fateshare: a plugin for managing child processes

For the reasons of modularity and security, it is useful
to have various functionality split into processes different from VPP.
However, this approach presents the challenges of managing those processes,
and is markedly different from simply running everything within VPP process.

This plugin is an experiment in having the VPP itself start off a monitor
process which in turn starts the child processes, and restarts them if they
quit.

If the VPP process ceases to exist, the monitor process terminates all
the descendant processes and quits itself.

This allows to preserve the "single entity to manage" approach of
simply running a barebones VPP.

An example of running it:

export DPDK_CONFIG=""
export DISABLED_PLUGINS=dpdk
export EXTRA_VPP_CONFIG="fateshare { monitor ./build-root/install-vpp_debug-native/vpp/bin/vpp_fateshare_monitor command ./test1 }"
make run

Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>
Change-Id: I66221fd7403f220d9652fe76958ca499cfd070a7
Type: feature

1 files changed, 48 insertions, 0 deletions

diff --git a/src/plugins/fateshare/fateshare.h b/src/plugins/fateshare/fateshare.h
new file mode 100644
index 00000000000..4ad7ac1df16
--- /dev/null
+++ b/src/plugins/fateshare/fateshare.h
@@ -0,0 +1,48 @@
+
+/*
+ * fateshare.h - skeleton vpp engine plug-in header file
+ *
+ * Copyright (c) 2022 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef __included_fateshare_h__
+#define __included_fateshare_h__
+
+#include <vnet/vnet.h>
+#include <vnet/ip/ip.h>
+
+#include <vppinfra/hash.h>
+#include <vppinfra/error.h>
+
+typedef struct
+{
+  /* convenience */
+  vlib_main_t *vlib_main;
+
+  u8 *monitor_cmd;
+  u8 *monitor_logfile;
+  pid_t monitor_pid;
+  u8 **commands;
+} fateshare_main_t;
+
+extern fateshare_main_t fateshare_main;
+
+#endif /* __included_fateshare_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */