From f5a64abb4e661850c3b59b1907d6ac4e5a8e4676 Mon Sep 17 00:00:00 2001
From: Dan Fuhry <dan@fuhry.com>
Date: Tue, 27 Feb 2024 10:31:16 -0500
Subject: [PATCH] utils/hostname: fix build on darwin, support openbsd

---
 utils/hostname/hostname.go         |  2 +-
 utils/hostname/hostname_macos.go   |  4 +-
 utils/hostname/hostname_openbsd.go | 91 ++++++++++++++++++++++++++++++
 3 files changed, 94 insertions(+), 3 deletions(-)
 create mode 100644 utils/hostname/hostname_openbsd.go

diff --git a/utils/hostname/hostname.go b/utils/hostname/hostname.go
index f99e32d..65431fb 100644
--- a/utils/hostname/hostname.go
+++ b/utils/hostname/hostname.go
@@ -1,4 +1,4 @@
-//go:build !darwin
+//go:build !darwin && !openbsd
 
 package hostname
 
diff --git a/utils/hostname/hostname_macos.go b/utils/hostname/hostname_macos.go
index 75e07da..73337bd 100644
--- a/utils/hostname/hostname_macos.go
+++ b/utils/hostname/hostname_macos.go
@@ -16,9 +16,9 @@ import (
 	"howett.net/plist"
 )
 
-const (
-	defaultDomainName = constants.DefaultHostDomain
+var defaultDomainName = constants.DefaultHostDomain
 
+const (
 	systemPreferencesPlist = "/Library/Preferences/SystemConfiguration/preferences.plist"
 )
 
diff --git a/utils/hostname/hostname_openbsd.go b/utils/hostname/hostname_openbsd.go
new file mode 100644
index 0000000..caf8ebe
--- /dev/null
+++ b/utils/hostname/hostname_openbsd.go
@@ -0,0 +1,91 @@
+// go:build openbsd
+
+package hostname
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"strings"
+	"time"
+
+	"go.fuhry.dev/runtime/constants"
+	"go.fuhry.dev/runtime/utils/log"
+)
+
+var defaultDomainName = constants.DefaultHostDomain
+var cachedFqdn string
+
+func Hostname() string {
+	fqdn := Fqdn()
+	return strings.Split(fqdn, ".")[0]
+}
+
+func DomainName() string {
+	fqdn := strings.Split(Fqdn(), ".")
+	if len(fqdn) > 1 {
+		return strings.Join(fqdn[1:], ".")
+	}
+	return defaultDomainName
+}
+
+func RegionName() string {
+	return strings.Split(DomainName(), ".")[0]
+}
+
+func Fqdn() string {
+	if cachedFqdn != "" {
+		return cachedFqdn
+	}
+	cachedFqdn = fqdn()
+	return cachedFqdn
+}
+
+func fqdn() string {
+	myName, myNameErr := os.ReadFile("/etc/myname")
+	if myNameErr == nil {
+		return maybeAppendDefaultDomainName(strings.Trim(string(myName), " \r\n"))
+	}
+
+	dnsFqdn, dnsErr := fqdnFromDns()
+	if dnsErr == nil {
+		return maybeAppendDefaultDomainName(dnsFqdn)
+	}
+
+	log.Panicf("failed to get fqdn: myname failed because %q, and dns failed because %q", myNameErr.Error(), dnsErr.Error())
+	return ""
+}
+
+func maybeAppendDefaultDomainName(name string) string {
+	parts := strings.Split(name, ".")
+	if len(parts) < 2 {
+		name = fmt.Sprintf("%s.%s", parts[0], defaultDomainName)
+	}
+
+	log.Default().V(1).Noticef("detected system hostname: %q", name)
+
+	return name
+}
+
+func fqdnFromDns() (string, error) {
+	resolver := &net.Resolver{}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
+	defer cancel()
+
+	result, err := resolver.LookupAddr(ctx, "127.0.0.1")
+	if err != nil {
+		return "", fmt.Errorf("failed to lookup hostname for 127.0.0.1: %v", err)
+	}
+
+	for _, name := range result {
+		parts := strings.Split(name, ".")
+		if parts[0] != "localhost" {
+			return parts[0], nil
+		}
+	}
+
+	return "", errors.New("failed to lookup any hostname for 127.0.0.1 that does not resolve to just \"localhost\"")
+}
-- 
2.50.1