf.Flags&net.FlagLoopback) != 0 {
continue
}
addrs, err := intf.Addrs()
if err != nil {
continue
}
var interfaceAddr4, interfaceAddr6 net.IP
for _, addr := range addrs {
ipAddr, ok := addr.(*net.IPNet)
// Skip loopback and link-local addresses
if !ok || !ipAddr.IP.IsGlobalUnicast() {
continue
}
if ipAddr.IP.To4() != nil {
// IPv4
// Ignore addresses in subnets that are managed by Docker.
for _, subnet := range v4Subnets {
if subnet.Contains(ipAddr.IP) {
continue ifaceLoop
}
}
if interfaceAddr4 != nil {
return nil, errMultipleIPs(intf.Name, intf.Name, interfaceAddr4, ipAddr.IP)
}
interfaceAddr4 = ipAddr.IP
} else {
// IPv6
// Ignore addresses in subnets that are managed by Docker.
for _, subnet := range v6Subnets {
if subnet.Contains(ipAddr.IP) {
continue ifaceLoop
}
}
if interfaceAddr6 != nil {
return nil, errMultipleIPs(intf.Name, intf.Name, interfaceAddr6, ipAddr.IP)
}
interfaceAddr6 = ipAddr.IP
}
}
// In the case that this interface has exactly one IPv4 address
// and exactly one IPv6 address, favor IPv4 over IPv6.
if interfaceAddr4 != nil {
if systemAddr != nil {
return nil, errMultipleIPs(systemInterface, intf.Name, systemAddr, interfaceAddr4)
}
systemAddr = interfaceAddr4
systemInterface = intf.Name
} else if interfaceAddr6 != nil {
if systemAddr != nil {
return nil, errMultipleIPs(systemInterface, intf.Name, systemAddr, interfaceAddr6)
}
systemAddr = interfaceAddr6
systemInterface = intf.Name
}
}
if systemAddr == nil {
return nil, errNoIP
}
return systemAddr, nil
return c.resolveSystemAddrViaSubnetCheck()
}