env

Documentation

Overview

Package env provides functions to incorporate environment variables into kubectl commands.

Index

• func Env(key string, defaultValue string) string
• func GetEnv(key string) (string, bool)
• func GetEnvVarRefString(from *v1.EnvVarSource) string
• func GetEnvVarRefValue(kc kubernetes.Interface, ns string, store *ResourceStore, ...) (string, error)
• func IsEnvironmentArgument(s string) bool
• func IsValidEnvironmentArgument(s string) bool
• func ParseEnv(spec []string, defaultReader io.Reader) ([]v1.EnvVar, []string, error)
• func SplitEnvironmentFromResources(args []string) (resources, envArgs []string, ok bool)
• type ResourceStore
  • func NewResourceStore() *ResourceStore

Examples

• Env (DefaultValue)
• Env (VariableExists)
• GetEnv (VariableDoesNotExist)
• GetEnv (VariableExists)
• IsEnvironmentArgument (False)
• IsEnvironmentArgument (True)
• IsValidEnvironmentArgument (False)
• IsValidEnvironmentArgument (True)
• ParseEnv (Bad)
• ParseEnv (Good)
• SplitEnvironmentFromResources

Functions

func Env

func Env(key string, defaultValue string) string

Env returns an environment variable if not nil, or a default value.

Example (DefaultValue)

fmt.Println(Env("TESTENVVAR", "default"))

Output:

default

Example (VariableExists)

os.Setenv("TESTENVVAR", "test value")
defer os.Unsetenv("TESTENVVAR")
fmt.Println(Env("TESTENVVAR", "default"))

Output:

test value

func GetEnv

func GetEnv(key string) (string, bool)

GetEnv returns an environment value if not nil, and an ok boolean.

Example (VariableDoesNotExist)

fmt.Println(GetEnv("THISVARDOESNOTEXIST"))

Output:

 false

Example (VariableExists)

os.Setenv("THISVAREXISTS", "value")
defer os.Unsetenv("THISVAREXISTS")
fmt.Println(GetEnv("THISVAREXISTS"))

Output:

value true

func GetEnvVarRefString

func GetEnvVarRefString(from *v1.EnvVarSource) string

GetEnvVarRefString returns a text description of whichever field is set within the supplied EnvVarSource argument.

func GetEnvVarRefValue

func GetEnvVarRefValue(kc kubernetes.Interface, ns string, store *ResourceStore, from *v1.EnvVarSource, obj runtime.Object, c *v1.Container) (string, error)

GetEnvVarRefValue returns the value referenced by the supplied EnvVarSource given the other supplied information.

func IsEnvironmentArgument

func IsEnvironmentArgument(s string) bool

IsEnvironmentArgument checks whether a string is an environment argument, that is, whether it matches the "anycharacters=anycharacters" pattern.

Example (False)

test := "returnsfalse"
fmt.Println(IsEnvironmentArgument(test))

Output:

false

Example (True)

test := "returns=true"
fmt.Println(IsEnvironmentArgument(test))

Output:

true

func IsValidEnvironmentArgument

func IsValidEnvironmentArgument(s string) bool

IsValidEnvironmentArgument checks whether a string is a valid environment argument, that is, whether it matches the "wordcharacters=anycharacters" pattern. Word characters can be letters, numbers, and underscores.

Example (False)

test := "not$word^characters=test"
fmt.Println(IsValidEnvironmentArgument(test))

Output:

false

Example (True)

test := "wordcharacters=true"
fmt.Println(IsValidEnvironmentArgument(test))

Output:

true

func ParseEnv

func ParseEnv(spec []string, defaultReader io.Reader) ([]v1.EnvVar, []string, error)

ParseEnv parses the elements of the first argument looking for environment variables in key=value form and, if one of those values is "-", it also scans the reader. The same environment variable cannot be both modified and removed in the same command.

Example (Bad)

var r io.Reader
bad := []string{"This not in the key=value format."}
fmt.Println(ParseEnv(bad, r))

Output:

[] [] environment variables must be of the form key=value and can only contain letters, numbers, and underscores

Example (Good)

r := strings.NewReader("FROM=READER")
ss := []string{"ENV=VARIABLE", "AND=ANOTHER", "REMOVE-", "-"}
fmt.Println(ParseEnv(ss, r))

Output:

[{ENV VARIABLE nil} {AND ANOTHER nil} {FROM READER nil}] [REMOVE] <nil>

func SplitEnvironmentFromResources

func SplitEnvironmentFromResources(args []string) (resources, envArgs []string, ok bool)

SplitEnvironmentFromResources separates resources from environment arguments. Resources must come first. Arguments may have the "DASH-" syntax.

Example

args := []string{`resource`, "ENV\\=ARG", `ONE\=MORE`, `DASH-`}
fmt.Println(SplitEnvironmentFromResources(args))

Output:

[resource] [ENV\=ARG ONE\=MORE DASH-] true

Types

type ResourceStore

type ResourceStore struct {
	SecretStore    map[string]*v1.Secret
	ConfigMapStore map[string]*v1.ConfigMap
}

ResourceStore defines a new resource store data structure.

func NewResourceStore

func NewResourceStore() *ResourceStore

NewResourceStore returns a pointer to a new resource store data structure.