Category Archives: Development

Using Azure Kubernetes Service (AKS) for your VSTS build agents

Sometimes hosted build agents in VSTS dont cut the mustard and you want full control over your build environment. That’s where self hosted build agents come in. The problem is … do you don’t want to run VMs ideally and if you are getting into Kubernetes then your dev cluster is probably sitting there idle 90%+ of the time with all those CPU cycles being wasted.

We decided to do something with that extra capacity and run a set of VSTS linux build agents (good for Nodejs and .net Core builds etc…) in our dev AKS cluster! We can scale them up for more concurrent builds really easily.

What you will need:

Lets go …

Helm is a tool that helps you install apps in your kubernetes environment. Helm charts are templates for your application. They define what your app needs and what containers should be deployed etc… Fortunately Microsoft make their linux build agent available as a Docker image that we can use in a helm chart to get it deployed. https://hub.docker.com/r/microsoft/vsts-agent/

This means all we need to do is deploy it (or many of them) to Kubernetes … and helm charts can help with that! We wrote a basic one to get things going.

Setup

First you will need to get our helm chart.

git clone git@github.com:Hyperfish/vsts-build.git

Next open up the values.yaml file and update the following properties:

  • VSTS_ACCOUNT – this is the name of your VSTS account e.g. “contoso”.
  • VSTS_POOL – this is the name of the agent pool you would like your agents registered in.
  • VSTS_TOKEN – this is your personal access token from VSTS that has been given at least the Agent Pools (read, manage) scope.
  • replicaCount – set this to how many agents you want deployed.

Note: for more information about these see the vsts agent docker image documentation.

Deploy

Once you have updated the values.yaml file you are ready to deploy!

Ensure you are in the /vsts-agent folder and have kubectl connected to the kubernetes cluster you want to deploy the application to. (tip: run “kubectl cluster-info” to check you are connected)

Deploy the chart:

helm install .

Once complete the agent will be started in your kubernetes cluster.

helm ls

This will show you the apps you ahve deployed and you should see the vets-agent chart deployed.

Check your VSTS build pool that you specified in the values.yaml file. You should see your new agents listed.

Troubleshooting:
If you don’t see them listed then its likely that the values you set are incorrect. You can check the logs of your agents using:

kubectl logs <pod name>

You might see something like “error: missing VSTS_ACCOUNT environment variable”

Summary

Kubernetes is a great way to deploy multiple vsts build agents! Deploying with a Helm chart is even nicer! It gives you are simple way to deploy and manage your agents in kubernetes.

Enjoy!

-CJ

Moving to Azure Kubernetes Service (AKS)

We recently moved our production service to the new Azure Kubernetes Service (AKS) from Microsoft. AKS is a managed Kubernetes (K8s) offering from Microsoft, which in this case, means Microsoft manage part of the cluster for you. With AKS you pay for your worker nodes, not your master nodes (and thus control plane) which is nice. 

Don’t know what Kubernetes is?

Kubernetes is an open-source system for automating deployment, scaling, and management of containerized applications. — https://kubernetes.io/

Why did we move

The short story is that we were forced to evaluate our options as the current orchestration software we were using to run our service was shutting down. Docker Cloud was a sass offering that offered capabilities around orchestration/management or our docker container based service. This meant we used it for deployment of new containers, rolling out updates, scheduling those containers on various nodes (VMs) and keeping an eye on it all. It was a very innovative offering 2 years ago when we started using it, was cloud based, easy to use and price competitive. Anyway, Docker with their new focus on making money the Enterprise decided to retire the product and we were forced to look elsewhere. 

Kubernetes was the obvious choice. It’s momentum in the industry means there are a plethora of tools, guidance, community and offerings around it. Our service was already being run in Docker containers and so didn’t require significant changes to run in Kubernetes. Our service is comprised of ~20 or so “services” e.g. frontend, API. Kubernetes helps you run these services. It offers things like scheduling those containers to run, managing spinning up new ones if they stop etc.

Every major cloud provider has a Kubernetes offering now. Googles GKE has been around since as early as Nov 2014 & Amazon’s AWS recently released their EKS (on June 2018).

Choosing AKS 

We are not a big team and we couldn’t afford to have a dedicated team to run our orchestration and management platform. We needed an offering that was run by Kubernetes experts who know the nitty gritty of running K8s. The team building AKS at Microsoft are those people. Lead by the co-founder of the Kubernetes project Brendan Burns the MS team know their stuff. It was compelling that they were looking at new approaches in the managed K8s space like not charging for the control plan/master nodes in a cluster and were set on having it just be vanilla K8s and not a weird fork with proprietary peculiarities. 

Summary of reasons (in no particular order):

  • Azure based. Our customers expect the security and trust that Microsoft offers. Plus we were already in Azure.
  • Managed offering. We didn’t want to have to run the cluster plumbing.
  • Cost. Solid price performance without master node costs.
  • Support. Backed by a team that know their stuff and offer support (more on this below).

AKS is relatively new and at the time we started considering our options for the move AKS was not a generally available service. We didn’t know when it would GA either.  This pained me to say the least, but we had a hunch it was coming soon. To mitigate this we investigated acs-engine which is a tool that AKS uses behind the scenes to generate ARM templates for Azure to stand up a K8s cluster. Our backup plan was to run our own K8s cluster for a while until AKS went GA. Fortunately we didn’t need to do this 🙂

Moving to Kubernetes

We were in the fortunate position that our service was already running in a set of Docker containers.  Tweaking these to run with Kubernetes only required minor changes. Those were all focused on supplying configuration to the containers. We used a naming convention for environment variables that wasn’t Kubernetes friendly, so we needed to tweak the way we read that configuration in our containers.

The major work required was in defining the “structure” of our application in Kubernetes configuration files. These files define the components in your application, the configuration of them, how they can be communicated with & resources they need. These files are just YAML files however manually building them can be tedious when you have quite a few to do. Also there can be repetition between them and keeping them in sync can be painful.

This is where Helm comes in.

Helm is the “package manager for Kubernetes” … but I prefer to think of it as a tool that helps you build templates (“charts”) of your application. 

In Azure speak they are like ARM templates for your application definition.

The great part about Helm is that it separates the definition of your application and the environmental specifics. For example, you build a chart for your application that might contain a definition for your frontend app and an API, what resources they need and the configuration they get e.g. DB connection string. But you don’t have to bake the connection string into your chart. That is supplied in an environment specific values file. This lets you define your application and then create environment specific values files for each environment you will deploy your application to e.g. test, stage, production etc. You can manage your chart in source control etc. and manage your environment specific values files (with secrets etc.) outside of source control in a safe location.

This means we can deploy our service on a developer laptop, AKS cluster in Azure for test or into Production using the exact same definition, but with different environment specific configuration.

Chart + Environment config == Full definition.

We already had a Docker Compose definition of our service that our engineers used to run the stack locally during development. We took this and translated it into a Helm chart. This took a bit of work as we were learning along the way, but the result is excellent. One definition of our service in a declarative, modular and configurable way that we use across development, test environments and production.

Helm charts are already available for loads of different applications too. This means if you want to run apps like redis, postgres or zookeeper you don’t have to build your own helm charts.

That’s a lot of words … what’s the pay off Chris?

The best way I can demonstrate in a blog post the value all this brings is to show you how simple it is to deploy our application.

Here are the CLI steps for deploying a brand new, fully functional 4 node environment in Azure with AKS + Helm for our application

az aks create –resource-group myCluster –name myCluster –admin-username cjadmin –dns-name-prefix appName –node-count 4 

helm upgrade myApp . -f values.yaml -f values.dev.yaml –install

Two commands to a fully functional environment, running on a 4 node K8s cluster in Azure. Not bad at all!! It takes us about 10 mins to spin up depending on how fast Azure is at provisioning nodes.

What didn’t go well

Of course there were things that didn’t go perfectly along with all this too.  Not specifically AKS related, but Azure related. One in particular that really pissed me off 🙂 During the production move we needed to move some static IP addresses around in our production environment. We started the move and it seemingly failed part the way through the move. This left our resource group in Azure locked for ~4 hours!! During this time we couldn’t update, edit or add anything to our resource group. We logged a Severity A support ticket with MS which is supposed to have a 1 hour response time … over 3 hours later we were still waiting. We couldn’t wait and needed to take mitigation steps which included spinning up a totally new and separate environment (easy with AKS!) and doing some hacky things with VMs and HAProxy to get traffic proxied correctly to it. Some of our customers whitelist our static IP addresses in their firewalls so we don’t have the luxury of a simple DNS change to point at a new environment. It was disappointing to say the least that we pay for a support contract from MS but Azure failed and more importantly our support with MS failed and left us high and dry for 4 hours.  PS: they still don’t know what happened, but are investigating it.

Summary

Docker closing it’s Docker Cloud offering was the motivation we needed to evaluate Kubernetes and other services. It left me with a bad taste in my mouth with Docker as a company and I will find it hard to recommend or trust taking a dependency on a product offering from them. Deprecating a SaaS product with 2 months notice is not the right way to operate a business if you are interested in keeping customers IMHO. But nevertheless a good thing for us ultimately!

Our experience moving to AKS has been nothing short of excellent. We are very glad the timing of AKS worked in our favor and that Microsoft have a great offering that meets our needs. It’s still early days with AKS and time will be the ultimate proof, however as of today we are very happy with the move.

If you are new to container based applications and are from a Microsoft development background I recommend checking out a short tutorial on ASP.Net + Docker. I have thoroughly enjoyed building a SaaS service that serves millions of users in a container based model and think many of the benefits it offers are worth considering for new projects.

If you want to learn Kubernetes in Azure I recommend their getting started tutorial. It’s will give you a basic understanding of K8s and how AKS works.

Try out the tutorial on AKS + Helm for deploying applications to get started on your journey to loving Helm.

Finally … I interviewed Gabe Monroy from the AKS team when I was at Build 2018 for the Microsoft Cloud show if you are interested in hearing more about AKS, the team behind it and Microsoft’s motivations for building it!

-CJ

SharePoint Conference North America thoughts and slide links

What a fun few days hanging out with friends and collegues in Las Vegas for the last few days. SPC NA seemed to go pretty well! I think the biggest thing for me this week was being surrounded by people who all share a common passion. That is what SPCs in the past were great at and i think some of that was rekindled this week. As always wandering the expo floor and talking with other vendors about what they are building is my favorite thing about conferences and this week was great for that. Some new faces popped up too!

For those looking for my slides from the session i did you can find them below. Unfortunatly there is a lot of content in the demos that isnt captured in the slides, but i hope it helps.

Office 365 development Slack

imageMany years back a small group of friends started the Office 365 developer slack network.  A bunch of people joined and then it rapidly went nowhere Smile

I think that is a crying shame. 

I recently joined a Slack network for Kubernetes and its a fantastic resource for asking people questions, working with others on issues you are having and generally learning and finding things.

Office 365 development has changed a lot over the years and people are finding new ways of doing things all the time. The Microsoft Graph is taking off in a HUGE way, SPfx is becoming a viable way to build on the SharePoint platform, Azure AD is the center of everything in the cloud for MS and the ecosystem is heating up with amazing new companies and products springing up.

Anyway … I miss having a Slack network for Office 365 development chats with people.

You can join the O365 Dev Slack here if you feel the same way …

http://officedevslack.azurewebsites.net/

-CJ

Domain Controller in Azure VM with expired password

Came across an interesting situation this morning and thought I would drop the solution I found here incase anyone else needs to figure this out.

Situation:

  • Active Driectory Domain Controller in an Azure VM
  • Your admin account has an expired password
  • RDP’ing to the machine says your password is expired and you need to set a new one, but it keeps prompting you around in the circle that you need to udpate it … but you can’t. 

The first thing you will likely try is the Reset Password option in the Azure portal. It doesnt work for Domain Controllers (this changed recently … no idea why). You get an error message that says:

VMAccess Extension does not support Domain Controller

At this point you start trying to figure out if there is another admin account you can use to log in with. In my case this as a dev/test AD box and it only had the one admin account on it.

Solution:

Before you go and delete the VM and build up a new one I found an interesting way to fix this.

You can use the azure portal and a VM extension to upload and run a script on the machine to reset the password for you. Here is how you do it.

  • Create a script called “ResetPassword.ps1”
  • Add one line to that script

net user <YouAdminUserName> <YourNewPassword>

  • Go to the VM in the azure portal
  • Go into the extensions menu for that VM
  • In the top mentu pick “Add”
  • Choose the Custom Script extension

 

  • Click Create
  • Pick your ResetPassword.ps1 script file 
  • Ok

Wait for the extension to be deployed and run. After a while you will see the status that looks something like this:

You should be set to RDP into your machine again with the new password you set in the script file.

I have no idea why the reset password functionality in Azure decided to exclude AD DCs … but if you get stuck i hope this helps.

-CJ

Importing and Exporting photos from Office 365 and Active Directory

Photos in Office 365 are a pain. This is because there are currently three(!) main places photos are stored in Office 365:

  • SharePoint Online (SPO
  • Exchange Online (EXO)
  • Azure Active Directory (AAD)

If you are syncing profiles using AD Connect those profiles are being synced into AAD. From there they take a rather arduous and rocky path to EXO and SPO via a number of intermediatary steps that may not work or may only complete after a period of time. e.g. from EXO to SPO photos may only sync if someones photo has not been set directly in SPO and a rather profile property attribute is not set correctly.

Needless to say it can be very hard to work out why you have one photo in AD on-prem, one in AAD, one in EXO and another in SPO … all potentially different!

At Hyperfish we built our product to push photos to all the places they should go when someone updates them. This means that when someone updates their photo and that update is appoved that it will be resized appropriately for each location and then saved into AD, EXO and SPO immediately. This results in the persons photo being the same everywhere at the same time. Happy place!

However, we have some customers who want to bulk move/copy photos around between these different systems to get things back in order all at once. To do this we created a helpful wee commandline utitility that we have published the source code for on GitHub and a precompiled release if you dont want to compile it yourself.

Photo Importer Exporter

Creative naming huh! 🙂

The Photo Importer Exporter is a very basic Windows command line utility that lets you:

  • Export photos from SharePoint Online
  • Export photos from Exchange Online
  • Import photos to Active Directory
  • Import photos to SharePoint Online
  • Import phtoso to Exchange Online

All you do is Export the photos from, say, Exchange Online (the highest resolution location) and it will download them all to the /photos directory. Then you can Import them to, say, Active Directory and the utility will resize them appropriately and save them to AD for you. Simple huh.

Code: https://github.com/Hyperfish/PhotoImporterExporter
Releases: https://github.com/Hyperfish/PhotoImporterExporter/releases

It’s a work in progress and we will be adding bits to it as we come accross other scenarios we want to support.

But for now you can grab the code and take a look, suggest additions, make pull requests if you like, log issues … or just use it 🙂

Happy coding,
-CJ

Sniffing Azure Storage Explorer traffic

A friend asked a question about looking at how Azure Storage Explorer makes its API calls to Azure using something like Fiddler.

The issue with just firing up Fiddler and watching traffic is that to decrypt HTTPS traffic fiddler installs a root certificate so that SSL is terminated in Fiddler first so that it can show you the decrypted payloads back and forth etc…

That is normally fine with apps that use the standard WinINET libraries etc… to make HTTPS calls (like chrome). However, Azure Storage Explorer an Electron app using NodeJS and doesnt use these. Node also handles root CAs a bit differently and a long story short is that it doesn’t by default trust Fiddlers Root Cert that it installs. This means that HTTPS calls fail with a “unable to verify the first certificate” error.

Setting up Fiddler

First you need to set up Fiddler to decypt HTTPS traffic. You do this in Fiddlers options under Tools > Options > HTTPS.

This will prompt you to install a certificate that Fiddler uses to terminate SSL in Fiddler so it can show you the decrypted traffic.

One You have completed this you need to export the certificate Fiddler installed so that you can set up Storage Explorer with it.

  1. Run MMC.exe
  2. File > Add Remove snap in
  3. Pick Certificates, when prompted choose “Computer account” and “Local computer”
  4. Navigate to Certificates > Trusted Root Certificates > Certificates
  5. Find “DO_NOT_TRUST_FiddlerRoot” certificate
  6. Right Click > All Tasks > Export  
  7. As you go through the wizard choose “Base-64 encoded X.509 (.CER)” for the file format
  8. Save it your desktop or somewhere you will be able to find it later


Setting up Azure Storage Explorer

First up you need to configure Azure Storage Explorer to use Fiddler as a proxy. This is pretty straightforward.

In Storage Explorer go to the Edit -> Configure Proxy menu and add 127.0.0.1 and 8888 (fiddler defaults). Note: Not authentication should be used.

Now Storage Explorer will use Fiddler … however, you will start getting “unable to verify the first certificate” errors as Storage Explorer still doesnt trust the root certificate that fiddler is using for SSL termination.

To add the Fiddler certificate go to the Edit > SSL Certificates > Import Certificates. Pick the .cer file you saved out earlier. Storage Explorer will prompt you to restart in order for these to take effect.

Now when you start using Storage Explorer you should start seeing its traffic in Fiddler and in a readable decrypted state like below.

Now you can navigate around and do various operations and see what and how Azure Storage Explorer is doing it.

Happy Coding.
-CJ

Microsoft Graph spanning on-prem and online!

One of the most interesting announcements, at least in my mind, this week from Ignite 2016 was the news that Microsoft is adding support for Microsoft Graph API in hybrid deployments.

This means you can call the Microsoft Graph API like you would normally for Office 365 based mailboxes, for example, but have it actually connect with a mailbox that resides in an on-prem exchange server!

Let that sink in for a moment. That is pretty sweet!

Typically, if you have an application that is not deployed behind the firewall, i.e. inside the orgnaizations network, you couldnt call things like SharePoint or Exchange APIs without doing network gymnastics like VPN, reverse proxy or putting holes in your firewall (yuk).

Now with this hybrid support in the graph you can simply call internet based REST APIs and Microsoft is doing the work of facilitating that communication back to the on-prem resource.

Currently in Preview the graph only supports Mail, Calendar and Contacts in this hybrid configuration right now, however I can only imagine that more support for other endpoints like Users, SharePoint etc… will come at some point.

You also have to have Exchange 2016 CU3 servers deployed on-prem to get this support and sync your AD to Azure AD as authentication is managed this way.

You can read more about these re-reqs here: http://graph.microsoft.io/en-us/docs/overview/hybrid_rest_support

I think this is a huge benefit for those who are looking to build applications or cloud services that connect to data wherever that sits.

Couple of interesting scenarios to think about:

  • Mobile app that works outside the firewall was either not possible or too hard due to connectivity issues.
  • Cloud service web apps that you want to connect to on-prem data
  • Tools and Apps that can now work with data either in Office 365 or on-prem

 

This to me is a huge step in the right direction for Microsoft in their quest to make developers lives better in a hybrid world.

Hybrid is not a transitional state. For many it’s the end state. 
John Ross and Randy Drisgill

I’m looking forward to more endpoints coming online in the months ahead!

-CJ

So long Windows Phone, hello more cross plat!

My Trips user:  The My Trips Live Tile doesn’t work on Windows 10 Mobile
Me: Strange let me look into it.
MS: Yes, you are hitting a bug in Win 10 Mobile for older phone apps
Me: When are you going to fix it?
MS:  Never, please rewrite your apps to work around it.

This was a recent exchange I had regarding a problem with My Trips live tile.  It’s a painful problem for my ardent users of My Trips, many of whom have been using it since I first brought it out for Windows Phone 7 many years ago.

It’s an interesting predicament for me. I appreciate the users of My Trips, but I don’t appreciate being told I need to rewrite part of the app to use new APIs to work around this bug.  Microsoft has always been very focused on backwards compatibility and this flies in the face of that.  Sure, my app code is old.  I wrote it with C# and XAML but back when Windows Phone used a Silverlight app model … so it is not a more modern Windows universal app.

What ticks me off is I have supported the platform for years and created a reasonably popular app that filled one of the app gaps in their ecosystem. You would think that given the widening app gap that MS would bend over backwards to ensure app developers were sticking on the platform.  It seems not. It sounds like there are very few apps hitting this bug and for that reason they are not going to fix it. Although this irritates me, im sure it irritates and frustrates the users more.

For me the equation is pretty simple.  Time to update the app vs. return, and to be honest it doesn’t make sense given the time I would need to put in to change this code.

Side note for those interested on the code changes needed: It’s not a couple of lines of code to change, it’s quite a bit.  It’s changing how the app generates tiles and how it registers for push notifications from Microsoft.

But I am conflicted. Because I know there are still die hard Windows 10 mobile fans out there that will not like me for abandoning the app. That pains me.

I have wanted to update My Trips for Windows 10 (for desktops, tablets etc…) for a while and I would much rather put effort into that. Now that Xamarin is in the MS family and I could quite easily target a version for iOS and Android at the same time whilst sharing 80% of the code.

Now that Xamarin is in the MS family and I could quite easily target a version for iOS and Android at the same time whilst sharing 80% of the code.

So with all this said I am pretty sure I am leaving the My Trips mobile code alone to wither and die.  It’s been a great ride.  I have wanted to bring it to iOS for a long time, especially since I’m an iOS user these days and I have had a bunch of requests for it.  So hopefully I can get that done and keep My Trips an app with a future.

 

-CJ

Running apps using Docker Cloud (aka Tutum)

Anyone who has listen to me rant on about how interesting Docker is on the Microsoft Cloud Show may have caught me talking about Tutum.  

imageThe short story on Tutum is that it provides an easy to use management application over Virtual Machines that you want to run your apps on with Docker.  It is (sort of) cloud provider agnostic in that it supports Amazon Web Services, Microsoft Azure and Digital Ocean among others.

It was bought by Docker late last year and recently was recently re-released as Docker Cloud

What does it provide?

At a high level you still pay for your VMs wherever you host them, but Docker Cloud provides you management of them for 2c an hour (after your first free node) no matter how big or small they are.   You write your code, package it in a Docker Image as per usual and then use Docker Cloud to deploy containers based on those docker images to your Docker nodes. You can do this manually or have it triggered when you push your image to somewhere like Docker Hub as part of a continuous integration set up.

Once you have deployed your app (“Services” in Docker Cloud terminology) you can use it to monitor them, scale them, check logs, redeploy a newer version or turn them off etc…  They provide an easy to use Web App, REST APIs and a Command Line Interface (CLI).

So how easy is it really?

Getting going …

The first thing you have to do is connect to your cloud provider like Azure.  For Azure this means downloading a certificate from Docker Cloud and uploading it into your Azure subscription.  This lets Docker Cloud use the Azure APIs to manage things in your subscription for you. (details here)

Once you have done that you can start deploying Virtual Machines, “Nodes” in Docker Cloud terminology.  Below I’m creating a 2 node cluster of A2 size in the West US region of Azure. 

image

That’s it.  Click “Launch node cluster” wait a few mins (ok quite a few) and you have a functional Docker cluster up and running in Azure.

image

In Azure you can take a look at what Docker Cloud has created for you.  Note that as of the time of writing that Docker Cloud is provisioning “Classic” style VMs in Azure and not using the newer ARM model.  They also deploy different VMs into their own cloud services and resource groups which isn’t good for production.  That said, Docker Cloud let you Bring Your Own Node (BYON) which lets you provision the VMs however you like, install the Docker Cloud agent on them and then register them in Docker Cloud.  Using this you can deploy your VMs using ARM in Azure and configure them however you like.

image

Deploy stuff …

Now you have a node or two ready you can start deploying your apps to them!  Before you do this you obviously need to write your app … or use something simple like a pre-canned demo Docker Image to test things out.

Docker Cloud makes this really simple through “Services”.  You create a new service, tell it where it should pull the Docker Image from and a few other configuration options like Ports to map etc… Then Create and your containers will be deployed to your nodes.

Try this once you have your nodes up and running.  Click Services in the top nav,  then Create Service. Under Jumpstarts & Miscellaneous category you should see the “dockercloud/hello-world” image. Select it and then set it up like this:

image

There are only a two things I changed from the default setup.

  1. I moved the slider to 2 in order to deploy 2 containers
  2. Mapped Port 80 of the container to Port 80 of the node and clicked Published.  This maps port 80 of the VM to port 80 of the container running on it so that we can hit it with a web browser.
  3. High availability in the deployment strategy.  This will ensure that the containers are spread across available nodes vs. both on one.

Click “Create and deploy” and you should see your containers starting up.   Pretty simple huh!

image

Note: There is obviously a lot more available via configuration for things like environment variables and volume management for data that you will eventually need to learn about as you develop and deploy apps using Docker.

Once your containers are deployed you will see them move to the running state:

image

Now you have two hello world containers running on your nodes.  If you go back to your list of Nodes you should see 1 container running on each:

image

I want to see the good man!

You can test your hello world app out by hitting its endpoint.  You can find out what that is under the Service you created in the Endpoints information.

image

  1. This is the service endpoint.  It will use DNS round robin to direct requests between your two running containers.
  2. These are the individual endpoints for each container.  You can hit each one independently.

Try it out!  Open the URL provided in a browser and you should see something like this:

image

Note that #1 will indicate what container you are hitting.

Want more containers?  Go into your Service and move the slider and hit apply.

image

You will get an error like this:

image

This is because we mapped port 80 of the Node to the Container and you can only do that mapping once per Node/VM. i.e. two containers cant both be listening on port 80.  So unless you use a HAProxy or similar to load balance your containers you will be limited to one container on each node mapped to port 80.  I might write up another post about how to do this better using HAProxy.

Automate all the things …

We are a small company and we want to automate things as much as possible to reduce the manual effort required for mundane tasks.  We have opted to use Docker Cloud for helping us deploy containers to Azure as part of our continuous integration and continuous deployment pipeline.

In a nutshell when a developer commits code it goes through the following pipeline and automatically is deployed to our staging environment:

  1. Code is committed to GitHub
  2. Travis-CI.com is notified and it pulls the code and builds it.  Once built it creates a Docker Image and pushes it to Docker Hub.
  3. Docker Cloud is triggered by a new image.  It picks it up and redeploys that Service using the new version of the image.

This way a few minutes after a developers commits code the app has been built and deployed seamlessly into Azure for us.  We have a Big Dev Ops Flashing Thing hanging on the wall telling us how the build is going.

Cool … what else …

At Hyperfish we have been using Tutum for a while during its preview period with what I think is great success.  Sure, there have been issues during the preview, but on the whole I think it has saved us a TON of time and effort setting up and configuring docker environments.  Hell I am a developer kinda guy, not much of a infrastructure one and I managed to get it working easily which I think is really saying something 🙂

Is this how you will run production?

Not 100% sure to be honest.  It is certainly a fantastic tool that helps you run your apps easily and quickly.  But there is a nagging sensation in the back of my head that it is yet another service dependency that will have its share of downtime and issues and that might complicate things.  But I guess you could say that about any additional bit of technology you introduce and take a dependency on. That said, traffic to and from your apps is not going through Docker Cloud, traffic goes direct to your nodes in Azure so if they have brief downtime your app should continue to run just fine.

I have said that for the size we currently are and with the team focusing on building product that we might consider something else only once we can do a better job that it does for us.

We might consider something else only once we can do a better job that it does for us.

All in all I think Docker Cloud has a lot of great things to offer.   It will be interesting to compare and contrast these with the likes of Azure’s new service, Azure Container Service (ACS) as it matures and approaches General Availability.  It’s definitely something we will look at also.

-CJ