Merge pull request #60 from /issues/53/pull-images

Pull Docker images matching filters specified

main.go

@@ -22,6 +22,7 @@ type options struct {
  Password string `short:"p" long:"password" default:"" description:"Docker registry password" env:"PASSWORD"`
  DockerJSON string `shord:"j" long:"docker-json" default:"~/.docker/config.json" env:"DOCKER_JSON"`
  Concurrency int `short:"c" long:"concurrency" default:"32" description:"Concurrent request limit while querying registry" env:"CONCURRENCY"`
+ PullImages bool `short:"P" long:"pull-images" description:"Pull images matched by filter" env:"PULL_IMAGES"`
  InsecureRegistry bool `short:"i" long:"insecure-registry" description:"Use insecure plain-HTTP registriy" env:"INSECURE_REGISTRY"`
  TraceRequests bool `short:"T" long:"trace-requests" description:"Trace registry HTTP requests" env:"TRACE_REQUESTS"`
  Version bool `short:"V" long:"version" description:"Show version and exit"`
@@ -135,7 +136,7 @@ func main() {
  os.Exit(0)
  }
  if o.Positional.Repository == "" {
- suicide(errors.New("You should provide a repository name, e.g. 'nginx' or 'mesosphere/chronos'"))
+ suicide(errors.New("You should provide a repository name, e.g. 'nginx~/^1\\\\.13/' or 'mesosphere/chronos'"))
  }
 
  if o.InsecureRegistry {
@@ -198,4 +199,26 @@ func main() {
  repoLocalName+":"+tg.GetName(),
  )
  }
+
+ if o.PullImages {
+ for _, key := range sortedKeys {
+ name := names[key]
+
+ tg := joinedTags[name]
+
+ if !matchesFilter(tg.GetName(), filter) {
+ continue
+ }
+
+ if tg.NeedsPull() {
+ ref := repoLocalName + ":" + tg.GetName()
+
+ fmt.Printf("Pulling: %s\n", ref)
+ err := local.PullImage(ref)
+ if err != nil {
+ suicide(err)
+ }
+ }
+ }
+ }
 }

tag/local/local.go

@@ -3,6 +3,7 @@ package local
 import (
  "encoding/json"
  "io"
+ "io/ioutil"
  "net/http"
  "strings"
  "time"
@@ -57,6 +58,20 @@ func detectAPIVersion() (string, error) {
  return parseAPIVersionJSON(resp.Body)
 }
 
+func newClient() (*client.Client, error) {
+ apiVersion, err := detectAPIVersion()
+ if err != nil {
+ return nil, err
+ }
+
+ cli, err := client.NewClient("unix://"+dockerSocket, apiVersion, nil, nil)
+ if err != nil {
+ return nil, err
+ }
+
+ return cli, err
+}
+
 func newImageListOptions(repo string) (types.ImageListOptions, error) {
  repoFilter := "reference=" + repo
  filterArgs := filters.NewArgs()
@@ -95,14 +110,7 @@ func extractTagNames(repoTags []string, repo string) []string {
 
 // FetchTags looks up Docker repo tags and IDs present on local Docker daemon
 func FetchTags(repo string) (map[string]*tag.Tag, error) {
- ctx := context.Background()
-
- apiVersion, err := detectAPIVersion()
- if err != nil {
- return nil, err
- }
-
- cli, err := client.NewClient("unix://"+dockerSocket, apiVersion, nil, nil)
+ cli, err := newClient()
  if err != nil {
  return nil, err
  }
@@ -111,7 +119,7 @@ func FetchTags(repo string) (map[string]*tag.Tag, error) {
  if err != nil {
  return nil, err
  }
- imageSummaries, err := cli.ImageList(ctx, listOptions)
+ imageSummaries, err := cli.ImageList(context.Background(), listOptions)
  if err != nil {
  return nil, err
  }
@@ -159,3 +167,20 @@ func FormatRepoName(repository, registry string) string {
 
  return registry + "/" + repository
 }
+
+// PullImage pulls Docker image specified locally
+func PullImage(ref string) error {
+ cli, err := newClient()
+ if err != nil {
+ return err
+ }
+
+ resp, err := cli.ImagePull(context.Background(), ref, types.ImagePullOptions{})
+ if err != nil {
+ return err
+ }
+
+ _, err = ioutil.ReadAll(resp)
+
+ return err
+}

tag/tag.go

@@ -77,6 +77,15 @@ func (tg *Tag) GetState() string {
  return tg.state
 }
 
+// NeedsPull tells us if tag/image needs pull
+func (tg *Tag) NeedsPull() bool {
+ if tg.state == "ABSENT" || tg.state == "CHANGED" {
+ return true
+ }
+
+ return false
+}
+
 // SetCreated sets image creation timestamp
 func (tg *Tag) SetCreated(created int64) {
  tg.created = created