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

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 | 99 ++++++++++++++++++++++++++++++++++
 3 files changed, 108 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..22902a4db9
--- /dev/null
+++ b/tests/socket-activation-name.c
@@ -0,0 +1,99 @@
+/* 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.
+   */
+  requires ("libnbd_sentinel=42 "
+            "nbdkit -fv -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);
+
+  /* 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 and check the LISTEN_FDNAMES environment
+   * variable is set.  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 -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=hello' "
DEBUG_FILE) == 0);
+  unlink (DEBUG_FILE);
+
+  exit (EXIT_SUCCESS);
+}
-- 
2.39.2

On 5/7/23 12:43, Richard W.M. Jones wrote:
> 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 | 99 ++++++++++++++++++++++++++++++++++
>  3 files changed, 108 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..22902a4db9
> --- /dev/null
> +++ b/tests/socket-activation-name.c
> @@ -0,0 +1,99 @@
> +/* 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.
> +   */
> +  requires ("libnbd_sentinel=42 "
> +            "nbdkit -fv -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);
> +
> +  /* 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 and check the LISTEN_FDNAMES environment
> +   * variable is set.  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 -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=hello' "
DEBUG_FILE) == 0);
I didn't remember the return value of system(); I've now tried to read
up (both the Linux man page and POSIX), and my head is spinning a bit :)

It seems like we should do something like:

  int rc;

  rc = system ("grep 'debug.*LISTEN_FDNAMES=hello' "
DEBUG_FILE);
  assert (rc != -1 && WIFEXITED (rc) && WEXITSTATUS (rc) == 0);

Also, should we invoke this "grep" with "-sq" as well (at
least "-q")?
Or do we want the match to show up in the test suite log?

Thanks!
Laszlo
> +  unlink (DEBUG_FILE);
> +
> +  exit (EXIT_SUCCESS);
> +}

On Sun, May 07, 2023 at 11:43:23AM +0100, Richard W.M. Jones
wrote:
> 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 | 99 ++++++++++++++++++++++++++++++++++
>  3 files changed, 108 insertions(+)
> 
> +  /* Check firstly that it defaults to empty string. */
> +  r = nbd_get_socket_activation_name (nbd);
> +  assert (r != NULL);
> +  assert (strcmp (r, "") == 0);
> +  free (r);
> +
> +  /* 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 and check the LISTEN_FDNAMES environment
> +   * variable is set.  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 -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);
> +  }
Should we run this twice, once with a set name (as you did here, to
prove LISTEN_FDNAMES=hello makes it through), and again with the
default name (to see that LISTEN_FDNAMES=unknown is now populated)?

Otherwise, this is a nice addition.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org