Canary release, how to simulate it with coding, if possible at all

Question

I'm in a project where I am building a simulator of a website. I am testing how feature toggling can provide some cons that can help a team release more often than they do now.

One thing I do like to simulate is how the Canary release is working. Lets say I just finished building a new feature and I need to have it tested in production. Canary release is just to push this feature out to a small number of users.

How do you simulate this with code? I'm building the applikation with angular2 anad with typescript. Have created configurationfiles for the features that I can use.

How do you, lets say pick only 5 percents of random people that visit the site to test the specific feature? Is it all done with server configuration (running another build at a different server).

If any could make a code example of how I could simulate this when the application starts, I've be happy.

Have made this code myself:

var switchKey: string = localStorage.getItem('featureSwitch');

    if (this.featureSwitch != null) {
        if (switchKey == "11") {
            this.featureSwitch = 1;
            localStorage.setItem('featureSwitch', this.featureSwitch.toString());
        }

    }
    else {
        if (switchKey != null) {
            if (switchKey == "11") {
                this.featureSwitch = 1;
                localStorage.setItem('featureSwitch', this.featureSwitch.toString());
            }
            else {
                this.featureSwitch = Number(switchKey) + 1;
                localStorage.setItem('featureSwitch', this.featureSwitch.toString());
            }
        }
        else {
            this.featureSwitch = 1;
            localStorage.setItem('featureSwitch', this.featureSwitch.toString());
        }

    }

This is maybe a bad example, cause I don't think it will work on a live site (on the internet), this is only tested on a localhost server. Basically I'm saving a number from 1-11 in localstorage, where I can show a feature based on one or more numbers.

Any have some ideas how I could do this easily?

score 0 · Answer 1 · answered May 23 '16 at 01:03

Basically I'm saving a number from 1-11 in localstorage, where I can show a feature based on one or more numbers.

You should do canary releases based on users (not browser sessions). Otherwise the user will be surprised as they switch browsers / devices / locations. And you will not know which users are participating in a test (a user can AND can't be in the test if they use two devices).

This needs server side support, the switch belongs in the server.

Canary release, how to simulate it with coding, if possible at all

1 Answers1