Traefik.io is a very cool open source project, providing a powerful reverse proxy. The project is focusing mainly on container based architectures like Docker Swarm. In such an environment Traefik.io is able to recognize new containers in a network and dynamically computes the route from the frontend to the corresponding backend service. I wrote about this functionality in combination with docker swarm already in my blog: Lightweight Docker Swarm Environment. This concept is also part of the Imixs-Workflow project.
But what if you just want to add a kind of static route, which has nothing to do with container based services. I had this situation as I wanted to redirect incoming requests for a specific host name to an external server – outside of my docker swarm.
To realize this, you can add a front-end rule under the section [file] at the end of your traefik.toml file. This is an example how such a rule can looks like:
url = "http://some.host.de:12345"
# note that you cannot add path in 'url' field
entryPoints = ["http"]
backend = "backend1"
passHostHeader = true
rule = "Host:www.myweb.com"
This rule proxies requests for “www.myweb.com” to the host “some.host.de:12345”. See also the discussion here.
Today I released version 4.2.6 of Imixs-Workflow. The new release is prepared for the Imixs-Archive feature which is the next big thing in Imixs-Workflow. The new version also includes some improvements of the Rest API and several bug fixes. The release notes can be seen on GitHub.
To setup a docker stack with Glassfish/Payara Server and a PostgreSQL Database Server is really easy, as the Payara project provides a good designed docker container. In the following short tutorial I will explain how to setup a simple development environment with a Glassfish/Payara server and a PostgreSQL Database. Continue reading “Running Payara and PostgreSQL in Docker”
I have written a docker service to be used for a periodically backup of a PostgreSQL Database. This container can be used to be part of a docker stack in a docker-compose.yml file.
SETUP_CRON: "0 3 * * *"
BACKUP_LOCAL_ROLLING: “5” ....
The service runs a cron job an uploads backup files automatically into a remote backup space via SFTP/SCP.
You can also use this Docker Image to backup a MySQL Database. Just change the environment variable ‘BACKUP_DB_TYPE’:
Of course the service also provides methods to restore the data. The Service is published on GitHub and DockerHub where you will find more details.
If you play around with Apache Hadoop, you can hardly find examples build on Docker. This is because Hadoop is rarely operated via Docker but mostly installed directly on bare metal. Above all, if you want to test built-in tools such as HBase, Spark or Hive, there are only a few Docker images available.
A project which fills this gap comes from the European Union and is named BIG DATA EUROPE. One of the project objectives it to design, realize and evaluate a Big Data Aggregator Platform infrastructure.
The platform is based on Apache Hadoop and competently build on Docker. The project offers basic building blocks to get started with Hadoop and Docker and make integration with other technologies or applications much easier. With the Docker images provided by this project, a Hadoop platform can be setup on a local development machine, or scale up to hundreds of nodes connected in a Docker Swarm. The project is well documented and all the results of this project are available on GitHub.
For example, to setup a Hadoop HBase local cluster environment takes only a few seconds:
$ git clone https://github.com/big-data-europe/docker-hbase.git
$ cd docker-hbase/
$ docker-compose -f docker-compose-standalone.yml up
Attaching to namenode, resourcemanager, hbase, datanode, nodemanager, historyserver
namenode | Configuring core
resourcemanager | Configuring core
“Meltdown and Spectre are errors. Grave errors, to be sure, but not evidently malicious. Everyone makes mistakes.
Intel has done far worse with its CPUs than make a mistake. It has built in an intentional back door called the Management Engine.
Important as these bugs are, don’t let Intel’s mistakes distract you from Intel’s deliberate attack!”
by Free Software Foundation president Richard Stallman
With security issues like the Spectre and Meltdown vulnerabilities discovered in Intel chips in early 2018, it became more important than ever to talk about the necessity of software freedom in these deeply embedded technologies. Serious as though these bugs may be, we cannot let them distract us from the broader issues: Intel considers the Intel Management Engine a feature, while it’s nothing more than a threat to user freedom. Take a look to Denis GNUtoo Carikli article which provides a new basis for that conversation.
In my previous blog I demonstrated how to setup a lightweight docker swarm environment with docker-machine. When you run this environment in the internet with real virtual machines, there can be some issues you need to take care. Anyway, these issues have cost me a lot of time. Therefore, I would like to give some hints on how to run Docker Swarm on public VMs. Continue reading “How to Run Docker-Swarm on VM Servers”
In the following short tutorial I want to show how to setup a lightweight and easy to manage docker-swarm environment. This environment is an alternative to the mostly heavyweight solutions like Rancher or Googles Kubernetes. For developers and companies that are not compelled to operate over 1000 machines on 4 different continents, this can be a clever alternative.
The docker-swarm environment, I am demonstrating here, uses Docker Engine CLI commands entered into a terminal. But as we’ll see, this environment also includes a very nice UI front end. You should be able to install Docker on networked machines and be comfortable with running commands in the shell of your choice.
Continue reading “Lightweight Docker Swarm Environment”
In these days I released the latest version 4.2.0 of the human-centric open source workflow engine Imixs-Workflow.
With version 4.2.0, the second minor release of Imixs-Workflow version 4 is now available. After the stability and performance improvements of version 4 were confirmed with the minor update 4.1, now the first feature update has been released. Imixs-Workflow 4.2 offers a number of additional features and technical improvements. You can join the project on GitHub.
Read more here.
Today I tried to connect a “August MS425” speaker box with my Linux Notebook running on Debian Jessie. To get the bluetooth connection running I installed the following additional packages:
sudo apt-get install pulseaudio-module-bluetooth, ofono, pavucontrol
After I established the bluetooth connection the speaker box was not working or displayed in the list of audio devices. To solve this issue I found this discussion.
The missing part was the the auto-connect a2dp option for the new device. So I had to edit the file “/etc/pulse/default.pa” and added the following line :
After a reboot it works fine. You can use pavucontrol to setup audio settings.