The envy Reference Manual

Table of Contents

The envy Reference Manual

This is the envy Reference Manual, version 0.1, generated automatically by Declt version 3.0 "Montgomery Scott" on Mon Apr 19 15:59:24 2021 GMT+0.

1 Introduction

Envy

Configuration switcher by an environment variable inspired by Perl's Config::ENV.

Usage

(defpackage :myapp.config
  (:use :cl
        :envy))
(in-package :myapp.config)

(setf (config-env-var) "APP_ENV")

(defconfig :common
  `(:application-root ,(asdf:component-pathname (asdf:find-system :myapp))))

(defconfig |development|
  '(:debug T
    :database-type :sqlite3
    :database-connection-spec (:database-name "sqlite3.db")))

(defconfig |production|
  '(:database-type :mysql
    :database-connection-spec (:database-name "test"
                               :usename "whoami"
                               :password "1234")))

(defconfig |staging|
  `(:debug T
    ,@|production|))

(defpackage :myapp
  (:use :cl)
  (:import-from :envy
                :config)
(in-package :myapp)

(getf (config :myapp.config) :database-type)

Description

Envy is a configuration manager for various applications.

Envy uses an environment variable to determine a configuration to use. I'm not sure this is ideal even for Common Lisp applications, but this can separate configuration system from an implementation.

Configurations

Normal configurations

ENVY:DEFCONFIG is a macro for defining a named configuration.

Don't forget to set (ENVY:CONFIG-ENV-VAR) which is a name of environment variable to determine a configuration.

(setf (config-env-var) "APP_ENV")

;; Use SQLite3 for development
(defconfig |development|
  '(:server :hunchentoot
    :database-type :sqlite3
    :database-connection-spec (:database-name "sqlite3.db")))

;; Use MySQL in production environment
(defconfig |production|
  '(:server :fcgi
    :database-type :mysql
    :database-connection-spec (:database-name "test"
                               :usename "whoami"
                               :password "1234")))

Merging

Each configurations are represented as property lists. It means you can merge them by the default way of merging lists -- cons, append or/and splicing unquote.

(defconfig |staging|
  `(:server :hunchentoot
    ,@|production|))

Common configurations

You can also define a common configuration which will be merged into every configurations.

(defconfig :common
  `(:application-root ,(asdf:component-pathname (asdf:find-system :myapp))))

Accessing to configuration

ENVY:CONFIG is an accessor to get the current configuration.

(config :<configuration-package-name>)

(config :myapp.config)
;=> '(:server :hunchentoot
      :database-type :sqlite3
      :database-connection-spec (:database-name "sqlite3.db")
      :application-root #P"/path/to/application/")

(getf (config :myapp.config) :database-type)
;=> :sqlite3

Tips

(defpackage myapp.config
  (:use :cl
        :envy)
  (:shadow :envy
           :config)
  (:export :config))
(in-package :myapp.config)

(defconfig :common
  ...)

;;
;; ... Configurations ...
;;

(defun config ()
  (envy:config #.(package-name *package*)))

See Also

Thank cho45 for the great product. I feel envy to you :)

• Config::ENV

Author

• Eitarow Fukamachi (e.arrows@gmail.com)

Copyright

Copyright (c) 2013 Eitarow Fukamachi (e.arrows@gmail.com)

License

Licensed under the BSD 2-Clause License.

2 Systems

The main system appears first, followed by any subsystem dependency.

2.1 envy

Author

Eitarow Fukamachi

License

BSD 2-Clause

Description

Configuration switcher by an environment variable.

Long Description

# Envy

Configuration switcher by an environment variable inspired by Perl’s [Config::ENV](http://search.cpan.org/~satoh/Config-ENV/lib/Config/ENV.pm).

## Usage

“‘common-lisp
(defpackage :myapp.config
(:use :cl
:envy))
(in-package :myapp.config)

(setf (config-env-var) "APP_ENV")

(defconfig :common
‘(:application-root ,(asdf:component-pathname (asdf:find-system :myapp))))

(defconfig |development|
’(:debug T
:database-type :sqlite3
:database-connection-spec (:database-name "sqlite3.db")))

(defconfig |production|
’(:database-type :mysql
:database-connection-spec (:database-name "test"
:usename "whoami"
:password "1234")))

(defconfig |staging|
‘(:debug T
,@|production|))
“‘

“‘common-lisp
(defpackage :myapp
(:use :cl)
(:import-from :envy
:config)
(in-package :myapp)

(getf (config :myapp.config) :database-type)
“‘

## Description

Envy is a configuration manager for various applications.

Envy uses an environment variable to determine a configuration to use. I’m not sure this is ideal even for Common Lisp applications, but this can separate configuration system from an implementation.

## Configurations

### Normal configurations

‘ENVY:DEFCONFIG‘ is a macro for defining a named configuration.

Don’t forget to set ‘(ENVY:CONFIG-ENV-VAR)‘ which is a name of environment variable to determine a configuration.

“‘common-lisp
(setf (config-env-var) "APP_ENV")

;; Use SQLite3 for development
(defconfig |development|
’(:server :hunchentoot
:database-type :sqlite3
:database-connection-spec (:database-name "sqlite3.db")))

;; Use MySQL in production environment
(defconfig |production|
’(:server :fcgi
:database-type :mysql
:database-connection-spec (:database-name "test"
:usename "whoami"
:password "1234")))
“‘

### Merging

Each configurations are represented as property lists. It means you can merge them by the default way of merging lists – cons, append or/and splicing unquote.

“‘common-lisp
(defconfig |staging|
‘(:server :hunchentoot
,@|production|))
“‘

### Common configurations

You can also define a common configuration which will be merged into every configurations.

“‘common-lisp
(defconfig :common
‘(:application-root ,(asdf:component-pathname (asdf:find-system :myapp))))
“‘

### Accessing to configuration

‘ENVY:CONFIG‘ is an accessor to get the current configuration.

“‘common-lisp
(config :<configuration-package-name>)

(config :myapp.config)
;=> ’(:server :hunchentoot
:database-type :sqlite3
:database-connection-spec (:database-name "sqlite3.db")
:application-root #P"/path/to/application/")

(getf (config :myapp.config) :database-type)
;=> :sqlite3
“‘

## Tips

“‘common-lisp
(defpackage myapp.config
(:use :cl
:envy)
(:shadow :envy
:config)
(:export :config))
(in-package :myapp.config)

(defconfig :common
...)

;;
;; ... Configurations ...
;;

(defun config ()
(envy:config #.(package-name *package*)))
“‘

## See Also

Thank cho45 for the great product. I feel envy to you :)

- [Config::ENV](http://search.cpan.org/~satoh/Config-ENV/lib/Config/ENV.pm)

## Author

* Eitarow Fukamachi (e.arrows@gmail.com)

## Copyright

Copyright (c) 2013 Eitarow Fukamachi (e.arrows@gmail.com)

# License

Licensed under the BSD 2-Clause License.

Version

0.1

Source

envy.asd (file)

Component

src (module)

3 Modules

Modules are listed depth-first from the system components tree.

3.1 envy/src

Parent

envy (system)

Location

src/

Component

envy.lisp (file)

4 Files

Files are sorted by type and then listed depth-first from the systems components trees.

4.1 Lisp

4.1.1 envy.asd

Location

envy.asd

Systems

envy (system)

Packages

envy-asd

4.1.2 envy/src/envy.lisp

Parent

src (module)

Location

src/envy.lisp

Packages

envy

Exported Definitions

• config (function)
• config-env-var (function)
• (setf config-env-var) (function)
• defconfig (macro)

Internal Definitions

• *config-env-map* (special variable)
• *package-common-configurations* (special variable)
• config* (function)
• package-config (function)

5 Packages

Packages are listed by definition order.

5.1 envy-asd

Source

envy.asd

Use List

• asdf/interface
• common-lisp

5.2 envy

Source

envy.lisp (file)

Use List

common-lisp

Exported Definitions

• config (function)
• config-env-var (function)
• (setf config-env-var) (function)
• defconfig (macro)

Internal Definitions

• *config-env-map* (special variable)
• *package-common-configurations* (special variable)
• config* (function)
• package-config (function)

6 Definitions

Definitions are sorted by export status, category, package, and then by lexicographic order.

6.1 Exported definitions

6.1.1 Macros

Macro: defconfig NAME CONFIGURATIONS

Package

envy

Source

envy.lisp (file)

6.1.2 Functions

Function: config PACKAGE-NAME &optional KEY

Package

envy

Source

envy.lisp (file)

Function: config-env-var &optional PACKAGE-NAME

Function: (setf config-env-var) VAL &optional PACKAGE-NAME

Package

envy

Source

envy.lisp (file)

6.2 Internal definitions

6.2.1 Special variables

Special Variable: *config-env-map*

Package

envy

Source

envy.lisp (file)

Special Variable: *package-common-configurations*

Package

envy

Source

envy.lisp (file)

6.2.2 Functions

Function: config* &optional KEY

Package

envy

Source

envy.lisp (file)

Function: package-config PACKAGE-NAME

Package

envy

Source

envy.lisp (file)

Appendix A Indexes

A.1 Concepts

A.2 Functions

A.3 Variables

A.4 Data types