Merge pull request #102524 from zr-msft/ds-faq-existing-assets

add FAQ entry for existing Dockerfile and Helm charts

Author: GitHubber17

articles/dev-spaces/faq.md

@@ -1,7 +1,7 @@
 ---
 title: "Frequently asked questions about Azure Dev Spaces"
 services: azure-dev-spaces
-ms.date: 09/25/2019
+ms.date: 01/28/2020
 ms.topic: "conceptual"
 description: "Find answers to some of the common questions about Azure Dev Spaces"
 keywords: "Docker, Kubernetes, Azure, AKS, Azure Kubernetes Service, containers, Helm, service mesh, service mesh routing, kubectl, k8s "
@@ -15,17 +15,34 @@ This addresses frequently asked questions about Azure Dev Spaces.
 
 See [supported regions][supported-regions] for a complete list of available regions.
 
+## Can I use Azure Dev Spaces with existing Dockerfiles or Helm charts?
+
+Yes, if your project already has a Dockerfile or a Helm chart, you can use those files with Azure Dev Spaces. When you run `azds prep`, use the `--chart` parameter and specify the location of the chart. Azure Dev Spaces will still generate an *azds.yaml* and *Dockerfile.develop* file, but it will not replace or modify an existing Dockerfile or a Helm chart. You may need to modify the *azds.yaml* and *Dockerfile.develop* files in order for everything to work correctly with your existing application when running `azds up`.
+
+When using your own Dockerfile or Helm chart, there are the following limitations:
+* If using only one Dockerfile, it must include everything you need to enable development scenarios, such as the language SDK not just the runtime. If using a separate Dockerfile for Azure Dev Spaces, such as a Dockerfile.develop, everything you need to enable development scenarios must be included in that Dockerfile.
+* Your Helm chart must support passing part of or the entire image tag as a value from *values.yaml*.
+* If you are modifying anything with ingress, you can also update your Helm chart to use the ingress solution provided by Azure Dev Spaces.
+* If you want to use the [routing capabilities provided by Azure Dev Spaces][dev-spaces-routing], all services for an individual project must fit within a single Kubernetes namespace and must be deployed with simple naming, for example *service-a*. In standard Helm charts, this naming update can be done by specifying a value for the *fullnameOverride* property.
+
+To compare your own Dockerfile or Helm chart to an existing version that works with Azure Dev Spaces, review the files generated in the [quickstart][quickstart-cli].
+
+
+## Can I modify the files generated by Azure Dev Spaces?
+
+Yes, you can modify the *azds.yaml* file, Dockerfile, and Helm chart [generated by Azure Dev Spaces when preparing your project][dev-spaces-prep]. Modifying these files changes how the project is built and run.
+
 ## Can I use Azure Dev Spaces without a public IP address?
 
 No, you can't provision Azure Dev Spaces on an AKS Cluster without a public IP. A public IP is [needed by Azure Dev Spaces for routing][dev-spaces-routing].
 
 ## Can I use my own ingress with Azure Dev Spaces?
 
-Yes, you can configure your own ingress along side the one Azure Dev Spaces creates. For example, you can use [traefik][ingress-traefik].
+Yes, you can configure your own ingress along side the ingress Azure Dev Spaces creates. For example, you can use [traefik][ingress-traefik] or [NGINX][ingress-nginx].
 
 ## Can I use HTTPS with Azure Dev Spaces?
 
-Yes, you can configure your own ingress with HTTPS using [traefik][ingress-https-traefik].
+Yes, you can configure your own ingress with HTTPS using [traefik][ingress-https-traefik] or [NGINX][ingress-https-nginx].
 
 ## Can I use Azure Dev Spaces on a cluster that uses CNI rather than kubenet? 
 
@@ -39,7 +56,7 @@ Currently, Azure Dev Spaces is intended to run on Linux pods and nodes only, but
 
 Yes, you can use Azure Dev Spaces on AKS clusters with [API server authorized IP address ranges][aks-auth-range] enabled. More information on using an AKS clusters with API server authorized IP address ranges enabled with Azure Dev Spaces is available [here](configure-networking.md#using-api-server-authorized-ip-ranges).
 
-### Can I use Azure Dev Spaces on AKS clusters with restricted egress traffic for cluster nodes?
+## Can I use Azure Dev Spaces on AKS clusters with restricted egress traffic for cluster nodes?
 
 Yes, you can use Azure Dev Spaces on AKS clusters with [restricted egress traffic for cluster nodes][aks-restrict-egress-traffic] enabled once the correct FQDNs have been allowed. More information on using an AKS clusters with restricted egress traffic for cluster nodes enabled with Azure Dev Spaces is available [here](configure-networking.md#ingress-and-egress-network-traffic-requirements).
 
@@ -48,8 +65,12 @@ Yes, you can use Azure Dev Spaces on AKS clusters with [restricted egress traffi
 [aks-auth-range-ranges]: https://github.com/Azure/dev-spaces/tree/master/public-ips
 [aks-auth-range-update]: ../aks/api-server-authorized-ip-ranges.md#update-a-clusters-api-server-authorized-ip-ranges
 [aks-restrict-egress-traffic]: ../aks/limit-egress-traffic.md
+[dev-spaces-prep]: how-dev-spaces-works.md#prepare-your-code
 [dev-spaces-routing]: how-dev-spaces-works.md#how-routing-works
+[ingress-nginx]: how-to/ingress-https-nginx.md#configure-a-custom-nginx-ingress-controller
 [ingress-traefik]: how-to/ingress-https-traefik.md#configure-a-custom-traefik-ingress-controller
+[ingress-https-nginx]: how-to/ingress-https-nginx.md#configure-the-nginx-ingress-controller-to-use-https
 [ingress-https-traefik]: how-to/ingress-https-traefik.md#configure-the-traefik-ingress-controller-to-use-https
+[quickstart-cli]: quickstart-cli.md
 [supported-regions]: https://azure.microsoft.com/global-infrastructure/services/?products=kubernetes-service
 [windows-containers]: how-to/run-dev-spaces-windows-containers.md