1
0
Fork 0
mirror of https://github.com/moby/moby.git synced 2022-11-09 12:21:53 -05:00
moby--moby/tags.go

153 lines
3.3 KiB
Go

package docker
import (
"encoding/json"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"strings"
)
const DEFAULT_TAG = "latest"
type TagStore struct {
path string
graph *Graph
Repositories map[string]Repository
}
type Repository map[string]string
func NewTagStore(path string, graph *Graph) (*TagStore, error) {
abspath, err := filepath.Abs(path)
if err != nil {
return nil, err
}
store := &TagStore{
path: abspath,
graph: graph,
Repositories: make(map[string]Repository),
}
// Load the json file if it exists, otherwise create it.
if err := store.Reload(); os.IsNotExist(err) {
if err := store.Save(); err != nil {
return nil, err
}
} else if err != nil {
return nil, err
}
return store, nil
}
func (store *TagStore) Save() error {
// Store the json ball
jsonData, err := json.Marshal(store)
if err != nil {
return err
}
if err := ioutil.WriteFile(store.path, jsonData, 0600); err != nil {
return err
}
return nil
}
func (store *TagStore) Reload() error {
jsonData, err := ioutil.ReadFile(store.path)
if err != nil {
return err
}
if err := json.Unmarshal(jsonData, store); err != nil {
return err
}
return nil
}
func (store *TagStore) LookupImage(name string) (*Image, error) {
img, err := store.graph.Get(name)
if err != nil {
// FIXME: standardize on returning nil when the image doesn't exist, and err for everything else
// (so we can pass all errors here)
repoAndTag := strings.SplitN(name, ":", 2)
if len(repoAndTag) == 1 {
repoAndTag = append(repoAndTag, DEFAULT_TAG)
}
if i, err := store.GetImage(repoAndTag[0], repoAndTag[1]); err != nil {
return nil, err
} else if i == nil {
return nil, fmt.Errorf("No such image: %s", name)
} else {
img = i
}
}
return img, nil
}
func (store *TagStore) Set(repoName, tag, revision string) error {
if tag == "" {
tag = DEFAULT_TAG
}
if err := validateRepoName(repoName); err != nil {
return err
}
if err := validateTagName(tag); err != nil {
return err
}
if err := store.Reload(); err != nil {
return err
}
var repo Repository
if r, exists := store.Repositories[repoName]; exists {
repo = r
} else {
repo = make(map[string]string)
store.Repositories[repoName] = repo
}
repo[tag] = revision
return store.Save()
}
func (store *TagStore) Get(repoName string) (Repository, error) {
if err := store.Reload(); err != nil {
return nil, err
}
if r, exists := store.Repositories[repoName]; exists {
return r, nil
}
return nil, nil
}
func (store *TagStore) GetImage(repoName, tag string) (*Image, error) {
repo, err := store.Get(repoName)
if err != nil {
return nil, err
} else if repo == nil {
return nil, nil
}
if revision, exists := repo[tag]; exists {
return store.graph.Get(revision)
}
return nil, nil
}
// Validate the name of a repository
func validateRepoName(name string) error {
if name == "" {
return fmt.Errorf("Repository name can't be empty")
}
if strings.Contains(name, ":") {
return fmt.Errorf("Illegal repository name: %s", name)
}
return nil
}
// Validate the name of a tag
func validateTagName(name string) error {
if name == "" {
return fmt.Errorf("Tag name can't be empty")
}
if strings.Contains(name, "/") || strings.Contains(name, ":") {
return fmt.Errorf("Illegal tag name: %s", name)
}
return nil
}