My app running in a docker container on Azure Webapps for Containers tries to access a connection string through an environment variable. I've added it to the Application Settings in the Azure UI but I can't access it through my code, specifically my ASP.NET Core application is returning null.
I know that the logs won't show it being added as a -e connstring=myconnstring argument in the docker run command, but it should never the less be present in the container.
It turns out, by using the Advanced Tools -> Environment Kudu service in Azure, the connection string environment variable names were being prefixed with SQLAZURECONNSTR_.
I know it is a convention to have these kind of prefixes on environment variables when reading them with the .NET Core environment variable configuration provider as described here, but quite why Azure adds these prefixes automatically, apparently without documenting this behaviour anywhere, is unclear to me.
Related
Is it possible to lookup the application name for an Azure app as it runs, i.e., get the information about that is displayed in the Azure portal? In the example below, I'd want something to tell me from within the application that I am running sitemap-prod-eastus.
I've been looking at the Azure Context object but not seeing what I need. There is an invocation ID, a name for the function, a directory - not the info in this window.
Maybe this can be done through Azure Application Insights?
I am working in Node JS.
I've not seen anything that would expose this to a function app. That said, there is one sort of workaround that you could do which would work - go to the Configuration blade for the function app, Application settings tab, and add a configuration key like function_name and set its value to the name of your app. Your app could then just read it out of configuration.
It's an extra step, but if you're doing it with something like ARM or Terraform, it's just another configuration entry with a variable you already declared to set up the app in the first place.
Answering my own question: Azure provides WEBSITE_SITE_NAME in the runtime environment that matches the name of the function app.
I created an environment variable in Azure App Service. However, I'm not able to pick the value from Azure while it is published.
So I added it to the appsettings.json, and it works.
My question would be, if I add an environment variable in Azure configuration settings, shall I add it in the appsettings.json as well, or is having it in the Azure environment settings enough?
When I navigate to
https://your-web-name.scm.azurewebsites.net/Env.cshtml
I can clearly see the variable is present there. Why is this not being picked up in the code? Am I doing something wrong?
appSettings["MailKitPassword"] <-- This is not being picked up, so I have to hard-code it.
In order to retrieve it you should use Environment.GetEnvironmentVariable("APPSETTING_MailKitPassword")
As Thiago Mentioned, you need to use GetEnvironmentVariable method to retrieve the AppSettings values,
so your code should be
Environment.GetEnvironmentVariable("APPSETTING_MailKitPassword")
However i would recommend you to store the passwords in Azure KeyVault.
I have a docker image being deployed from Azure Container Registry. Everything works fine except that I expect to be able to
see environment variables being passed to my running docker image from the Application Settings configured in the portal. It is a Node app accessing environment variables with process.env.VariableName.
As an example its says here
https://blogs.msdn.microsoft.com/waws/2017/09/08/things-you-should-know-web-apps-and-linux/#SetEnvVar …
"App Settings are injected into your app as environment variables at runtime"
I have tried the following.
Setting Applications Settings in the Azure Portal. These are supposed to get passed to the running Docker image as per the documentation but process.env.VariableName in my Node application is not set.
I have tried using a Docker compose file that sets the environment variables but again process.env.VariableName is empty.
I have even updated the VSTS build arguments passing the Variable to my Docker file on build which in turn sets the environment variable. Again no variable passed to the running Docker image.
My conclusion is that custom environment variables are not allowed in Azure Web App for Containers?
Am I doing something wrong?
As per the documentation the app settings are injected into the process as environment variables, however the environment variable name is prefixed with APPSETTING_, so in your Node application you would need to access the app setting with process.env.APPSETTING_VariableName.
Reading through the azure documentation and various posts on here, i understand there should be a number of settings available to web apps running on azure, among them WEBSITE_HOSTNAMEand WEBSITE_SITE_NAME. These should also overwrite any existing configuration appsettings with same key.
When i attempt to run my app, it is reading the key from the config file (i.e. its not being overwritten by azure). If i remove the value from the config, i get an exception about not being able to pick up a config value.
Is there a step im missing? Are these values only available at certain tiers?
Those values are only available as environment variables, so you'll need to read them from there.
App settings set in the Web App blade override settings and become env variables, but these are just environment variables.
I'm creating a kubernetes cluster, and in it I have several services. I know based on https://github.com/GoogleCloudPlatform/kubernetes/blob/master/docs/services.md#discovering-services I have two options.
use the environment variables set by the kubelet.
use skydns
I want to try to use the environment variables first before I go adding another dependency into the mix. However, I'm unsure where the environment variables are for each service. I haven't found them when doing env or sudo env on the kubelet. Are they within a certain container and/or pod? If so do I have to link the other pods to that one to get its environment variables for services?
I have several NodeJS services in containers, so I'm wondering if talking to each service would require this to get the ip:
process.env('SERVICE_X_PUBLIC_IPV4') once I have the environment variable thing sorted out.
Not as important, but related, how does this all work across multiple nodes?
The environment variables for a given service are put in every container that is started after the service was created.
For example, if you create a pod foo and then later a service bar, the pod's containers won't have any environment variables for bar.
If you instead create service bar and then a pod foo, the pod's containers should have environment variables something like:
BAR_PORT=tcp://10.167.240.1:80
BAR_SERVICE_HOST=10.167.240.1
You can test this out by attaching a terminal to one of your containers, as explained here.