github.com/flavio/docker@v0.1.3-0.20170117145210-f63d1a6eec47/pkg/aaparser/aaparser.go (about)

     1  // Package aaparser is a convenience package interacting with `apparmor_parser`.
     2  package aaparser
     3  
     4  import (
     5  	"fmt"
     6  	"os/exec"
     7  	"strconv"
     8  	"strings"
     9  )
    10  
    11  const (
    12  	binary = "apparmor_parser"
    13  )
    14  
    15  // GetVersion returns the major and minor version of apparmor_parser.
    16  func GetVersion() (int, error) {
    17  	output, err := cmd("", "--version")
    18  	if err != nil {
    19  		return -1, err
    20  	}
    21  
    22  	return parseVersion(output)
    23  }
    24  
    25  // LoadProfile runs `apparmor_parser -r` on a specified apparmor profile to
    26  // replace the profile.
    27  func LoadProfile(profilePath string) error {
    28  	_, err := cmd("", "-r", profilePath)
    29  	return err
    30  }
    31  
    32  // cmd runs `apparmor_parser` with the passed arguments.
    33  func cmd(dir string, arg ...string) (string, error) {
    34  	c := exec.Command(binary, arg...)
    35  	c.Dir = dir
    36  
    37  	output, err := c.CombinedOutput()
    38  	if err != nil {
    39  		return "", fmt.Errorf("running `%s %s` failed with output: %s\nerror: %v", c.Path, strings.Join(c.Args, " "), output, err)
    40  	}
    41  
    42  	return string(output), nil
    43  }
    44  
    45  // parseVersion takes the output from `apparmor_parser --version` and returns
    46  // a representation of the {major, minor, patch} version as a single number of
    47  // the form MMmmPPP {major, minor, patch}.
    48  func parseVersion(output string) (int, error) {
    49  	// output is in the form of the following:
    50  	// AppArmor parser version 2.9.1
    51  	// Copyright (C) 1999-2008 Novell Inc.
    52  	// Copyright 2009-2012 Canonical Ltd.
    53  
    54  	lines := strings.SplitN(output, "\n", 2)
    55  	words := strings.Split(lines[0], " ")
    56  	version := words[len(words)-1]
    57  
    58  	// split by major minor version
    59  	v := strings.Split(version, ".")
    60  	if len(v) == 0 || len(v) > 3 {
    61  		return -1, fmt.Errorf("parsing version failed for output: `%s`", output)
    62  	}
    63  
    64  	// Default the versions to 0.
    65  	var majorVersion, minorVersion, patchLevel int
    66  
    67  	majorVersion, err := strconv.Atoi(v[0])
    68  	if err != nil {
    69  		return -1, err
    70  	}
    71  
    72  	if len(v) > 1 {
    73  		minorVersion, err = strconv.Atoi(v[1])
    74  		if err != nil {
    75  			return -1, err
    76  		}
    77  	}
    78  	if len(v) > 2 {
    79  		patchLevel, err = strconv.Atoi(v[2])
    80  		if err != nil {
    81  			return -1, err
    82  		}
    83  	}
    84  
    85  	// major*10^5 + minor*10^3 + patch*10^0
    86  	numericVersion := majorVersion*1e5 + minorVersion*1e3 + patchLevel
    87  	return numericVersion, nil
    88  }