Libguestfs - May 2023 - [PATCH libnbd v2] tests: Add a test of nbd_{set, get}_socket_activation_name

I added a test of the LISTEN_FDNAMES=unknown case as well, otherwise
only minor cosmetic changes from last time.

Rich.

Also test that the expected environment variable is set when
connecting to nbdkit.

This test requires nbdkit >= 1.35.2 which added support for -D
nbdkit.environ=1 to dump the environment, and will be skipped with
other versions.
---
 .gitignore                     |   1 +
 tests/Makefile.am              |   8 +++
 tests/socket-activation-name.c | 122 +++++++++++++++++++++++++++++++++
 3 files changed, 131 insertions(+)

diff --git a/.gitignore b/.gitignore
index df4b6ca249..fe7feffa5b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -254,6 +254,7 @@ Makefile.in
 /tests/read-write-flag
 /tests/server-death
 /tests/shutdown-flags
+/tests/socket-activation-name
 /tests/synch-parallel
 /tests/synch-parallel-tls
 /ublk/nbdublk
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 81a7db38f6..3a93251efe 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -231,6 +231,7 @@ check_PROGRAMS += \
 	meta-base-allocation \
 	closure-lifetimes \
 	pread-initialize \
+	socket-activation-name \
 	$(NULL)
 
 TESTS += \
@@ -301,6 +302,7 @@ TESTS += \
 	meta-base-allocation \
 	closure-lifetimes \
 	pread-initialize \
+	socket-activation-name \
 	$(NULL)
 
 # This test is compiled but not run because it requires a fixed port:
@@ -642,6 +644,12 @@ closure_lifetimes_LDADD = $(top_builddir)/lib/libnbd.la
 pread_initialize_SOURCES = pread-initialize.c
 pread_initialize_LDADD = $(top_builddir)/lib/libnbd.la
 
+socket_activation_name_SOURCES = \
+	socket-activation-name.c \
+	requires.c \
+	requires.h
+socket_activation_name_LDADD = $(top_builddir)/lib/libnbd.la
+
 #----------------------------------------------------------------------
 # Testing TLS support.
 
diff --git a/tests/socket-activation-name.c b/tests/socket-activation-name.c
new file mode 100644
index 0000000000..66da654f13
--- /dev/null
+++ b/tests/socket-activation-name.c
@@ -0,0 +1,122 @@
+/* NBD client library in userspace
+ * Copyright Red Hat
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/* Test nbd_{set,get}_socket_activation_name API. */
+
+#undef NDEBUG
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <assert.h>
+
+#include <libnbd.h>
+
+#include "requires.h"
+
+#define DEBUG_FILE "socket-activation-name.out"
+
+int
+main (int argc, char *argv[])
+{
+  struct nbd_handle *nbd;
+  char *r;
+
+  /* Test that this version of nbdkit supports -D nbdkit.environ=1
+   * added in nbdkit 1.35.2.
+   *
+   * As a side-effect, also checks we have nbdkit, the null plugin and
+   * a working grep command, all needed below.
+   */
+  requires ("libnbd_sentinel=42 "
+            "nbdkit -v -D nbdkit.environ=1 null --run true 2>&1 |
"
+            "grep -sq 'debug.*libnbd_sentinel=42'");
+
+  nbd = nbd_create ();
+  if (nbd == NULL) {
+    fprintf (stderr, "%s\n", nbd_get_error ());
+    exit (EXIT_FAILURE);
+  }
+
+  /* Check firstly that it defaults to empty string. */
+  r = nbd_get_socket_activation_name (nbd);
+  assert (r != NULL);
+  assert (strcmp (r, "") == 0);
+  free (r);
+
+  /* Run external nbdkit and check the LISTEN_FDNAMES environment
+   * variable is set to "unknown".  We need to capture the debug
+   * output of nbdkit, hence the journey through the shell.
+   */
+  unlink (DEBUG_FILE);
+  char *cmd[] = {
+    "sh", "-c",
+    "exec 2> " DEBUG_FILE "\n"
+    "exec nbdkit --exit-with-parent -v -D nbdkit.environ=1 null
1024\n",
+    NULL
+  };
+  if (nbd_connect_systemd_socket_activation (nbd, cmd) == -1) {
+    fprintf (stderr, "%s\n", nbd_get_error ());
+    exit (EXIT_FAILURE);
+  }
+
+  /* Check the size is expected so we know we managed to connect to nbdkit. */
+  assert (nbd_get_size (nbd) == 1024);
+
+  nbd_close (nbd);
+
+  /* nbdkit doesn't know anything about socket activation names, but
+   * the LISTEN_FDNAMES environment variable should appear in the
+   * debug output.
+   */
+  assert (system ("grep 'debug.*LISTEN_FDNAMES=unknown' "
DEBUG_FILE) == 0);
+  unlink (DEBUG_FILE);
+
+  /* Test again with a specific name. */
+  nbd = nbd_create ();
+  if (nbd == NULL) {
+    fprintf (stderr, "%s\n", nbd_get_error ());
+    exit (EXIT_FAILURE);
+  }
+  /* Check we can set it to something and read that back. */
+  assert (nbd_set_socket_activation_name (nbd, "hello") == 0);
+  r = nbd_get_socket_activation_name (nbd);
+  assert (r != NULL);
+  assert (strcmp (r, "hello") == 0);
+  free (r);
+
+  /* Run external nbdkit again (same command as above). */
+  if (nbd_connect_systemd_socket_activation (nbd, cmd) == -1) {
+    fprintf (stderr, "%s\n", nbd_get_error ());
+    exit (EXIT_FAILURE);
+  }
+
+  assert (nbd_get_size (nbd) == 1024);
+
+  nbd_close (nbd);
+
+  /* Check LISTEN_FDNAMES was set to the known value. */
+  assert (system ("grep 'debug.*LISTEN_FDNAMES=hello' "
DEBUG_FILE) == 0);
+  unlink (DEBUG_FILE);
+
+  exit (EXIT_SUCCESS);
+}
-- 
2.39.2