COVID-19 experience working from home

Like tens or hundreds of thousands of others, I am working from home while the coronavirus pandemic sweeps the United States and the rest of the world.

Here are a few observations about my experience working from home. I’m a software engineer, and I realize that my experience is different from that of hardware engineers, QA folks, customer solutions agents, teachers, and even from other software engineers.

Sleep. The first several days, I worked from my bedroom, which has a great view of the outside world, but I found it difficult to sleep restfully at night. Once my wife shut down her in-home preschool, I moved to working from one of the two preschool rooms, and now I sleep quite well at night. It’s good to have a separate work place.

Exercise. Working from home, I feel more fidgety… maybe I move around less, because there are fewer meetings, and fewer impromptu discussions. So I feel a strong need to get out of the house and work in the yard (pruning, since it’s spring), take a walk or ride a bike.

Convenience. The kitchen and bathroom are closer. If I want to take a nap, no problem — I’ve got a comfortable bed nearby. Taking a walk around the block is a piece of cake — the front door isn’t that far away compared to when I’m working in the office.

Interruptions. Most of my children are teenagers, and believe it or not, I have fewer interruptions at home than I do at work. When my children are doing their remote school, two of them are in the same room as me, with headphones in their ears, and it’s so quiet that I can hear a pin drop.

Social. I enjoy the more frequent face to face interactions with my wife and children. I miss the face to face interactions with my coworkers. Video conferencing is a great invention, and yet it’s not the same as being there.

Communication. There are a lot fewer impromptu hallway discussions with coworkers, and more with family members. I’m not sure if we’re better at communicating with slack now that we’re all remote or not.

Internet. We have excellent wireless internet service. Since our entire family is working/schooling from home, we notice much more quickly when there’s network latency or poor quality.

Up to now, we’ve used a Disney Circle for parental control, and we knew it caused problems on a nearly weekly basis (it does ARP poisoning of a local network), especially for managed devices. With remote school, Circle started breaking things on a daily basis, so I turned Circle off.

I found that 5 Ghz WiFi on the main floor of our house doesn’t penetrate the floor and walls to the basement, and so I pulled my old ASUS WiFi router out of storage, put it in access point mode in our basement, installed a firmware update, and wired it to the router upstairs. Now I get better speeds and connectivity.

Commute. I had a great commute before, but it’s even better now. With so many people staying home, the air is cleaner.

Productivity. My productivity ebbs and flows at work, and the same is true while working from home. Overall, I feel a bit less productive working from home. I’m more inclined to put my Slack app in “do not disturb” mode when I finish working.

Captive portal detection

I did a wireshark dump on my Ubuntu 18.04 laptop and noticed that both Firefox and Ubuntu do captive portal detection. Of the two, I think the Firefox method is simpler to implement and use.

Firefox does an HTTP GET on http://detectportal.firefox.com/success.txt
Responds with HTTP 200 OK with a Content Type of text/plain and a body of “success\n”

Ubuntu does an HTTP GET on http://connectivity-check.ubuntu.com
Responds with HTTP 204 and a header of X-NetworkManager-Status: online\r\n

Notice that captive portal detection uses an unencrypted transport — http, and not https.

Simulate dropped or latent packets in Linux

I’m documenting this more for my own reference than anything, partly because I’ve used ‘tc’ off and on over the years.

  • https://stackoverflow.com/questions/614795/simulate-delayed-and-dropped-packets-on-linux
  • https://wiki.linuxfoundation.org/networking/netem

    
    tc qdisc add dev tun0 root netem loss 30%
    tc qdisc show dev tun0
    tc qdisc change dev tun0 root netem loss 0.1%
    

    When finished:

    tc qdisc del dev tun0 root
    
  • Programmer Productivity

    Twenty years ago, an extended family relation, a patent lawyer, expressed his opinion that there’s not that much variance between engineers — at least, not as much as people suppose. Companies draw from the same pool of talent, and the idea that one company has the bulk of talent is a misconception.

    This article confirms that idea in the realm of programmers.

    Programmer Moneyball: Challenging the Myth of Individual Programmer Productivity

    My view is that hard work (and good health), persistence, consistency, the ability to work with others make a big difference. On the other hand, poor health, inconsistency and confusion of priorities lead to mediocre results.

    Ubuntu on Windows: Refreshing & Fast

    Microsoft has been doing interesting things with Windows, such as adding Windows Subsystem for Linux, which allowed me to install and run Ubuntu from the Windows app store.

    I love having a full and familiar Linux bash command shell at my fingertips, with the utilities I know and love, including ssh. It’s fast.

    https://www.microsoft.com/en-us/p/ubuntu/9nblggh4msv6

    Prior to this, I used cygwin on Windows, which was also good. However, I prefer Ubuntu, mostly.

    There are some caveats:

    • The home directory is in a different place from the Windows home. So for easy access, I symlink Documents, Downloads, Pictures and Videos to my Ubuntu homedir.
    • Still need to keep the Ubuntu software up-to-date. Microsoft’s app store doesn’t do it for you. Run sudo apt-get update ; sudo apt-get upgrade
    • Removable drives aren’t mapped into the filesystem automatically — cygwin was better in this regard.
    • It’s a subsystem — a container, so it doesn’t manage Windows. E.g.
      — Can’t reboot from the command line
      — Can’t manage Windows processes or users

    Worth the read: Metrics That Matter

    There’s a book titled “Measure What Matters”, and it’s fascinating and worth the read. This article from acmqueue with nearly the same title is quite interesting, because it turns some of my previous thinking on it’s head.

    Metrics That Matter

    Summary: “Speed matters”; Instrument client code to measure user experience; Measure “long-tail” latency at the 95th and 99th percentiles; even minor changes to code or user behavior can effect things; build bench-marking into release testing procedures.

    OpenWRT + SafeSearch

    I’ve got an OpenWRT router, and here’s how I configured it to enable safesearch on my home network.

    uci add dhcp cname
    uci set dhcp.@cname[-1].cname="www.google.com"
    uci set dhcp.@cname[-1].target="forcesafesearch.google.com"
    uci commit dhcp
    
    uci add dhcp cname
    uci set dhcp.@cname[-1].cname="www.bing.com"
    uci set dhcp.@cname[-1].target="strict.bing.com"
    uci commit dhcp
    
    uci add dhcp cname
    uci set dhcp.@cname[-1].cname="duckduckgo.com"
    uci set dhcp.@cname[-1].target="safe.duckduckgo.com"
    uci commit dhcp
    
    for name in www.youtube.com m.youtube.com youtubei.googleapis.com youtube.googleapis.com www.youtube-nocookie.com ; do
        uci add dhcp cname
        uci set dhcp.@cname[-1].cname="$name"
        uci set dhcp.@cname[-1].target="restrict.youtube.com"
        uci commit dhcp
    done
    
    service dnsmasq restart
    

    See the configuration:

    grep -A2 cname /etc/config/dhcp
    

    Python: How to reduce memory usage

    Useful information for reducing memory usage of Python programs:

    • https://m.habr.com/en/post/458518/
    • https://stackoverflow.com/questions/472000/usage-of-slots

    TLDR: Dictionaries use a lot of memory. Possible solutions include using a class and slots, namedtuple, recordclass, cython, or numpy.

    Screen brightness: Linux + Lenovo P50

    I run Ubuntu on my Lenovo P50, and the backlight keys haven’t ever worked. Here’s how I got it working.

    
    sudo apt install xbacklight
    

    Then I mapped the keys using Settings > Devices > Keyboard and added mappings for the following:

    Windows-F5: xbacklight -inc 5 -time 1 -steps 1
    Windows-F6: xbacklight -dec 5 -time 0 -steps 1