support/testing: add netsnmp runtime test

Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 639f507479)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

DEVELOPERS

@@ -1823,6 +1823,8 @@ F:	support/testing/tests/package/test_mtools.py
 F:	support/testing/tests/package/test_mtr.py
 F:	support/testing/tests/package/test_ncdu.py
 F:	support/testing/tests/package/test_netcat.py
+F:	support/testing/tests/package/test_netsnmp.py
+F:	support/testing/tests/package/test_netsnmp/
 F:	support/testing/tests/package/test_nftables.py
 F:	support/testing/tests/package/test_nftables/
 F:	support/testing/tests/package/test_ngrep.py

support/testing/tests/package/test_netsnmp.py

@@ -0,0 +1,44 @@
+import os
+
+import infra.basetest
+
+
+class TestNetSNMP(infra.basetest.BRTest):
+    rootfs_overlay = \
+        infra.filepath("tests/package/test_netsnmp/rootfs-overlay")
+    config = infra.basetest.BASIC_TOOLCHAIN_CONFIG + \
+        f"""
+        BR2_PACKAGE_NETSNMP=y
+        BR2_ROOTFS_OVERLAY="{rootfs_overlay}"
+        BR2_TARGET_ROOTFS_CPIO=y
+        # BR2_TARGET_ROOTFS_TAR is not set
+        """
+
+    def test_run(self):
+        cpio_file = os.path.join(self.builddir, "images", "rootfs.cpio")
+        self.emulator.boot(arch="armv5",
+                           kernel="builtin",
+                           options=["-initrd", cpio_file])
+        self.emulator.login()
+
+        # We check the daemon and a client program can execute.
+        self.assertRunOk("snmpd --version")
+        self.assertRunOk("snmpget --version")
+
+        # The daemon is supposed to be started by the initscript,
+        # since we included a /etc/snmp/snmpd.conf file. We should be
+        # able to walk through the SNMPv2 system MIB.
+        self.assertRunOk("snmpwalk -v 2c -c public 127.0.0.1 system")
+
+        # We check few OIDs has the expected values. sysContact and
+        # sysLocation are set in the snmpd.conf file.
+        tests = [
+            ("system.sysName.0", "STRING: buildroot"),
+            ("system.sysContact.0", "STRING: Buildroot Test User"),
+            ("system.sysLocation.0", "STRING: Buildroot Test Infra")
+        ]
+        for oid, expected_out in tests:
+            cmd = f"snmpget -v 2c -c public -Ov 127.0.0.1 {oid}"
+            out, ret = self.emulator.run(cmd)
+            self.assertEqual(ret, 0)
+            self.assertEqual(out[0], expected_out)

support/testing/tests/package/test_netsnmp/rootfs-overlay/etc/snmp/snmpd.conf

@@ -0,0 +1,4 @@
+# This is a simple configuration for testing.
+syslocation Buildroot Test Infra
+syscontact Buildroot Test User
+rocommunity public default system