feat(lang): init py env by generating the bulid.envd (#827)

* feat(lang): init py env by generating the bulid.envd from existing project

Signed-off-by: Keming <kemingyang@tensorchord.ai>

* add test

Signed-off-by: Keming <kemingyang@tensorchord.ai>

* fix test

Signed-off-by: Keming <kemingyang@tensorchord.ai>

* fix lint

Signed-off-by: Keming <kemingyang@tensorchord.ai>

* only use the first file

Signed-off-by: Keming <kemingyang@tensorchord.ai>

Signed-off-by: Keming <kemingyang@tensorchord.ai>

e2e/cli/init_test.go

@@ -0,0 +1,74 @@
+// Copyright 2022 The envd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cli
+
+import (
+	"os"
+	"path/filepath"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	"github.com/tensorchord/envd/e2e"
+	"github.com/tensorchord/envd/pkg/app"
+	"github.com/tensorchord/envd/pkg/home"
+	"github.com/tensorchord/envd/pkg/util/fileutil"
+)
+
+var _ = Describe("init project", Ordered, func() {
+	var path string
+	BeforeAll(func() {
+		Expect(home.Initialize()).To(Succeed())
+		envdApp := app.New()
+		err := envdApp.Run([]string{"envd.test", "--debug", "bootstrap"})
+		Expect(err).To(Succeed())
+		e2e.ResetEnvdApp()
+		path, err = os.MkdirTemp("", "envd_init_test_*")
+		Expect(err).To(Succeed())
+		err = os.WriteFile(filepath.Join(path, "requirements.txt"), []byte("via"), 0666)
+		Expect(err).To(Succeed())
+	})
+
+	It("init python env", func() {
+		envdApp := app.New()
+		err := envdApp.Run([]string{"envd.test", "--debug", "init", "-p", path})
+		Expect(err).To(Succeed())
+		exist, err := fileutil.FileExists(filepath.Join(path, "build.envd"))
+		Expect(err).To(Succeed())
+		Expect(exist).To(BeTrue())
+	})
+
+	Describe("run init env", Ordered, func() {
+		var e *e2e.Example
+		BeforeAll(func() {
+			// have to use `path` inside ginkgo closure
+			e = e2e.NewExample(path, "init_test")
+			e.RunContainer()()
+		})
+		It("exec installed command inside container", func() {
+			_, err := e.Exec("via --help")
+			Expect(err).To(Succeed())
+		})
+		AfterAll(func() {
+			e.DestroyContainer()()
+			e.RemoveImage()()
+		})
+
+	})
+
+	AfterAll(func() {
+		os.RemoveAll(path)
+	})
+})

pkg/app/init.go

@@ -15,8 +15,12 @@
 package app
 
 import (
+	"bytes"
 	"embed"
+	"fmt"
+	"io/fs"
 	"io/ioutil"
+	"path/filepath"
 	"strings"
 
 	"github.com/cockroachdb/errors"
@@ -38,14 +42,21 @@ var CommandInit = &cli.Command{
 			Name:     "lang",
 			Usage:    "language usage. Support Python, R, Julia",
 			Aliases:  []string{"l"},
-			Required: true,
+			Required: false,
+			Value:    "python",
 		},
 		&cli.BoolFlag{
 			Name:     "force",
 			Usage:    "overwrite the build.envd if existed",
 			Aliases:  []string{"f"},
 			Required: false,
 		},
+		&cli.PathFlag{
+			Name:    "path",
+			Usage:   "Path to the directory containing the build.envd",
+			Aliases: []string{"p"},
+			Value:   ".",
+		},
 	},
 	Action: initCommand,
 }
@@ -61,26 +72,116 @@ func isValidLang(lang string) bool {
 	return false
 }
 
+type pythonEnv struct {
+	pythonVersion string
+	requirements  string
+	condaEnv      string
+	indent        string
+	notebook      bool
+}
+
+func NewPythonEnv(dir string) (*pythonEnv, error) {
+	requirements := ""
+	condaEnv := ""
+	err := filepath.WalkDir(dir, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if d.IsDir() {
+			return nil
+		}
+		relPath, err := filepath.Rel(dir, path)
+		if err != nil {
+			return err
+		}
+		if d.Name() == "requirements.txt" && len(requirements) <= 0 {
+			requirements = relPath
+			return nil
+		}
+		if isCondaEnvFile(d.Name()) && len(condaEnv) <= 0 {
+			condaEnv = relPath
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	return &pythonEnv{
+		pythonVersion: "python", // use the default one
+		requirements:  requirements,
+		condaEnv:      condaEnv,
+		indent:        "    ",
+		notebook:      false,
+	}, nil
+}
+
+func (pe *pythonEnv) generate() []byte {
+	var buf bytes.Buffer
+	buf.WriteString("def build():\n")
+	buf.WriteString(fmt.Sprintf("%sbase(os=\"ubuntu20.04\", language=\"%s\")\n", pe.indent, pe.pythonVersion))
+	if len(pe.requirements) > 0 {
+		buf.WriteString(fmt.Sprintf("%sinstall.python_packages(requirements=\"%s\")\n", pe.indent, pe.requirements))
+	}
+	if len(pe.condaEnv) > 0 {
+		buf.WriteString(fmt.Sprintf("%sinstall.conda_packages(env_file=\"%s\")\n", pe.indent, pe.condaEnv))
+	}
+	if pe.notebook {
+		buf.WriteString(fmt.Sprintf("%sconfig.jupyter()\n", pe.indent))
+	}
+	return buf.Bytes()
+}
+
+// naive check
+func isCondaEnvFile(file string) bool {
+	switch file {
+	case
+		"environment.yml",
+		"environment.yaml",
+		"env.yml",
+		"env.yaml":
+		return true
+	}
+	return false
+}
+
+func initPythonEnv(dir string) ([]byte, error) {
+	env, err := NewPythonEnv(dir)
+	if err != nil {
+		return nil, err
+	}
+	return env.generate(), nil
+}
+
 func initCommand(clicontext *cli.Context) error {
 	lang := strings.ToLower(clicontext.String("lang"))
+	buildContext, err := filepath.Abs(clicontext.Path("path"))
 	force := clicontext.Bool("force")
+	if err != nil {
+		return err
+	}
 	if !isValidLang(lang) {
-		return errors.Errorf("invalid language %s", lang)
+		return errors.Errorf("invalid language (%s)", lang)
 	}
 
-	exists, err := fileutil.FileExists("build.envd")
+	filePath := filepath.Join(buildContext, "build.envd")
+	exists, err := fileutil.FileExists(filePath)
 	if err != nil {
 		return err
 	}
 	if exists && !force {
 		return errors.Errorf("build.envd already exists, use --force to overwrite it")
 	}
 
-	buildEnvdContent, err := templatef.ReadFile("template/" + lang + ".envd")
+	var buildEnvdContent []byte
+	if lang == "python" {
+		buildEnvdContent, err = initPythonEnv(buildContext)
+	} else {
+		buildEnvdContent, err = templatef.ReadFile("template/" + lang + ".envd")
+	}
 	if err != nil {
 		return err
 	}
-	err = ioutil.WriteFile("build.envd", buildEnvdContent, 0644)
+	err = ioutil.WriteFile(filePath, buildEnvdContent, 0644)
 	if err != nil {
 		return errors.Wrapf(err, "Failed to create build.envd")
 	}