Why PWA might be the future of headless eCommerce
Progressive Web Apps (PWAs) are designed to address the mobile revenue gap indicated below.
In most markets, online retail has a higher proportional audience reach among mobile users than desktop. However, mobile sales numbers are much lower. There can be many reasons for this, some in the realm of technology.
At one time it was thought mobile engagement was best achieved using an app. This was based on data for mobile users in general, but was possibly skewed towards gaming and social media. An app has advantages of being able to deliver notifications, use mobile features the way a typically website cannot, be installed as an icon resulting in easier access.
On the flip side, there is data suggesting mobile users were reluctant to install apps due to issues like memory limitations. Other disadvantages include a need for an OK from Apple to be on the app store, lack of easy-to-test infrastructure, the rather slow process of distributing updates – for example some users may not have auto update on.
Using service worker technology, widely supported by browsers today, the PWA (or progressive web application) will give some of the benefits of an app without the cost of consuming memory, requiring an OK from Apple and being as easy to deploy new updates as it is to update a website. PWAs are also as easy to test as a website. A PWA will install on a mobile as an icon – much like an app, service workers allow push notifications as well local storage, allowing for some offline capabilities.
From a technology perspective PWAs pose a completely different problem – the relative newness of technology means developers are limited, as are systems to reliably host & deploy. The cost of development will come down as more developers and websites adopt the technology.
Hosting related issues with PWA for Magento
From a hosting and code deployment perspective. Vue-storefront for example, replicates the entire catalog in elasticsearch and uses 2 nodejs processes to run the frontend of the store. PWA Studio is expected to be Magento (read php) native, yet the reference implementation of its Upward Specifcation Is in nodejs. Both developer and production environments pose challenges.
It is no more a localhost WAMP stack that you can deploy and get a development environment for PWA setup. A single project will require setup of various components (vue-storefront, vue-storefront-api, Magento, graphql, elasticsearch, redis, rabbitmq, etc).
The developer environment will affect the learning curve of the many new developers starting with these new technologies as well as the productivity of experienced developers.
Here are some challenges
- Launch a development environment for a new project
- Setup a developer environment for an existing project
- An ability to change and test any component easily – for example if a js file was modified that affects the UI, what component(s) need be redeployed? Can this process be automated?
It is too early for us to start work on solutions for developers – since we do not do project work ourselves. However, we are working with our partners and we have an eye on releasing a “developer stack”. Contact us if you would be interested.
We recently took a PWA website live. Developed by our partner Codilar, it was a first for us. Some of the challenges faced and lessons learnt are summarized below.
- Setting up a production environment.
Since there were so many components, not natively supported by Magento, many configuration files had to be manually modified.
- Vue-storefront (the UI end that replaces varnish in a classic Magento 2) needs to communicate to Redis for Full Page Cache and the vue-storefont-api
- Vue-storefront-api communicates with elasticsearch and Magento 2 backend via a rest API. Ideally vue-storefront should replicate the entire catalog through a indexing process into elasticsearch, but that is not fully operational yet.
- Magento 2 has its own redis cache and redis session. Magento 2 FPC is not used. Magento 2.3 uses RabbitMQ in addition to connection to its database.
Here is our architecture for the deployment. We used Virtual machines as shown. We did not use a containerised architecture. The reasons will possibly be a different blog post.
- Starting nodejs processes automatically. Vue-storefront uses pm2 for process management. However, developer information and documentation is written using yarn to run the pm2 processes with log files being stored in ~/.pm2. In order for better control from a system administration perspective, we installed pm2 at the global level, generated systemd files (using pm2 startup) and modified them to suit the environment. We can now use “service vue-storefront start/stop/restart”.
- Monitoring all the components.
Log files for each component are taken to a central log processing server using CNCF project fluentd.
A key challenge is observability of failures. A Magento 2 API failure is not obvious. An error return code from vue-storefront needs to be traced to vue-storefront-api to Magento. Correlating the actual hit that caused a non-fatal Magento error is another challenge.
- How to deploy new code with minimum or even 0 downtime
For Magento 2, until a database change is required (via a bin/magento setup:upgrade and/or indexing), we have a process to make a deployable package, giving an opportunity to deploy with 0-downtime. Check out our bitbucket pipeline presentation.
- How can one deploy a vue-storefront based PWA?
The project we migrated ran on 2 git repos – one for Magento, the other for vue. Upon deploy we need to find the files that changed since the last release and decide if the change is in Magento, vue-storefront or vue-storefront-api and decide the build steps appropriately. Presently since the repos are different, we have 2 separate builds running on the production servers. A pipeline based deploy is our next step.
Note: We think a monorepo for both Magento and vue is essential in the long run due to possibility of versioning incompatibilities.
This is yet early work-in-progress and we hope to update our process and keep updating this article as we go.