environment: Add '--emulate-fhs'.

* guix/scripts/environment.scm (show-environment-options-help, %options): Add
'--emulate-fhs'.
(setup-fhs): New procedure.  Setup for the Filesystem Hierarchy Standard (FHS)
container.  Defines and uses FHS-SYMLINKS and LINK-CONTENTS to create FHS
expected directories and creates /etc/ld.so.conf.
(launch-environment): Add 'emulate-fhs?' key and implement it to set $PATH and
generate /etc/ld.so.cache before calling COMMAND.
(launch-environment/container): Add 'emulate-fhs?' and 'setup-hook' keys and
implement them.  Define and use FHS-MAPPINGS, to set up additional bind mounts
in the container to follow FHS expectations.
(guix-environment*): Add glibc-for-fhs to the container packages when
'emulate-fhs?' key is in OPTS.
* doc/guix.texi (Invoking guix shell): Document '--emulate-fhs'.
(Invoking guix environment): Document '--emulate-fhs'.
* tests/guix-environment-container.sh: Add tests for '--emulate-fhs'.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

1 files changed, 34 insertions, 0 deletions

diff --git a/tests/guix-environment-container.sh b/tests/guix-environment-container.sh
index 2e238c501d6..898c57f41bf 100644
--- a/tests/guix-environment-container.sh
+++ b/tests/guix-environment-container.sh
@@ -197,3 +197,37 @@ then false;
 else
     test $? -gt 127
 fi
+
+# Test the Filesystem Hierarchy Standard (FHS) container option, --emulate-fhs (-F)
+
+# As this option requires a glibc package (glibc-for-fhs), try to run these
+# tests with the user's global store to make it easier to build or download a
+# substitute.
+storedir="`guile -c '(use-modules (guix config))(display %storedir)'`"
+localstatedir="`guile -c '(use-modules (guix config))(display %localstatedir)'`"
+NIX_STORE_DIR="$storedir"
+GUIX_DAEMON_SOCKET="$localstatedir/guix/daemon-socket/socket"
+export NIX_STORE_DIR GUIX_DAEMON_SOCKET
+
+if ! guile -c '(use-modules (guix)) (exit (false-if-exception (open-connection)))'
+then
+    exit 77
+fi
+
+# Test that the container has FHS specific files/directories.  Note that /bin
+# exists in a non-FHS container as it will contain sh, a symlink to the bash
+# package, so we don't test for it.
+guix environment -C --emulate-fhs --ad-hoc --bootstrap guile-bootstrap \
+     -- guile -c '(exit (and (file-exists? "/etc/ld.so.cache")
+                             (file-exists? "/lib")
+                             (file-exists? "/sbin")
+                             (file-exists? "/usr/bin")
+                             (file-exists? "/usr/include")
+                             (file-exists? "/usr/lib")
+                             (file-exists? "/usr/libexec")
+                             (file-exists? "/usr/sbin")
+                             (file-exists? "/usr/share")))'
+
+# Test that the ld cache was generated and can be successfully read.
+guix environment -C --emulate-fhs --ad-hoc --bootstrap guile-bootstrap \
+     -- guile -c '(execlp "ldconfig" "ldconfig" "-p")'