From 6f7a8fa4d4ec786630ed785a43e9a9f18e34426b Mon Sep 17 00:00:00 2001
From: Kyle Isom <kyle@imap.cc>
Date: Fri, 26 Apr 2024 14:15:08 -0700
Subject: [PATCH] Add host tool.

---
 .bazelrc         |  2 ++
 MODULE.bazel     |  9 +++++++++
 WORKSPACE        | 32 --------------------------------
 WORKSPACE.bazel  | 11 +++++++++++
 cmd/host/README  |  5 +++++
 cmd/host/main.go | 41 +++++++++++++++++++++++++++++++++++++++++
 6 files changed, 68 insertions(+), 32 deletions(-)
 create mode 100644 .bazelrc
 create mode 100644 MODULE.bazel
 delete mode 100644 WORKSPACE
 create mode 100644 WORKSPACE.bazel
 create mode 100644 cmd/host/README
 create mode 100644 cmd/host/main.go

diff --git a/.bazelrc b/.bazelrc
new file mode 100644
index 0000000..e8138cb
--- /dev/null
+++ b/.bazelrc
@@ -0,0 +1,2 @@
+# Enable Bzlmod for every Bazel command
+common --enable_bzlmod
diff --git a/MODULE.bazel b/MODULE.bazel
new file mode 100644
index 0000000..e6cd18a
--- /dev/null
+++ b/MODULE.bazel
@@ -0,0 +1,9 @@
+###############################################################################
+# Bazel now uses Bzlmod by default to manage external dependencies.
+# Please consider migrating your external dependencies from WORKSPACE to MODULE.bazel.
+#
+# For more details, please check https://github.com/bazelbuild/bazel/issues/18958
+###############################################################################
+
+bazel_dep(name = "rules_go", version = "0.47.0")
+bazel_dep(name = "gazelle", version = "0.36.0")
\ No newline at end of file
diff --git a/WORKSPACE b/WORKSPACE
deleted file mode 100644
index 2e1bc16..0000000
--- a/WORKSPACE
+++ /dev/null
@@ -1,32 +0,0 @@
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-
-
-### Go tooling, including Gazelle to generate and maintain BUILD files.
-http_archive(
-    name = "io_bazel_rules_go",
-    sha256 = "6b65cb7917b4d1709f9410ffe00ecf3e160edf674b78c54a894471320862184f",
-    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.39.0/rules_go-v0.39.0.zip",
-        "https://github.com/bazelbuild/rules_go/releases/download/v0.39.0/rules_go-v0.39.0.zip",
-    ],
-)
-
-http_archive(
-    name = "bazel_gazelle",
-    sha256 = "ecba0f04f96b4960a5b250c8e8eeec42281035970aa8852dda73098274d14a1d",
-    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/bazel-gazelle/releases/download/v0.29.0/bazel-gazelle-v0.29.0.tar.gz",
-        "https://github.com/bazelbuild/bazel-gazelle/releases/download/v0.29.0/bazel-gazelle-v0.29.0.tar.gz",
-    ],
-)
-
-load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_dependencies")
-load("@bazel_gazelle//:deps.bzl", "gazelle_dependencies")
-load("//:deps.bzl", "go_dependencies")
-
-# gazelle:repository_macro deps.bzl%go_dependencies
-go_dependencies()
-go_rules_dependencies()
-go_register_toolchains(version = "1.20.4")
-gazelle_dependencies()
-
diff --git a/WORKSPACE.bazel b/WORKSPACE.bazel
new file mode 100644
index 0000000..8be24c8
--- /dev/null
+++ b/WORKSPACE.bazel
@@ -0,0 +1,11 @@
+### Go tooling, including Gazelle to generate and maintain BUILD files.
+load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_dependencies")
+load("@bazel_gazelle//:deps.bzl", "gazelle_dependencies")
+load("//:deps.bzl", "go_dependencies")
+
+# gazelle:repository_macro deps.bzl%go_dependencies
+go_dependencies()
+go_rules_dependencies()
+go_register_toolchains(version = "1.20.4")
+gazelle_dependencies()
+
diff --git a/cmd/host/README b/cmd/host/README
new file mode 100644
index 0000000..24d7e38
--- /dev/null
+++ b/cmd/host/README
@@ -0,0 +1,5 @@
+host
+
+This is a utility to display CNAME records and IPs for a hostname. It
+was born of my frustration in trying to figure out how to get the host(1)
+tool installed on Fedora.
\ No newline at end of file
diff --git a/cmd/host/main.go b/cmd/host/main.go
new file mode 100644
index 0000000..856fbbd
--- /dev/null
+++ b/cmd/host/main.go
@@ -0,0 +1,41 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"net"
+)
+
+func lookupHost(host string) error {
+	cname, err := net.LookupCNAME(host)
+	if err != nil {
+		return err
+	}
+
+	if cname != host {
+		fmt.Printf("%s is a CNAME for %s\n", host, cname)
+		host = cname
+	}
+
+	addrs, err := net.LookupHost(host)
+	if err != nil {
+		return err
+	}
+
+	for _, addr := range addrs {
+		fmt.Printf("\t%s\n", addr)
+	}
+
+	return nil
+}
+
+func main() {
+	flag.Parse()
+
+	for _, arg := range flag.Args() {
+		if err := lookupHost(arg); err != nil {
+			log.Println("%s: %s", arg, err)
+		}
+	}
+}