debug backend plugin

DEVELOPMENT_GUIDE.md

@@ -0,0 +1,28 @@
+# Plugin development
+
+### Debugging backend plugin
+
+For debugging backend part written on Go, you should go through a few steps. First, build a plugin with special flags for debugging:
+
+```sh
+make build-debug
+```
+
+Then, configure your editor to connect to [delve](https://github.com/go-delve/delve) debugger running in headless mode. This is an example for VS Code:
+```json
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "Debug backend plugin",
+      "type": "go",
+      "request": "attach",
+      "mode": "remote",
+      "port": 3222,
+      "host": "127.0.0.1",
+    },
+  ]
+}
+```
+
+Finally, run grafana-server and then execute `./debug-backend.sh` from grafana-zabbix root folder. This script will attach delve to running plugin. Now you can go to the VS Code and run _Debug backend plugin_ debug config.

Makefile

@@ -13,6 +13,8 @@ build-frontend:
 	yarn dev-build
 build-backend:
 	env GOOS=linux go build -mod=vendor -o ./dist/zabbix-plugin_linux_amd64 ./pkg
+build-debug:
+	env GOOS=linux go build -mod=vendor -gcflags=all="-N -l" -o ./dist/zabbix-plugin_linux_amd64 ./pkg
 
 dist: dist-frontend dist-backend
 dist-frontend:

debug-backend.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+if [ "$1" == "-h" ]; then
+  echo "Usage: ${BASH_SOURCE[0]} [plugin process name] [port]"
+  exit
+fi
+
+PORT="${2:-3222}"
+PLUGIN_NAME="${1:-'zabbix-plugin_'}"
+echo $PORT $PLUGIN_NAME
+
+ptrace_scope=`cat /proc/sys/kernel/yama/ptrace_scope`
+if [ "$ptrace_scope" != 0 ]; then
+  echo "WARNING: ptrace_scope set to value other than 0, this might prevent debugger from connecting, try writing \"0\" to /proc/sys/kernel/yama/ptrace_scope.
+Read more at https://www.kernel.org/doc/Documentation/security/Yama.txt"
+fi
+
+dlv attach `pgrep ${PLUGIN_NAME}` --headless --listen 0.0.0.0:${PORT} --api-version 2
+pkill dlv