vars.go

Documentation: github.com/redhat-developer/odo/pkg/vars

     1  package vars
     2  
     3  import (
     4  	"bufio"
     5  	"fmt"
     6  	"strings"
     7  	"unicode"
     8  
     9  	"github.com/redhat-developer/odo/pkg/testingutil/filesystem"
    10  )
    11  
    12  // GetVariables returns a map of key/value from pairs defined in the file and in the list of strings in the format KEY=VALUE or KEY
    13  // For a KEY entry, the value will be obtained from the environment, and if the value is not defined in the environment, the entry KEY will be ignored
    14  // An empty filename will skip the extraction of pairs from file
    15  func GetVariables(fs filesystem.Filesystem, filename string, override []string, lookupEnv func(string) (string, bool)) (map[string]string, error) {
    16  
    17  	result := map[string]string{}
    18  	var err error
    19  	if len(filename) > 0 {
    20  		result, err = parseKeyValueFile(fs, filename, lookupEnv)
    21  		if err != nil {
    22  			return nil, err
    23  		}
    24  	}
    25  	overrideVars, err := parseKeyValueStrings(override, lookupEnv)
    26  	if err != nil {
    27  		return nil, err
    28  	}
    29  
    30  	for k, v := range overrideVars {
    31  		result[k] = v
    32  	}
    33  
    34  	return result, nil
    35  }
    36  
    37  // parseKeyValueFile parses a file for "KEY=VALUE" lines and returns a map of keys/values
    38  // If a key is defined without a value as "KEY", the value is searched into the environment with lookupEnv function
    39  // Note that "KEY=" defines an empty value for KEY, but "KEY" indicates to search for value in environment
    40  // If the KEY environment variable is not defined, this entry will be skipped
    41  func parseKeyValueFile(fs filesystem.Filesystem, filename string, lookupEnv func(string) (string, bool)) (map[string]string, error) {
    42  	f, err := fs.Open(filename)
    43  	if err != nil {
    44  		return nil, err
    45  	}
    46  	defer f.Close()
    47  
    48  	result := map[string]string{}
    49  
    50  	scanner := bufio.NewScanner(f)
    51  	for scanner.Scan() {
    52  		scannedText := scanner.Text()
    53  
    54  		key, value, err := parseKeyValueString(scannedText, lookupEnv)
    55  		if err != nil {
    56  			return nil, err
    57  		}
    58  		if len(key) == 0 {
    59  			continue
    60  		}
    61  		result[key] = value
    62  	}
    63  
    64  	return result, nil
    65  }
    66  
    67  func parseKeyValueStrings(strs []string, lookupEnv func(string) (string, bool)) (map[string]string, error) {
    68  	result := map[string]string{}
    69  
    70  	for _, str := range strs {
    71  		key, value, err := parseKeyValueString(str, lookupEnv)
    72  		if err != nil {
    73  			return nil, err
    74  		}
    75  		if len(key) == 0 {
    76  			continue
    77  		}
    78  		result[key] = value
    79  	}
    80  	return result, nil
    81  }
    82  
    83  // parseKeyValueString parses a string to extract a key and its associated value
    84  // if a line is empty or a comment, a nil error and an empty key are returned
    85  // if a key does not define a value, the value will be obtained from the environment
    86  // in this case, if the environment does not define the variable, the entry will be ignored
    87  func parseKeyValueString(s string, lookupEnv func(string) (string, bool)) (string, string, error) {
    88  	line := strings.TrimLeftFunc(s, unicode.IsSpace)
    89  	if len(line) == 0 || strings.HasPrefix(line, "#") {
    90  		return "", "", nil
    91  	}
    92  	parts := strings.SplitN(line, "=", 2)
    93  	key := parts[0]
    94  
    95  	// TODO validate key format
    96  
    97  	if len(key) == 0 {
    98  		return "", "", NewErrBadKey(fmt.Sprintf("no key defined in line %q", s))
    99  	}
   100  
   101  	var value string
   102  	if len(parts) > 1 {
   103  		value = parts[1]
   104  	} else {
   105  		var found bool
   106  		value, found = lookupEnv(key)
   107  		if !found {
   108  			return "", "", nil
   109  		}
   110  	}
   111  
   112  	return key, value, nil
   113  }
   114
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