Modernizing the Monolithic User Interface

There is a lot of treatment on the topic of decomposing a monolithic applications. Most of the existing literature deals with disentangling the business logic into logical bounded contexts and sub-domains. Not enough attention is paid to the separation, composition and co-existence of of the new user interface with the old user interface. So what are the techniques for decomposing and modernizing User Interfaces from a legacy UI technology like  Oracle ADF to a modern composable javascript based UI.

Plethora of options for UI decomposition

The existing theory of microservices UI  composition leads us towards micro-frontends.  How does one stitch together a series of micro-frontends decomposed from a monolithic UI ? What are the different options available to decompose a monolithic frontend and assemble a modernized micro-frontend UI.

1. Monolithic UI
2. Single Page Application Javasceript  (SPA) meta- framework single-spa
3. Micro Front-Ends - micro-frontends
4. Front End Server Transclusion  microservice-websites
5. Mosaic project-mosaic-front-end-services
6. Single SPA with multiple similar apps
7. Resource Oriented Architecture roca
8. iFrame Palooza iframes

So which option did we chose ? Option # 6

References

• https://news.ycombinator.com/item?id=13009285
• https://medium.com/@tomsoderlund/micro-frontends-a-microservice-approach-to-front-end-web-development-f325ebdadc16
• 
  

Top 10 reasons for containerizing legacy COTS software ?

What does cloud transformation mean for legacy custom off the shelf software aka COTS ? Yes we are talking of rules engines , portals, commerce engines, BPMs, etc and other products from IBM, Redhat, Oracle and other vendors built on big application servers and other forms of middleware....

1. Operational efficiency provided by PKS for managing the upgrade of both the platform(K8s) and the CustomOffTheShelf software. If done right zero downtime, rolling updates, canary blue/green upgrades can be done with minimal fuss. Advanced deployment policies provided by K8s enables the deploy and release of builds without impact on upstream / downstream systems  providing loose coupling.

2. Infrastructure consolidation and better utilization of hardware via horizontal auto-scaling. Depending on the workload you can attach certain COTS to certain nodes if hardware affinity is required. PKS/K8s has a better story for hardware affinity if the COTS needs some special GPU/CPU/Memory.

3. Most COTS vendors will move to a container based deployment model in the future. Installers shall become moot. This is the future. K8s dial-tone is a must for all future deployment of COTS.

4. Through various value adds that PKS provides for logs. metrics, telemetry, clusters, fine-grained security, health-watch, network micro-segmentation - you will get better uptime, stability and resiliency of your COTS platform if deployed right. Monitor end-to-end to gain insight and make informed decisions using the insights provided by PKS. Kubernetes along with BOSH provides proactive system health and automated health management at the container level

5. Developer Benefits include more consistent environments. On demand environments for COTS can be stamped out as opposed to manual provisioning. Putting it in a container allows deployment across zones and across different cloud providers realizing the multi-cloud dream and avoiding BIG cloud vendor lockin.

6. Putting  the COTs in a Container and deploying with a K8s platform like PKS provides flexibility in dynamic routing and service discovery to start strangling the functionality from COTs if so desired. This provides a gateway to modernization.

7. If the COTS is non-strategic, deploying it in k8s provides a long term resting place that is coherent with the cloud strategy.

8. COTS in PKS + microservices in PAS provides for the right abstraction to run at the right platform level. Recommend keeping COTS vanilla, build customization using Boot microservices

9. K8s updates every quarters. COTS vendors and everyone else are playing catchup and moving to a faster upgrade - AsAService cycle. As an IT organization COTS in PKS helps you get ahead of this curve. If done right Pace is an immense leverage to your organization.

10. Developers love containers and can run the COTS locally through a docker image whereas earlier they would have to spend a lot of hours in arcane setup. They get all the goodness of docker aka OCI compliant container images.

Top 10 challenges in containerizing legacy enterprise apps

1. Vendor Support: Independent of the K8s distribution PKS or Openshift or GKE the availability of vendor supported images and deployment models via helm or operators. Who will support us on the platform ? Will we get a single throat to choke ? See IBM support model for containers here. Oracle Weblogic guidance for containers. 

2. Upgrades including Security: Upgrade and patching of the said COTs software and apps packed in the images. Since you bring your own image in Docker it behooves the app owner to update the entire stack OS, JVM. App-Server/middleware and the app itself. Are best practices being followed for container creation ?

3. State: Usually when containerizing legacy apps the intent is to do 0 refactoring of the app itself => this leads to embedded state within the app. This complicates the deployment and day-2 ops of the app on K8s ranging from autoscaling , liveliness and readiness  probes and proper use of stateful sets.

4. Plethora of choices: In the K8s world there are five ways of doing anything. Lets take service discovery for example - Do you want to use native DNS, cluster-IP, Istio sidecar, environment variables, OSBAPI service brokers, Eureka, client based or server based discovery. Picking the right one for your technical stack is a drag that most ignore. These choices multiple as you consider logging, security, metrics etc., This is where PKS/Pivotal/AppTx can help. We know what works for you.

5. Day-2 App Ops: Very few understand how to operationally keep a fleet of K8s clusters alive. The care and feeding of a K8s cluster requires a level of operational maturity that is hard to visualize and estimate. The care and feeding of your K8s cluster and the pods is usually an after-thought. 

6. ROI: Show me the Money? : There is a wave of buzzwords raining down on the industry right now - microservices, serverless, devops, containers, agile, etc.,. The return on investment by rehosting, refactoring, replatforming or rebuilding/retiring an application is NOT clear. Developers follow mandates from the top. Is containerization really the right choice for your technical and business outcomes ? Is this a strategic play or a tactical play. All these options needs to be considered before a decision is made to containerize your legacy app. Pivotal AppTx has a structured funnel approach see here to make the right choice. What is the right choice from P to V to C [link]. Remember CaaS is only a means to the end. If the end is unclear you may not be making the right choices along the way.

7. Code Provenance:  Dude where is the source code ? : Sometimes the provenance of the code of the legacy app cannot be established. The source code is owned by a third-party partner who has been maintaining the app for years. Development happens offshore with only a few key customer coordinators who manage the project from  on-shore. In such a situation the outsourced partner has little incentive to containerize and eliminate waste because it translates to a material impact on consulting `$$$`. This is really a question of alignment of priorities between you and any major offshore partner.

8. Process: I am a big fan of the Theory of Constraints by Dr. Eliyahu Goldratt. The Theory of Constraints is a methodology for identifying the most important limiting factor (i.e. constraint) that stands in the way of achieving a goal and then systematically improving that constraint until it is no longer the limiting factor. If you don't eliminate the top bottlenecks you may be solving the wrong problem. How do you pick the right set of workloads to be run  at the right level of abstraction. Have you eliminated waste in your release management process. There is no point in optimizing the 20% of the time spent in developing the software and keeping the 80% of the time spent in  Q&A and release gates intact.

9. Resiliency: Often packaging an app in containers changes the environment and assumptions of the app enough to have a detrimental effect on the stability of the app. You have to be careful about how the application is dockerized and run in K8s. The inherent assumption in all the container orchestrators is that the container is fungible and location transparent. If the legacy app violates these constraints then you are fitting a round peg in square hole.

10. Skills: The subset of developers who understand cloud native and furthermore Kubernetes and Platform  as a Service is small. K8s is a fast moving target. Significant features show up in releases in alpha or beta form every 3 months. It is critical that your application is written with cloud native principles thereby making it cloud agnostic therefore enabling it to consume these platform features whenever and as soon as they show up. It is critical to architect and develop the legacy or greenfield application in the right way to ride the surf waves of K8s releases. 

SNAP Not Analysis and Paralysis

SNAP is a technique we employ extensively in Pivotal App Transformation to triage an application and determine technical feasibility. SNAP can be done for an individual application as well as for a bucket of applications that groups like apps. We typically grade each answer along S, M, L, XL t-shirt sizes and determine an overall technical feasibility of the application aka its cloud readiness score. 

SNAP Analysis of Apps :½ hour per app:

Questions to ask:

0. Versions and APIs in-use of Java, JavaEE, J2EE & Spring Framework
1. External Integrations - Databases, Caching, Messaging Queues
4. In-house frameworks
5. Logging
6. Configuration
7. SLAs
8. Packaging and Build (ear/war/jar)
9. CI/CD in place ?
10. Use of Distributed 2PC XA Transactions
11. Persistent File System Access like NFS or SMB/CIFS... ?
12. People location
13. non-HTTP inbound networking protocols like RMI-IIOP, etc ..
14. Total LOC
15. App Server ? and appserver specific code
15. Security Requirements (Siteminder, Ping, SSO)
16. Batch/ETL
17. Front-end tech
18. Runs on PCF
19. Statefulness - session state
20. Data Access - JDBC, ORM, JMS
21. Startup/shudown times
22. 3rd party frameworks/libraries- 32/64 bit References - bit.ly/app-replat & bit.ly/migrate-jee


Typical Outcomes of a SNAP include: (0. Characteristics, 1. User Stories, 2. Metrics, 3. Risks, 4. Score aka Summary))

Outcome for each app is a list of stories to get the app to the degree of cloud nativeness desired by customer. Each App maps to multiple MVPs. The first MVP is always getting the app running on PCF. Thereafter there can be multiple MVPs gradually moving the app on the modernization scale. The scorecard of each app is used to map all the apps on a quadrant of Business Value/ Technical Risk. Apps of low tech. Risk and high business value are chosen first

Auto Generating cloud pipelines for existing applications - THANKS TO Marcin Grzejszczak

This is a guest post where I copy - paste complete nuggets of wisdom from Spring and Pipelines guru Marcin Grzejszczak

The question I posed Marcin was how do we mass generate CI pipelines for existing enterprise applications ?

Marcin indicated that this functionality already exists in spring-cloud-pipelines via project crawler. However this functionality is currently only restricted to Jenkins because there’s no Java API to work with Concourse YAML or Concourse as such.

Project Crawler -  In Jenkins, you can generate the deployment pipelines by passing an environment variable with a comma separated list of repositories. This however doesn’t scale. We would like to automatically fetch a list of all repositories from a given organization / team.

Documentation for Crawler support 

Cloud Pipelines Concourse comes with a crawler.groovy file that allows to go through the repositories in an organization in an SCM server (e.g. Github, Gitlab, Bitbucket) and for each repo it will create a pipeline in Concourse.

How does this work with Jenkins ?

This is the logic for Jenkins that does the creation of pipelines -

https://github.com/spring-cloud/spring-cloud-pipelines/blob/master/jenkins/jobs/jenkins_pipeline_crawler_sample.groovy

This is the crawler logic that creates the crawler -

https://github.com/spring-cloud/spring-cloud-pipelines/blob/master/jenkins/jobs/jenkins_pipeline_crawler_sample.groovy#L34-L41

This is the logic that fetches the repos -

https://github.com/spring-cloud/spring-cloud-pipelines/blob/master/jenkins/jobs/jenkins_pipeline_crawler_sample.groovy#L43-L45


Here you have the logic that iterates over repos and does some stuff (generates pipelines)

https://github.com/spring-cloud/spring-cloud-pipelines/blob/master/jenkins/src/main/groovy/org/springframework/cloud/pipelines/common/PipelineFactory.groovy#L40-L73


What can we do for Concourse ?

The following Groovy script to mass - generate pipelines:
// crawl the org
ProjectCrawler crawler = new ProjectCrawler(OptionsBuilder
    .builder().rootUrl(urlRoot)
    .username(gitUsername)
    .password(gitPassword)
    .token(gitToken)
    .exclude(repoProjectsExcludePattern)
    .repository(repoType).build())

// get the repos from the org
ListRepository repositories = crawler.repositories(org)
MapString, Exception errors = [:]

repositories.each { Repository repo ->
            try {
                // fetch the descriptor
                String descriptor = projectCrawler.fileContent(org, repo.name, repo.requestedBranch, "sc-pipelines.yml")
                // parse it
                PipelineDescriptor pipeline = PipelineDescriptor.from(descriptor)
                if (pipeline.hasMonoRepoProjects()) {
                    // for monorepos treat the single repo as multiple ones
                    pipeline.pipeline.project_names.each { String monoRepo ->
                        Repository monoRepository = new Repository(monoRepo, repo.ssh_url, repo.clone_url, repo.requestedBranch)
                        // generate a concourse pipeline for monoRepository
                    }
                } else {
                        // generate a concourse pipeline for pipeline
                }
            } catch (Exception e) {
                errors.put(repo.name, e)
            }
        }

if (generatedJobs.hasErrors()) {
    println "\n\n\nWARNING, THERE WERE ERRORS WHILE TRYING TO BUILD PROJECTS\n\n\n"
    generatedJobs.errors.each { String key, Exception error ->
        println "Exception for project [${key}], [${error}]"
        println "Stacktrace:"
        error.printStackTrace()
    }
}


In the future the spring cloud pipelines developer workflows shall be simplified such that

As a developer, you will clone one of our sc-pipelines prepared sample apps, alter it to suit your needs (and maintain the conventions that are already there). You’re done.

As an ops, ensure that the Jenkins seed job is running every now or then (or is triggered when a new repo is added to your Github org). That way a pipeline is created out of the box.

Thank you Marcin!!!

Are PHP Microservices a Thing ?

So cloud native architecture does not  apply only to .NET or Java . Cloud native is a secular term that applies to applications in any language including PHP. The concepts and 15 factors of cloud native can apply to any language.

So PHP Microservices are indeed a thing. There is even a book published Mar 17 https://www.packtpub.com/mapt/book/application_development/9781787125377/1

Not only can you write cloud native apps in PHP you can also practice domain driven design in PHP. The book Domain-Driven Design in PHP is an excellent resource to get started.

Please also checkout True Tales of publishing PHP Microservices.

So with a combination of cloud native 15 factor implementation techniques and monolith decomposition driven by DDD you too can achieve nirvana with PHP microservices.

PHP microservices can be pushed to PCF using the PHP buildpack.  For practice take a look at the getting-starter guide to easily push PHP apps to Pivotal Cloud Foundry in under 5 minutes.

Migrating WebLogic workloads to the cloud

# CaaS

0. Containerize the app - PAS ... zero changes to the app - research - Weblogic standalone. Single inbound route. Stateful workload => volume services on PCF. Docker images.
1. Containerize the app - PKS ... zero changes to the app - Use existing Helm charts or operators to run on PKS - Weblogic clustered https://github.com/oracle/weblogic-kubernetes-operator/blob/master/site/design.md

#PaaS

2. Using a buildpack - Weblogic buildpack https://github.com/pivotal-cf/weblogic-buildpack
3. Using a buildpack - TomEE buildpack - Runs JavaEE. YMMW if there is a lot of ORCL specific deployment descriptors and API usage
4. Using the Java buildpack - Java Buildpack - Bootify the app and replace all EE framework usage with corresponding Spring components and frameworks - some changes - very well understood - and recipes exist for ALL mods EJB Migration
5. Using the Java buildpack - Package up the app as a fat app in WebLogic and then run it simply as a jar with the JBP. - experimental but could yield replatforming with 0 changes. same restrictions as PAS apply.

# FaaS

- Does not apply

#VM 

7. BOSH to deploy Weblogic as a release. BOSH release for weblogic
8. Ansible, chef recipes ...

# Bare Metal

9. Run as-is today on servers with NO virtualization.

GKE-on prem, Azure on-prem , AWS on-prem

All the major clouds are coming to a datacenter near you*. You can get Google, or Azure megascale in your own house datacenter. You can start taking advantage of the cloud platforms to improve and shift your workloads to the cloud and get the benefits of being cloud native. The cloud will be a force function for innovation and change in your organizations allowing you to finally throw away the yolk of agilefall or wagile or DAD or Scrum whatever has kept you behind. Your software can eat the world. You will no longer be threatened by the millennial's of Silicon Valley. 

wait a minute ... there is something missing here !! ... 

Humans. Where is the human cloud ? Where is the Cloud Native Transformation as a service. Where is the Platform as a Product Service. Where is the Domain Driven Design as a Service. Where is the SRE as a service. Where is the Outside-in product thinking as a service. Where is the  Training as a service. Where is the Incident Management as a Service. Where is the Busting Canonical Domain Model as a service. Where is decomposing monoliths as a service. Where is the Refactoring databases as a service. Where is Decomposing UIs as a service ? Where is the Outcomes as a service ? Where is the Human as a Service. 

Remember that the human aspect of the cloud is the biggest force function enabler that will enforce the razor focus on outcomes rather than technology envy. As I sit here reflecting on all the technology choices that are passing through > microservices, serverless, kubernetes, cloud foundry, the million choices from CNCF,  please remember the cloud revolution needs to be customized to your needs and not the other way around. 

Pick and chose the boring technology choices available that get the job done and allow you to reach your objectives and key results. Do not forget that the ultimate goal is increased frequency software releases, reduced change failure rate, reduced lead and cycle time to iterate fast and converge on the right outcome. 

So yeah please install PCF, gke, aws, openstack, vmware , azure or whatever but remember software is a means to the end and it is the END that has always to be kept in mind unless your core business is the business of software itself. 

* I have money on AWS-on-prem being announced this ReInvent. 

Day 2 Application Operations

What are the set of practices you need to inculcate and internalize to keep your app alive in production ? Here is a checklist that can help ...

1/ Use spring boot actuators in production … AppManager has secret sauce integrating with actuator allowing for easier management  and visibility of your app of PCF. all your actuator endpoints

2/ When it makes sense add custom health indicators that add to the default health indicators

3/ Add spring cloud sleuth to your classpath dependencies so that you can visualize the call flow across microservices threads with zipkin in PCF Metrics http://docs.pivotal.io/pcf-metrics/1-4/using.html

4/ Plug a syslog drain to the end of the Firehose using the appropriate nozzle like https://docs.pivotal.io/partners/splunk/index.html

5/ Emit application or domain level metrics using Micrometer https://docs.spring.io/spring-boot/docs/current/reference/html/production-ready-metrics.html

6/ Starting PCF 2.2 you can configure alerting and autoscaling on any custom app metric. Custom rules for autoscaling.

7/ Use VisualVM and sister tools from the JVM to get deeper insight particularly for performance issues. Here is a good article on setting up VisualVM with an app running on Cloud Foundry. Furthermore the ability to take threaddumps and heapdumps is critical in analyzing performance issues specifically How to generate Java Application thread dump from Cloud Foundry container and How to generate and download Java Application heap dump from Cloud Foundry container and How to know if an app is responsible for high CPU in a Diego Cell and how to find it

8/ Leverage canaries to understand the quality of the app and then scale up with Blue/Green. concourse-pipeline.

9/ Create a SLI/SLO dashboard to get immediate visibility into your error budgets and uptime.

10/ Practice an outage handling event and run through debugging common scenarios like OOM, hangs, deadlocks using cf-ssh, and boot actuator endpoints. Create a program around incident response management.

Tools for scanning apps for cloud readiness

Spring Migration Analyzer
  https://github.com/spring-projects/spring-migration-analyzer

Ephemerol
  https://github.com/Pivotal-Field-Engineering/ephemerol

Migration Toolkit for App Binaries from IBM
  https://developer.ibm.com/wasdev/docs/migration-toolkit-application-binaries-tech/#evaluate

Application Migration Toolkit from Redhat
  https://developers.redhat.com/products/rhamt/hello-world/