build: add pull flag to force image pulling

Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com>

api/client/commands.go

@@ -77,6 +77,7 @@ func (cli *DockerCli) CmdBuild(args ...string) error {
 	noCache := cmd.Bool([]string{"#no-cache", "-no-cache"}, false, "Do not use cache when building the image")
 	rm := cmd.Bool([]string{"#rm", "-rm"}, true, "Remove intermediate containers after a successful build")
 	forceRm := cmd.Bool([]string{"-force-rm"}, false, "Always remove intermediate containers, even after unsuccessful builds")
+	pull := cmd.Bool([]string{"-pull"}, false, "Always attempt to pull a newer version of the image")
 	if err := cmd.Parse(args); err != nil {
 		return nil
 	}
@@ -213,6 +214,9 @@ func (cli *DockerCli) CmdBuild(args ...string) error {
 		v.Set("forcerm", "1")
 	}
 
+	if *pull {
+		v.Set("pull", "1")
+	}
 	cli.LoadConfigFile()
 
 	headers := http.Header(make(map[string][]string))

api/server/server.go

@@ -1016,6 +1016,9 @@ func postBuild(eng *engine.Engine, version version.Version, w http.ResponseWrite
 	} else {
 		job.Setenv("rm", r.FormValue("rm"))
 	}
+	if r.FormValue("pull") == "1" && version.GreaterThanOrEqualTo("1.16") {
+		job.Setenv("pull", "1")
+	}
 	job.Stdin.Add(r.Body)
 	job.Setenv("remote", r.FormValue("remote"))
 	job.Setenv("t", r.FormValue("t"))

builder/dispatchers.go

@@ -115,6 +115,12 @@ func from(b *Builder, args []string, attributes map[string]bool, original string
 	name := args[0]
 
 	image, err := b.Daemon.Repositories().LookupImage(name)
+	if b.Pull {
+		image, err = b.pullImage(name)
+		if err != nil {
+			return err
+		}
+	}
 	if err != nil {
 		if b.Daemon.Graph().IsNotExist(err) {
 			image, err = b.pullImage(name)

builder/evaluator.go

@@ -90,6 +90,7 @@ type Builder struct {
 	// controls how images and containers are handled between steps.
 	Remove      bool
 	ForceRemove bool
+	Pull        bool
 
 	AuthConfig     *registry.AuthConfig
 	AuthConfigFile *registry.ConfigFile

builder/job.go

@@ -35,6 +35,7 @@ func (b *BuilderJob) CmdBuild(job *engine.Job) engine.Status {
 		noCache        = job.GetenvBool("nocache")
 		rm             = job.GetenvBool("rm")
 		forceRm        = job.GetenvBool("forcerm")
+		pull           = job.GetenvBool("pull")
 		authConfig     = &registry.AuthConfig{}
 		configFile     = &registry.ConfigFile{}
 		tag            string
@@ -111,6 +112,7 @@ func (b *BuilderJob) CmdBuild(job *engine.Job) engine.Status {
 		UtilizeCache:    !noCache,
 		Remove:          rm,
 		ForceRemove:     forceRm,
+		Pull:            pull,
 		OutOld:          job.Stdout,
 		StreamFormatter: sf,
 		AuthConfig:      authConfig,

docs/sources/reference/api/docker_remote_api_v1.16.md

@@ -1156,6 +1156,7 @@ Query Parameters:
         the resulting image in case of success
 -   **q** – suppress verbose build output
 -   **nocache** – do not use the cache when building the image
+-   **pull** - attempt to pull the image even if an older image exists locally
 -   **rm** - remove intermediate containers after a successful build (default behavior)
 -   **forcerm - always remove intermediate containers (includes rm)
 

docs/sources/reference/commandline/cli.md

@@ -312,6 +312,7 @@ To kill the container, use `docker kill`.
 
       --force-rm=false     Always remove intermediate containers, even after unsuccessful builds
       --no-cache=false     Do not use cache when building the image
+      --pull=false         Always attempt to pull a newer version of the image
       -q, --quiet=false    Suppress the verbose output generated by the containers
       --rm=true            Remove intermediate containers after a successful build
       -t, --tag=""         Repository name (and optionally a tag) to be applied to the resulting image in case of success