Initial import

Signed-off-by: Janos Bonic <[email protected]>
Co-authored-by: James Humphries <[email protected]>

.github/workflows/verify.yml

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+# Copyright (c) The OpenTofu Authors
+# SPDX-License-Identifier: MPL-2.0, MIT
+name: Verify
+permissions: {}
+on:
+  pull_request:
+  push:
+jobs:
+  generate:
+    name: Go generate
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Setup go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: 'go.mod'
+      - name: Check license headers
+        run: go run github.com/opentofu/tofudl/tools/license-headers -check-only
+      - name: Check GPG key
+        working-directory: branding
+        run: go run github.com/opentofu/tofudl/tools/bundle-gpg-key -check-only
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Setup go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: 'go.mod'
+      - name: Lint
+        run: go run github.com/opentofu/tofudl/tools/lint
+  tests:
+    name: Tests
+    strategy:
+      matrix:
+        os: [ubuntu, windows, macos]
+    runs-on: ${{ matrix.os }}-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Setup go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: 'go.mod'
+      - name: Run tests
+        run: |
+          go test ./...

.gitignore

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+.idea
+*~

.golangci.yml

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+linters:
+  disable-all: true
+  enable:
+    - asasalint
+    - asciicheck
+    - bidichk
+    - bodyclose
+    - dupl
+    - durationcheck
+    - errcheck
+    - errname
+    - errorlint
+    - exhaustive
+    - exportloopref
+    - forbidigo
+    - gocheckcompilerdirectives
+    - gochecknoinits
+    - goconst
+    - gocritic
+    - goimports
+    - gomoddirectives
+    - gomodguard
+    - goprintffuncname
+    - gosec
+    - gosimple
+    - govet
+    - ineffassign
+    - loggercheck
+    - makezero
+    - mirror
+    - musttag
+    - nakedret
+    - nestif
+    - nilerr
+    - nilnil
+    - noctx
+    - nolintlint
+    - nonamedreturns
+    - nosprintfhostport
+    - predeclared
+    - promlinter
+    - reassign
+    - revive
+    - rowserrcheck
+    - sqlclosecheck
+    - staticcheck
+    - stylecheck
+    - tenv
+    - testableexamples
+    - tparallel
+    - typecheck
+    - unconvert
+    - unparam
+    - unused
+    - usestdlibvars
+    - wastedassign
+    - whitespace

README.md

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+# TofuDL: OpenTofu downloader library for Go with minimal dependencies
+
+This library provides an easy way to download, verify, and unpack OpenTofu binaries for local use in Go. It has a minimal set of dependencies and is easy to integrate.
+
+**Note:** This is not a standalone tool to download OpenTofu, it is purely meant to be used as Go library in support of other tools that need to run `tofu`. Please check the [installation instructions](https://opentofu.org/docs/intro/install/) for supported ways to perform an OpenTofu installation.
+
+## Basic usage
+
+The downloader will work without any extra configuration out of the box:
+
+```go
+package main
+
+import (
+	"context"
+	"os"
+	"os/exec"
+	"runtime"
+
+	"github.com/opentofu/tofudl"
+)
+
+func main() {
+	// Initialize the downloader:
+	dl, err := tofudl.New()
+	if err != nil {
+		panic(err)
+	}
+
+	// Download the latest stable version
+	// for the current architecture and platform:
+	binary, err := dl.Download(context.TODO())
+	if err != nil {
+		panic(err)
+	}
+
+	// Write out the tofu binary to the disk:
+	file := "tofu"
+	if runtime.GOOS == "windows" {
+		file += ".exe"
+	}
+	if err := os.WriteFile(file, binary, 0755); err != nil {
+		panic(err)
+	}
+
+	// Run tofu:
+	cmd := exec.Command("./"+file, "init")
+	if err := cmd.Run(); err != nil {
+		panic(err)
+	}
+}
+```
+
+## Advanced usage
+
+Both `New()` and `Download()` accept a number of options. You can find the detailed documentation [here](https://pkg.go.dev/github.com/opentofu/tofudl).

architecture.go

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+// Copyright (c) The OpenTofu Authors
+// SPDX-License-Identifier: MPL-2.0
+
+package tofudl
+
+import (
+	"regexp"
+	"runtime"
+)
+
+// Architecture describes the architecture to download OpenTofu for. It defaults to the current system architecture.
+type Architecture string
+
+const (
+	// ArchitectureAuto is the default value and defaults to downloading OpenTofu for the current architecture.
+	ArchitectureAuto Architecture = ""
+	// Architecture386 describes the 32-bit Intel CPU architecture.
+	Architecture386 Architecture = "386"
+	// ArchitectureAMD64 describes the 64-bit Intel/AMD CPU architecture.
+	ArchitectureAMD64 Architecture = "amd64"
+	// ArchitectureARM describes the 32-bit ARM (v7) architecture.
+	ArchitectureARM Architecture = "arm"
+	// ArchitectureARM64 describes the 64-bit ARM (v8) architecture.
+	ArchitectureARM64 Architecture = "arm64"
+)
+
+var architectureRe = regexp.MustCompile("^[a-z0-9]*$")
+
+// Validate returns an error if the platform is not a valid platform descriptor.
+func (a Architecture) Validate() error {
+	if !architectureRe.MatchString(string(a)) {
+		return &InvalidArchitectureError{a}
+	}
+	return nil
+}
+
+// ResolveAuto resolves the value of ArchitectureAuto if needed based on the current runtime.GOARCH.
+func (a Architecture) ResolveAuto() (Architecture, error) {
+	if a != ArchitectureAuto {
+		return a, nil
+	}
+	switch runtime.GOARCH {
+	case "386":
+		return Architecture386, nil
+	case "amd64":
+		return ArchitectureAMD64, nil
+	case "arm":
+		return ArchitectureARM, nil
+	case "arm64":
+		return ArchitectureARM64, nil
+	default:
+		return ArchitectureAuto, UnsupportedArchitectureError{
+			Architecture(runtime.GOARCH),
+		}
+	}
+}
+
+// ArchitectureValues returns all supported values for Architecture excluding ArchitectureAuto.
+func ArchitectureValues() []Architecture {
+	return []Architecture{
+		Architecture386,
+		ArchitectureAMD64,
+		ArchitectureARM,
+		ArchitectureARM64,
+	}
+}

branding/README.md

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+# Branding settings
+
+This package contains a set of constants to change the built-in behavior and configuration of `tofudl`, such as the bundled GPG key, etc.

branding/branding.go

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+// Copyright (c) The OpenTofu Authors
+// SPDX-License-Identifier: MPL-2.0
+
+package branding
+
+// ProductName describes the name of the product being downloaded.
+const ProductName = "OpenTofu"
+
+// DefaultDownloadAPIURL describes the API serving the version and file information.
+const DefaultDownloadAPIURL = "https://get.opentofu.org/tofu/api.json"
+
+// DefaultMirrorURLTemplate is a Go template that describes the download URL with the {{ .Version }} and {{ .Artifact }}
+// embedded into the URL.
+const DefaultMirrorURLTemplate = "https://github.com/opentofu/opentofu/releases/download/v{{ .Version }}/{{ .Artifact }}"
+
+// BinaryName holds the name of the binary in the artifact. This may be suffixed .exe on Windows.
+const BinaryName = "tofu"
+
+// GPGKeyURL describes the URL to download the bundled GPG key from. The GPG key bundler uses this to download the
+// GPG key for verification.
+const GPGKeyURL = "https://get.opentofu.org/opentofu.asc"
+
+// GPGKeyFingerprint is the GPG key fingerprint the bundler should expect to find when downloading the key.
+const GPGKeyFingerprint = "E3E6E43D84CB852EADB0051D0C0AF313E5FD9F80"
+
+// SPDXAuthorsName describes the name of the authors to be attributed in copyright notices in this repository.
+const SPDXAuthorsName = "The OpenTofu Authors"
+
+// SPDXLicense describes the license for copyright attribution in this repository.
+const SPDXLicense = "MPL-2.0"
+
+// MaximumUncompressedFileSize indicates the maximum file size when uncompressed.
+const MaximumUncompressedFileSize = 1024 * 1024 * 1024 * 1024