docker: the docker image will now contain just the static binary

Docker.md

@@ -0,0 +1,16 @@
+# docker run
+
+To run docker image:
+```docker run -p 9000:9000 minio/minio:latest```
+
+This will start minio server in the docker container, the data however is not persistent.
+If you need persistent storage you can use the command:
+
+```docker run -p 9000:9000 -v /home/krishna/.minio:/.minio -v /home/user/export:/export minio:latest```
+
+Here the data uploaded to the minio server will be persisted to /home/user/export directory.
+
+# docker build
+
+To build the docker image:
+```make dockerimage TAG="<tag>"```

Dockerfile

@@ -1,38 +1,8 @@
-FROM ubuntu-debootstrap:14.04
-
-MAINTAINER Minio Community
-
-ENV GOLANG_TARBALL go1.5.1.linux-amd64.tar.gz
-
-ENV GOROOT /usr/local/go/
-ENV GOPATH /go-workspace
-ENV PATH ${GOROOT}/bin:${GOPATH}/bin/:$PATH
-
-ENV MINIOHOME /home/minio
-ENV MINIOUSER minio
-RUN useradd -m -d $MINIOHOME $MINIOUSER
-
-RUN apt-get update -y && apt-get install -y -q \
-		curl \
-		git \
-		build-essential \
-		ca-certificates
-
-RUN curl -O -s https://storage.googleapis.com/golang/${GOLANG_TARBALL} && \
-		tar -xzf ${GOLANG_TARBALL} -C ${GOROOT%*go*} && \
-		rm ${GOLANG_TARBALL}
-
-ADD . ${GOPATH}/src/github.com/minio/minio
-
-RUN cd ${GOPATH}/src/github.com/minio/minio && \
-		make
-
-RUN apt-get remove -y build-essential curl git && \
-        apt-get -y autoremove && \
-        rm -rf /var/lib/apt/lists/*
-
-USER minio
-
+# use "make dockerimage" to build
+FROM scratch
+ENV DOCKERIMAGE 1
+ADD minio.dockerimage /minio
+ADD export /export
 EXPOSE 9000
-
-CMD ["sh", "-c", "${GOPATH}/bin/minio server"]
+ENTRYPOINT ["/minio"]
+CMD ["server", "/export"]

Makefile

@@ -1,4 +1,6 @@
 LDFLAGS = $(shell go run buildscripts/gen-ldflags.go)
+DOCKER_LDFLAGS = '-extldflags "-static"'
+TAG = latest
 
 all: install
 
@@ -53,7 +55,7 @@ test: build
 	@GO15VENDOREXPERIMENT=1 go test $(GOFLAGS) github.com/minio/minio/pkg...
 
 gomake-all: build
-	@GO15VENDOREXPERIMENT=1 go build -ldflags $(LDFLAGS) -o $(GOPATH)/bin/minio
+	@GO15VENDOREXPERIMENT=1 go build --ldflags $(LDFLAGS) -o $(GOPATH)/bin/minio
 
 pkg-add:
 	@GO15VENDOREXPERIMENT=1 govendor add $(PKG)
@@ -66,6 +68,14 @@ pkg-remove:
 
 install: gomake-all
 
+dockerimage: install
+	@echo "Building docker image:" minio:$(TAG)
+	@GO15VENDOREXPERIMENT=1 go build --ldflags $(LDFLAGS) --ldflags $(DOCKER_LDFLAGS) -o minio.dockerimage
+	@mkdir -p export
+	@docker build --rm --tag=minio:$(TAG) .
+	@rmdir export
+	@rm minio.dockerimage
+
 clean:
 	@echo "Cleaning up all the generated files:"
 	@rm -fv cover.out

main.go

@@ -19,7 +19,6 @@ package main
 import (
 	"fmt"
 	"os"
-	"os/user"
 	"runtime"
 	"strconv"
 
@@ -29,18 +28,24 @@ import (
 )
 
 func init() {
+	// Check if minio was compiled using a supported version of Golang.
+	checkGolangRuntimeVersion()
+
 	// Check for the environment early on and gracefuly report.
-	_, err := user.Current()
+	_, err := userCurrent()
 	if err != nil {
 		Fatalf("Unable to obtain user's home directory. \nError: %s\n", err)
 	}
 
+	if os.Getenv("DOCKERIMAGE") == "1" {
+		// the further checks are ignored for docker image
+		return
+	}
+
 	if os.Geteuid() == 0 {
 		Fatalln("Please run ‘minio’ as a non-root user.")
 	}
 
-	// Check if minio was compiled using a supported version of Golang.
-	checkGolangRuntimeVersion()
 }
 
 func migrate() {

pkg/fs/config.go

@@ -17,6 +17,7 @@
 package fs
 
 import (
+	"os"
 	"os/user"
 	"path/filepath"
 
@@ -24,13 +25,33 @@ import (
 	"github.com/minio/minio-xl/pkg/quick"
 )
 
+// workaround for docker images with fully static binary.
+// for static binaries NSS library will not be a part of the static binary
+// hence user.Current() fails
+// more here : http://gnu.ist.utl.pt/software/libc/FAQ.html
+// FAQ says : NSS (for details just type `info libc "Name Service Switch"') won't work properly without shared libraries
+func userCurrent() (*user.User, *probe.Error) {
+	if os.Getenv("DOCKERIMAGE") == "1" {
+		wd, err := os.Getwd()
+		if err != nil {
+			return nil, probe.NewError(err)
+		}
+		return &user.User{Uid: "0", Gid: "0", Username: "root", Name: "root", HomeDir: wd}, nil
+	}
+	user, err := user.Current()
+	if err != nil {
+		return nil, probe.NewError(err)
+	}
+	return user, nil
+}
+
 func getFSBucketsConfigPath() (string, *probe.Error) {
 	if customBucketsConfigPath != "" {
 		return customBucketsConfigPath, nil
 	}
-	u, err := user.Current()
+	u, err := userCurrent()
 	if err != nil {
-		return "", probe.NewError(err)
+		return "", err.Trace()
 	}
 	fsBucketsConfigPath := filepath.Join(u.HomeDir, ".minio", "buckets.json")
 	return fsBucketsConfigPath, nil
@@ -40,9 +61,9 @@ func getFSMultipartsSessionConfigPath() (string, *probe.Error) {
 	if customMultipartsConfigPath != "" {
 		return customMultipartsConfigPath, nil
 	}
-	u, err := user.Current()
+	u, err := userCurrent()
 	if err != nil {
-		return "", probe.NewError(err)
+		return "", err.Trace()
 	}
 	fsMultipartsConfigPath := filepath.Join(u.HomeDir, ".minio", "multiparts-session.json")
 	return fsMultipartsConfigPath, nil

server-config.go

@@ -21,7 +21,6 @@ import (
 	"errors"
 	"fmt"
 	"os"
-	"os/user"
 	"path/filepath"
 
 	"github.com/fatih/color"
@@ -124,9 +123,9 @@ func getConfigPath() (string, *probe.Error) {
 	if customConfigPath != "" {
 		return customConfigPath, nil
 	}
-	u, err := user.Current()
+	u, err := userCurrent()
 	if err != nil {
-		return "", probe.NewError(err)
+		return "", err.Trace()
 	}
 	configPath := filepath.Join(u.HomeDir, ".minio")
 	return configPath, nil

utils.go

@@ -18,8 +18,12 @@ package main
 
 import (
 	"encoding/base64"
+	"os"
+	"os/user"
 	"strconv"
 	"strings"
+
+	"github.com/minio/minio-xl/pkg/probe"
 )
 
 // isValidMD5 - verify if valid md5
@@ -51,3 +55,23 @@ func isMaxObjectSize(size string) bool {
 	}
 	return false
 }
+
+// workaround for docker images with fully static binary.
+// for static binaries NSS library will not be a part of the static binary
+// hence user.Current() fails
+// more here : http://gnu.ist.utl.pt/software/libc/FAQ.html
+// FAQ says : NSS (for details just type `info libc "Name Service Switch"') won't work properly without shared libraries
+func userCurrent() (*user.User, *probe.Error) {
+	if os.Getenv("DOCKERIMAGE") == "1" {
+		wd, err := os.Getwd()
+		if err != nil {
+			return nil, probe.NewError(err)
+		}
+		return &user.User{Uid: "0", Gid: "0", Username: "root", Name: "root", HomeDir: wd}, nil
+	}
+	user, err := user.Current()
+	if err != nil {
+		return nil, probe.NewError(err)
+	}
+	return user, nil
+}