pkg/parsers/parsers.go

// Package parsers provides helper functions to parse and validate different type
// of string. It can be hosts, unix addresses, tcp addresses, filters, kernel
// operating system versions.
package parsers

import (
	"fmt"
	"path"
	"strconv"
	"strings"
)

// PartParser parses and validates the specified string (data) using the specified template
// e.g. ip:public:private -> 192.168.0.1:80:8000
func PartParser(template, data string) (map[string]string, error) {
	// ip:public:private
	var (
		templateParts = strings.Split(template, ":")
		parts         = strings.Split(data, ":")
		out           = make(map[string]string, len(templateParts))
	)
	if len(parts) != len(templateParts) {
		return nil, fmt.Errorf("Invalid format to parse. %s should match template %s", data, template)
	}

	for i, t := range templateParts {
		value := ""
		if len(parts) > i {
			value = parts[i]
		}
		out[t] = value
	}
	return out, nil
}

// ParseKeyValueOpt parses and validates the specified string as a key/value pair (key=value)
func ParseKeyValueOpt(opt string) (string, string, error) {
	parts := strings.SplitN(opt, "=", 2)
	if len(parts) != 2 {
		return "", "", fmt.Errorf("Unable to parse key/value option: %s", opt)
	}
	return strings.TrimSpace(parts[0]), strings.TrimSpace(parts[1]), nil
}

// ParsePortRange parses and validates the specified string as a port-range (8000-9000)
func ParsePortRange(ports string) (uint64, uint64, error) {
	if ports == "" {
		return 0, 0, fmt.Errorf("Empty string specified for ports.")
	}
	if !strings.Contains(ports, "-") {
		start, err := strconv.ParseUint(ports, 10, 16)
		end := start
		return start, end, err
	}

	parts := strings.Split(ports, "-")
	start, err := strconv.ParseUint(parts[0], 10, 16)
	if err != nil {
		return 0, 0, err
	}
	end, err := strconv.ParseUint(parts[1], 10, 16)
	if err != nil {
		return 0, 0, err
	}
	if end < start {
		return 0, 0, fmt.Errorf("Invalid range specified for the Port: %s", ports)
	}
	return start, end, nil
}

// ParseLink parses and validates the specified string as a link format (name:alias)
func ParseLink(val string) (string, string, error) {
	if val == "" {
		return "", "", fmt.Errorf("empty string specified for links")
	}
	arr := strings.Split(val, ":")
	if len(arr) > 2 {
		return "", "", fmt.Errorf("bad format for links: %s", val)
	}
	if len(arr) == 1 {
		return val, val, nil
	}
	// This is kept because we can actually get an HostConfig with links
	// from an already created container and the format is not `foo:bar`
	// but `/foo:/c1/bar`
	if strings.HasPrefix(arr[0], "/") {
		_, alias := path.Split(arr[1])
		return arr[0][1:], alias, nil
	}
	return arr[0], arr[1], nil
}

// ParseUintList parses and validates the specified string as the value
// found in some cgroup file (e.g. `cpuset.cpus`, `cpuset.mems`), which could be
// one of the formats below. Note that duplicates are actually allowed in the
// input string. It returns a `map[int]bool` with available elements from `val`
// set to `true`.
// Supported formats:
//     7
//     1-6
//     0,3-4,7,8-10
//     0-0,0,1-7
//     03,1-3      <- this is gonna get parsed as [1,2,3]
//     3,2,1
//     0-2,3,1
func ParseUintList(val string) (map[int]bool, error) {
	if val == "" {
		return map[int]bool{}, nil
	}

	availableInts := make(map[int]bool)
	split := strings.Split(val, ",")
	errInvalidFormat := fmt.Errorf("invalid format: %s", val)

	for _, r := range split {
		if !strings.Contains(r, "-") {
			v, err := strconv.Atoi(r)
			if err != nil {
				return nil, errInvalidFormat
			}
			availableInts[v] = true
		} else {
			split := strings.SplitN(r, "-", 2)
			min, err := strconv.Atoi(split[0])
			if err != nil {
				return nil, errInvalidFormat
			}
			max, err := strconv.Atoi(split[1])
			if err != nil {
				return nil, errInvalidFormat
			}
			if max < min {
				return nil, errInvalidFormat
			}
			for i := min; i <= max; i++ {
				availableInts[i] = true
			}
		}
	}
	return availableInts, nil
}