github.com/campoy/docker@v1.8.0-rc1/pkg/parsers/filters/parse.go (about)

     1  package filters
     2  
     3  import (
     4  	"encoding/json"
     5  	"errors"
     6  	"regexp"
     7  	"strings"
     8  )
     9  
    10  type Args map[string][]string
    11  
    12  // Parse the argument to the filter flag. Like
    13  //
    14  //   `docker ps -f 'created=today' -f 'image.name=ubuntu*'`
    15  //
    16  // If prev map is provided, then it is appended to, and returned. By default a new
    17  // map is created.
    18  func ParseFlag(arg string, prev Args) (Args, error) {
    19  	var filters Args = prev
    20  	if prev == nil {
    21  		filters = Args{}
    22  	}
    23  	if len(arg) == 0 {
    24  		return filters, nil
    25  	}
    26  
    27  	if !strings.Contains(arg, "=") {
    28  		return filters, ErrorBadFormat
    29  	}
    30  
    31  	f := strings.SplitN(arg, "=", 2)
    32  	name := strings.ToLower(strings.TrimSpace(f[0]))
    33  	value := strings.TrimSpace(f[1])
    34  	filters[name] = append(filters[name], value)
    35  
    36  	return filters, nil
    37  }
    38  
    39  var ErrorBadFormat = errors.New("bad format of filter (expected name=value)")
    40  
    41  // packs the Args into an string for easy transport from client to server
    42  func ToParam(a Args) (string, error) {
    43  	// this way we don't URL encode {}, just empty space
    44  	if len(a) == 0 {
    45  		return "", nil
    46  	}
    47  
    48  	buf, err := json.Marshal(a)
    49  	if err != nil {
    50  		return "", err
    51  	}
    52  	return string(buf), nil
    53  }
    54  
    55  // unpacks the filter Args
    56  func FromParam(p string) (Args, error) {
    57  	args := Args{}
    58  	if len(p) == 0 {
    59  		return args, nil
    60  	}
    61  	if err := json.NewDecoder(strings.NewReader(p)).Decode(&args); err != nil {
    62  		return nil, err
    63  	}
    64  	return args, nil
    65  }
    66  
    67  func (filters Args) MatchKVList(field string, sources map[string]string) bool {
    68  	fieldValues := filters[field]
    69  
    70  	//do not filter if there is no filter set or cannot determine filter
    71  	if len(fieldValues) == 0 {
    72  		return true
    73  	}
    74  
    75  	if sources == nil || len(sources) == 0 {
    76  		return false
    77  	}
    78  
    79  outer:
    80  	for _, name2match := range fieldValues {
    81  		testKV := strings.SplitN(name2match, "=", 2)
    82  
    83  		for k, v := range sources {
    84  			if len(testKV) == 1 {
    85  				if k == testKV[0] {
    86  					continue outer
    87  				}
    88  			} else if k == testKV[0] && v == testKV[1] {
    89  				continue outer
    90  			}
    91  		}
    92  
    93  		return false
    94  	}
    95  
    96  	return true
    97  }
    98  
    99  func (filters Args) Match(field, source string) bool {
   100  	fieldValues := filters[field]
   101  
   102  	//do not filter if there is no filter set or cannot determine filter
   103  	if len(fieldValues) == 0 {
   104  		return true
   105  	}
   106  	for _, name2match := range fieldValues {
   107  		match, err := regexp.MatchString(name2match, source)
   108  		if err != nil {
   109  			continue
   110  		}
   111  		if match {
   112  			return true
   113  		}
   114  	}
   115  	return false
   116  }