First version

Signed-off-by: Knut Ahlers <knut@ahlers.me>

Dockerfile

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+FROM golang
+
+MAINTAINER Knut Ahlers <knut@ahlers.me>
+
+ADD . /go/src/github.com/Luzifer/tex-api
+WORKDIR /go/src/github.com/Luzifer/tex-api
+
+RUN set -ex \
+ && apt-get update \
+ && apt-get install -y git ca-certificates \
+ && go install -ldflags "-X main.version=$(git describe --tags || git rev-parse --short HEAD || echo dev)" \
+ && apt-get install -y texlive-full \
+ && apt-get clean \
+ && rm -rf /var/lib/apt/lists/*
+
+EXPOSE 3000
+
+VOLUME ["/store"]
+
+ENTRYPOINT ["/go/bin/tex-api"]
+CMD ["--"]

main.go

@@ -0,0 +1,331 @@
+package main
+
+import (
+	"archive/zip"
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"math"
+	"net/http"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/Luzifer/rconfig"
+	log "github.com/Sirupsen/logrus"
+	"github.com/gorilla/mux"
+	uuid "github.com/satori/go.uuid"
+)
+
+var (
+	cfg = struct {
+		ExecutionScript string `flag:"script" default:"tex-build.sh" description:"Script to execute (needs to generate output directory)"`
+		Listen          string `flag:"listen" default:":3000" description:"IP/Port to listen on"`
+		StorageDir      string `flag:"storage-dir" default:"/storage" description:"Where to store uploaded ZIPs and resulting files"`
+		VersionAndExit  bool   `flag:"version" default:"false" description:"Prints current version and exits"`
+	}{}
+
+	version = "dev"
+	router  = mux.NewRouter()
+)
+
+type status string
+
+const (
+	statusCreated  = "created"
+	statusStarted  = "started"
+	statusError    = "error"
+	statusFinished = "finished"
+)
+
+const (
+	filenameInput     = "input.zip"
+	filenameStatus    = "status.json"
+	filenameOutputDir = "output"
+	sleepBase         = 1.5
+)
+
+type statusOutput struct {
+	UUID      string    `json:"uuid"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+	Status    status    `json:"status"`
+}
+
+func loadStatusByUUID(uid uuid.UUID) (*statusOutput, error) {
+	statusFile := pathFromUUID(uid, filenameStatus)
+
+	status := statusOutput{}
+	if f, err := os.Open(statusFile); err == nil {
+		defer f.Close()
+		if err = json.NewDecoder(f).Decode(&status); err != nil {
+			return nil, err
+		}
+	} else {
+		return nil, err
+	}
+
+	return &status, nil
+}
+
+func (s *statusOutput) UpdateStatus(st status) {
+	s.Status = st
+	s.UpdatedAt = time.Now()
+}
+
+func (s statusOutput) Save() error {
+	uid, _ := uuid.FromString(s.UUID)
+	f, err := os.Create(pathFromUUID(uid, filenameStatus))
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	return json.NewEncoder(f).Encode(s)
+}
+
+func init() {
+	if err := rconfig.Parse(&cfg); err != nil {
+		log.Fatalf("Unable to parse commandline options: %s", err)
+	}
+
+	if cfg.VersionAndExit {
+		fmt.Printf("tex-api %s\n", version)
+		os.Exit(0)
+	}
+}
+
+func main() {
+	router.HandleFunc("/", apiDocs).Methods("GET").Name("apiDocs")
+	router.HandleFunc("/job", startNewJob).Methods("POST").Name("startNewJob")
+	router.HandleFunc("/job/{uid:[0-9a-z-]{36}}", getJobStatus).Methods("GET").Name("getJobStatus")
+	router.HandleFunc("/job/{uid:[0-9a-z-]{36}}/wait", waitForJob).Methods("GET").Name("waitForJob")
+	router.HandleFunc("/job/{uid:[0-9a-z-]{36}}/download", downloadAssets).Methods("GET").Name("downloadAssets")
+
+	log.Fatalf("%s", http.ListenAndServe(cfg.Listen, router))
+}
+
+func pathFromUUID(uid uuid.UUID, filename string) string {
+	return path.Join(cfg.StorageDir, uid.String(), filename)
+}
+
+func apiDocs(res http.ResponseWriter, r *http.Request) {
+	http.Error(res, "Not implemented yet", http.StatusInternalServerError)
+}
+
+func startNewJob(res http.ResponseWriter, r *http.Request) {
+	jobUUID := uuid.NewV4()
+	inputFile := pathFromUUID(jobUUID, filenameInput)
+	statusFile := pathFromUUID(jobUUID, filenameStatus)
+
+	if err := os.Mkdir(path.Dir(inputFile), 0755); err != nil {
+		log.Errorf("Unable to create job dir %q: %s", path.Dir(inputFile), err)
+	}
+
+	if f, err := os.Create(inputFile); err == nil {
+		io.Copy(f, r.Body)
+		f.Close()
+	} else {
+		log.Errorf("Unable to write input file %q: %s", inputFile, err)
+		http.Error(res, "An error ocurred. See details in log.", http.StatusInternalServerError)
+		return
+	}
+
+	status := statusOutput{
+		UUID:      jobUUID.String(),
+		CreatedAt: time.Now(),
+		UpdatedAt: time.Now(),
+		Status:    statusCreated,
+	}
+	if err := status.Save(); err != nil {
+		log.Errorf("Unable to create status file %q: %s", statusFile, err)
+		http.Error(res, "An error ocurred. See details in log.", http.StatusInternalServerError)
+		return
+	}
+
+	go jobProcessor(jobUUID)
+
+	u, _ := router.Get("getJobStatus").URL(jobUUID.String())
+	http.Redirect(res, r, u.String(), http.StatusFound)
+}
+
+func checkJobStatus(res http.ResponseWriter, r *http.Request) (uuid.UUID, string) {
+	vars := mux.Vars(r)
+	uid, err := uuid.FromString(vars["uid"])
+	if err != nil {
+		http.Error(res, "UUID had unexpected format!", http.StatusBadRequest)
+		return uid, ""
+	}
+
+	statusFile := pathFromUUID(uid, filenameStatus)
+	if _, err := os.Stat(statusFile); err != nil {
+		http.Error(res, "Status for this UUID not found.", http.StatusNotFound)
+		return uid, ""
+	}
+
+	return uid, statusFile
+}
+
+func getJobStatus(res http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	uid, err := uuid.FromString(vars["uid"])
+	if err != nil {
+		http.Error(res, "UUID had unexpected format!", http.StatusBadRequest)
+		return
+	}
+
+	if status, err := loadStatusByUUID(uid); err == nil {
+		if err := json.NewEncoder(res).Encode(status); err != nil {
+			log.Errorf("Unable to serialize status file: %s", err)
+			http.Error(res, "An error ocurred. See details in log.", http.StatusInternalServerError)
+			return
+		}
+	} else {
+		log.Errorf("Unable to read status file: %s", err)
+		http.Error(res, "An error ocurred. See details in log.", http.StatusInternalServerError)
+		return
+	}
+}
+
+func waitForJob(res http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	uid, err := uuid.FromString(vars["uid"])
+	if err != nil {
+		http.Error(res, "UUID had unexpected format!", http.StatusBadRequest)
+		return
+	}
+
+	var loop int
+	if v := r.URL.Query().Get("loop"); v != "" {
+		if pv, err := strconv.Atoi(v); err == nil {
+			loop = pv
+		}
+	}
+	loop++
+
+	status, err := loadStatusByUUID(uid)
+	if err != nil {
+		log.Errorf("Unable to read status file: %s", err)
+		http.Error(res, "An error ocurred. See details in log.", http.StatusInternalServerError)
+		return
+	}
+
+	if status.Status != statusFinished {
+		u, _ := router.Get("waitForJob").URL(uid.String())
+		u.Query().Set("loop", strconv.Itoa(loop))
+
+		<-time.After(time.Duration(math.Pow(sleepBase, float64(loop))) * time.Second)
+
+		http.Redirect(res, r, u.String(), http.StatusFound)
+	}
+
+	u, _ := router.Get("downloadAssets").URL(uid.String())
+	http.Redirect(res, r, u.String(), http.StatusFound)
+}
+
+func buildAssetsZIP(uid uuid.UUID) (io.Reader, error) {
+	buf := new(bytes.Buffer)
+	w := zip.NewWriter(buf)
+
+	basePath := pathFromUUID(uid, filenameOutputDir)
+	err := filepath.Walk(basePath, func(p string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		zipInfo, err := zip.FileInfoHeader(info)
+		if err != nil {
+			return err
+		}
+		zipInfo.Name = strings.TrimLeft(strings.Replace(p, basePath, "", 1), "/\\")
+		zipFile, err := w.CreateHeader(zipInfo)
+		if err != nil {
+			return err
+		}
+		osFile, err := os.Open(p)
+		if err != nil {
+			return err
+		}
+
+		io.Copy(zipFile, osFile)
+		osFile.Close()
+
+		return nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	return buf, w.Close()
+}
+
+func downloadAssets(res http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	uid, err := uuid.FromString(vars["uid"])
+	if err != nil {
+		http.Error(res, "UUID had unexpected format!", http.StatusBadRequest)
+		return
+	}
+
+	var (
+		content  io.Reader
+		filename string
+	)
+
+	switch r.Header.Get("Accept") {
+	default:
+		content, err = buildAssetsZIP(uid)
+		filename = uid.String() + ".zip"
+	}
+
+	if err != nil {
+		log.Errorf("Unable to generate downloadable asset: %s", err)
+		http.Error(res, "An error ocurred. See details in log.", http.StatusInternalServerError)
+		return
+	}
+
+	res.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=%q", filename))
+	res.Header().Set("Content-Type", "application/octet-stream") // TODO(luzifer): Use a correct type?
+	res.WriteHeader(http.StatusOK)
+
+	io.Copy(res, content)
+}
+
+func jobProcessor(uid uuid.UUID) {
+	processingDir := path.Dir(pathFromUUID(uid, filenameStatus))
+	status, err := loadStatusByUUID(uid)
+	if err != nil {
+		log.Errorf("Unable to load status file in processing job: %s", err)
+		return
+	}
+
+	cmd := exec.Command("/bin/bash", cfg.ExecutionScript)
+	cmd.Dir = processingDir
+
+	status.UpdateStatus(statusStarted)
+	if err := status.Save(); err != nil {
+		log.Errorf("Unable to save status file: %s")
+		return
+	}
+
+	if err := cmd.Run(); err != nil {
+		status.UpdateStatus(statusError)
+		if err := status.Save(); err != nil {
+			log.Errorf("Unable to save status file: %s")
+			return
+		}
+		return
+	}
+
+	status.UpdateStatus(statusFinished)
+	if err := status.Save(); err != nil {
+		log.Errorf("Unable to save status file: %s")
+		return
+	}
+}

tex-build.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+set -ex
+set -o pipefail
+
+BUILD_DIR=$1
+
+cd $BUILD_DIR
+
+# TODO(kahlers): Add logic