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#Scoped Invitation System for User Groups with Rails#

Starting out with the following models and associations:

####User

• has_many :memberships
• has_many :organizations through :memberships

####Organization (User Group)

• has_many :memberships

thapakazi

AWS region code	AWS region name	Number of AZs	AZ names
us-east-1	Virginia	4	us-east-1a, us-east-1b, us-east-1c, us-east-1e
us-west-1	N. California	2	us-west-1a, us-west-1b
us-west-2	Oregon	3	us-west-2a, us-west-2b, us-west-2c
eu-west-1	Ireland	3	eu-west-1a, eu-west-1b, eu-west-1c
eu-central-1	Frankfurt	2	eu-central-1a, eu-central-1b
ap-southeast-1	Singapore	2	ap-southeast-1a, ap-southeast-1b
ap-southeast-2	Sydney	2	ap-southeast-2a, ap-southeast-2b, ap-southeast-2c
ap-northeast-1	Tokyo	2	ap-northeast-1a, ap-nort

thapakazi

api: bundle exec puma -C config/puma.rb

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// kills long running ops in MongoDB (taking seconds as an arg to define "long")
// attempts to be a bit safer than killing all by excluding replication related operations
// and only targeting queries as opposed to commands etc.
 
killLongRunningOps = function(maxSecsRunning) {
    currOp = db.currentOp();
    for (oper in currOp.inprog) {
        op = currOp.inprog[oper-0];
        if (op.secs_running > maxSecsRunning && op.op == "query" && !op.ns.startsWith("local")) {
            print("Killing opId: " + op.opid

thapakazi

Kubectl output options

Let's look at some basic kubectl output options.

Our intention is to list nodes (with their AWS InstanceId) and Pods (sorted by node).

We can start with:

kubectl get no

thapakazi

#!/bin/bash
FILENAME="/tmp/random-lines.$$.tmp"
NUMLINES=10000000
seq -f 'line %.0f' $NUMLINES > $FILENAME;

echo "10 random lines with nl:"
$(which time) -v nl -ba $filename | sort -r | sed 's/.*[0-9]\t//' | head > /dev/null

echo "10 random lines with shuf:"
$(which time) -v shuf $FILENAME -n10 | head > /dev/null

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#!/bin/bash
# Run with:
#
# bash get_twitter_oauth2_token.sh $KEY $SECRET > oauth2_token
#
# Then enjoy Twitter's API app functions such as search/tweets or lists/members:
#
# curl -H "$(cat oauth2_token)" "https://api.twitter.com/1.1/search/tweets.json?q=assembleenat+OR+deputes&count=200"
# curl -H "$(cat oauth2_token)" "https://api.twitter.com/1.1/lists/members.json?slug=les-d%C3%A9put%C3%A9s&owner_screen_name=AssembleeNat&skip_status=1"

thapakazi

-- show running queries (pre 9.2)
SELECT procpid, age(query_start, clock_timestamp()), usename, current_query 
FROM pg_stat_activity 
WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%' 
ORDER BY query_start desc;

-- show running queries (9.2)
SELECT pid, age(query_start, clock_timestamp()), usename, query 
FROM pg_stat_activity 
WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%' 

thapakazi

Virtual Hosts on nginx (CSC309)

When hosting our web applications, we often have one public IP address (i.e., an IP address visible to the outside world) using which we want to host multiple web apps. For example, one may wants to host three different web apps respectively for example1.com, example2.com, and example1.com/images on the same machine using a single IP address.

How can we do that? Well, the good news is Internet browsers

thapakazi

Live Stream to YouTube from your RPi with Docker

Normally ffmpeg needed to stream to YouTube takes 8-9 hours to build on a PiZero. You can download my image here and run it with your secret key:

docker run --privileged -ti alexellis2/streaming:17-5-2017 <secret>

Bill of materials: