In Google's latest docs, they say to test Go 1.12+ apps locally, one should just go build.
However, this doesn't take into account all the routing etc that would happen in the app engine utilizing the app.yaml config file.
I see that the dev_appserver.py is still included in the sdk. But it doesn't seem to work in Windows 10.
How does one test their Go App Engine App locally with the app.yaml. ie: as an actual emulated app engine app.
Thank you!
On one hand, if your application consists of just the default service I would recommend to follow #cerise-limón comment suggestion. In general, it is recommended for the routing logic of the application to be handled within the code. Although I'm not a Go programmer, for single service applications that use static_files and static_dir there shouldn't be any problems when testing the application locally. You might also deploy the new version without promoting traffic to it in order to test it as explained here.
On the other hand, if your application is distributed across multiple services and the routing is managed through the dispatch.yaml configuration file you might follow two approaches:
Test each service locally one by one. This could be the way to go if each service has a single responsibility/functionality that could be tested in isolation from the other services. In fact, with this kind of architecture the testing procedure would be more or less the same as for single service applications.
Run all services locally at once and build your own routing layer. This option would allow to test applications where services needs to reach one another in order to fulfill the requests made to them.
Another approach that is widely used is to have a separate project for development purposes where you could just deploy the application and observe it's behavior in the App Engine environment. As for applications with highly coupled services it would be the easiest option. But it largely depends on your budget.
Related
Our cloud-deployed app is composed of (simplified):
A web front-end
Some back-end services
A database
When developing the front-end, I can easily debug by running the front-end locally, and redirecting its back-end calls to the actual services, since their endpoint routes are public.
However, I also want to debug back-end service code, together with the front-end. I can run back-end services locally, but they can't access the database, since the database doesn't have any publicly-accessible endpoint.
Question: How can I conveniently develop the service code? I can think of these options:
Expose the database publicly, maybe just the dev env's database. This doesn't sound like a good practice security-wise, and I haven't found a way to do it in my cloud platform (CloudFoundry).
Test everything using local unit- and component- tests. We do this, but can't cover everything, and certainly not the integration with the front-end.
Deploy my code changes to a dev environment, and test that way. This is what we do now, but:
It's a much slower development turn-around that running locally
I can't connect a debugger to the deployed app, so I must debug using logs, which again is slow
We have a limited number of dev environments, and this creates contention for them.
Somehow deploy a replica of the database locally as well, using some kind of test data.
Tech details: For cloud we use CloudFoundry over AWS. My back-end services are written in C# + .NET core 5. Locally, we develop them using Visual Studio 2019 on Windows.
For now, I managed to expose my database locally using an SSH tunnel. Specifically, by running cf ssh [AppName] -L [local_port]:[db_hostname]:[port], with [db_hostname]:[port] taken from the app's configuration, taken by running cf env [AppName].
Say I have a front end node and three backed nodes tools, blog, and store. Each node communicates with the other. Each of these nodes have their own set of languages and libraries, and have their own Dockerfile.
I understand the DevOps lifecycle of a single monolithic web application, but cannot workout how a DevOps pipeline would work for microservices.
Would each micro-service get its own github repo and CI/CD pipeline?
How do I keep the versions in sync? Let's say the tools microservice uses blog version 2.3. But blog just got pushed to version 2.4, which is incompatible with tools. How do I keep the staging and production environments in sync onto which version they are supposed to rely on?
If I'm deploying the service tools to multiple different servers, whose IP's may change, how do the other services find the nearest location of this service?
For a monolithic application, I can run one command and simply navigate to a site to interact with my code. What are good practices for developing locally with several different services?
Where can I go to learn more?
Would each micro-service get its own github repo and CI/CD pipeline?
From my experience you can do both. I saw some teams putting multiple micro-services in one Repository.
We where putting each micro-service in a separate repository as the Jenkins pipeline was build in a generic
way to build them that way. This included having some configuration files in specific directories like
"/Scripts/microserviceConf.json"
This was helping us in some cases. In general you should also consider the Cost as GitHub has a pricing model
which does take into account how many private repositories you have.
How do I keep the versions in sync? Let's say the tools micro-service uses blog version 2.3. But blog just got pushed to version 2.4, which
is incompatible with tools. How do I keep the staging and production
environments in sync onto which version they are supposed to rely on?
You need to be backwards compatible. Means if your blogs 2.4 version is not compatible with tools version 2.3 you will have high dependency
and coupling which is going again one of the key benefits of micro-services. There are many ways how you get around this.
You can introduce a versioning system to your micro-services. If you have a braking change to lets say an api you need to support
the old version for some time still and create a new v2 of the new api. Like POST "blogs/api/blog" would then have a new api
POST "blogs/api/v2/blog" which would have the new features and tools micro-service will have some brige time in which you support
bot api's so it can migrate to v2.
Also take a look at Semantic versioning here.
If I'm deploying the service tools to multiple different servers, whose IP's may change, how do the other services find the nearest
location of this service?
I am not quite sure what you mean here. But this goes in the direction of micro-service orchestration. Usually your Cloud provider specific
service has tools to deal with this. You can take a look at AWS ECS and/or AWS EKS Kubernetes service and how they do it.
For a monolithic application, I can run one command and simply navigate to a site to interact with my code. What are good practices
for developing locally with several different services?
I would suggest to use docker and docker-compose to create your development setup. You would create a local development network of docker
containers which would represent your whole system. This would include: your micro-services, infrastructure(database, cache, helpers) and others. You can read about it more in this answer here. It is described in the section "Considering the Development Setup".
Where can I go to learn more?
There are multiple sources for learning this. Some are:
https://microservices.io/
https://www.datamation.com/applications/devops-and-microservices.html
https://www.mindtree.com/blog/look-devops-microservices
https://learn.microsoft.com/en-us/dotnet/standard/microservices-architecture/multi-container-microservice-net-applications/multi-container-applications-docker-compose
I have basically two URL's http://xyzwebsite.com (for Development Testing) and http://abcwebsite.com (For Production). I have a simple Login mechanism where a user can click on Google Plus icon to log in rather than using their Username and Password. I created one Project for Development with obviously different Client ID and different for Production with a separate client ID.
But I tested both the URL's above with the client ID of Development project and it worked fine. I am wondering why there is a need ot having multiple projects in Google API console?
There is no particular need. A single project can have several URLs and client IDs for use.
Some reasons you might use multiple projects include:
Changing project settings in dev without worrying about breaking production
If you have a development script that gets into an endless loop or something it might use up all of the quota and the production app might start throwing errors
You might want clear branding on the dev app that explicitly identifies as not production.
Some unknown reason I can't think of.
I have a project and I'm planning to start the web app as an Azure Web Site and then migrate it to an Azure Cloud Service (also called Hosted Service) if it is needed as a scale strategy.
The decision is because I read that Azure Web Sites are more simple and fast to develop with almost no Azure-specific configurations or code. So starting fast and simple is a good starting point for the project.
But, is that a good starting point for you?
Is migrating an Azure Web Site to an Azure Cloud Service the same as you were migrating a normal ASP.NET Website to an Azure Cloud Service?
Would you start with an Azure Cloud Service right from the beginning? If yes, why?
Thanks for your time.
There are benefits to both deployment models, it will eventually come down to what you are trying to achieve and ultimately the success of your application.
Below I've outlined the Pros and Cons of each of the models to ensure that you're making the right choice for your applications goals.
Windows Azure Web Sites
You have properly identified that Windows Azure Web Sites is a great starting point for an application, however you could also consider that Web Sites does offer enough scalability for many solutions.
Pros
10 Free sites during preview [Free for 12 months]
Easy Deployment (use Git, TFS, Web Deploy or FTP)
Quick Scalability (You can move to your own dedicated cluster [aka reserved standard])
Simple Development (Supports Classic ASP, ASP.NET, Node.js, Python & PHP)
Persistent Environment (most people are used to this)
Cons
No SSL Support on Custom Domains
in Preview (currently no SLA)
Windows Azure Cloud Services
Cloud Services (formerly known as Hosted Services) is definitely the vision for the future of Web Applications. It is built with resiliency in mind to keep the cost of applications affordable by scaling to meet demand, and dial back capacity when your traffic slows.
Pros
Increased control over the cost of your application (if architected correctly)
Flexibility (You have full control over the environment)
SSL Support
Language Agnostic
Web Server Agnostic (although IIS is available by default)
Auto Management of Servers
Cons
Architecture should be carefully considered
Deployment time is slower (Slows development cycle)
Things to consider for Portability
The items above might have given you enough to plan the immediate future of the application and it is very likely that you might want to consider Cloud Services in the future (it fits a number of application scenarios better in the long run).
Here is a list of things to help portability between Web Sites to Cloud Services:
Start thinking Stateless
Windows Azure Web Sites is nice as it is a persistent environment, which means you are able to store things like session state and assets to the disk.
Although this is a good feature, it's best to start planning towards a stateless application, if your end goal is to be in Cloud Services. Here are a few things you can do to start thinking stateless:
Don't rely on Session State
If you need it, come up with a strategy to make it scale (Caching Service, SQL, or Storage)
Use the Storage Service
Assets such as Static HTML, css, javascript and images are better placed in Storage
Avoids additional bandwidth on your Web Site (potentially stay shared longer for lower cost)
Can be CDN Enabled, provides a better experience for International markets
Easier to update web assets when application is migrated to Cloud Services
Storing User content
If your application already stores to the Storage Service, there is one less code modification in the future when moving to cloud services.
Make it easy to discover patterns in your Data
The benefit of Cloud Services is it enables you to reduce cost by only scaling what needs scaled. Starting the process of identifying your scale units i.e. How you partition your database or Tables in Storage.
I read all post and all of them are very helpful.
In addition to all post , I found an info on msdn : Windows Azure Websites, Cloud Services, and VMs: When to use which?
With Windows Azure Websites you can:
Build highly scalable web sites on Windows Azure.
Quickly and easily deploy sites to a highly scalable cloud environment that allows you to start small and scale as needed.
Use the languages and open source applications of your choice then deploy with FTP, Git or TFS, and easily integrate Windows Azure services like SQL Database, Caching, CDN and Storage.
With Cloud Services you can:
Build or extend your enterprise applications on Windows Azure.
Create highly-available, scalable applications and services using a rich PaaS environment. Support advanced multi-tier scenarios, automated deployments and elastic scale. Deliver great SaaS solutions to customers anywhere around the world.
And also there is summarizes the option on msdn :
And comparing some features Web Sites and Cloud Services on msdn:
Azure is a great place to have your app, but there are some considerations you need to know before start migrating it.
Azure Websites and Hosted Services are really trivial to deploy. With
Visual studio you generate the package and simply upload it. Then you
have a Development environment to check it. If it's ok for you, swap
ips. If it's not ok for you, upgrade again.
Your instances have some properties that could be annoying. For
example, you cannot be sure about your IP. Then if your app works
with some provider using IP restriction, you will need to figure out
how to proceed.
More considerations. Your "server" could be reimaged at any moment.
If you store something on the local disc, that file could go away at any moment.
Azure works very nice if you have at least 2 instances or more for
each website. Maybe your app is not prepared for that. The first step
will be managing the sessions with the appFabric. Is really
easy, just a change on your web config. Be careful because this
session state doesn't work exactly as the "old one". You cannot store
non-serializable objects (should be easy to adapt) or a very large objects (more than 8MB).
If you are going to develop something from zero, I suggest you to start into azure from the beginning. The reason is simple: it's really cheap to start and you will not pay serious money until the app have lot's of visits. It's also very cheap to setup a SQLAzure and a storage account. One you have all in place, it's easy to add more instances or scale up.
Example:
Imagine you have an idea and you wish to show up to some possible investors.
You start setting up a little SQLAzure database (1GB ), $9,99 monthly.
Then you build a site and you put 2 extra small instances, $18,72 monthly.
Let's say you need 100 GB of space (images, backups, ...), $12,50 monthly.
At his point, you have all in place to start your business paying less than $50 monthly.
If you site have exit and the visits starts to come, you change your instances for small instances (it's really dangerous to have production environment with extra small instances, because do not have cpu reservation). Then you change the extra small cost ($18,71) up to $57,60. Maybe you need more space to that SQL Azure? etc...
prices calculated from here: http://www.windowsazure.com/en-us/pricing/calculator/?scenario=web .
Those are few tips, there is a lot more. My advice is to start a trial account and play with it.
Final advice: Its very easy to solve everything just purchasing more resources. Sometimes you need to refactor and optimize your code. If you simply add more resources each time you have a problem, you could end with a huge bill and a very messy code.
Hope it helps!
Another advantage of Windows Azure Cloud Services over Web Sites is that a cloud service can be added to an Azure Virtual Network. This can give it access to on-premises resources like databases. So if your requirements are such that you need the scalability offered by Azure but need to keep your data on-premises due to security restrictions, cloud services is a better choice.
Azure web sites cannot be part of an Azure virtual network. To access on-premises resources mechanisms such as Azure Service Bus Relay must be configured.
We've had our web site running on PHP on some hosting and at some point decided to move it to Azure (where sits main part of our service). We've started with Azure Web Sites which was great from development point of view (mainly integration with git). But after about a week of testing (when we've decided to actually move the production web site) we've found that currently
No SSL for custom domains
Custom domains are available only for reserved instances (no shared infrastructure)
SLA
So we moved to Hosted Service. The main problem for us was lack of ability of simple deployment (need to build package and upload whole package of the web site), and found solution was to use dropbox - as a startup task for role, we're installing dropbox service on the machine, which takes all the web site from dropbox, which in turn have SVN checked out folder, so site updates became very easy.
I just started learning Ruby on rails and I was wondering what Heroku really is? I know that its a cloud that helps us to avoid using servers? When do we actually use it?
Heroku is a cloud platform as a service. That means you do not have to worry about infrastructure; you just focus on your application.
In addition to what Jonny said, there are a few features of Heroku:
Instant Deployment with Git push - build of your application is performed by Heroku using your build scripts
Plenty of Add-on resources (applications, databases etc.)
Processes scaling - independent scaling for each component of your app without affecting functionality and performance
Isolation - each process (aka dyno) is completely isolated from each other
Full Logging and Visibility - easy access to all logging output from every component of your app and each process (dyno)
Heroku provides very well written tutorial which allows you to start in minutes. Also they provide first 750 computation hours free of charge which means you can have one processes (aka Dyno) at no cost. Also performance is very good e.g. simple web application written in node.js can handle around 60 - 70 requests per second.
Heroku competitors are:
OpenShift by Red Hat
Windows Azure
Amazon Web Services
Google App Engine
VMware
HP Cloud Services
Force.com
It's a cloud-based, scalable server solution that allows you to easily manage the deployment of your Rails (or other) applications provided you subscribe to a number of conventions (e.g. Postgres as the database, no writing to the filesystem).
Thus you can easily scale as your application grows by bettering your database and increasing the number of dynos (Rails instances) and workers.
It doesn't help you avoid using servers, you will need some understanding of server management to effectively debug problems with your platform/app combination. However, while it is comparatively expensive (i.e. per instance when compared to renting a slice on Slicehost or something), there is a free account and it's a rough trade off between whether it's more cost effective to pay someone to build your own solution or take the extra expense.
Heroku Basically provides with webspace to upload your app
If you are uploading a Rails app then you can follow this tutorial
https://github.com/mrkushjain/herokuapp
As I see it, it is a scalable administrated web hosting service, ready to grow in any sense so you don't have to worry about it.
It's not useful for a normal PHP web application, because there are plenty of web hosting services with ftp over there for a simple web without scalability needs, but if you need something bigger Heroku or something similar is what you need.
It is exposed as a service via a command line tool so you can write scripts to automate your deployments. Anyway it is pretty similar to other web hosting services with Git enabled, but Heroku makes it simpler.
That's its thing, to make the administration stuff simpler to you, so it saves you time. But I'm not sure, as I'm just starting with it!
A nice introduction of how it works in the official documentation is:
https://devcenter.heroku.com/articles/how-heroku-works
Per DZone: https://dzone.com/articles/heroku-or-amazon-web-services-which-is-best-for-your-startup
Heroku is a Platform as a Service (PaaS) product based on AWS, and is vastly different from Elastic Compute Cloud. It’s very important to differentiate ‘Infrastructure as a Service’ and ‘Platform as a Service’ solutions as we consider deploying and supporting our application using these two solutions.
Heroku is way simpler to use than AWS Elastic Compute Cloud. Perhaps it’s even too simple. But there’s a good reason for this simplicity. The Heroku platform equips us with a ready runtime environment and application servers. Plus, we benefit from seamless integration with various development instruments, a pre-installed operating system, and redundant servers.
Therefore, with Heroku, we don’t need to think about infrastructure management, unlike with AWS EC2. We only need to choose a subscription plan and change our plan when necessary.
That article does a good job explaining the differences between Heroku and AWS but it looks like you can choose other iaas (infrastructure) providers other than AWS. So ultimately Heroku seems to just simplify the process of using a cloud provider but at a cost.