Adding QEMU static arm binary to build ARM images

.travis.yml

@@ -9,17 +9,20 @@ env:
     - DOCKER_BUILD=qmcgaw/private-internet-access
     - MICROBADGER_CODE=tQFy7AxtSUNANPe6aoVChYdsI_I=
   matrix:
+    - TARGET_IMAGE=${DOCKER_BUILD}
     - ARCH=armhf
       BASE_IMAGE=arm32v6/alpine
       TARGET_IMAGE=${DOCKER_BUILD}:${ARCH}
+      QEMU=https://github.com/multiarch/qemu-user-static/releases/download/v3.1.0-3/qemu-arm-static
     - ARCH=aarch64
       BASE_IMAGE=arm64v8/alpine
       TARGET_IMAGE=${DOCKER_BUILD}:${ARCH}
+      QEMU=https://github.com/multiarch/qemu-user-static/releases/download/v3.1.0-3/qemu-arm-static
 script:
   - set -e
   - echo "$DOCKER_PASSWORD" | docker login -u qmcgaw --password-stdin
   - docker run --rm --privileged multiarch/qemu-user-static:register --reset
-  - docker build -t ${TARGET_IMAGE} --build-arg BASE_IMAGE=${BASE_IMAGE} --build-arg VCF=${TRAVIS_COMMIT} --build-arg BUILD_DATE="$(date -u +"%Y-%m-%dT%H:%M:%SZ")" .
+  - docker build -t ${TARGET_IMAGE} --build-arg BASE_IMAGE=${BASE_IMAGE} --build-arg QEMU=${QEMU} --build-arg VCF=${TRAVIS_COMMIT} --build-arg BUILD_DATE="$(date -u +"%Y-%m-%dT%H:%M:%SZ")" .
   - '[ "${TRAVIS_PULL_REQUEST}" = "false" ] && docker push ${DOCKER_BUILD} || false'
   - "curl -X POST https://hooks.microbadger.com/images/${DOCKER_BUILD}/${MICROBADGER_CODE}"
   

Dockerfile

@@ -1,8 +1,11 @@
 ARG BASE_IMAGE
 
 FROM ${BASE_IMAGE:-alpine}:3.9
+ARG QEMU=
 ARG BUILD_DATE
 ARG VCS_REF
+# Only installed for ARM devices
+ADD .void ${QEMU}? /usr/bin/
 LABEL org.label-schema.schema-version="1.0.0-rc1" \
       maintainer="quentin.mcgaw@gmail.com" \
       org.label-schema.build-date=$BUILD_DATE \
@@ -64,4 +67,5 @@ RUN chown nonrootuser -R /etc/unbound && \
         /etc/unbound/root.hints \
         /etc/unbound/root.key \
         /etc/unbound/unbound.conf \
-        /etc/unbound/*.bz2
+        /etc/unbound/*.bz2 && \
+    rm -f /usr/bin/qemu-arm-static /usr/bin/.void

README.md

@@ -75,7 +75,7 @@
     modprobe tun
     ```
 
-1. **IF YOU HAVE AN ARM DEVICE, depending on your cpu architecture:** replace `qmcgaw/private-internet-access`
+1. **ONLY IF YOU HAVE AN ARM DEVICE, depending on your cpu architecture,** replace `qmcgaw/private-internet-access`
    with either `qmcgaw/private-internet-access:armhf` (32 bit) or `qmcgaw/private-internet-access:aarch64` (64 bit).
 
 1. Launch the container with:
@@ -246,6 +246,27 @@ services:
     # add more volumes etc.
 ```
 
+## ARM devices
+
+If you want to save 3-5MB on the image (because of QEMU), use the following command on
+your ARM device:
+
+- If your architecture is ARMHF (32 bit)
+
+    ```sh
+    docker build -t qmcgaw/private-internet-access:armhf \
+    --build-arg BASE_IMAGE=arm32v6/alpine \
+    https://github.com/qdm12/private-internet-access-docker.git
+    ```
+
+- If your architecture is AARCH64 (64 bit)
+
+    ```sh
+    docker build -t qmcgaw/private-internet-access:aarch64 \
+    --build-arg BASE_IMAGE=arm64v8/alpine \
+    https://github.com/qdm12/private-internet-access-docker.git
+    ```
+
 ## For the paranoids
 
 - You can review the code which essential consits in the [Dockerfile](https://github.com/qdm12/private-internet-access-docker/blob/master/Dockerfile) and [entrypoint.sh](https://github.com/qdm12/private-internet-access-docker/blob/master/entrypoint.sh)