provider/azurerm: Add example of Spark and Cassrandra on CentOS (#15123)

* initial commit - 101-vm-from-user-image

* changed branch name

* not deploying - storage problems

* provisions vm but image not properly prepared

* storage not correct

* provisions properly

* changed main.tf to azuredeploy.tf

* added tfvars and info for README

* tfvars ignored and corrected file ext

* added CI config; added sane defaults for variables; updated deployment script, added mac specific deployment for local testing

* deploy.sh to be executable

* executable deploy files

* added CI files; changed vars

* prep for PR

* removal of old folder

* prep for PR

* wrong args for travis

* more PR prep

* updated README

* commented out variables in terraform.tfvars

* Topic 101 vm from user image (#2)

* initial commit - 101-vm-from-user-image
* added tfvars and info for README
* added CI config; added sane defaults for variables; updated deployment script, added mac specific deployment for local testing
* prep for PR

* added new template

* oops, left off master

* prep for PR

* correct repository for destination

* renamed scripts to be more intuitive; added check for docker

* merge vm simple; vm from image

* initial commit

* deploys locally

* updated deploy

* consolidated deploy and after_deploy into a single script; simplified ci process; added os_profile_linux_config

* added terraform show

* changed to allow http & https (like ARM tmplt)

* changed host_name & host_name variable desc

* added az cli check

* on this branch, only build test_dir; master will aggregate all the examples

* merge master

* added new constructs/naming for deploy scripts, etc.

* suppress az login output

* suppress az login output

* forgot about line breaks

* breaking build as an example

* fixing broken build example

* merge of CI config

* fixed grammar in readme

* prep for PR

* took out armviz button and minor README changes

* changed host_name

* fixed merge conflicts

* changed host_name variable

* updating Hashicorp's changes to merged simple linux branch

* updating files to merge w/master and prep for Hashicorp pr

* Revert "updating files to merge w/master and prep for Hashicorp pr"

This reverts commit b850cd5d2a858eff073fc5a1097a6813d0f8b362.

* Revert "updating Hashicorp's changes to merged simple linux branch"

This reverts commit dbaf8d14a9cdfcef0281919671357f6171ebd4e6.

* removing vm from user image example from this branch

* removed old branch

* azure-2-vms-loadbalancer-lbrules (#13)

* initial commit

* need to change lb_rule & nic

* deploys locally

* updated README

* updated travis and deploy scripts for Hari's repo

* renamed deploy script

* clean up

* prep for PR

* updated readme

* fixing conflict in .travis.yml

* initial commit; in progress

* in progress

* in progress; encryption fails

* in progress

* deploys successfully locally

* clean up; deploy typo fixed

* merging hashi master into this branch

* troubleshooting deploy

* added missing vars to deploy script

* updated README, outputs, and added graph

* simplified outputs

* provisions locally

* cleaned up vars

* fixed chart on README

* prepping for pr

* fixed merge conflict

* switching to Hashicorp's .travis.yml

* edited comments

* removed graph

* reverting travis.yml to original

added return line at 45

examples/spark-and-cassandra-on-centos/README.md

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+# Spark & Cassandra on CentOS 7.x
+
+This Terraform template was based on [this](https://github.com/Azure/azure-quickstart-templates/tree/master/spark-and-cassandra-on-centos) Azure Quickstart Template. Changes to the ARM template that may have occurred since the creation of this example may not be reflected here.
+
+This project configures a Spark cluster (1 master and n-slave nodes) and a single node Cassandra on Azure using CentOS 7.x.  The base image starts with CentOS 7.3, and it is updated to the latest version as part of the provisioning steps.
+
+Please note that [Azure Resource Manager][3] is used to provision the environment.
+
+### Software ###
+
+| Category | Software | Version | Notes |
+| --- | --- | --- | --- |
+| Operating System | CentOS | 7.x | Based on CentOS 7.1 but it will be auto upgraded to the lastest point release |
+| Java | OpenJDK | 1.8.0 | Installed on all servers |
+| Spark | Spark | 1.6.0 with Hadoop 2.6 | The installation contains libraries needed for Hadoop 2.6 |
+| Cassandra | Cassandra | 3.2 | Installed through DataStax's YUM repository |
+
+
+### Defaults ###
+
+| Component | Setting | Default | Notes |
+| --- | --- | --- | --- |
+| Spark - Master | VM Size | Standard D1 V2 | |
+| Spark - Master | Storage | Standard LRS | |
+| Spark - Master | Internal IP | 10.0.0.5 | |
+| Spark - Master | Service User Account | spark | Password-less access |
+| | | |
+| Spark - Slave | VM Size | Standard D3 V2 | |
+| Spark - Slave | Storage | Standard LRS | |
+| Spark - Slave | Internal IP Range | 10.0.1.5 - 10.0.1.255 | |
+| Spark - Slave | # of Nodes | 2 | Maximum of 200 |
+| Spark - Slave | Availability | 2 fault domains, 5 update domains | |
+| Spark - Slave | Service User Account | spark | Password-less access |
+| | | |
+| Cassandra | VM Size | Standard D3 V2 | |
+| Cassandra | Storage | Standard LRS | |
+| Cassandra | Internal IP | 10.2.0.5 | |
+| Cassandra | Service User Account | cassandra | Password-less access |
+
+## Prerequisites
+
+1.  Ensure you have an Azure subscription.  
+2.  Ensure you have enough available vCPU cores on your subscription.  Otherwise, you will receive an error during the process.  The number of cores can be increased through a support ticket in Azure Portal.
+
+## main.tf
+The `main.tf` file contains the actual resources that will be deployed. It also contains the Azure Resource Group definition and any defined variables.
+
+## outputs.tf
+This data is outputted when `terraform apply` is called, and can be queried using the `terraform output` command.
+
+## provider.tf
+Azure requires that an application is added to Azure Active Directory to generate the `client_id`, `client_secret`, and `tenant_id` needed by Terraform (`subscription_id` can be recovered from your Azure account details). Please go [here](https://www.terraform.io/docs/providers/azurerm/) for full instructions on how to create this to populate your `provider.tf` file.
+
+## terraform.tfvars
+If a `terraform.tfvars` file is present in the current directory, Terraform automatically loads it to populate variables. We don't recommend saving usernames and password to version control, but you can create a local secret variables file and use `-var-file` to load it.
+
+If you are committing this template to source control, please insure that you add this file to your `.gitignore` file.
+
+## variables.tf
+The `variables.tf` file contains all of the input parameters that the user can specify when deploying this Terraform template.
+
+## Post-Deployment
+
+1. All servers will have a public IP and SSH port enabled by default. These can be disabled or modified in the template or by using Azure Portal.
+2. All servers are configured with the same username and password. You may SSH into each server and ensure connectivity.
+3. Spark WebUI is running on **port 8080**.  Access it using MASTER_WEB_UI_PUBLIC_IP:8080 on your browser.  Public IP is available in the outputs as well as through Azure Portal.
+4. Delete the Resource Group that was created to stage the provisioning scripts.

examples/spark-and-cassandra-on-centos/deploy.ci.sh

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+#!/bin/bash
+
+set -o errexit -o nounset
+
+docker run --rm -it \
+  -e ARM_CLIENT_ID \
+  -e ARM_CLIENT_SECRET \
+  -e ARM_SUBSCRIPTION_ID \
+  -e ARM_TENANT_ID \
+  -v $(pwd):/data \
+  --workdir=/data \
+  --entrypoint "/bin/sh" \
+  hashicorp/terraform:light \
+  -c "/bin/terraform get; \
+      /bin/terraform validate; \
+      /bin/terraform plan -out=out.tfplan \
+        -var resource_group=$KEY \
+        -var unique_prefix=$KEY \
+        -var vm_admin_username=$KEY \
+        -var vm_admin_password=$PASSWORD; \
+      /bin/terraform apply out.tfplan"
+
+# cleanup deployed azure resources via azure-cli
+docker run --rm -it \
+  azuresdk/azure-cli-python \
+  sh -c "az login --service-principal -u $ARM_CLIENT_ID -p $ARM_CLIENT_SECRET --tenant $ARM_TENANT_ID > /dev/null; \
+         az vm list -g $KEY"
+
+# cleanup deployed azure resources via terraform
+docker run --rm -it \
+  -e ARM_CLIENT_ID \
+  -e ARM_CLIENT_SECRET \
+  -e ARM_SUBSCRIPTION_ID \
+  -e ARM_TENANT_ID \
+  -v $(pwd):/data \
+  --workdir=/data \
+  --entrypoint "/bin/sh" \
+  hashicorp/terraform:light \
+  -c "/bin/terraform destroy -force \
+     -var resource_group=$KEY \
+     -var unique_prefix=$KEY \
+     -var vm_admin_username=$KEY \
+     -var vm_admin_password=$PASSWORD;"

examples/spark-and-cassandra-on-centos/deploy.mac.sh

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+#!/bin/bash
+
+set -o errexit -o nounset
+
+if docker -v; then
+
+  # generate a unique string for CI deployment
+  export KEY=$(cat /dev/urandom | env LC_CTYPE=C tr -cd 'a-z' | head -c 12)
+  export PASSWORD=$KEY$(cat /dev/urandom | env LC_CTYPE=C tr -cd 'A-Z' | head -c 2)$(cat /dev/urandom | env LC_CTYPE=C tr -cd '0-9' | head -c 2)
+
+/bin/sh ./deploy.ci.sh
+
+else
+  echo "Docker is used to run terraform commands, please install before run:  https://docs.docker.com/docker-for-mac/install/"
+fi