build: Makefile to build Dgraph inside docker container. (#6423)

The script is useful for situations in which the host system creates a
binary that's incompatible with the docker container (e.g different
versions of glibc).

contrib/docker-build/Makefile

@@ -0,0 +1,4 @@
+install:
+	@docker-compose up
+	@sudo chown $(USER) ../../dgraph/dgraph
+	@mv ../../dgraph/dgraph $(GOPATH)/bin

contrib/docker-build/README.md

@@ -0,0 +1,13 @@
+# Docker build script
+
+This directory contains a Makefile that can be used to build Dgraph inside the
+official Dgraph Docker container. This is useful for situations when the host
+system cannot be used to build a binary that will work with the container (for
+example, if the host system has a different version of glibc).
+
+## Usage
+
+Run `make install` in this directory. The script will ask you for your password
+in order to change ownership of the compiled binary. By default, files written
+by Docker will be owned by root. This script also takes care of moving the
+binary to $GOPATH/bin.

contrib/docker-build/build.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+export DEBIAN_FRONTEND=noninteractive
+apt-get update
+apt-get install -y build-essential git golang
+cd /dgraph/dgraph
+make

contrib/docker-build/docker-compose.yml

@@ -0,0 +1,14 @@
+version: "3.5"
+services:
+  build:
+    image: dgraph/dgraph:latest
+    container_name: build
+    working_dir: /data/build
+    labels:
+      cluster: test
+      service: build
+    volumes:
+      - type: bind
+        source: ../../
+        target: /dgraph
+    command: /dgraph/contrib/docker-build/build.sh

dgraph/Makefile

@@ -14,6 +14,7 @@
 # limitations under the License.
 #
 
+USER_ID         = $(shell id -u)
 BIN             = dgraph
 BUILD          ?= $(shell git rev-parse --short HEAD)
 BUILD_CODENAME  = unnamed
@@ -90,14 +91,18 @@ install: jemalloc
 
 jemalloc:
 	@if [ -z "$(HAS_JEMALLOC)" ] ; then \
-	    mkdir -p /tmp/jemalloc-temp && cd /tmp/jemalloc-temp ; \
-	    echo "Downloading jemalloc" ; \
-	    curl -s -L ${JEMALLOC_URL} -o jemalloc.tar.bz2 ; \
-	    tar xjf ./jemalloc.tar.bz2 ; \
-	    cd jemalloc-5.2.1 ; \
-	    ./configure --with-jemalloc-prefix='je_' ; \
-	    make ; \
-	    echo "==== Need sudo access to install jemalloc" ; \
-	    sudo make install ; \
+		mkdir -p /tmp/jemalloc-temp && cd /tmp/jemalloc-temp ; \
+		echo "Downloading jemalloc" ; \
+		curl -s -L ${JEMALLOC_URL} -o jemalloc.tar.bz2 ; \
+		tar xjf ./jemalloc.tar.bz2 ; \
+		cd jemalloc-5.2.1 ; \
+		./configure --with-jemalloc-prefix='je_' ; \
+		make ; \
+		if [ "$(USER_ID)" = "0" ]; then \
+			make install ; \
+		else \
+			echo "==== Need sudo access to install jemalloc" ; \
+			sudo make install ; \
+		fi \
 	fi