sic v2 client WP7: parseHostsConfig — minimal hosts.toml subset parser (stdlib only)

cmd/sic/addr.go

@@ -1,6 +1,9 @@
 package main
 
-import "fmt"
+import (
+	"fmt"
+	"strings"
+)
 
 func parseTarget(s string) (host string, hops []string) {
 	for i := 0; i < len(s); i++ {
@@ -61,3 +64,45 @@ func resolveVerbs(hops []string, nest []string) ([]string, error) {
 	}
 	return verbs, nil
 }
+
+func parseHostsConfig(data string) (map[string][]string, error) {
+	cfg := make(map[string][]string)
+	lines := strings.Split(data, "\n")
+	var currentHost string
+	for _, line := range lines {
+		line = strings.TrimSpace(line)
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		if strings.HasPrefix(line, "[") && strings.HasSuffix(line, "]") {
+			currentHost = line[1 : len(line)-1]
+			if _, ok := cfg[currentHost]; !ok {
+				cfg[currentHost] = nil
+			}
+			continue
+		}
+		if strings.HasPrefix(line, "nest = ") || strings.HasPrefix(line, "nest=") {
+			eqIdx := strings.Index(line, "=")
+			if eqIdx == -1 {
+				continue
+			}
+			rest := strings.TrimSpace(line[eqIdx+1:])
+			if !strings.HasPrefix(rest, "[") || !strings.HasSuffix(rest, "]") {
+				continue
+			}
+			inner := rest[1 : len(rest)-1]
+			if strings.TrimSpace(inner) == "" {
+				cfg[currentHost] = []string{}
+				continue
+			}
+			var items []string
+			for _, item := range strings.Split(inner, ",") {
+				item = strings.TrimSpace(item)
+				item = strings.Trim(item, "\"")
+				items = append(items, item)
+			}
+			cfg[currentHost] = items
+		}
+	}
+	return cfg, nil
+}

cmd/sic/hostscfg_test.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+// WP7: parseHostsConfig parses the minimal hosts.toml subset (no external dep — stdlib only):
+//   # comment
+//   [<host>]
+//   nest = ["incus", "docker"]
+// into map[host] -> ordered runtime types. Comments and blank lines are ignored; an empty nest
+// list is a present host with zero hops.
+func TestParseHostsConfig(t *testing.T) {
+	data := "# fleet nest config\n" +
+		"[boltzmann]\n" +
+		"nest = [\"incus\", \"docker\"]\n" +
+		"\n" +
+		"[data]\n" +
+		"nest = [\"pct\"]\n" +
+		"\n" +
+		"[bosch]\n" +
+		"nest = []\n"
+	cfg, err := parseHostsConfig(data)
+	if err != nil {
+		t.Fatalf("unexpected err: %v", err)
+	}
+	if !reflect.DeepEqual(cfg["boltzmann"], []string{"incus", "docker"}) {
+		t.Fatalf("boltzmann nest = %#v, want [incus docker]", cfg["boltzmann"])
+	}
+	if !reflect.DeepEqual(cfg["data"], []string{"pct"}) {
+		t.Fatalf("data nest = %#v, want [pct]", cfg["data"])
+	}
+	b, ok := cfg["bosch"]
+	if !ok || len(b) != 0 {
+		t.Fatalf("bosch must be present with an empty nest; got %#v ok=%v", b, ok)
+	}
+}