system: Add /etc/ssl symlink; set needed variables in /etc/profile.

* gnu/build/activation.scm (activate-etc): Create /etc/ssl symlink.
* gnu/system.scm (etc-directory): Set SSL_CERT_DIR, SSL_CERT_FILE,
  and GIT_SSL_CAINFO in /etc/profile.

Co-Authored-By: Ludovic Courtès <ludo@gnu.org>

gnu/build/activation.scm

@@ -1,5 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2013, 2014 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -200,6 +201,15 @@ numeric gid or #f."
 
   (format #t "populating /etc from ~a...~%" etc)
 
+  ;; Create the /etc/ssl -> /run/current-system/profile/etc/ssl symlink.  This
+  ;; symlink, to a target outside of the store, probably doesn't belong in the
+  ;; static 'etc' store directory.  However, if it were to be put there,
+  ;; beware that if /run/current-system/profile/etc/ssl doesn't exist at the
+  ;; time of activation (e.g. when installing a fresh system), the call to
+  ;; 'file-is-directory?' below will fail because it uses 'stat', not 'lstat'.
+  (rm-f "/etc/ssl")
+  (symlink "/run/current-system/profile/etc/ssl" "/etc/ssl")
+
   (rm-f "/etc/static")
   (symlink etc "/etc/static")
   (for-each (lambda (file)

gnu/system.scm

@@ -453,6 +453,11 @@ export EMACSLOADPATH=:/etc/emacs
 # when /etc/machine-id is missing.  Make sure these warnings are non-fatal.
 export DBUS_FATAL_WARNINGS=0
 
+# These variables are honored by OpenSSL (libssl) and Git.
+export SSL_CERT_DIR=/etc/ssl/certs
+export SSL_CERT_FILE=\"$SSL_CERT_DIR/ca-certificates.crt\"
+export GIT_SSL_CAINFO=\"$SSL_CERT_FILE\"
+
 # Allow Aspell to find dictionaries installed in the user profile.
 export ASPELL_CONF=\"dict-dir $HOME/.guix-profile/lib/aspell\"
 "))