initial go implementation

.gitignore

@@ -0,0 +1 @@
+fup

base/fup.go

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+package base
+
+import (
+	"gopkg.in/yaml.v3"
+	"io"
+	"os"
+)
+
+type Settings struct {
+	ArchiveDir string                    `yaml:"archive_dir"`
+	HostFacts  map[string]map[string]any `yaml:"host_facts"`
+}
+
+type Unless struct {
+	Cmd  string `yaml:"cmd"`
+	Post string `yaml:"post"`
+	Ls   string `yaml:"ls"`
+}
+
+type Archive struct {
+	Url     string   `yaml:"url"`
+	Unless  Unless   `yaml:"unless"`
+	Version string   `yaml:"version"`
+	Symlink []string `yaml:"symlink"`
+	Binary  string   `yaml:"binary"`
+}
+
+func (a Archive) ExpandArchive(property string) string {
+	if property == "version" {
+		return a.Version
+	}
+
+	return ""
+}
+
+type Config struct {
+	Settings *Settings `yaml:"settings"`
+	Archives []Archive `yaml:"archives"`
+}
+
+func ReadConfig(filename string) (Config, error) {
+	config := Config{}
+
+	f, err := os.Open(filename)
+	if err != nil {
+		return config, err
+	}
+
+	data, err := io.ReadAll(f)
+	err = yaml.Unmarshal(data, &config)
+	if err != nil {
+		return config, err
+	}
+	return config, nil
+}

contrib/simple.yml

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+settings:
+  archive_dir: ~/fup
+  host_facts:
+    lock_period:
+      '*': 600
+      natrium: 3600
+archives:
+  - url: https://github.com/cli/cli/releases/download/v${version}/gh_${version}_linux_amd64.tar.gz
+    version: 2.18.1
+    unless:
+      cmd: gh version
+      post: 'head 0 | split 2'
+    symlink:
+      - gh_${version}_linux_amd64/bin/gh
+  - url: https://github.com/tectonic-typesetting/tectonic/releases/download/tectonic%40${version}/tectonic-${version}-x86_64-unknown-linux-gnu.tar.gz
+    version: 0.11.0
+    unless:
+      cmd: tectonic --version
+      post: split 1
+    binary: tectonic

go.mod

@@ -0,0 +1,10 @@
+module github.com/femnad/fup
+
+go 1.18
+
+require (
+	github.com/alexflint/go-arg v1.4.3
+	gopkg.in/yaml.v3 v3.0.1
+)
+
+require github.com/alexflint/go-scalar v1.1.0 // indirect

go.sum

@@ -0,0 +1,18 @@
+github.com/alexflint/go-arg v1.4.3 h1:9rwwEBpMXfKQKceuZfYcwuc/7YY7tWJbFsgG5cAU/uo=
+github.com/alexflint/go-arg v1.4.3/go.mod h1:3PZ/wp/8HuqRZMUUgu7I+e1qcpUbvmS258mRXkFH4IA=
+github.com/alexflint/go-scalar v1.1.0 h1:aaAouLLzI9TChcPXotr6gUhq+Scr8rl0P9P4PnltbhM=
+github.com/alexflint/go-scalar v1.1.0/go.mod h1:LoFvNMqS1CPrMVltza4LvnGKhaSpc3oyLEBUZVhhS2o=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"github.com/alexflint/go-arg"
+	"github.com/femnad/fup/base"
+	"github.com/femnad/fup/provision"
+	"log"
+)
+
+var args struct {
+	File string `arg:"required,-f,--file"`
+}
+
+func main() {
+	arg.MustParse(&args)
+	config, err := base.ReadConfig(args.File)
+	if err != nil {
+		log.Fatalf("%v\n", err)
+	}
+
+	p := provision.Provisioner{Config: config}
+	p.Apply()
+}

provision/archive.go

@@ -0,0 +1,188 @@
+package provision
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+
+	"github.com/femnad/fup/base"
+)
+
+const (
+	bufferSize = 8192
+	dirMode    = 0755
+)
+
+var (
+	okStatuses = []int{http.StatusOK}
+)
+
+// Yoinked from https://gosamples.dev/generics-slice-contains/.
+func contains[T comparable](elems []T, needle T) bool {
+	for _, elem := range elems {
+		if needle == elem {
+			return true
+		}
+	}
+	return false
+}
+
+func expandUser(path string) string {
+	return strings.Replace(path, "~", os.Getenv("HOME"), 1)
+}
+
+func processDownload(archive base.Archive, archiveDir string, processor func(closer io.ReadCloser, target string) error) error {
+	url := archive.Url
+	if url == "" {
+		return fmt.Errorf("no URL given for archive %v", archive)
+	}
+
+	url = os.Expand(url, archive.ExpandArchive)
+	log.Printf("Downloading %s", url)
+
+	cl := http.Client{}
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return err
+	}
+
+	resp, err := cl.Do(req)
+	if err != nil {
+		return err
+	}
+
+	statusCode := resp.StatusCode
+	if !contains(okStatuses, statusCode) {
+		log.Printf("Skipping archive download, got response %d from URL %s", statusCode, url)
+		return nil
+	}
+
+	dirName := expandUser(archiveDir)
+	err = os.MkdirAll(dirName, dirMode)
+	if err != nil {
+		return err
+	}
+
+	if archive.Binary != "" {
+		dirName = filepath.Join(dirName, archive.Binary)
+	}
+
+	return processor(resp.Body, dirName)
+}
+
+func mkdirAll(dir string, mode os.FileMode) error {
+	err := os.MkdirAll(dir, mode)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Shamelessly lifted from https://golangdocs.com/tar-gzip-in-golang
+func untar(tarfile io.ReadCloser, target string) error {
+	defer func() {
+		err := tarfile.Close()
+		if err != nil {
+			log.Fatalf("Error closing tarfile: %v", err)
+		}
+	}()
+
+	gzipReader, err := gzip.NewReader(tarfile)
+	if err != nil {
+		return err
+	}
+
+	tarReader := tar.NewReader(gzipReader)
+	for {
+		header, err := tarReader.Next()
+		if errors.Is(err, io.EOF) {
+			break
+		} else if err != nil {
+			panic(err)
+		}
+
+		outputPath := filepath.Join(target, header.Name)
+		info := header.FileInfo()
+		if info.IsDir() {
+			if err = mkdirAll(outputPath, info.Mode()); err != nil {
+				return err
+			}
+			continue
+		}
+
+		dir, _ := path.Split(outputPath)
+		if err = os.MkdirAll(dir, dirMode); err != nil {
+			return err
+		}
+		file, err := os.OpenFile(outputPath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, info.Mode())
+		if err != nil {
+			return err
+		}
+
+		_, err = io.Copy(file, tarReader)
+		if err != nil {
+			return err
+		}
+
+		err = file.Close()
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func Extract(archive base.Archive, archiveDir string) error {
+	return processDownload(archive, archiveDir, untar)
+}
+
+func download(closer io.ReadCloser, target string) error {
+	f, err := os.Create(target)
+	if err != nil {
+		return fmt.Errorf("error creating target %s: %w", target, err)
+	}
+
+	for {
+		buf := make([]byte, bufferSize)
+
+		readBytes, readErr := closer.Read(buf)
+		if !errors.Is(readErr, io.EOF) && err != nil {
+			return readErr
+		}
+
+		_, writeErr := f.Write(buf[:readBytes])
+		if writeErr != nil {
+			return err
+		}
+		if errors.Is(readErr, io.EOF) {
+			break
+		}
+	}
+
+	err = closer.Close()
+	if err != nil {
+		return err
+	}
+
+	err = f.Close()
+	if err != nil {
+		return err
+	}
+
+	return nil
+
+}
+
+func Download(archive base.Archive, archiveDir string) error {
+	return processDownload(archive, archiveDir, download)
+}

provision/provision.go

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+package provision
+
+import (
+	"github.com/femnad/fup/base"
+	"log"
+)
+
+type Provisioner struct {
+	Config base.Config
+}
+
+func (p Provisioner) Apply() {
+	p.downloadArchives()
+}
+
+func (p Provisioner) downloadArchives() {
+	for _, archive := range p.Config.Archives {
+		err := Extract(archive, p.Config.Settings.ArchiveDir)
+		if err != nil {
+			log.Fatalf("Error downloading archive %v: %v", archive.Url, err)
+		}
+	}
+}