environment: Turn "lo" up in network-less containers.

This is a followup to 0f53c801b91919380a924b402d1ff822bb1dc6ea.

* guix/scripts/environment.scm (launch-environment/container): Add call
to 'set-network-interface-up'.
* tests/guix-environment-container.sh: Add test.

1 files changed, 11 insertions, 0 deletions

diff --git a/tests/guix-environment-container.sh b/tests/guix-environment-container.sh
index 3674aa60269..f2d15c8d0c7 100644
--- a/tests/guix-environment-container.sh
+++ b/tests/guix-environment-container.sh
@@ -48,6 +48,17 @@ fi
 guix environment --container --ad-hoc --bootstrap guile-bootstrap \
      -- guile -c '(exit (pair? (getaddrinfo "localhost" "80")))'
 
+# We should get ECONNREFUSED, not ENETUNREACH, which would indicate that "lo"
+# is down.
+guix environment --container --ad-hoc --bootstrap guile-bootstrap \
+     -- guile -c "(exit (= ECONNREFUSED
+  (catch 'system-error
+    (lambda ()
+      (let ((sock (socket AF_INET SOCK_STREAM 0)))
+        (connect sock AF_INET INADDR_LOOPBACK 12345)))
+    (lambda args
+      (pk 'errno (system-error-errno args))))))"
+
 # Make sure '--preserve' is honored.
 result="`FOOBAR=42; export FOOBAR; guix environment -C --ad-hoc --bootstrap \
    guile-bootstrap -E ^FOO -- guile -c '(display (getenv \"FOOBAR\"))'`"