diff options
| -rw-r--r-- | doc/guix.texi | 73 | ||||
| -rw-r--r-- | gnu/services/base.scm | 75 |
2 files changed, 147 insertions, 1 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index 359c9b7a47..9a6a653d86 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -113,7 +113,7 @@ Copyright @copyright{} 2022 Bruno Victal@* Copyright @copyright{} 2022 Ivan Vilata-i-Balaguer@* Copyright @copyright{} 2023 Giacomo Leidi@* Copyright @copyright{} 2022 Antero Mejr@* -Copyright @copyright{} 2022 Bruno Victal@* +Copyright @copyright{} 2023 Bruno Victal@* Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or @@ -40473,6 +40473,77 @@ In this example, the effect would be to add an @file{/etc/issue} file pointing to the given file. @end defvar +@defvar hosts-service-type +Type of the service that populates the entries for (@file{/etc/hosts}). +This service type can be extended by passing it a list of +@code{host} records. + +@c TRANSLATORS: The domain names below SHOULD NOT be translated. +@c They're domains reserved for use in documentation. (RFC6761 Section 6.5) +@c The addresses used are explained in RFC3849 and RFC5737. +@lisp +(simple-service 'add-extra-hosts + hosts-service-type + (list (host "192.0.2.1" "example.com" + '("example.net" "example.org")) + (host "2001:db8::1" "example.com" + '("example.net" "example.org")))) +@end lisp + +@quotation Note +@cindex @file{/etc/host} default entries +By default @file{/etc/host} comes with the following entries: +@example +127.0.0.1 localhost @var{host-name} +::1 localhost @var{host-name} +@end example + +For most setups this is what you want though if you find yourself in +the situation where you want to change the default entries, you can +do so in @code{operating-system}.@pxref{operating-system Reference,@code{essential-services}} + +The following example shows how one would unset @var{host-name} +from being an alias of @code{localhost}. +@lisp +(operating-system + ;; @dots{} + + (essential-services + (modify-services + (operation-system-default-essential-services this-operating-system) + (hosts-service-type config => (list + (host "127.0.0.1" "localhost") + (host "::1" "localhost")))))) +@end lisp +@end quotation + +@deftp {Data Type} host +Available @code{host} fields are: + +@table @asis +@item @code{address} (type: string) +IP address. + +@item @code{canonical-name} (type: string) +Hostname. + +@item @code{aliases} (default: @code{'()}) (type: list-of-string) +Additional aliases that map to the same @code{canonical-name}. + +@end table +@end deftp + +@defun host address canonical-name [aliases] +Procedure for creating @code{host} records. +@end defun + +@quotation Note +The @code{host} data type constructor is @code{%host} though it is +tiresome to create multiple records with it so in practice the procedure +@code{host} (which wraps around @code{%host}) is used instead. +@end quotation +@end defvar + @defvar setuid-program-service-type Type for the ``setuid-program service''. This service collects lists of executable file names, passed as gexps, and adds them to the set of diff --git a/gnu/services/base.scm b/gnu/services/base.scm index 9e799445d2..e9fdafd5d0 100644 --- a/gnu/services/base.scm +++ b/gnu/services/base.scm @@ -20,6 +20,7 @@ ;;; Copyright © 2022 Guillaume Le Vaillant <glv@posteo.net> ;;; Copyright © 2022 Justin Veilleux <terramorpha@cock.li> ;;; Copyright © 2022 ( <paren@disroot.org> +;;; Copyright © 2023 Bruno Victal <mirai@makinata.eu> ;;; ;;; This file is part of GNU Guix. ;;; @@ -103,6 +104,14 @@ console-font-service virtual-terminal-service-type + host + %host + host? + host-address + host-canonical-name + host-aliases + hosts-service-type + static-networking static-networking? static-networking-addresses @@ -685,6 +694,72 @@ to add @var{device} to the kernel's entropy pool. The service will fail if (rngd-configuration (rng-tools rng-tools) (device device)))) + +;;; +;;; /etc/hosts +;;; + +(define (valid-name? name) + "Return true if @var{name} is likely to be a valid host name." + (false-if-exception (not (string-any char-set:whitespace name)))) + +(define-compile-time-procedure (assert-valid-name (name valid-name?)) + "Ensure @var{name} is likely to be a valid host name." + ;; TODO: RFC compliant implementation. + (unless (valid-name? name) + (raise + (make-compound-condition + (formatted-message (G_ "host name '~a' contains invalid characters") + name) + (condition (&error-location + (location + (source-properties->location procedure-call-location))))))) + name) + +(define-record-type* <host> %host + ;; XXX: Using the record type constructor becomes tiresome when + ;; there's multiple records to make. + make-host host? + (address host-address) + (canonical-name host-canonical-name + (sanitize assert-valid-name)) + (aliases host-aliases + (default '()) + (sanitize (cut map assert-valid-name <>)))) + +(define* (host address canonical-name #:optional (aliases '())) + "Return a new record for the host at @var{address} with the given +@var{canonical-name} and possibly @var{aliases}. + +@var{address} must be a string denoting a valid IPv4 or IPv6 address, and +@var{canonical-name} and the strings listed in @var{aliases} must be valid +host names." + (%host + (address address) + (canonical-name canonical-name) + (aliases aliases))) + +(define hosts-service-type + ;; Extend etc-service-type with a entry for @file{/etc/hosts}. + (let* ((serialize-host-record + (lambda (record) + (match-record record <host> (address canonical-name aliases) + (format #f "~a~/~a~{~^~/~a~}~%" address canonical-name aliases)))) + (host-etc-service + (lambda (lst) + `(("hosts" ,(plain-file "hosts" + (format #f "~{~a~}" + (map serialize-host-record + lst)))))))) + (service-type + (name 'etc-hosts) + (extensions + (list + (service-extension etc-service-type + host-etc-service))) + (compose concatenate) + (extend append) + (description "Populate the @file{/etc/hosts} file.")))) ;;; |