Apache Cassandra in Docker with JMX enabled

It’s a bit tricky to enable JMX for Cassandra when running in Docker. I create a Cassandra Docker image alexcheng/cassandra of version 3.11.2 with JMX authentication enabled, see the Dockerfile. The username and password to access JMX are both cassandra. The environment variable JMX_HOST has the default value of localhost, and it should work most of the time. If localhost doesn’t work , you can use the host’s IP address. After starting the container, you can access JMX using VisualVM or JConsole with address service:jmx:rmi://localhost/jndi/rmi://localhost:7199/jmxrmi. Change localhost to the same value as JMX_HOST if localhost is not used. Since SSL is not enabled, you need to use insecure connections.

On Mac, the local IP address can be obtained using ipconfig getifaddr en0, so we can use following command to start the container when using IP address is required.

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docker run --rm -p 7199:7199 -e "JMX_HOST=`ipconfig getifaddr en0`" alexcheng/cassandra

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Akka Streams Camel integration

Akka Streams and Alpakka provide a good an alternative to Apache Camel when integrating different services and data. Alpakka has a rich set of connectors, including file, JMS, Cassandra and more. We can still use Camel endpoints if Alpakka doesn’t provide the connectors.

This post shows a complete example of integrating Camel endpoints with Akka Streams. This example reads file content in one directory, tranforms the content, then writes to another directory. It uses the Camel file endpoint.

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ChatOps journey with Ansible, Hubot, AWS and Windows - Part 3

This is Part 3 of the series of setting up a Chatbot for deploying artifacts to AWS EC2 Windows instances. In this post, I’ll discuss using AWS Lambda to make sure instances are not left running for too long to save money.

The Chatbot makes deployment much easier and encourages developers to run more tests. However, those launched instances are more likely to be left running for a long time. The situation is worse for Windows instances, which are way more expensive that Linux instances ($0.15 comparing to $0.03). So I need a way to terminate those instances when not used.

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ChatOps journey with Ansible, Hubot, AWS and Windows - Part 1

Comparing to DevOps, ChatOps, a word coined by GitHub, is trying to leverage Chatbots to make developers’ life much easier. Comparing to CLI or web pages, ChatBots are more user-friendly to interact with, and bots are COOL!!!

This series of posts takes you through the process of setting up a Chatbot for deploying artifacts to AWS EC2 Windows instances. Tools and services used in this post include:

This series assumes you have basic knowledge of Ansible and Docker. If not, you should start from tutorials for these two.

Update 2018-02-08: Use 7zip to extract tar.gz files.

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