env

README

env - Environment Variable Manager

The env middleware manages the handling of environment variables.

Arguments

It takes two arguments:

Save

The save argument is an optional string that causes the result of the pipe's execution to be stored in an environment variable of that name (excluding the $). The output is not swallowed, but still passed on as usual. This behavior might change in a future version of pipedream.

private:
    some-pipe:
        shell:
            run: "command"
        env:
            # the result of "command" will be saved in the environment as $ENV_VAR
            save: ENV_VAR

Interpolate

The interpolate argument is a string that determines how environment variables will be interpolated when the pipe is invoked. Possible values are: - deep: Values located within a nested map of arguments will be interpolated, irrespective of the level of nesting. - shallow: Only string values with a single level of nesting will be interpolated at invocation time. - none (default): No interpolation takes place at invocation time.

Note that environment variables that are not interpolated by the env middleware may still be evaluated at execution time, e.g. by the shell middleware. For this reason, you will only need to use this feature if interpolation should take place before execution - for example, to make conditional execution (using the when middleware) dependent on the value of an environment variable.

private:
    some-pipe:
        env:
            # added for clarity, `none` is the default value
            # note that using `deep` could cause problems here,
            # if the value of ENV_VAR is not yet set at the time of parent invocation
            interpolate: none
        pipe:
            - child-pipe:
                env:
                    interpolate: shallow
                # this value will be evaluated at child invocation time
                # note that if the value is set by another pipe,
                # the child's invocation must be delayed
                # until after the env var has been set
                # e.g. using the `waitFor` middleware
                when: "'$ENV_VAR' == 'YES!!'"

Documentation

Overview

Package env provides a middleware managing environment variables

Index

• type Middleware
  • func NewMiddleware() Middleware
  • func NewMiddlewareWithProvider(setenv func(string, string) error, expandEnv func(string) string) Middleware
  • func (envMiddleware Middleware) Apply(run *pipeline.Run, next func(*pipeline.Run), _ *middleware.ExecutionContext)
  • func (envMiddleware Middleware) String() string

Types

type Middleware

type Middleware struct {
	Setenv    func(string, string) error
	ExpandEnv func(string) string
}

Middleware is an environment variable manager

func NewMiddleware

func NewMiddleware() Middleware

NewMiddleware creates a new middleware instance

func NewMiddlewareWithProvider

func NewMiddlewareWithProvider(
	setenv func(string, string) error,
	expandEnv func(string) string,
) Middleware

NewMiddlewareWithProvider creates a new middleware instance with the specified env functions

func (Middleware) Apply

func (envMiddleware Middleware) Apply(
	run *pipeline.Run,
	next func(*pipeline.Run),
	_ *middleware.ExecutionContext,
)

Apply is where the middleware's logic resides

It adapts the run based on its slice of the run's arguments. It may also trigger side effects such as executing shell commands or full runs of other pipelines. When done, this function should call next in order to continue unwinding the stack.

func (Middleware) String

func (envMiddleware Middleware) String() string

String is a human-readable description