github.com/wlan0/docker@v1.5.0/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  	err := json.Unmarshal([]byte(p), &args)
    62  	if err != nil {
    63  		return nil, err
    64  	}
    65  	return args, nil
    66  }
    67  
    68  func (filters Args) Match(field, source string) bool {
    69  	fieldValues := filters[field]
    70  
    71  	//do not filter if there is no filter set or cannot determine filter
    72  	if len(fieldValues) == 0 {
    73  		return true
    74  	}
    75  	for _, name2match := range fieldValues {
    76  		match, err := regexp.MatchString(name2match, source)
    77  		if err != nil {
    78  			continue
    79  		}
    80  		if match {
    81  			return true
    82  		}
    83  	}
    84  	return false
    85  }