woahbase / alpine-blynk

Blynkkk server for MCU/IOT devices built on Alpine + OpenJDK8

Alpine-Blynk

Container for Alpine Linux + OpenJDK8 + Blynk Server

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This image containerizes Blynk IOT server, a platform for visualizing/controlling microcontrollers like Arduino, RaspberryPi etc that use their library, over the web, running under OpenJDK 8.*.*.

Based on Alpine Linux from my alpine-openjdk8 image with the s6 init system and GNU LibC overlayed in it.

Auto updated according to the Github releases.

The image is tagged respectively for the following architectures,

• armhf
• x86_64 (retagged as the latest )

armhf builds have embedded binfmt_misc support and contain the qemu-user-static binary that allows for running it also inside an x64 environment that has it.

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Get the Image

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Pull the image for your architecture it's already available from Docker Hub.

# make pull
docker pull woahbase/alpine-blynk:x86_64

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Configuration defaults

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• Blynk home is at /opt/blynk. User data is at /opt/blynk/data. Mount this directory in local to persist blynk configuration data.

• Default configurations for server and mail is provided right inside the Blynk home directory as /opt/blynk/server.properties and /opt/blynk/mail.properties. Edit or remount these files to use custom configurations.

• By default, Blynk binds to the following ports :

  • 7443: Administration UI HTTPS port
  • 8080: HTTP port
  • 8081: Web socket ssl/tls port
  • 8082: Web sockets plain tcp/ip port
  • 8441: Hardware ssl/tls port (for hardware that supports SSL/TLS sockets)
  • 8442: Hardware plain tcp/ip port
  • 8443: Application mutual ssl/tls port
  • 9443: HTTPS port

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Run

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If you want to run images for other architectures, you will need to have binfmt support configured for your machine. multiarch, has made it easy for us containing that into a docker container.

# make regbinfmt
docker run --rm --privileged multiarch/qemu-user-static:register --reset

Without the above, you can still run the image that is made for your architecture, e.g for an x86_64 machine..

This image already has a user alpine configured to drop privileges to the passed PUID/PGID which is ideal if its used to run in non-root mode. That way you only need to specify the values at runtime and pass the -u alpine if need be. (run id in your terminal to see your own PUID/PGID values.)

Running make starts the service.

# make
docker run --rm -it \
  --name docker_blynk --hostname blynk \
  -e PGID=1000 -e PUID=1000 \
  -p 7443:7443 -p 8080:8080 \
  -p 8081:8081 -p 8082:8082 \
  -p 8441:8441 -p 8442:8442 \
  -p 8443:8443 -p 9443:9443 \
  -v /etc/localtime:/etc/localtime:ro \
  woahbase/alpine-blynk:x86_64

Stop the container with a timeout, (defaults to 2 seconds)

# make stop
docker stop -t 2 docker_blynk

Removes the container, (always better to stop it first and -f only when needed most)

# make rm
docker rm -f docker_blynk

Restart the container with

# make restart
docker restart docker_blynk

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Shell access

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Get a shell inside a already running container,

# make shell
docker exec -it docker_blynk /bin/bash

set user or login as root,

# make rshell
docker exec -u root -it docker_blynk /bin/bash

To check logs of a running container in real time

# make logs
docker logs -f docker_blynk

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Development

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If you have the repository access, you can clone and build the image yourself for your own system, and can push after.

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Setup

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Before you clone the repo, you must have Git, GNU make, and Docker setup on the machine.

git clone https://github.com/woahbase/alpine-blynk
cd alpine-blynk

You can always skip installing make but you will have to type the whole docker commands then instead of using the sweet make targets.

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Build

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You need to have binfmt_misc configured in your system to be able to build images for other architectures.

Otherwise to locally build the image for your system. [ARCH defaults to x86_64, need to be explicit when building for other architectures.]

# make ARCH=x86_64 build
# sets up binfmt if not x86_64
docker build --rm --compress --force-rm \
  --no-cache=true --pull \
  -f ./Dockerfile_x86_64 \
  --build-arg ARCH=x86_64 \
  --build-arg DOCKERSRC=alpine-openjdk8 \
  --build-arg USERNAME=woahbase \
  -t woahbase/alpine-blynk:x86_64 \
  .

To check if its working..

# make ARCH=x86_64 test
docker run --rm -it \
  --name docker_blynk --hostname blynk \
  -e PGID=1000 -e PUID=1000 \
  woahbase/alpine-blynk:x86_64 \
  sh -ec 'sleep 5; java -version; cat /opt/blynk/version'

And finally, if you have push access,

# make ARCH=x86_64 push
docker push woahbase/alpine-blynk:x86_64

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Maintenance

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Sources at Github. Built at Travis-CI.org (armhf / x64 builds). Images at Docker hub. Metadata at Microbadger.

Maintained by WOAHBase.

alpine-blynk's Issues

Error: Unable to access jarfile /opt/blynk/blynk.jar

#1 still relevant for woahbase/alpine-blynk:latest :(

PUID and PGID don't work

Hi, setting the PUID and PGID variables doesn't seem to affect the uid and gid of the alpine user at all. id alpine always returns uid=1000(alpine) gid=1000(alpine) groups=1000(alpine),1000(alpine).

$ docker run --rm -it \
  --name docker_blynk --hostname blynk \
  -e PGID=995 -e PUID=996 \
  -p 7443:7443 -p 8080:8080 \
  -p 8081:8081 -p 8082:8082 \
  -p 8441:8441 -p 8442:8442 \
  -p 8443:8443 -p 9443:9443 \
  -v /etc/localtime:/etc/localtime:ro \
  woahbase/alpine-blynk:x86_64

$ docker exec -it docker_blynk bash
bash-5.0# id alpine
uid=1000(alpine) gid=1000(alpine) groups=1000(alpine),1000(alpine)

Maybe I'm missing something, but it seems like the PUID and PGID are hardcoded to 1000 in https://github.com/woahbase/alpine-openjdk/blob/master/Dockerfile_x86_64?

missing blynk.jar

In the newest build there is a problem with blynk.jar file. I have checked inside container and this file have size 9 bytes. The problem is original blynk github - the java8 version for the newest build is missing .