internal/controller: add cache directory creation in NewAtlasExec

internal/controller/common.go

@@ -102,17 +102,27 @@ func NewAtlasExec(dir string, c *Cloud, home string) (AtlasExec, error) {
 		return nil, err
 	}
 	env := atlasexec.NewOSEnviron()
+	cacheHome := ""
 	// If DATA_DIR is set, create a resource-specific directory and set HOME.
 	if dataDir := os.Getenv(envDataDir); dataDir != "" {
 		homeDir := filepath.Join(dataDir, home)
 		if err := os.MkdirAll(homeDir, 0755); err != nil {
 			return nil, fmt.Errorf("creating resource home directory: %w", err)
 		}
 		env["HOME"] = homeDir
-	} else if env["HOME"] == "" {
+		cacheHome = filepath.Join(homeDir, ".cache")
+	} else if env["HOME"] == "" || env["HOME"] == "/" {
 		// Ensure HOME is set to a safe default when not provided by the environment
 		// and no DATA_DIR-based home directory is configured.
 		env["HOME"] = "/tmp"
+		cacheHome = "/tmp/.cache"
+	}
+	if cacheHome != "" {
+		if err := os.MkdirAll(cacheHome, 0755); err != nil {
+			return nil, fmt.Errorf("creating cache directory: %w", err)
+		}
+		env["XDG_CACHE_HOME"] = cacheHome
+		env["GOCACHE"] = filepath.Join(cacheHome, "go-build")
 	}
 	if c != nil && c.Token != "" {
 		env["ATLAS_TOKEN"] = c.Token

internal/controller/common_test.go

@@ -15,12 +15,18 @@
 package controller
 
 import (
+	"context"
+	"os"
+	"path/filepath"
 	"reflect"
+	"strings"
 	"testing"
 	"time"
 
+	"ariga.io/atlas/atlasexec"
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/hclwrite"
+	"github.com/stretchr/testify/require"
 )
 
 func Test_mergeBlocks(t *testing.T) {
@@ -303,3 +309,89 @@ func Test_backoffDelayAt(t *testing.T) {
 		})
 	}
 }
+
+func TestNewAtlasExec_HomeAndCache(t *testing.T) {
+	tests := []struct {
+		name         string
+		homeEnv      string
+		dataDir      string
+		resourceHome string
+		wantHome     string
+		wantCache    string
+	}{
+		{
+			name:         "data dir overrides home root",
+			homeEnv:      "/",
+			dataDir:      "data",
+			resourceHome: "ns/name",
+			wantHome:     "data/ns/name",
+			wantCache:    "data/ns/name/.cache",
+		},
+		{
+			name:         "empty home falls back to tmp",
+			homeEnv:      "",
+			resourceHome: "ignored",
+			wantHome:     "/tmp",
+			wantCache:    "/tmp/.cache",
+		},
+		{
+			name:         "root home falls back to tmp",
+			homeEnv:      "/",
+			resourceHome: "ignored",
+			wantHome:     "/tmp",
+			wantCache:    "/tmp/.cache",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tmp := t.TempDir()
+			capture := filepath.Join(tmp, "env.txt")
+			path := filepath.Join(tmp, "atlas")
+			script := `#!/bin/sh
+{
+  printf 'HOME=%s\n' "${HOME}"
+  printf 'XDG_CACHE_HOME=%s\n' "${XDG_CACHE_HOME}"
+  printf 'GOCACHE=%s\n' "${GOCACHE}"
+} > "${CAPTURE_ENV}"
+printf '{"Org":"test"}'
+`
+			require.NoError(t, os.WriteFile(path, []byte(script), 0755))
+			t.Setenv("PATH", tmp+string(os.PathListSeparator)+os.Getenv("PATH"))
+			t.Setenv("CAPTURE_ENV", capture)
+			t.Setenv("HOME", tt.homeEnv)
+			if tt.dataDir == "" {
+				t.Setenv(envDataDir, "")
+			} else {
+				dataDir := filepath.Join(tmp, tt.dataDir)
+				require.NoError(t, os.MkdirAll(dataDir, 0755))
+				t.Setenv(envDataDir, dataDir)
+				tt.wantHome = filepath.Join(tmp, tt.wantHome)
+				tt.wantCache = filepath.Join(tmp, tt.wantCache)
+			}
+			exec, err := NewAtlasExec(tmp, nil, tt.resourceHome)
+			require.NoError(t, err)
+			_, err = exec.WhoAmI(context.Background(), &atlasexec.WhoAmIParams{})
+			require.NoError(t, err)
+			require.DirExists(t, tt.wantCache)
+			if tt.dataDir != "" {
+				require.DirExists(t, tt.wantHome)
+			}
+			data, err := os.ReadFile(capture)
+			require.NoError(t, err)
+			got := make(map[string]string)
+			for _, line := range strings.Split(strings.TrimSpace(string(data)), "\n") {
+				if line == "" {
+					continue
+				}
+				k, v, ok := strings.Cut(line, "=")
+				require.True(t, ok)
+				got[k] = v
+			}
+			require.Equal(t, map[string]string{
+				"HOME":           tt.wantHome,
+				"XDG_CACHE_HOME": tt.wantCache,
+				"GOCACHE":        filepath.Join(tt.wantCache, "go-build"),
+			}, got)
+		})
+	}
+}