EnvP

EnvP is a simple CLI util that passes your file through golang/Template with your environment, allowing you to do more advanced configurations in things like Docker without very much effort. It also provides several helpers that will aid in this task, and make your life generally easy.

Usage

Flag	Type	Description	Repeatable (Array)
--write-to	string	the file to write to	false
--file	string	the file, or dir	true

Leaving --file empty will print the final result to stdout, this is really meant for testing before you make commits but can be used any way you wish. As well, if you set --file to a directory, it will glob for .gohtml (even if it's gotxt)

Helpers

split

{{ split [string] [delim] }}

{{ myStr := "1,2,3" }}
{{ range $_, $e := (split $myStr ",") }}
  {{ $e }}
{{ end }}

chomp

{{ chomp [string] [cutset] }}

{{ myStr := "hello" }}
{{ chomp $myStr "o" }}

indent

Strips indentation to the edge at the smallest length, and reindents to the specified length.

{{ indent [string] [n] }}

{{ define "myTemplate" }}
  hello {
    world
  }
{{ end }}
{{ str := templateString "myTemplate" }}
{{ indent $str 6 }}

      hello {
        world
      }

addSpace

Add space to the beginning of a string

{{ addSpace [string] [int] }}

templateString

Get a template as a string that can be manipulated

{{ templateString [template] }}

{{ define "myTemplate" }}
  hello {
    world
  }
{{ end }}
{{ $template := (templateString "myTemplate") }}
{{ indent $template 8 }}

strippedTemplate

Strips lines of empty space, and removes all edge space.

{{ strippedTemplate [template] }}

{{ define "myTemplate" }}
  hello {
    world
  }



{{ end }}
{{ strippedTemplate "myTemplate" }}

  hello {
    world
  }

strip

Strips lines of empty space, and removes all edge space.

{{ strip [string] }}

{{ define "myTemplate" }}
  hello {
    world
  }



{{ end }}
{{ $myVar := (templateString "myTemplate" }}
{{ strip $myVar }}

  hello {
    world
  }

fixIndentedTemplate

Strips indentation to the edge like String#strip_heredoc or <<~STR in Ruby.

{{ fixIndentedTemplate [template] }}

{{ define "myTemplate" }}
  hello {
    world
  }
{{ end }}
{{ fixIndentedTemplate "myTemplate" }}

hello {
  world
}

templateExists

Allows you to perform booleans on a template

{{ templateExists [template] }}

{{ if (templateExists "myTemplate") }}
  {{ template "myTemplate" }}
{{ end }}

fixIndentation

Strips indentation to the edge like String#strip_heredoc or <<~STR in Ruby.

{{ fixIndentation [string] }}

{{ define "myTemplate" }}
  hello {
    world
  }
{{ end }}
{{ myVar := (templateString "myTemplate") }}
{{ fixIndentation $myVar }}

hello {
  world
}

envExists

Lets you check if an environment variable exists.

{{ envExists [key] }}

{{ if (envExists "key") }}
  Do Work
{{ end }}

boolEnv

Extracts an environment variable as a boolean.

{{ boolEnv [key] }}

{{ if (boolEnv "key") }}
  Do Work
{{ end }}

env

Extracts an environment variable as a string.

{{ env [key] }}

randomPassword

Generate an alphanumeric password using cryptographically derived random numbers.

{{ randomPassword [length] }}

An Example

Given you did

export GHOST_PORT=8080
export GHOST_ENV=production
export CADDY_TLS_EMAIL=user@example.com
export CADDY_TLS=true

envp \
  -prefix=ghost \
  -file=ghost.gohtml \
  -stdout

And ghost.gohtml was

{{- define "hostnames" -}}
  {{- if eq (env "ghost_env") "development" -}}
    http://localhost
  {{- else -}}
    {{ $g := env "ghost_hostname" }}
    {{- if boolEnv "caddy_tls" -}}
      http://{{$g}} https://{{$g}}
    {{- else -}}
      http://{{$g}}
    {{- end -}}
  {{- end -}}
{{- end -}}
{{- define "tls" -}}
  {{- if and (ne (env "ghost_env") "development") (boolEnv "caddy_tls") -}}
    tls {{ env "caddy_tls_email" }}
  {{- end -}}
{{- end -}}

{{ template "tls" }}
{{ template "hostnames" }}
root /srv/caddy/ghost
ext .html .htm

{{ if and (envExists "ghost_port") (ne (env "ghost_port") "") }}
proxy localhost:{{ env "ghost_port" }} {
  transparent
  websocket
}
{{ end }}

You would get

tls user@example.com
http://example.com
root /srv/caddy/ghost
ext .html .htm

proxy localhost:8080 {
  transparent
  websocket
}