gcloud: move package hacks ot its own module

pkgs/gcloud-wrapped/default.nix

@@ -0,0 +1,23 @@
+{ buildGoModule, pkgs }:
+let
+  gcloud-wrapper = buildGoModule {
+    name = "gcloud-wrapper";
+    src = ./.;
+    vendorHash = null;
+  };
+in
+pkgs.symlinkJoin {
+  name = "google-cloud-sdk-wrapped";
+  paths = [ pkgs.google-cloud-sdk ];
+  nativeBuildInputs = [ pkgs.makeWrapper ];
+  postBuild = ''
+    # Remove the original gcloud symlink
+    rm $out/bin/gcloud
+
+    # Create a shell wrapper called gcloud-wrapped that executes the real gcloud
+    makeWrapper ${pkgs.google-cloud-sdk}/bin/gcloud $out/bin/gcloud-wrapped
+
+    # Replace gcloud with our caching wrapper
+    ln -s ${gcloud-wrapper}/bin/gcloud-wrapper $out/bin/gcloud
+  '';
+}

pkgs/gcloud-wrapped/go.mod

@@ -0,0 +1,3 @@
+module git.jakstys.lt/motiejus/config/pkgs/gcloud-wrapper
+
+go 1.23

pkgs/gcloud-wrapped/main.go

@@ -0,0 +1,139 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"time"
+)
+
+const (
+	cachePath      = ".config/gcloud/config-helper-cache.json"
+	cacheThreshold = 1 * time.Second
+)
+
+type credentialCache struct {
+	Credential struct {
+		TokenExpiry string `json:"token_expiry"`
+	} `json:"credential"`
+}
+
+func getCachePath() (string, error) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(home, cachePath), nil
+}
+
+func argsMatch(args []string) bool {
+	return len(args) == 4 &&
+		args[0] == "config" &&
+		args[1] == "config-helper" &&
+		args[2] == "--format" &&
+		args[3] == "json"
+}
+
+func parseISO8601(s string) (time.Time, error) {
+	return time.Parse(time.RFC3339, s)
+}
+
+func execGcloud(args []string) {
+	argv := make([]string, len(args))
+	argv[0] = "gcloud-wrapped"
+	copy(argv[1:], args[1:])
+
+	cmd := exec.Command(argv[0], argv[1:]...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	cmd.Stdin = os.Stdin
+
+	if err := cmd.Run(); err != nil {
+		if exitErr, ok := err.(*exec.ExitError); ok {
+			os.Exit(exitErr.ExitCode())
+		}
+		os.Exit(1)
+	}
+	os.Exit(0)
+}
+
+func runGcloudAndCache(cachePath string) error {
+	cmd := exec.Command("gcloud-wrapped", "config", "config-helper", "--format", "json")
+	output, err := cmd.CombinedOutput()
+
+	if err != nil {
+		os.Remove(cachePath)
+		os.Stderr.Write(output)
+		if exitErr, ok := err.(*exec.ExitError); ok {
+			os.Exit(exitErr.ExitCode())
+		}
+		os.Exit(1)
+	}
+
+	if err := os.MkdirAll(filepath.Dir(cachePath), 0755); err != nil {
+		return err
+	}
+
+	if err := os.WriteFile(cachePath, output, 0600); err != nil {
+		return err
+	}
+
+	os.Stdout.Write(output)
+	return nil
+}
+
+func main() {
+	args := os.Args[1:]
+
+	if !argsMatch(args) {
+		execGcloud(os.Args)
+	}
+
+	cachePath, err := getCachePath()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "failed to get cache path: %v\n", err)
+		os.Exit(1)
+	}
+
+	cacheData, err := os.ReadFile(cachePath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			if err := runGcloudAndCache(cachePath); err != nil {
+				fmt.Fprintf(os.Stderr, "failed to run gcloud: %v\n", err)
+				os.Exit(1)
+			}
+			return
+		}
+		fmt.Fprintf(os.Stderr, "failed to read cache: %v\n", err)
+		os.Exit(1)
+	}
+
+	var cache credentialCache
+	if err := json.Unmarshal(cacheData, &cache); err != nil {
+		if err := runGcloudAndCache(cachePath); err != nil {
+			fmt.Fprintf(os.Stderr, "failed to run gcloud: %v\n", err)
+			os.Exit(1)
+		}
+		return
+	}
+
+	expiry, err := parseISO8601(cache.Credential.TokenExpiry)
+	if err != nil {
+		if err := runGcloudAndCache(cachePath); err != nil {
+			fmt.Fprintf(os.Stderr, "failed to run gcloud: %v\n", err)
+			os.Exit(1)
+		}
+		return
+	}
+
+	if time.Until(expiry) > cacheThreshold {
+		os.Stdout.Write(cacheData)
+	} else {
+		if err := runGcloudAndCache(cachePath); err != nil {
+			fmt.Fprintf(os.Stderr, "failed to run gcloud: %v\n", err)
+			os.Exit(1)
+		}
+	}
+}