[feature/OFFICIALLY UNSUPPORTED] add nowasm build tag to disable building with WebAssembly (#3429)

* add experimental build-tag 'nowasm' which uses local ffmpeg / ffprobe

* updated experimental support message

* add comment to build script explaining build tag

* add nowasm build tags to moderncsqlite files

internal/db/sqlite/driver.go

@@ -15,7 +15,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-//go:build !moderncsqlite3
+//go:build !moderncsqlite3 && !nowasm
 
 package sqlite
 

internal/db/sqlite/driver_moderncsqlite3.go

@@ -15,7 +15,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-//go:build moderncsqlite3
+//go:build moderncsqlite3 || nowasm
 
 package sqlite
 

internal/db/sqlite/errors.go

@@ -15,7 +15,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-//go:build !moderncsqlite3
+//go:build !moderncsqlite3 && !nowasm
 
 package sqlite
 

internal/db/sqlite/errors_moderncsqlite3.go

@@ -15,7 +15,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-//go:build moderncsqlite3
+//go:build moderncsqlite3 || nowasm
 
 package sqlite
 

internal/media/ffmpeg/args.go

@@ -0,0 +1,28 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package ffmpeg
+
+import (
+	"codeberg.org/gruf/go-ffmpreg/wasm"
+)
+
+// Args encapsulates the passing of common
+// configuration options to run an instance
+// of a compiled WebAssembly module that is
+// run in a typical CLI manner.
+type Args = wasm.Args

internal/media/ffmpeg/exec_nowasm.go

@@ -0,0 +1,142 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+//go:build nowasm
+
+package ffmpeg
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"io/fs"
+	"os/exec"
+
+	"codeberg.org/gruf/go-ffmpreg/wasm"
+	"github.com/tetratelabs/wazero"
+	"github.com/tetratelabs/wazero/sys"
+)
+
+func init() {
+	fmt.Println("!! you are using an unsupported build configuration of gotosocial with WebAssembly disabled !!")
+	fmt.Println("!! please do not file bug reports regarding media processing with this configuration !!")
+	fmt.Println("!! it is also less secure; this does not enforce version checks on ffmpeg / ffprobe versions !!")
+}
+
+// runCmd will run 'name' with the given arguments, returning exit code or error.
+func runCmd(ctx context.Context, name string, args wasm.Args) (uint32, error) {
+	cmd := exec.CommandContext(ctx, name, args.Args...) //nolint:gosec
+
+	// Set provided std files.
+	cmd.Stdin = args.Stdin
+	cmd.Stdout = args.Stdout
+	cmd.Stderr = args.Stderr
+
+	if args.Config != nil {
+		// Gather some information
+		// from module config func.
+		var cfg falseModuleConfig
+		_ = args.Config(&cfg)
+
+		// Extract from conf.
+		cmd.Env = cfg.env
+	}
+
+	// Run prepared command, catching err type.
+	switch err := cmd.Run(); err := err.(type) {
+
+	// Extract code from
+	// any exit error type.
+	case *exec.ExitError:
+		rc := err.ExitCode()
+		return uint32(rc), err
+
+	default:
+		return 0, err
+	}
+}
+
+type falseModuleConfig struct{ env []string }
+
+func (cfg *falseModuleConfig) WithArgs(...string) wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithEnv(key string, value string) wazero.ModuleConfig {
+	cfg.env = append(cfg.env, key+"="+value)
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithFS(fs.FS) wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithFSConfig(wazero.FSConfig) wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithName(string) wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithStartFunctions(...string) wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithStderr(io.Writer) wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithStdin(io.Reader) wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithStdout(io.Writer) wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithWalltime(sys.Walltime, sys.ClockResolution) wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithSysWalltime() wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithNanotime(sys.Nanotime, sys.ClockResolution) wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithSysNanotime() wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithNanosleep(sys.Nanosleep) wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithOsyield(sys.Osyield) wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithSysNanosleep() wazero.ModuleConfig {
+	return cfg // noop
+}
+
+func (cfg *falseModuleConfig) WithRandSource(io.Reader) wazero.ModuleConfig {
+	return cfg // noop
+}

internal/media/ffmpeg/ffmpeg.go

@@ -15,10 +15,14 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+//go:build !nowasm
+
 package ffmpeg
 
 import (
 	"context"
+
+	"codeberg.org/gruf/go-ffmpreg/wasm"
 )
 
 // ffmpegRunner limits the number of
@@ -36,5 +40,7 @@ func InitFfmpeg(ctx context.Context, max int) error {
 
 // Ffmpeg runs the given arguments with an instance of ffmpeg.
 func Ffmpeg(ctx context.Context, args Args) (uint32, error) {
-	return ffmpegRunner.Run(ctx, ffmpeg, args)
+	return ffmpegRunner.Run(ctx, func() (uint32, error) {
+		return wasm.Run(ctx, runtime, ffmpeg, args)
+	})
 }

internal/media/ffmpeg/ffmpeg_nowasm.go

@@ -0,0 +1,49 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+//go:build nowasm
+
+package ffmpeg
+
+import (
+	"context"
+	"os/exec"
+)
+
+// ffmpegRunner limits the number of
+// ffmpeg WebAssembly instances that
+// may be concurrently running, in
+// order to reduce memory usage.
+var ffmpegRunner runner
+
+// InitFfmpeg looks for a local copy of ffmpeg in path, and prepares
+// the runner to only allow max given concurrent running instances.
+func InitFfmpeg(ctx context.Context, max int) error {
+	_, err := exec.LookPath("ffmpeg")
+	if err != nil {
+		return err
+	}
+	ffmpegRunner.Init(max)
+	return nil
+}
+
+// Ffmpeg runs the given arguments with an instance of ffmpeg.
+func Ffmpeg(ctx context.Context, args Args) (uint32, error) {
+	return ffmpegRunner.Run(ctx, func() (uint32, error) {
+		return runCmd(ctx, "ffmpeg", args)
+	})
+}

internal/media/ffmpeg/ffprobe.go

@@ -15,10 +15,14 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+//go:build !nowasm
+
 package ffmpeg
 
 import (
 	"context"
+
+	"codeberg.org/gruf/go-ffmpreg/wasm"
 )
 
 // ffprobeRunner limits the number of
@@ -36,5 +40,7 @@ func InitFfprobe(ctx context.Context, max int) error {
 
 // Ffprobe runs the given arguments with an instance of ffprobe.
 func Ffprobe(ctx context.Context, args Args) (uint32, error) {
-	return ffprobeRunner.Run(ctx, ffprobe, args)
+	return ffmpegRunner.Run(ctx, func() (uint32, error) {
+		return wasm.Run(ctx, runtime, ffprobe, args)
+	})
 }

internal/media/ffmpeg/ffprobe_nowasm.go

@@ -0,0 +1,49 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+//go:build nowasm
+
+package ffmpeg
+
+import (
+	"context"
+	"os/exec"
+)
+
+// ffprobeRunner limits the number of
+// ffprobe WebAssembly instances that
+// may be concurrently running, in
+// order to reduce memory usage.
+var ffprobeRunner runner
+
+// InitFfprobe looks for a local copy of ffprobe in path, and prepares
+// the runner to only allow max given concurrent running instances.
+func InitFfprobe(ctx context.Context, max int) error {
+	_, err := exec.LookPath("ffprobe")
+	if err != nil {
+		return err
+	}
+	ffprobeRunner.Init(max)
+	return nil
+}
+
+// Ffprobe runs the given arguments with an instance of ffprobe.
+func Ffprobe(ctx context.Context, args Args) (uint32, error) {
+	return ffprobeRunner.Run(ctx, func() (uint32, error) {
+		return runCmd(ctx, "ffprobe", args)
+	})
+}

internal/media/ffmpeg/runner.go

@@ -19,9 +19,6 @@ package ffmpeg
 
 import (
 	"context"
-
-	"codeberg.org/gruf/go-ffmpreg/wasm"
-	"github.com/tetratelabs/wazero"
 )
 
 // runner simply abstracts away the complexities
@@ -53,7 +50,7 @@ func (r *runner) Init(n int) {
 
 // Run will attempt to pass the given compiled WebAssembly module with args to run(), waiting on
 // the receiving runner until a free slot is available to run an instance, (if a limit is enabled).
-func (r *runner) Run(ctx context.Context, cmod wazero.CompiledModule, args Args) (uint32, error) {
+func (r *runner) Run(ctx context.Context, run func() (uint32, error)) (uint32, error) {
 	select {
 	// Context canceled.
 	case <-ctx.Done():
@@ -66,6 +63,6 @@ func (r *runner) Run(ctx context.Context, cmod wazero.CompiledModule, args Args)
 	// Release slot back to pool on end.
 	defer func() { r.pool <- struct{}{} }()
 
-	// Pass to main module runner function.
+	// Call run.
-	return wasm.Run(ctx, runtime, cmod, args)
+	return run()
 }

internal/media/ffmpeg/wasm.go

@@ -15,6 +15,8 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+//go:build !nowasm
+
 package ffmpeg
 
 import (
@@ -41,12 +43,6 @@ var (
 	ffprobe wazero.CompiledModule
 )
 
-// Args encapsulates the passing of common
-// configuration options to run an instance
-// of a compiled WebAssembly module that is
-// run in a typical CLI manner.
-type Args = wasm.Args
-
 // compileFfmpeg ensures the ffmpeg WebAssembly has been
 // pre-compiled into memory. If already compiled is a no-op.
 func compileFfmpeg(ctx context.Context) error {

scripts/build.sh

@@ -23,6 +23,8 @@ GO_GCFLAGS=${GO_GCFLAGS-}
 # - debug:          enables /debug/pprof endpoint                                  (adds debug, at performance cost)
 # - debugenv:       enables /debug/pprof endpoint if DEBUG=1 env during runtime    (adds debug, at performance cost)
 # - moderncsqlite3: reverts to using the C-to-Go transpiled SQLite driver          (disables the WASM-based SQLite driver)
+# - nowasm:         [UNSUPPORTED] removes all WebAssembly from builds including 
+#                   ffmpeg, ffprobe and SQLite (instead falling back to modernc).
 log_exec env CGO_ENABLED=0 go build -trimpath -v \
                        -tags "${GO_BUILDTAGS}" \
                        -ldflags="${GO_LDFLAGS}" \