Adventures in GELF

If you are running apps in containers and are using Docker’s GELF logging driver (or are considering using it), the following musings might be relevant to your interests.

Some context

When you run applications in containers, the easiest logging method is to write on standard output. You can’t get simpler than that: just echo, print, write (or the equivalent in your programming language!) and the container engine will capture your application’s output.

Other approaches are still possible, of course; for instance:

• you can use syslog, by running a syslog daemon in your container or exposing a /dev/log socket;
• you can write to regular files and share these log files with your host, or with other containers, by placing them on a volume;
• your code can directly talk to the API of a logging service.

In the last scenario, this service can be:

• a proprietary logging mechanism operated by your cloud provider, e.g. AWS CloudWatch or Google Stackdriver;
• provided by a third-party specialized in managing logs or events, e.g. Honeycomb, Loggly, Splunk, etc.;
• something running in-house, that you deploy and maintain yourself.

If your application is very terse, or Continue reading

Docker + Golang =

This is a short collection of tips and tricks showing how Docker can be useful when working with Go code. For instance, I’ll show you how to compile Go code with different versions of the Go toolchain, how to cross-compile to a different platform (and test the result!), or how to produce really small container images.

The following article assumes that you have Docker installed on your system. It doesn’t have to be a recent version (we’re not going to use any fancy feature here).

Go without go

… And by that, we mean “Go without installing go”.

If you write Go code, or if you have even the slightest interest into the Go language, you certainly have the Go compiler and toolchain installed, so you might be wondering “what’s the point?”; but there are a few scenarios where you want to compile Go without installing Go.

• You still have this old Go 1.2 on your machine (that you can’t or won’t upgrade), and you have to work on this codebase that requires a newer version of the toolchain.
• You want to play with cross compilation features of Go 1.5 (for instance, to make sure Continue reading