dotcloud/docker

package opts // import "github.com/docker/docker/opts"

import (
    "net"
    "net/url"
    "path/filepath"
    "strconv"
    "strings"

    "github.com/docker/docker/pkg/homedir"
    "github.com/pkg/errors"
)

const (
    // DefaultHTTPPort Default HTTP Port used if only the protocol is provided to -H flag e.g. dockerd -H tcp://
    // These are the IANA registered port numbers for use with Docker
    // see http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=docker
    DefaultHTTPPort = 2375 // Default HTTP Port
    // DefaultTLSHTTPPort Default HTTP Port used when TLS enabled
    DefaultTLSHTTPPort = 2376 // Default TLS encrypted HTTP Port
    // DefaultUnixSocket Path for the unix socket.
    // Docker daemon by default always listens on the default unix socket
    DefaultUnixSocket = "/var/run/docker.sock"
    // DefaultTCPHost constant defines the default host string used by docker on Windows
    DefaultTCPHost = "tcp://" + DefaultHTTPHost + ":2375"
    // DefaultTLSHost constant defines the default host string used by docker for TLS sockets
    DefaultTLSHost = "tcp://" + DefaultHTTPHost + ":2376"
    // DefaultNamedPipe defines the default named pipe used by docker on Windows
    DefaultNamedPipe = `//./pipe/docker_engine`
    // HostGatewayName is the string value that can be passed
    // to the IPAddr section in --add-host that is replaced by
    // the value of HostGatewayIP daemon config value
    HostGatewayName = "host-gateway"
)

// ValidateHost validates that the specified string is a valid host and returns it.
func ValidateHost(val string) (string, error) {
    host := strings.TrimSpace(val)
    // The empty string means default and is not handled by parseDaemonHost
    if host != "" {
        _, err := parseDaemonHost(host)
        if err != nil {
            return val, err
        }
    }
    // Note: unlike most flag validators, we don't return the mutated value here
    //       we need to know what the user entered later (using ParseHost) to adjust for TLS
    return val, nil
}

// ParseHost and set defaults for a Daemon host string.
// defaultToTLS is preferred over defaultToUnixXDG.
func ParseHost(defaultToTLS, defaultToUnixXDG bool, val string) (string, error) {
    host := strings.TrimSpace(val)
    if host == "" {
        if defaultToTLS {
            host = DefaultTLSHost
        } else if defaultToUnixXDG {
            runtimeDir, err := homedir.GetRuntimeDir()
            if err != nil {
                return "", err
            }
            host = "unix://" + filepath.Join(runtimeDir, "docker.sock")
        } else {
            host = DefaultHost
        }
    } else {
        var err error
        host, err = parseDaemonHost(host)
        if err != nil {
            return val, err
        }
    }
    return host, nil
}

// parseDaemonHost parses the specified address and returns an address that will be used as the host.
// Depending on the address specified, this may return one of the global Default* strings defined in hosts.go.
func parseDaemonHost(address string) (string, error) {
    proto, addr, ok := strings.Cut(address, "://")
    if !ok && proto != "" {
        addr = proto
        proto = "tcp"
    }

    switch proto {
    case "tcp":
        return ParseTCPAddr(address, DefaultTCPHost)
    case "unix":
        a, err := parseSimpleProtoAddr(proto, addr, DefaultUnixSocket)
        if err != nil {
            return "", errors.Wrapf(err, "invalid bind address (%s)", address)
        }
        return a, nil
    case "npipe":
        a, err := parseSimpleProtoAddr(proto, addr, DefaultNamedPipe)
        if err != nil {
            return "", errors.Wrapf(err, "invalid bind address (%s)", address)
        }
        return a, nil
    case "fd":
        return address, nil
    default:
        return "", errors.Errorf("invalid bind address (%s): unsupported proto '%s'", address, proto)
    }
}

// parseSimpleProtoAddr parses and validates that the specified address is a valid
// socket address for simple protocols like unix and npipe. It returns a formatted
// socket address, either using the address parsed from addr, or the contents of
// defaultAddr if addr is a blank string.
func parseSimpleProtoAddr(proto, addr, defaultAddr string) (string, error) {
    if strings.Contains(addr, "://") {
        return "", errors.Errorf("invalid %s address: %s", proto, addr)
    }
    if addr == "" {
        addr = defaultAddr
    }
    return proto + "://" + addr, nil
}

// ParseTCPAddr parses and validates that the specified address is a valid TCP
// address. It returns a formatted TCP address, either using the address parsed
// from tryAddr, or the contents of defaultAddr if tryAddr is a blank string.
// tryAddr is expected to have already been Trim()'d
// defaultAddr must be in the full `tcp://host:port` form
func ParseTCPAddr(tryAddr string, defaultAddr string) (string, error) {
    def, err := parseTCPAddr(defaultAddr, true)
    if err != nil {
        return "", errors.Wrapf(err, "invalid default address (%s)", defaultAddr)
    }

    addr, err := parseTCPAddr(tryAddr, false)
    if err != nil {
        return "", errors.Wrapf(err, "invalid bind address (%s)", tryAddr)
    }

    host := addr.Hostname()
    if host == "" {
        host = def.Hostname()
    }
    port := addr.Port()
    if port == "" {
        port = def.Port()
    }

    return "tcp://" + net.JoinHostPort(host, port), nil
}

// parseTCPAddr parses the given addr and validates if it is in the expected
// format. If strict is enabled, the address must contain a scheme (tcp://),
// a host (or IP-address) and a port number.
func parseTCPAddr(address string, strict bool) (*url.URL, error) {
    if !strict && !strings.Contains(address, "://") {
        address = "tcp://" + address
    }
    parsedURL, err := url.Parse(address)
    if err != nil {
        return nil, err
    }
    if parsedURL.Scheme != "tcp" {
        return nil, errors.Errorf("unsupported proto '%s'", parsedURL.Scheme)
    }
    if parsedURL.Path != "" {
        return nil, errors.New("should not contain a path element")
    }
    if strict && parsedURL.Host == "" {
        return nil, errors.New("no host or IP address")
    }
    if parsedURL.Port() != "" || strict {
        if p, err := strconv.Atoi(parsedURL.Port()); err != nil || p == 0 {
            return nil, errors.Errorf("invalid port: %s", parsedURL.Port())
        }
    }
    return parsedURL, nil
}

// ValidateExtraHost validates that the specified string is a valid extrahost and returns it.
// ExtraHost is in the form of name:ip where the ip has to be a valid ip (IPv4 or IPv6).
func ValidateExtraHost(val string) (string, error) {
    // allow for IPv6 addresses in extra hosts by only splitting on first ":"
    name, ip, ok := strings.Cut(val, ":")
    if !ok || name == "" {
        return "", errors.Errorf("bad format for add-host: %q", val)
    }
    // Skip IPaddr validation for special "host-gateway" string
    if ip != HostGatewayName {
        if _, err := ValidateIPAddress(ip); err != nil {
            return "", errors.Errorf("invalid IP address in add-host: %q", ip)
        }
    }
    return val, nil
}