Add ability to resolve and install transitive dependencies

pkg/packages.go

@@ -0,0 +1,144 @@
+// Copyright 2018 jsonnet-bundler 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 pkg
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+	"path/filepath"
+
+	"github.com/jsonnet-bundler/jsonnet-bundler/spec"
+	"github.com/pkg/errors"
+)
+
+var (
+	JsonnetFile     = "jsonnetfile.json"
+	JsonnetLockFile = "jsonnetfile.lock.json"
+	VersionMismatch = errors.New("multiple colliding versions specified")
+)
+
+func Install(ctx context.Context, m spec.JsonnetFile, dir string) (lock *spec.JsonnetFile, err error) {
+	lock = &spec.JsonnetFile{}
+	for _, dep := range m.Dependencies {
+		tmp := filepath.Join(dir, ".tmp")
+		err = os.MkdirAll(tmp, os.ModePerm)
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to create general tmp dir")
+		}
+		tmpDir, err := ioutil.TempDir(tmp, fmt.Sprintf("jsonnetpkg-%s-%s", dep.Name, dep.Version))
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to create tmp dir")
+		}
+		defer os.RemoveAll(tmpDir)
+
+		subdir := ""
+		var p Interface
+		if dep.Source.GitSource != nil {
+			p = NewGitPackage(dep.Source.GitSource)
+			subdir = dep.Source.GitSource.Subdir
+		}
+
+		lockVersion, err := p.Install(ctx, tmpDir, dep.Version)
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to install package")
+		}
+		// need to deduplicate/error when multiple entries
+		lock.Dependencies, err = insertDependency(lock.Dependencies, spec.Dependency{
+			Name:    dep.Name,
+			Source:  dep.Source,
+			Version: lockVersion,
+		})
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to insert dependency to lock dependencies")
+		}
+
+		destPath := path.Join(dir, dep.Name)
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to find destination path for package")
+		}
+
+		err = os.MkdirAll(path.Dir(destPath), os.ModePerm)
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to create parent path")
+		}
+
+		err = os.RemoveAll(destPath)
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to clean previous destination path")
+		}
+		err = os.Rename(path.Join(tmpDir, subdir), destPath)
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to move package")
+		}
+
+		if _, err := os.Stat(path.Join(destPath, JsonnetFile)); !os.IsNotExist(err) {
+			depsDeps, err := LoadJsonnetfile(path.Join(destPath, JsonnetFile))
+			if err != nil {
+				return nil, err
+			}
+
+			depsInstalledByDependency, err := Install(ctx, depsDeps, dir)
+			if err != nil {
+				return nil, err
+			}
+
+			for _, d := range depsInstalledByDependency.Dependencies {
+				lock.Dependencies, err = insertDependency(lock.Dependencies, d)
+				if err != nil {
+					return nil, errors.Wrap(err, "failed to insert dependency to lock dependencies")
+				}
+			}
+		}
+	}
+
+	return lock, nil
+}
+
+func insertDependency(deps []spec.Dependency, newDep spec.Dependency) ([]spec.Dependency, error) {
+	res := []spec.Dependency{}
+	for _, d := range deps {
+		if d.Name == newDep.Name {
+			if d.Version != newDep.Version {
+				return nil, VersionMismatch
+			}
+			res = append(res, d)
+		} else {
+			res = append(res, d)
+		}
+	}
+
+	return res, nil
+}
+
+func LoadJsonnetfile(filename string) (spec.JsonnetFile, error) {
+	m := spec.JsonnetFile{}
+
+	f, err := os.Open(filename)
+	if err != nil {
+		return m, err
+	}
+	defer f.Close()
+
+	err = json.NewDecoder(f).Decode(&m)
+	if err != nil {
+		return m, err
+	}
+
+	return m, nil
+}