8/28

Another day in the life.

I want to get into the habit of sharing with the community so i'm starting a week-daily post where I share three(ish) things i've learned or found interesting while I nurse my afternoon tea.

1. Kubernetes.Academy

Source: Coworker Why I like it: This launched recently and seems like a great way to get started with Kubernetes. Between Octant and this, they seem to be killing it at VMWare.

2. Csysdig tool

Source: Csysdig blog post I stumbled on. I have been using the standard Sysdig command line tool to capture traces for the other engineers to review however today I just discovered the interactive ncurses interface that you can use with csysdig. You can easily use F2 to jump over to containers and then F6 to dig as you normally would, but now there are a ton of other things to play around with.

Also, pretty colors:

3. "Negative" subprocess error codes in Python.

Source: This Stackoverflow page I found while troubleshooting an issue.

Often times I troubleshoot exit codes as a means to determine why something failed. Today's issue was with a Python exit code of -11. Hidden in the comments it's written that these negative return codes correspond to the typical Linux signals. This is specifically when using the Python subprocess module, nevertheless handy to note these signals for troubleshooting.

Signal Name Description SIGHUP 1 Hangup (POSIX) SIGINT 2 Terminal interrupt (ANSI) SIGQUIT 3 Terminal quit (POSIX) SIGILL 4 Illegal instruction (ANSI) SIGTRAP 5 Trace trap (POSIX) SIGIOT 6 IOT Trap (4.2 BSD) SIGBUS 7 BUS error (4.2 BSD) SIGFPE 8 Floating point exception (ANSI) SIGKILL 9 Kill(can't be caught or ignored) (POSIX) SIGUSR1 10 User defined signal 1 (POSIX) SIGSEGV 11 Invalid memory segment access (ANSI) SIGUSR2 12 User defined signal 2 (POSIX) SIGPIPE 13 Write on a pipe with no reader, Broken pipe (POSIX) SIGALRM 14 Alarm clock (POSIX) SIGTERM 15 Termination (ANSI) SIGSTKFLT 16 Stack fault SIGCHLD 17 Child process has stopped or exited, changed (POSIX) SIGCONTv 18 Continue executing, if stopped (POSIX) SIGSTOP 19 Stop executing(can't be caught or ignored) (POSIX) SIGTSTP 20 Terminal stop signal (POSIX) SIGTTIN 21 Background process trying to read, from TTY (POSIX) SIGTTOU 22 Background process trying to write, to TTY (POSIX) SIGURG 23 Urgent condition on socket (4.2 BSD) SIGXCPU 24 CPU limit exceeded (4.2 BSD) SIGXFSZ 25 File size limit exceeded (4.2 BSD) SIGVTALRM 26 Virtual alarm clock (4.2 BSD) SIGPROF 27 Profiling alarm clock (4.2 BSD) SIGWINCH 28 Window size change (4.3 BSD, Sun) SIGIO 29 I/O now possible (4.2 BSD) SIGPWR 30 Power failure restart (System V)

4. Bonus! - Kubectl describe pod

This is kind of silly, but I figured out that I don't need to type the full pod name when using "describe pod" it seems to glob the name :D

Doesn't work. ``` kubectl get pod kubernetes-dashboard Error from server (NotFound): pods "kubernetes-dashboard" not found

``` Works!

Name: kubernetes-dashboard-7947fffdf5-f9vz5 Namespace: kube-system