internal/env: relocate from app

This package is much cleaner to stub independently, and makes no sense to lump into app.

Signed-off-by: Ophestra <cat@gensokyo.uk>

9 files changed, 108 insertions, 114 deletions

diff --git a/cmd/hakurei/command.go b/cmd/hakurei/command.go
index 53db7533..968bb561 100644
--- a/cmd/hakurei/command.go
+++ b/cmd/hakurei/command.go
@@ -20,6 +20,7 @@ import (
 	"hakurei.app/internal"
 	"hakurei.app/internal/app"
 	"hakurei.app/internal/app/state"
+	"hakurei.app/internal/env"
 	"hakurei.app/message"
 	"hakurei.app/system/dbus"
 )
@@ -320,7 +321,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 		var flagShort bool
 		c.NewCommand("ps", "List active instances", func(args []string) error {
 			var sc hst.Paths
-			app.CopyPaths().Copy(&sc, new(app.Hsu).MustID(nil))
+			env.CopyPaths().Copy(&sc, new(app.Hsu).MustID(nil))
 			printPs(os.Stdout, time.Now().UTC(), state.NewMulti(msg, sc.RunDirPath), flagShort, flagJSON)
 			return errSuccess
 		}).Flag(&flagShort, "short", command.BoolFlag(false), "Print instance id")
diff --git a/cmd/hakurei/parse.go b/cmd/hakurei/parse.go
index 13f4d37a..70419751 100644
--- a/cmd/hakurei/parse.go
+++ b/cmd/hakurei/parse.go
@@ -13,6 +13,7 @@ import (
 	"hakurei.app/hst"
 	"hakurei.app/internal/app"
 	"hakurei.app/internal/app/state"
+	"hakurei.app/internal/env"
 	"hakurei.app/message"
 )
 
@@ -83,7 +84,7 @@ func shortIdentifierString(s string) string {
 func tryIdentifier(msg message.Msg, name string) (config *hst.Config, entry *hst.State) {
 	return tryIdentifierEntries(msg, name, func() map[hst.ID]*hst.State {
 		var sc hst.Paths
-		app.CopyPaths().Copy(&sc, new(app.Hsu).MustID(nil))
+		env.CopyPaths().Copy(&sc, new(app.Hsu).MustID(nil))
 		s := state.NewMulti(msg, sc.RunDirPath)
 		if entries, err := state.Join(s); err != nil {
 			msg.GetLogger().Printf("cannot join store: %v", err) // not fatal
diff --git a/cmd/hakurei/print.go b/cmd/hakurei/print.go
index 06c8b2a9..0dcb59ee 100644
--- a/cmd/hakurei/print.go
+++ b/cmd/hakurei/print.go
@@ -14,6 +14,7 @@ import (
 	"hakurei.app/internal"
 	"hakurei.app/internal/app"
 	"hakurei.app/internal/app/state"
+	"hakurei.app/internal/env"
 	"hakurei.app/message"
 )
 
@@ -23,7 +24,7 @@ func printShowSystem(output io.Writer, short, flagJSON bool) {
 	defer t.MustFlush()
 
 	info := &hst.Info{Version: internal.Version(), User: new(app.Hsu).MustID(nil)}
-	app.CopyPaths().Copy(&info.Paths, info.User)
+	env.CopyPaths().Copy(&info.Paths, info.User)
 
 	if flagJSON {
 		encodeJSON(log.Fatal, output, short, info)
diff --git a/internal/app/env.go b/internal/app/env.go
deleted file mode 100644
index e6d137fc..00000000
--- a/internal/app/env.go
+++ /dev/null
@@ -1,59 +0,0 @@
-package app
-
-import (
-	"strconv"
-
-	"hakurei.app/container/check"
-	"hakurei.app/hst"
-)
-
-// EnvPaths holds paths copied from the environment and is used to create [hst.Paths].
-type EnvPaths struct {
-	// TempDir is returned by [os.TempDir].
-	TempDir *check.Absolute
-	// RuntimePath is copied from $XDG_RUNTIME_DIR.
-	RuntimePath *check.Absolute
-}
-
-// Copy expands [EnvPaths] into [hst.Paths].
-func (env *EnvPaths) Copy(v *hst.Paths, userid int) {
-	if env == nil || env.TempDir == nil || v == nil {
-		panic("attempting to use an invalid EnvPaths")
-	}
-
-	v.TempDir = env.TempDir
-	v.SharePath = env.TempDir.Append("hakurei." + strconv.Itoa(userid))
-
-	if env.RuntimePath == nil {
-		// fall back to path in share since hakurei has no hard XDG dependency
-		v.RunDirPath = v.SharePath.Append("run")
-		v.RuntimePath = v.RunDirPath.Append("compat")
-	} else {
-		v.RuntimePath = env.RuntimePath
-		v.RunDirPath = env.RuntimePath.Append("hakurei")
-	}
-}
-
-// CopyPaths returns a populated [EnvPaths].
-func CopyPaths() *EnvPaths { return copyPaths(direct{}) }
-
-// copyPaths returns a populated [EnvPaths].
-func copyPaths(k syscallDispatcher) *EnvPaths {
-	const xdgRuntimeDir = "XDG_RUNTIME_DIR"
-
-	var env EnvPaths
-
-	if tempDir, err := check.NewAbs(k.tempdir()); err != nil {
-		k.fatalf("invalid TMPDIR: %v", err)
-		panic("unreachable")
-	} else {
-		env.TempDir = tempDir
-	}
-
-	r, _ := k.lookupEnv(xdgRuntimeDir)
-	if a, err := check.NewAbs(r); err == nil {
-		env.RuntimePath = a
-	}
-
-	return &env
-}
diff --git a/internal/app/outcome.go b/internal/app/outcome.go
index 237095af..59cdfbd8 100644
--- a/internal/app/outcome.go
+++ b/internal/app/outcome.go
@@ -8,6 +8,7 @@ import (
 	"hakurei.app/container"
 	"hakurei.app/container/check"
 	"hakurei.app/hst"
+	"hakurei.app/internal/env"
 	"hakurei.app/message"
 	"hakurei.app/system"
 	"hakurei.app/system/acl"
@@ -58,7 +59,7 @@ type outcomeState struct {
 
 	// Copied from [EnvPaths] per-process.
 	sc hst.Paths
-	*EnvPaths
+	*env.Paths
 
 	// Copied via populateLocal.
 	k syscallDispatcher
@@ -72,7 +73,7 @@ func (s *outcomeState) valid() bool {
 		s.Shim.valid() &&
 		s.ID != nil &&
 		s.Container != nil &&
-		s.EnvPaths != nil
+		s.Paths != nil
 }
 
 // newOutcomeState returns the address of a new outcomeState with its exported fields populated via syscallDispatcher.
@@ -82,7 +83,7 @@ func newOutcomeState(k syscallDispatcher, msg message.Msg, id *hst.ID, config *h
 		ID:        id,
 		Identity:  config.Identity,
 		UserID:    hsu.MustID(msg),
-		EnvPaths:  copyPaths(k),
+		Paths:     env.CopyPathsFunc(k.fatalf, k.tempdir, func(key string) string { v, _ := k.lookupEnv(key); return v }),
 		Container: config.Container,
 	}
 
diff --git a/internal/app/outcome_test.go b/internal/app/outcome_test.go
index 740e7db5..5ea3ff99 100644
--- a/internal/app/outcome_test.go
+++ b/internal/app/outcome_test.go
@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"hakurei.app/hst"
+	"hakurei.app/internal/env"
 )
 
 func TestOutcomeStateValid(t *testing.T) {
@@ -16,11 +17,11 @@ func TestOutcomeStateValid(t *testing.T) {
 	}{
 		{"nil", nil, false},
 		{"zero", new(outcomeState), false},
-		{"shim", &outcomeState{Shim: &shimParams{PrivPID: -1, Ops: []outcomeOp{}}, Container: new(hst.ContainerConfig), EnvPaths: new(EnvPaths)}, false},
-		{"id", &outcomeState{Shim: &shimParams{PrivPID: 1, Ops: []outcomeOp{}}, Container: new(hst.ContainerConfig), EnvPaths: new(EnvPaths)}, false},
-		{"container", &outcomeState{Shim: &shimParams{PrivPID: 1, Ops: []outcomeOp{}}, ID: new(hst.ID), EnvPaths: new(EnvPaths)}, false},
+		{"shim", &outcomeState{Shim: &shimParams{PrivPID: -1, Ops: []outcomeOp{}}, Container: new(hst.ContainerConfig), Paths: new(env.Paths)}, false},
+		{"id", &outcomeState{Shim: &shimParams{PrivPID: 1, Ops: []outcomeOp{}}, Container: new(hst.ContainerConfig), Paths: new(env.Paths)}, false},
+		{"container", &outcomeState{Shim: &shimParams{PrivPID: 1, Ops: []outcomeOp{}}, ID: new(hst.ID), Paths: new(env.Paths)}, false},
 		{"envpaths", &outcomeState{Shim: &shimParams{PrivPID: 1, Ops: []outcomeOp{}}, ID: new(hst.ID), Container: new(hst.ContainerConfig)}, false},
-		{"valid", &outcomeState{Shim: &shimParams{PrivPID: 1, Ops: []outcomeOp{}}, ID: new(hst.ID), Container: new(hst.ContainerConfig), EnvPaths: new(EnvPaths)}, true},
+		{"valid", &outcomeState{Shim: &shimParams{PrivPID: 1, Ops: []outcomeOp{}}, ID: new(hst.ID), Container: new(hst.ContainerConfig), Paths: new(env.Paths)}, true},
 	}
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
diff --git a/internal/app/shim_test.go b/internal/app/shim_test.go
index e207dfda..19dedd6f 100644
--- a/internal/app/shim_test.go
+++ b/internal/app/shim_test.go
@@ -14,6 +14,7 @@ import (
 	"hakurei.app/container/seccomp"
 	"hakurei.app/container/stub"
 	"hakurei.app/hst"
+	"hakurei.app/internal/env"
 )
 
 func TestShimEntrypoint(t *testing.T) {
@@ -128,7 +129,7 @@ func TestShimEntrypoint(t *testing.T) {
 				Container: hst.Template().Container,
 				Mapuid:    1000,
 				Mapgid:    100,
-				EnvPaths:  &EnvPaths{TempDir: fhs.AbsTmp, RuntimePath: fhs.AbsRunUser.Append("1000")},
+				Paths:     &env.Paths{TempDir: fhs.AbsTmp, RuntimePath: fhs.AbsRunUser.Append("1000")},
 			}, nil}, nil, nil),
 			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
 			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
diff --git a/internal/env/env.go b/internal/env/env.go
new file mode 100644
index 00000000..ebb816d6
--- /dev/null
+++ b/internal/env/env.go
@@ -0,0 +1,66 @@
+// Package env provides the [Paths] struct for efficiently building paths from the environment.
+package env
+
+import (
+	"log"
+	"os"
+	"strconv"
+
+	"hakurei.app/container/check"
+	"hakurei.app/hst"
+)
+
+// Paths holds paths copied from the environment and is used to create [hst.Paths].
+type Paths struct {
+	// TempDir is returned by [os.TempDir].
+	TempDir *check.Absolute
+	// RuntimePath is copied from $XDG_RUNTIME_DIR.
+	RuntimePath *check.Absolute
+}
+
+// Copy expands [Paths] into [hst.Paths].
+func (env *Paths) Copy(v *hst.Paths, userid int) {
+	if env == nil || env.TempDir == nil || v == nil {
+		panic("attempting to use an invalid Paths")
+	}
+
+	v.TempDir = env.TempDir
+	v.SharePath = env.TempDir.Append("hakurei." + strconv.Itoa(userid))
+
+	if env.RuntimePath == nil {
+		// fall back to path in share since hakurei has no hard XDG dependency
+		v.RunDirPath = v.SharePath.Append("run")
+		v.RuntimePath = v.RunDirPath.Append("compat")
+	} else {
+		v.RuntimePath = env.RuntimePath
+		v.RunDirPath = env.RuntimePath.Append("hakurei")
+	}
+}
+
+// CopyPaths returns a populated [Paths].
+func CopyPaths() *Paths { return CopyPathsFunc(log.Fatalf, os.TempDir, os.Getenv) }
+
+// CopyPathsFunc returns a populated [Paths],
+// using the provided [log.Fatalf], [os.TempDir], [os.Getenv] functions.
+func CopyPathsFunc(
+	fatalf func(format string, v ...any),
+	tempdir func() string,
+	getenv func(key string) string,
+) *Paths {
+	const xdgRuntimeDir = "XDG_RUNTIME_DIR"
+
+	var env Paths
+
+	if tempDir, err := check.NewAbs(tempdir()); err != nil {
+		fatalf("invalid TMPDIR: %v", err)
+		panic("unreachable")
+	} else {
+		env.TempDir = tempDir
+	}
+
+	if a, err := check.NewAbs(getenv(xdgRuntimeDir)); err == nil {
+		env.RuntimePath = a
+	}
+
+	return &env
+}
diff --git a/internal/app/env_test.go b/internal/env/env_test.go
index 9e2c959e..8a07d6b5 100644
--- a/internal/app/env_test.go
+++ b/internal/env/env_test.go
@@ -1,4 +1,4 @@
-package app
+package env_test
 
 import (
 	"fmt"
@@ -10,26 +10,27 @@ import (
 	"hakurei.app/container/fhs"
 	"hakurei.app/container/stub"
 	"hakurei.app/hst"
+	"hakurei.app/internal/env"
 )
 
-func TestEnvPaths(t *testing.T) {
+func TestPaths(t *testing.T) {
 	t.Parallel()
 
 	testCases := []struct {
 		name string
-		env  *EnvPaths
+		env  *env.Paths
 		want hst.Paths
 
 		wantPanic string
 	}{
-		{"nil", nil, hst.Paths{}, "attempting to use an invalid EnvPaths"},
-		{"zero", new(EnvPaths), hst.Paths{}, "attempting to use an invalid EnvPaths"},
+		{"nil", nil, hst.Paths{}, "attempting to use an invalid Paths"},
+		{"zero", new(env.Paths), hst.Paths{}, "attempting to use an invalid Paths"},
 
-		{"nil tempdir", &EnvPaths{
+		{"nil tempdir", &env.Paths{
 			RuntimePath: fhs.AbsTmp,
-		}, hst.Paths{}, "attempting to use an invalid EnvPaths"},
+		}, hst.Paths{}, "attempting to use an invalid Paths"},
 
-		{"nil runtime", &EnvPaths{
+		{"nil runtime", &env.Paths{
 			TempDir: fhs.AbsTmp,
 		}, hst.Paths{
 			TempDir:     fhs.AbsTmp,
@@ -38,7 +39,7 @@ func TestEnvPaths(t *testing.T) {
 			RunDirPath:  fhs.AbsTmp.Append("hakurei.3735928559/run"),
 		}, ""},
 
-		{"full", &EnvPaths{
+		{"full", &env.Paths{
 			TempDir:     fhs.AbsTmp,
 			RuntimePath: fhs.AbsRunUser.Append("1000"),
 		}, hst.Paths{
@@ -76,16 +77,16 @@ func TestCopyPaths(t *testing.T) {
 		env   map[string]string
 		tmp   string
 		fatal string
-		want  EnvPaths
+		want  env.Paths
 	}{
 		{"invalid tempdir", nil, "\x00",
-			"invalid TMPDIR: path \"\\x00\" is not absolute", EnvPaths{}},
+			"invalid TMPDIR: path \"\\x00\" is not absolute", env.Paths{}},
 		{"empty environment", make(map[string]string), container.Nonexistent,
-			"", EnvPaths{TempDir: check.MustAbs(container.Nonexistent)}},
+			"", env.Paths{TempDir: check.MustAbs(container.Nonexistent)}},
 		{"invalid XDG_RUNTIME_DIR", map[string]string{"XDG_RUNTIME_DIR": "\x00"}, container.Nonexistent,
-			"", EnvPaths{TempDir: check.MustAbs(container.Nonexistent)}},
+			"", env.Paths{TempDir: check.MustAbs(container.Nonexistent)}},
 		{"full", map[string]string{"XDG_RUNTIME_DIR": "/\x00"}, container.Nonexistent,
-			"", EnvPaths{TempDir: check.MustAbs(container.Nonexistent), RuntimePath: check.MustAbs("/\x00")}},
+			"", env.Paths{TempDir: check.MustAbs(container.Nonexistent), RuntimePath: check.MustAbs("/\x00")}},
 	}
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
@@ -94,8 +95,16 @@ func TestCopyPaths(t *testing.T) {
 				defer stub.HandleExit(t)
 			}
 
-			k := copyPathsDispatcher{t: t, env: tc.env, tmp: tc.tmp, expectsFatal: tc.fatal}
-			got := copyPaths(k)
+			got := env.CopyPathsFunc(func(format string, v ...any) {
+				if tc.fatal == "" {
+					t.Fatalf("unexpected call to fatalf: format = %q, v = %#v", format, v)
+				}
+
+				if got := fmt.Sprintf(format, v...); got != tc.fatal {
+					t.Fatalf("fatalf: %q, want %q", got, tc.fatal)
+				}
+				panic(stub.PanicExit)
+			}, func() string { return tc.tmp }, func(key string) string { return tc.env[key] })
 
 			if tc.fatal != "" {
 				t.Fatalf("copyPaths: expected fatal %q", tc.fatal)
@@ -107,31 +116,3 @@ func TestCopyPaths(t *testing.T) {
 		})
 	}
 }
-
-// copyPathsDispatcher implements enough of syscallDispatcher for all copyPaths code paths.
-type copyPathsDispatcher struct {
-	env map[string]string
-	tmp string
-
-	// must be checked at the conclusion of the test
-	expectsFatal string
-
-	t *testing.T
-	panicDispatcher
-}
-
-func (k copyPathsDispatcher) tempdir() string { return k.tmp }
-func (k copyPathsDispatcher) lookupEnv(key string) (value string, ok bool) {
-	value, ok = k.env[key]
-	return
-}
-func (k copyPathsDispatcher) fatalf(format string, v ...any) {
-	if k.expectsFatal == "" {
-		k.t.Fatalf("unexpected call to fatalf: format = %q, v = %#v", format, v)
-	}
-
-	if got := fmt.Sprintf(format, v...); got != k.expectsFatal {
-		k.t.Fatalf("fatalf: %q, want %q", got, k.expectsFatal)
-	}
-	panic(stub.PanicExit)
-}