From 8a18d561fc0df212894c3be1e5eda765f695b45b Mon Sep 17 00:00:00 2001
From: Simon Ruderich <simon@ruderich.org>
Date: Fri, 1 Nov 2024 09:37:16 +0100
Subject: [PATCH] Add "cmd" option to start commands on each node

---
 config.go | 15 ++++++++++++++-
 main.go   |  9 +++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/config.go b/config.go
index 3e69cad..ab29d16 100644
--- a/config.go
+++ b/config.go
@@ -17,6 +17,7 @@ type Config struct {
 	Nets  map[string]*Net
 	Nodes map[string]*Node
 	Links []*Link
+	Cmds  []string
 }
 
 type Net struct {
@@ -91,8 +92,11 @@ func LoadConfig(path string) (*Config, error) {
 		case "link":
 			usage = `"link" <node> <node> <net-name>`
 			err = parseConfigLink(&cfg, xs[1:])
+		case "cmd":
+			usage = `"cmd" <string-passed-to-sh-c>`
+			err = parseConfigCmd(&cfg, xs[1:])
 		default:
-			usage = `"net" | "node" | "link"`
+			usage = `"net" | "node" | "link" | "cmd"`
 			err = fmt.Errorf("unknown option %q", xs[0])
 		}
 		if err != nil {
@@ -218,4 +222,13 @@ func parseConfigLink(cfg *Config, args []string) error {
 	return nil
 }
 
+func parseConfigCmd(cfg *Config, args []string) error {
+	if len(args) < 1 {
+		return fmt.Errorf("not enough arguments")
+	}
+
+	cfg.Cmds = append(cfg.Cmds, strings.Join(args, " "))
+	return nil
+}
+
 // vi: set noet ts=4 sw=4 sts=4:
diff --git a/main.go b/main.go
index 85ddd3b..0ceeadf 100644
--- a/main.go
+++ b/main.go
@@ -122,6 +122,15 @@ func main() {
 		ip("-n", nsa, "link", "set", la, "up")
 		ip("-n", nsb, "link", "set", lb, "up")
 	}
+
+	log.Printf("Starting cmds ...")
+	for _, node := range cfg.Nodes {
+		log.Printf(" For node %q", node.Name)
+		ns := node.Name
+		for _, cmd := range cfg.Cmds {
+			ip("netns", "exec", ns, "sh", "-c", cmd, "argv0", ns)
+		}
+	}
 }
 
 func ip(args ...string) {
-- 
2.45.2