Docker Export The export takes a snapshot of the container file system and export it’s as a tarball, all container layers are flattened. Any metadata about the entry point is lost, such as ENTRYPOINT and CMD. You can run docker import to create a Docker image from that tarball. Docker Save Creates a tarball on the image and not the container so all the layers are saved, and any metadata around it such as ENTRYPOINT. Read more

You can use the go trace tool to look at the CPU traces to see how your program is behaving for example. package main import ( "fmt" "os" "runtime/trace" ) func main() { f, err := os.Create("trace.out") if err != nil { panic(err) } defer f.Close() err = trace.Start(f) if err != nil { panic(err) } trace.Stop() fmt.Println("hello") } When you run the program you will see a new file trace. Read more

At work, I was debugging an issue where it was failing to update the systemd configuration to the new installation path. By default, systemd service definitions go under /etc/systemd/system/name.service. There are cases where you as an administrator have no control over the service generated. So how do you override a service configuration without overriding the original service or the service definition from scratch? Systemd has a functionality called drop-in units where you can write parts of the service definition and it will override it. Read more