SYS-CON MEDIA Authors: Liz McMillan, Carmen Gonzalez, Zakia Bouachraoui, Roger Strukhoff, David Linthicum

Related Topics: @DevOpsSummit, Microservices Expo, Linux Containers, Containers Expo Blog

@DevOpsSummit: Blog Feed Post

WordPress Docker Container | @DevOpsSummit #DevOps #Docker #Microservices

... and the Devious XML-RPC Denial of Service Attack

I have an article in the recently released “DZone Guide to Building and Deploying Applications on the Cloud” entitled “Fullstack Engineering in the Age of Hybrid Cloud”. In this article I discuss the need and skills of a Fullstack Engineer with relation to troubleshooting and repairing complex, distributed hybrid cloud applications. My recent experiences with troubleshooting issues with my Docker WordPress container only reinforce the details I wrote about in this piece. Without my comprehensive understanding of both the infrastructure and application layer I don’t believe I could have achieved resolution (if I have, but more on that later).

1969479-dz-cloud2016cover-lgMy Docker WordPress container has always had issues with the “Error Connecting to Database” issue, but initially it would happen once a month and I would just re-start the container. I had read that the issue was fixed by moving to WordPress 4.5, so I upgraded, which came with its own challenges given these containers are supposed to be immutable.

Unfortunately, I designed my container when Docker architecture was in its infancy and so separating out and linking a MySQL container and the WordPress container as well as storing data on a separate volume are all features which emerged, or became more easily used, in later versions. Eventually, I will need redesign around 1.11 features, but for now, I’m just trying to keep up what I currently have. I did try just moving the database files onto permanent storage mapped in to the container as a volume, but all I did was fight with file permissions for a day and MySQL never ended up starting.

Recently, it became more and more difficult to keep the container up, so I upgraded to the latest Ubuntu 14.04 kernel and when that didn’t seem to help the issue I upgraded Docker from 1.4 to 1.11. None of these seemed to correct the issue. However, Docker 1.11 leverages the new architecture and uses cgroups, which resulted in cgroup out of memory thread killer posting messages to my console.

Screen Shot 2016-04-29 at 6.13.20 AM

Now, I could see that mysqld was being terminated at some point due to insufficient memory. To solve the memory issue, I tried optimizing the WordPress LAMP stack for low memory and even migrated from a 1G virtual machine to a 2G instance. It seems no matter how much memory I threw at this problem the longest the WordPress site would be active before the database connection issue appeared was an hour.

Totally baffled at this point, I started chasing down a lead regarding WordPress issues occurring on my cloud service provider. It seemed the issue I was seeing was happening to many others on Digital Ocean, perhaps this was a VPS (DO’s Droplet architecture is VPS-based) issue and not a Docker issue. DO responded on its forum to the various postings stating that running out of memory is common result of the known XML-RPC Denial of Service attack.  XML-RPC is the API interface for WordPress.

Wait! What am I doing? No one’s going to bother attacking my little old blog, it can’t be that. Back to optimizing memory use. Oh crud, this is still not getting me anywhere after two weeks.

Unfortunately, again my immutable container architecture limited my ability to see logs and SSH connections were often terminated due to low memory as well. Once I terminated the container without committing the container the logs were lost. So, I had to modify the current container to use an external volume for all the log files and now wrote them out to permanent storage.

Whoa! What do I find in the apache2 access.log after the next time the issue occurs? Well, when I did a tail of the last 200 entries I found my site was being attacked by a Googlebot, and there were a lot more entries in addition to those. In the end, I was a victim of a denial of service attack.

I believe its important to look at what data I had available and the characteristics identified by the logs and error messages. Nothing screamed DoS attack consuming mass number of threads on the Apache server and driving memory usage to 0 so that the memory manager was sacrificing threads to keep the OS alive (does that make anyone else think of Kirk screaming to Scotty, “all power to life support”?). When the attack stopped, mysqld_safe restored the thread, but it seems the socket or some other interprocess mechanism didn’t allow WordPress to communicate with the MySQL.

Piecing this together after the fact required a mix of skills. It might have been easier if I was doing live monitoring and tracking inbound requests while also constantly checking that WordPress could communicate MySQL, but realistically, this is a dramatic step when all else has failed.

Through this I learned a lot about container architecture, but this issue is probably still lingering. I’m just denying all requests to access XML-RPC from outside IP addresses at this time and the WordPress has been up for over 24 hours. More importantly, it really reinforces what I wrote about in the article and I don’t believe I could have reached this point if I didn’t have a good understanding of the infrastructure, operating system, networking, Docker and LAMP stack.

Read the original blog entry...

More Stories By JP Morgenthal

JP Morgenthal is a veteran IT solutions executive and Distinguished Engineer with CSC. He has been delivering IT services to business leaders for the past 30 years and is a recognized thought-leader in applying emerging technology for business growth and innovation. JP's strengths center around transformation and modernization leveraging next generation platforms and technologies. He has held technical executive roles in multiple businesses including: CTO, Chief Architect and Founder/CEO. Areas of expertise for JP include strategy, architecture, application development, infrastructure and operations, cloud computing, DevOps, and integration. JP is a published author with four trade publications with his most recent being “Cloud Computing: Assessing the Risks”. JP holds both a Masters and Bachelors of Science in Computer Science from Hofstra University.

Latest Stories
When you're operating multiple services in production, building out forensics tools such as monitoring and observability becomes essential. Unfortunately, it is a real challenge balancing priorities between building new features and tools to help pinpoint root causes. Linkerd provides many of the tools you need to tame the chaos of operating microservices in a cloud native world. Because Linkerd is a transparent proxy that runs alongside your application, there are no code changes required. I...
In his general session at 21st Cloud Expo, Greg Dumas, Calligo’s Vice President and G.M. of US operations, discussed the new Global Data Protection Regulation and how Calligo can help business stay compliant in digitally globalized world. Greg Dumas is Calligo's Vice President and G.M. of US operations. Calligo is an established service provider that provides an innovative platform for trusted cloud solutions. Calligo’s customers are typically most concerned about GDPR compliance, application p...
Modern software design has fundamentally changed how we manage applications, causing many to turn to containers as the new virtual machine for resource management. As container adoption grows beyond stateless applications to stateful workloads, the need for persistent storage is foundational - something customers routinely cite as a top pain point. In his session at @DevOpsSummit at 21st Cloud Expo, Bill Borsari, Head of Systems Engineering at Datera, explored how organizations can reap the bene...
"NetApp's vision is how we help organizations manage data - delivering the right data in the right place, in the right time, to the people who need it, and doing it agnostic to what the platform is," explained Josh Atwell, Developer Advocate for NetApp, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
At CloudEXPO Silicon Valley, June 24-26, 2019, Digital Transformation (DX) is a major focus with expanded DevOpsSUMMIT and FinTechEXPO programs within the DXWorldEXPO agenda. Successful transformation requires a laser focus on being data-driven and on using all the tools available that enable transformation if they plan to survive over the long term. A total of 88% of Fortune 500 companies from a generation ago are now out of business. Only 12% still survive. Similar percentages are found throug...
Druva is the global leader in Cloud Data Protection and Management, delivering the industry's first data management-as-a-service solution that aggregates data from endpoints, servers and cloud applications and leverages the public cloud to offer a single pane of glass to enable data protection, governance and intelligence-dramatically increasing the availability and visibility of business critical information, while reducing the risk, cost and complexity of managing and protecting it. Druva's...
Kubernetes as a Container Platform is becoming a de facto for every enterprise. In my interactions with enterprises adopting container platform, I come across common questions: - How does application security work on this platform? What all do I need to secure? - How do I implement security in pipelines? - What about vulnerabilities discovered at a later point in time? - What are newer technologies like Istio Service Mesh bring to table?In this session, I will be addressing these commonly asked ...
BMC has unmatched experience in IT management, supporting 92 of the Forbes Global 100, and earning recognition as an ITSM Gartner Magic Quadrant Leader for five years running. Our solutions offer speed, agility, and efficiency to tackle business challenges in the areas of service management, automation, operations, and the mainframe.
Blockchain has shifted from hype to reality across many industries including Financial Services, Supply Chain, Retail, Healthcare and Government. While traditional tech and crypto organizations are generally male dominated, women have embraced blockchain technology from its inception. This is no more evident than at companies where women occupy many of the blockchain roles and leadership positions. Join this panel to hear three women in blockchain share their experience and their POV on the futu...
The Jevons Paradox suggests that when technological advances increase efficiency of a resource, it results in an overall increase in consumption. Writing on the increased use of coal as a result of technological improvements, 19th-century economist William Stanley Jevons found that these improvements led to the development of new ways to utilize coal. In his session at 19th Cloud Expo, Mark Thiele, Chief Strategy Officer for Apcera, compared the Jevons Paradox to modern-day enterprise IT, examin...
With 10 simultaneous tracks, keynotes, general sessions and targeted breakout classes, @CloudEXPO and DXWorldEXPO are two of the most important technology events of the year. Since its launch over eight years ago, @CloudEXPO and DXWorldEXPO have presented a rock star faculty as well as showcased hundreds of sponsors and exhibitors! In this blog post, we provide 7 tips on how, as part of our world-class faculty, you can deliver one of the most popular sessions at our events. But before reading...
Cloud-Native thinking and Serverless Computing are now the norm in financial services, manufacturing, telco, healthcare, transportation, energy, media, entertainment, retail and other consumer industries, as well as the public sector. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long development cycles that pro...
DSR is a supplier of project management, consultancy services and IT solutions that increase effectiveness of a company's operations in the production sector. The company combines in-depth knowledge of international companies with expert knowledge utilising IT tools that support manufacturing and distribution processes. DSR ensures optimization and integration of internal processes which is necessary for companies to grow rapidly. The rapid growth is possible thanks, to specialized services an...
At CloudEXPO Silicon Valley, June 24-26, 2019, Digital Transformation (DX) is a major focus with expanded DevOpsSUMMIT and FinTechEXPO programs within the DXWorldEXPO agenda. Successful transformation requires a laser focus on being data-driven and on using all the tools available that enable transformation if they plan to survive over the long term. A total of 88% of Fortune 500 companies from a generation ago are now out of business. Only 12% still survive. Similar percentages are found throug...
Docker and Kubernetes are key elements of modern cloud native deployment automations. After building your microservices, common practice is to create docker images and create YAML files to automate the deployment with Docker and Kubernetes. Writing these YAMLs, Dockerfile descriptors are really painful and error prone.Ballerina is a new cloud-native programing language which understands the architecture around it - the compiler is environment aware of microservices directly deployable into infra...