Implement 'cargo func deploy' Command

[t-eckert]

I know you've had thoughts towards this, @peterhuene. Just wanted a bucket to drop my research into.

[t-eckert]

Research for Adding cargo func deploy Command

Context

Azure Function runtimes allow for a command-line based approach to publishing the locally run function app into Azure. It would be beneficial to mirror that approach with a tool leveraging cargo. Currently the cargo func command is used to create function apps and add functions to that app.

Current User Story: Deploying a Function App to Azure

Requirements

• All requirements for building the Rust Function App must be met (for development purposes)
• Docker 18.06+ with BuildKit support

Deployment Story

(From README as of 22 March 2019)

Build the image using Docker

docker build -t $TAG_NAME .

$TAG_NAME can be, for example, username/my-functions-app.

Use docker push to push the image to a repository accessible by Azure Functions.

docker push $TAG_NAME

Create a Linux Azure Function App. Publish with "Docker Image".
From the "Configure Container" section, select the repo and enter the image pushed.

Pure Command Line Implementation

We can leverage the Azure CLI to better programmatize this task. (Programmatizing (what a word...) on the path to automation)

Should a dependency on the CLI be used? What is the cost of adding this dependency? Are there RESTful ways of doing this that we can hook into and not add dependencies?

The CLI can be downloaded here.
(The CLI can also be run using a Docker container.)

Using the CLI, the commands can be issued:

Create a Resource Group. This is where your container registry and function app will be deployed.

az group create --name resourceGroupName --location eastus

Create a Container Registry.

az acr create --resource-group resourceGroupName --name containerRegistryName --sku Basic

Log into the registry

az acr login --name containerRegistryName

Build the image (with the tag including the acr name? I don't fully understand this part... Not great at Docker yet)

docker build -t $TAG_NAME .

Push the image to the registry

docker push $TAG_NAME

Create an Azure Storage Account

az storage account create --name storageName --location westeurope --resource-group resourceGroupName

Create a Linux App Service Plan. Currently, Azure Functions running Docker images on Linux doesn't support consumption plans :(.

az appservice plan create --name myAppServicePlan --resource-group resourceGroupName --sku B1 --is-linux

Deploy your image. (I need to test this... How do I make sure it is connected to the ACR? This is pulled from a reference that uses Docker Hub. Should we just use Docker Hub for this? What are the security implications?)

az functionapp create --name <app_name> --storage-account  <storage_name>  --resource-group resourceGroupName \
--plan myAppServicePlan --deployment-container-image-name $TAG_NAME

Configure the function app

storageConnectionString=$(az storage account show-connection-string \
--resource-group resourceGroupName --name <storage_name> \
--query connectionString --output tsv)

az functionapp config appsettings set --name <app_name> \
--resource-group resourceGroupName \
--settings AzureWebJobsDashboard=$storageConnectionString \
AzureWebJobsStorage=$storageConnectionString

[peterhuene]

Thanks for this, @t-eckert! 😄