Re-enables and fixes buildozer build

Disabled earlier in 223c67b and fixed in `buildozer` master branch.
Also simplifies and fixes `xvfb` service.

.travis.yml

@@ -4,25 +4,15 @@ language: generic
 
 services:
   - docker
+  - xvfb
 
 env:
-  global:
-    - DISPLAY=:99.0
   matrix:
     - TAG=zbarcam-linux DOCKERFILE=dockerfiles/Dockerfile-linux COMMAND='make test'
-    # broken in:
-    # https://github.com/kivy/python-for-android/pull/1986
-    # - TAG=zbarcam-android DOCKERFILE=dockerfiles/Dockerfile-android COMMAND='buildozer android debug'
-
-before_install:
-  - sudo apt update -qq > /dev/null
-  - sudo apt install --yes --no-install-recommends xvfb
-
-install:
-  - docker build --tag=$TAG --file=$DOCKERFILE --build-arg CI .
+    - TAG=zbarcam-android DOCKERFILE=dockerfiles/Dockerfile-android COMMAND='buildozer android debug'
 
 before_script:
-  - sh -e /etc/init.d/xvfb start
+  - docker build --tag=$TAG --file=$DOCKERFILE --build-arg CI .
 
 script:
-  - travis_wait docker run --env-file dockerfiles/env.list -v /tmp/.X11-unix:/tmp/.X11-unix $TAG $COMMAND
+  - travis_wait 30 docker run --env-file dockerfiles/env.list -v /tmp/.X11-unix:/tmp/.X11-unix $TAG $COMMAND

README.md

@@ -38,7 +38,7 @@ make system_dependencies
 
 Install zbarcam:
 ```sh
-pip install --upgrade zbarcam
+pip install zbarcam
 ```
 Then import it in your Python code via:
 ```python

dockerfiles/Dockerfile-android

@@ -17,7 +17,7 @@ ENV WORK_DIR="${HOME_DIR}" \
 ENV DOCKERFILES_VERSION="v20190902" \
     DOCKERFILES_URL="https://raw.githubusercontent.com/AndreMiras/dockerfiles"
 ENV MAKEFILES_URL="${DOCKERFILES_URL}/${DOCKERFILES_VERSION}/buildozer_android"
-ENV BUILDOZER_VERSION="182d13f"
+ENV BUILDOZER_VERSION="81c31c4"
 
 
 # configure locale
@@ -29,7 +29,7 @@ ENV LANG="en_US.UTF-8" \
     LC_ALL="en_US.UTF-8"
 
 # install system dependencies
-RUN apt install -qq --yes --no-install-recommends \
+RUN apt update -qq > /dev/null && apt install -qq --yes --no-install-recommends \
     autoconf \
     automake \
     ca-certificates \
@@ -54,20 +54,18 @@ RUN apt install -qq --yes --no-install-recommends \
     xz-utils \
     zip
 
-# prepare non root env
-RUN useradd --create-home --shell /bin/bash ${USER}
-# with sudo access and no password
-RUN usermod -append --groups sudo ${USER}
-RUN echo "%sudo ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers
+# prepare non root env, with sudo access and no password
+RUN useradd --create-home --shell /bin/bash ${USER} && \
+    usermod -append --groups sudo ${USER} && \
+    echo "%sudo ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers
 
 USER ${USER}
 WORKDIR ${WORK_DIR}
 
-# install buildozer and dependencies
-RUN curl --location --progress-bar ${MAKEFILES_URL}/buildozer.mk --output buildozer.mk
-RUN make -f buildozer.mk
-# enforces buildozer master until next release
-RUN pip3 install --upgrade https://github.com/kivy/buildozer/archive/${BUILDOZER_VERSION}.zip
+# install buildozer & dependencies and enforces buildozer master until next release
+RUN curl --location --progress-bar ${MAKEFILES_URL}/buildozer.mk --output buildozer.mk && \
+    make -f buildozer.mk && \
+    pip3 install --upgrade https://github.com/kivy/buildozer/archive/${BUILDOZER_VERSION}.zip
 
 COPY . ${WORK_DIR}
 # limits the amount of logs for Travis