If your Salt Minion version is too far removed from the Salt Master version, you may find yourself with unexplained errors. This problem can be faced when the OS template you are deploying was packaged years earlier with an older Salt minion while the Salt Master has been kept up to date. But it can … SaltStack: Installing an older Salt Master or Minion for compatibility
Many developers like to use Vagrant from HashiCorp to standardize the workflow of virtual machines: creation, running, destroying, taking snapshots, etc.. Usually Vagrant is used for Linux hosts, but it also works with Windows as long as you prepare the template properly. In a previous article I went over the detailed steps to create a template image for … Windows: Windows 2012 Sysprep for Vagrant readiness
In the world of Linux containers where deployment takes on the order of seconds, even the best-case scenario for spinning up a new Windows host can seem like an eternity. Clearly, you don’t want to wait for the entire Windows install process each time you bring up a Windows guest OS. Even automated, this would … Ubuntu: Standing up a Windows 2012 instance on Ubuntu using Sysprep
Android is one of the leading platforms of the mobile industry. By installing an Android emulator on your Ubuntu desktop, you can bring this power to your desktop. More often than not, an Android emulator is used for custom development of mobile apps, but don’t overlook its utility as a way to access your favorite … Ubuntu: Installing the Genymotion Android emulator
The Tor project is free software that helps protect your privacy by making it difficult for a 3rd party to analyze your network requests or link your traffic back to your network access point. See the Tor overview page for reasons why this may be important to world citizens, corporations, or specific professions. Simplified, this … Ubuntu: Installing Tor on Ubuntu 14.04 and 16.04
SMTP mail relays exposed to the internet typically use a combination of SSL and authenticated SMTP to avoid abuse by malicious actors. This is an excellent choice from a security perspective, but makes smoke testing a bit more complex than just opening telnet.
Ansible is an agentless configuration management tool that helps operations teams manage installation, patching, and command execution across a set of servers. In this article I’ll describe how to deploy the latest release of Ansible using pip on Ubuntu 16.04, and then perform a quick validation against a client.
Ansible is an agentless configuration management tool that helps operations teams manage installation, patching, and command execution across a set of servers. Ansible was started as a Linux only solution, leveraging ssh to provide a management channel to a target server. However, starting at Ansible 1.7, support for Windows hosts was added by using Powershell … Ansible: Managing a Windows host using Ansible
Ansible is an agentless configuration management tool that helps operations teams manage installation, patching, and command execution across a set of servers. In this article I’ll describe how to deploy the latest release of Ansible using pip on Ubuntu 14.04, and then perform a quick validation against a client.
Syslog is a message logging standard has been around for decades, but has renewed popularity as a method of log capture with the advent of containerization and centralized logging solutions. Enabling an Ubutu 14.04 or 16.04 host to act as a syslog server only takes a few simple steps.
Update Oct 2022: This article has now been written for GoLang 1.19 on Ubuntu 22.04. Go has changed the way it handles SIGURG signals, and Systemd services no longer directly forward to syslog. Read my newer article here. The Go language with its simplicity, concurrency support, rich package ecosystem, and ability to compile down to a single … GoLang: Running a Go binary as a systemd service on Ubuntu 16.04
The Go language with its simplicity, concurrency support, rich package ecosystem, and ability to compile down to a single binary is an attractive solution for writing services on Ubuntu. However, the Go language does not natively provide a reliable way to daemonize itself. In this article I will describe how to take a couple of simple Go language programs, … GoLang: Running a Go binary as a SysV service on Ubuntu 14.04
A nice feature of the Go language is the ability to build binaries for multiple platforms directly from a single source system. As an example, even from a development Windows 7 32-bit machine, you can build binaries for both 64 bit Linux and Windows 2012 Servers. Before Go 1.5, you needed a compiler for the target architecture, … GoLang: Cross Compiling for Linux and Windows platforms
The Go programming language has gotten considerable momentum, and the fact that it compiles down to machine code has made it popular in containers like Docker where a single executable binary fits the execution model perfectly. This article will detail installation on Ubuntu 14.04 with the standard hello world validation.
Configuration Management tools like SaltStack are invaluable for managing infrastructure at scale. Even in the growing world of containerization where immutable image deployment is the norm, those images need to be built in a repeatable and auditable fashion. This article will detail installation of the SaltStack master on Ubuntu 14.04, with validation using a single Minion. Note that Minion … SaltStack: Installing a Salt Master on Ubuntu 14.04
When building complex, real-world Logstash filters, there can be a fair bit of processing logic. There are typically multiple grok patterns as well as fields used as flags for conditional processing. The problem is, these intermediate extracted fields and processing flags are often ephemeral and unnecessary in your ultimate persistent store (e.g. ElasticSearch), but they will be inserted … ELK: metadata fields in Logstash for grok and conditional processing
Logstash provides a powerful mechanism for listening to various input sources, filtering and extracting the fields, and then sending events to a persistence store like ElasticSearch. Installing Logstash on Ubuntu is well documented, so in this article I will focus on Ubuntu specific steps required for Logstash 2.x and 5.x.
Log rotation is an essential maintenance task for managed servers. The logrotate package available in the main Ubuntu repository is easily configurable and is invoked by the cron service for automated log retention.
ElastAlert from the Yelp Engineering group provides a very flexible platform for alerting on conditions coming from ElasticSearch. In a previous article I fully describe running interactively on an Ubuntu server, and now I’ll expand on that by running it at system startup using a System-V init script. One of the challenges of getting ElastAlert to run as a … ELK: Running ElastAlert as a service on Ubuntu 14.04
ElasticSearch’s commercial X-Pack has alerting functionality based on ElasticSearch conditions, but there is also a strong open-source contender from Yelp’s Engineering group called ElastAlert. ElastAlert offers developers the ultimate control, with the ability to easily create new rules, alerts, and filters using all the power and libraries of Python.
Docker is a container platform that streamlines software delivery and provides isolation, scalability, and efficiency with less overhead than OS level virtualization. These instructions are taken directly from the official Docker for Ubuntu page, but I wanted to reiterate those tasks essential for installing the Docker Community Edition on Ubuntu 14.04 and 16.04.
Once you have a Squid proxy setup as described in my article here, the next challenge is configuring your Ubuntu servers so that they use this proxy by default instead of attempting direct internet connections. There are several entities we want using Squid by default: apt package manager, interactive consoles and wget/curl, and Java applications.
Having your production servers go through a proxy like Squid for internet access can be an architectural best practice that provides network security as well as caching efficiencies. For further security, denying access to all requests but an explicit whitelist of domains provides auditable control.
HAProxy is a high performance TCP/HTTP (Level 4 and Level 7) load balancer and reverse proxy. A common pattern is allowing HAProxy to be the fronting SSL-termination point, and then HAProxy determines which pooled backend server serves the request.
Nginx is a popular reverse proxy and load balancer that focuses on level 7 (application) traffic. A common pattern is allowing Nginx to be the fronting SSL-termination point, and then Nginx determines which pooled backend server is best available to serve the request.
Some web applications leave authentication as an orthogonal concern to the application – not including any kind of login functionality and instead leaving authentication as an operational concern. When this happens, a reverse proxy that has an LDAP integration can act as an architectural sentry in front of the web application and also fulfills the … Apache2: Enable LDAP authentication and SSL termination for Ubuntu
There are numerous articles I’ve written where a certificate is a prerequisite for deploying a piece of infrastructure. Here are the quick steps for installing a simple self-signed certificate on an Ubuntu server. If you instead need to create a certificate with SAN (Subject Alternative Name) support, read my article here. Some of you will … Ubuntu: Creating a self-signed certificate using OpenSSL on Ubuntu
Jenkins is the open-source automation server that is critical in building a continuous integration and delivery pipeline. It is extensible and has a wealth of plugins that integrate with numerous enterprise systems. Here are the detailed steps for installing a Jenkins server on Ubuntu.
Java JMX (Java Management Extensions) is a standardized way of monitoring Java based applications. The managed resources (MBeans) are defined and exposed by the JVM, application server, and application – and offer a view into these layers that can provide invaluable monitoring data. But in order to report back the JMX data you must know … Monitoring: Java JMX exploration from the console using jmxterm
strace is a handy utility for tracing system, file, and network calls on a Linux system. It can produce trace output for either an already running process, or it can create a new process. Some of the most common troubleshooting scenarios are needing to isolate either the network or file system activity of a process. … Ubuntu: Using strace to get a view into file and network activity of a process
tcpdump comes standard on Ubuntu servers and is an invaluable tool in determining traffic coming in and out of a host. As network infrastructures have become more complex and security conscious, validating network flow from client hosts through potentially multiple proxies and ultimately to a destination host and port has become more important than ever. … Ubuntu: Using tcpdump for analysis of network traffic and port usage
Nginx is a powerful application level proxy server. Whether for troubleshooting or analysis, enabling log levels and custom formats for the access/error logs is a common requirement. Error Logs By default, only messages in the error category are logged. If you want to enable more details, then modify nginx.conf like: error_log file [level] Enabling debug … Nginx: Custom access log format and error levels
The PingFederate server provides best-in-class Identity Management and SSO. However, due to US laws governing export of cryptography, the default SSL protocols and cipher suites need to be configured to harden the solution. Below are the steps involved with making these post-installation changes.
As an exploration of AppDynamics’ APM functionality, you may find it useful to deploy a sample application that can quickly return back useful data. The Java Spring PetClinic connecting back to a PostgreSQL database provides a simple code base that exercises both database and application monitoring. In a previous article, I went over the detailed … AppDynamics: Java Spring PetClinic and PostgreSQL configured for monitoring
Update Feb 2023: enumerating the secure protocols and ciphers of a remote site can be done more efficiently by nmap, as described in my other article here. While enabling HTTPS is a important step in securing your web application, it is critical that you take steps to disable legacy protocols and low strength ciphers that … OpenSSL: Using OpenSSL to enumerate protocols and ciphers in use by web applications
If you have worked on deploying packages via apt-get, you are probably familiar with a couple of forms of interruption during the package installation and upgrade process. The first is the text menu shown during package upgrades that informs you that a new configuration file is available and asks if you want to keep your … Ubuntu: Silent package installation and debconf
The AppDynamics Machine Agent is used not only to report back on basic hardware metrics (cpu/memory/disk/network), but also as the hook for custom plugins that can report back on any number of applications including: .NET, Apache, AWS, MongoDB, Cassandra, and many others. In this article, I’ll go over the details to install the Machine Agent … AppDynamics: Installing a Machine Agent on Ubuntu 14.04
Grafana is an open-source visualization suite that is able to generate graphs and dashboards, in addition to alerting. It is designed to retrieve data from various backends including: Graphite, ElasticSearch, Prometheus, and Zabbix. This article will lead you through an installation of the latest stable version on Ubuntu 14.04.
As part of normal long-term operations, the number of kernel images on your system will accumulate and take up disk space. This issue with space will be even more pronounced if /boot is mounted to its own smaller partition. With Ubuntu 16.04, ‘apt autoremove –purge’ and configuration of the unattended upgrades can ensure that old … Unbutu: Removing unused kernel images and headers
If you are running an Ubuntu server for any extended period of time, security issues will arise that affect the kernel, distribution, or packages installed on that host. While there is a minimal stability risk with automatically applying security fixes, I feel those are dwarfed by the risks of running hosts that have known security … Ubuntu: Unattended Upgrades for security patches