config: Automatically load defaults, system and user configuration.

* gnu/gnunet/config/fs.scm
  (locate-defaults,load-configuration): New procedures.
* doc/scheme-gnunet.tm
  (Loading configuration files): Document new procedure.
* gnu/gnunet/config/default.conf: New file.
* Makefile.am (nobase_dist_guilesite_DATA): Add new file.

2 files changed, 52 insertions, 2 deletions

diff --git a/gnu/gnunet/config/default.conf b/gnu/gnunet/config/default.conf
new file mode 100644
index 0000000..ea019ef
--- /dev/null
+++ b/gnu/gnunet/config/default.conf
@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+# Copyright (C) 2020, 2021 Maxime Devos
+# SPDX-License-Identifier: FSFAP
+# Copying and distribution of this file, with or without modification,
+# are permitted in any medium without royalty provided the copyright
+# notice and this notice are preserved.  This file is offered as-is,
+# without any warranty.
+#
+# For compatibility with C GNUnet, it is important that the default UNIXPATH,
+# GNUNET_RUNTIME_DIR and GNUNET_USER_RUNTIME_DIR is the same.
+
+[nse]
+UNIXPATH = $GNUNET_RUNTIME_DIR/gnunet-service-nse.sock
+
+[PATHS]
+# Directory for UNIX domain sockets of system-wide services.
+GNUNET_RUNTIME_DIR = ${TMPDIR:-${TMP:-/tmp}}/gnunet-system-runtime/
+# Likewise, for per-user services
+GNUNET_USER_RUNTIME_DIR = ${TMPDIR:-${TMP:-/tmp}}/gnunet-${USERHOME:-${USER:-user}}-runtime/
diff --git a/gnu/gnunet/config/fs.scm b/gnu/gnunet/config/fs.scm
index dfd10a5..1a073ab 100644
--- a/gnu/gnunet/config/fs.scm
+++ b/gnu/gnunet/config/fs.scm
@@ -34,12 +34,15 @@
 (define-library (gnu gnunet config fs)
   (export locate-system-configuration
           locate-user-configuration
+          load-configuration
           load-configuration/port!
           make-expanded-configuration)
   (import (only (rnrs base)
                 begin define and not or cond define-syntax identifier-syntax
                 if ... eq? values + lambda quote vector car cdr cons string?
                 string-length vector? vector-ref string=? list)
+          (only (rnrs control)
+                when)
           (prefix (rnrs hashtables)
                   rnrs:)
           (only (ice-9 optargs)
@@ -50,13 +53,18 @@
                 getenv in-vicinity string-null? define-syntax-rule eof-object?
                 substring error syntax-error define-syntax-parameter
                 syntax-parameterize syntax-violation identity
-                make-hash-table hash-set! hash-ref hash-for-each)
+                make-hash-table hash-set! hash-ref hash-for-each
+                call-with-input-file for-each file-exists?
+                search-path %load-path)
           (only (gnu gnunet utils hat-let)
                 let^)
           (gnu gnunet config db)
           (gnu gnunet config expand)
           (gnu gnunet config parser))
   (begin
+    (define (locate-defaults)
+      (search-path %load-path "gnu/gnunet/config/default.conf"))
+
     (define (locate-system-configuration)
       "/etc/gnunet.conf")
 
@@ -212,6 +220,29 @@ are added to the configuration and every variable is expanded."
        hash)
       config)
 
+    ;; XXX no tests
+    (define* (load-configuration #:key (getenv getenv)
+                                 (files (list (locate-defaults)
+                                              (locate-system-configuration)
+                                              (locate-user-configuration
+                                               #:getenv getenv))))
+      "Load the user configuration, system configuration and defaults.
+The configuration files to load can be overridden by setting @var{files}
+appropriately."
+      (define configurations
+        (list (locate-system-configuration)
+              (locate-user-configuration)))
+      (define (load! set-value!)
+        (define (load-file! file)
+          (when (and file (file-exists? file))
+            (call-with-input-file file
+              (lambda (p)
+                (load-configuration/port! set-value! p))
+              #:guess-encoding #t
+              #:encoding "UTF-8")))
+        (for-each load-file! configurations))
+      (define c (make-expanded-configuration load! #:getenv getenv))
+      c)
+
     ;; TODO error reporting
-    ;; TODO actually load the configuration, defaults, ...
     ))