env functions
env.Getenv
Alias: getenv
Exposes the os.Getenv function.
Retrieves the value of the environment variable named by the key. If the
variable is unset, but the same variable ending in _FILE
is set, the contents
of the file will be returned. Otherwise the provided default (or an empty
string) is returned.
This is a more forgiving alternative to using .Env
, since missing keys will
return an empty string, instead of panicking.
The _FILE
fallback is especially useful for use with 12-factor-style
applications configurable only by environment variables, and especially in
conjunction with features like Docker Secrets.
Added in gomplate v0.2.0
Usage
env.Getenv var [default]
Arguments
name | description |
---|---|
var |
(required) the environment variable name |
default |
(optional) the default |
Examples
$ gomplate -i 'Hello, {{env.Getenv "USER"}}'
Hello, hairyhenderson
$ gomplate -i 'Hey, {{getenv "FIRSTNAME" "you"}}!'
Hey, you!
$ echo "safe" > /tmp/mysecret
$ export SECRET_FILE=/tmp/mysecret
$ gomplate -i 'Your secret is {{getenv "SECRET"}}'
Your secret is safe
env.ExpandEnv
Exposes the os.ExpandEnv function.
Replaces ${var}
or $var
in the input string according to the values of the
current environment variables. References to undefined variables are replaced by the empty string.
Like env.Getenv
, the _FILE
variant of a variable is used.
Added in gomplate v2.5.0
Usage
env.ExpandEnv input
Arguments
name | description |
---|---|
input |
(required) the input |
Examples
$ gomplate -i '{{env.ExpandEnv "Hello $USER"}}'
Hello, hairyhenderson
$ gomplate -i 'Hey, {{env.ExpandEnv "Hey, ${FIRSTNAME}!"}}'
Hey, you!
$ echo "safe" > /tmp/mysecret
$ export SECRET_FILE=/tmp/mysecret
$ gomplate -i '{{env.ExpandEnv "Your secret is $SECRET"}}'
Your secret is safe
$ gomplate -i '{{env.ExpandEnv (file.Read "foo")}}
contents of file "foo"...