Explicit documentation for configuring custom DNS servers in ACI.

[rakesh08]

When ACI is deployed to an existing vnet and the vnet is configured with custom DNS server, ACI will not inherent the custom DNS servers. And to configure ACI with custom DNS servers, the only option i see is to deploy the ACI through yaml file and not via cli or portal. Specify the DNS sever in specification of dnsConfig like below.

Configuring ACI with custom DNS servers, can this be documented?

Reference: microsoftfeedback/aci-issues#25

Below are the inhouse steps to deploy an ACI in an existing vnet with custom DNS servers.

a. Below yaml file, to deploy an ACI with nginx image in an existing vnet using network profile and configure custom DNS servers.

~$ cat aci-deploy01.yaml
apiVersion: 2018-10-01
location: eastus
name: test-aci01
properties:
containers:

• name: nginx01
  properties:
  image: nginx
  resources:
  requests:
  cpu: 1
  memoryInGb: 1.5
  ports:
  • port: 80
    dnsConfig:
    nameServers:
  • 8.8.8.8
    searchDomains: cluster.local svc.cluster.local
    options: ndots:2
    osType: Linux
    networkProfile:
    id: /subscriptions//resourceGroups//providers/Microsoft.Network/networkProfiles/

b. Below is the command to deploy the ACI.

az container create --resource-group aci-rg01 --file aci-deploy01.yaml

c. Verify the DNS servers in above deployed nginx ACI.

az container exec --name test-aci01 --resource-group aci-rg01 --exec-command /bin/bash
0067055fbf4e4ac29171957539d2864b-13f8519aaa3d1c0b9b3af1:/# cat /etc/resolv.conf
nameserver 8.8.8.8
search cluster.local svc.cluster.local
options ndots:2

References:
https://docs.microsoft.com/en-us/azure/container-instances/container-instances-multi-container-yaml#configure-a-yaml-file
https://docs.microsoft.com/en-us/azure/container-instances/container-instances-vnet#example---yaml
https://docs.microsoft.com/en-us/azure/container-instances/container-instances-reference-yaml

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Document Details

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• ID: 81e00caf-dd95-441b-d2d5-0b3c979cb11b
• Version Independent ID: 83ed8e59-7ae8-332e-9ce0-7d80e8a973f8
• Content: Deploy container group to Azure virtual network - Azure Container Instances
• Content Source: articles/container-instances/container-instances-vnet.md
• Service: container-instances
• GitHub Login: @dlepow
• Microsoft Alias: danlep

[VikasPullagura-MSFT]

@rakesh08
Thanks for the feedback! I have assigned the issue to content author to check and update the document as appropriate.

[VikasPullagura-MSFT]

@dlepow
Can you please check and add your comments on this doc update request as applicable.

[dlepow]

Reassigning doc ownership
#reassign: @macolso

[macolso]

hi @rakesh08, this is intended behavior for ACI today. We are happy to take a feature request for this process to be automated by ACI once the container is associated with a particular subnet.

[VikasPullagura-MSFT]

@rakesh08 You can add the feature request here.

[Pete-rePete]

@VikasPullagura-MSFT @macolso I think the issue isn't regarding the intended behaviour, Rakesh is asking for the intended behaviour to be documented explicitly? The best we have is this which is hard to follow because there is no concrete example

Separately it could be nice to make a feature request to add DNS nameServer via Azure CLI when doing a az container create without needing the yaml, but that's not the scope of this issue