anujmodi1/appd-machine-agent-installation

This solution is an example of how to get started with monitoring and observability using AppDynamics's Machine Agent.

Automated deployment of virtual machines and AppDynamics Machine Agent

This solution is an example of how to get started with monitoring and observability using AppDynamics's Machine Agent. The example details how to use Terraform to deploy 5 virtual machines in vSphere followed by the installation of Apache and the AppDynamics Machine Agent using Ansible. After Terraform provisions the virtual machines, a provisioner within Terraform calls the Ansible playbook which installs Apache, Docker, and the AppDynamics Machine Agent.

The main objective is to get you started with monitoring your infrastructure by showing you an automated way of getting the AppDynamics agent installed so that you have observability baked into your environment from the onset. We first start with the use case of monitoring virtual machines with follow-on use cases showing how Kubernetes clusters, databases, and applications are brought into the fold to ultimately provide a full-stack view of your operations in real time.

Requirements

Here is a list of dependencies to make this work in your environment:

• vSphere 6.7 or higher
• Terraform v0.15.2 or higher
• Ansible 2.10.2
• AppDynamics controller instance along with its credentials
• A virtual machine template with CentOS 8.2 installed as the guest OS

Credentials

We purposely did not add credentials and other sensitive information to the repo by including them in the .gitignore file. As such, if you clone this repo, you will need to create two files. The first file named secret.tfvars contains sensitive Terraform variables. The second file named variables.yml is used by Ansible. In this scenario, we encrypted variables.yml using the command ansible-vault command and decrypt it as needed locally. You could take the same approach or leave the file unencrypted if you are confident it won't be shared or inadvertently uploaded to a repo.

Here is a list of variables you'll need to include and define for each file

• secret.tfvars in HCL format (file is in the same directory as the terraform.tfvars file):
  • vsphere_user
  • vsphere_password
  • vsphere_server (the IP address or FQDN)
  • vsphere_vm_firmware (default is vsphere_vm_firmware = bios)
  • ssh-pub-key (an SSH key used with a service account that allows Ansible to connect over SSH)
  • service_account_username
  • service_account_password
• variables.yml (written in YAML) file:
  • CONTROLLER_HOST (the URI of the AppDynamics Controller)
  • CONTROLLER_PORT (typically 443)
  • ACCOUNT_NAME (AppDynamics Account Name)
  • MACHINE_PATH (This is a heirarchy separated with a |. For example: San Jose|Rack1|)
  • ACCOUNT_ACCESS_KEY (this value is available in the AppDynamics Controller)
  • APPD_BEARER_TOKEN (this is the token derived from the available image download via cURL)

What Terraform Provisions

In this example, Terraform uses the vsphere provider and a vsphere_virtual_machine resource to:

• Create 5 virtual machines from virtual machine template
• Add the SSH key of a service account to each host
• Run an Ansible playbook that performs the steps in the next section

What Ansible Installs and Configures

After Terraform creates 5 virtual machines, the Ansible playbook installs and configures:

• Apache Web Server
• Firewall with port 80 opened
• Docker
• DNS (resolv.conf is configured)
• AppDynamics Machine Agent

Each Apache Web Server is configured with a custom (using a Jinja template) index.html page that displays the hostname.

The same approach is taken with the AppDynamics Machine Agent. In other words, a Jinja template creates a custom file for each containing the hostname.

Creating and Applying the Terraform Plan

Here are the steps needed to run Terraform along with examples of each:

1. Initialize Terraform:

terraform init -var-file="secret.tfvars"

2. Create a Terraform Plan:

terraform plan -out appd-machine-agent-installation.tfplan -var-file="secret.tfvars"

3. Apply the Terraform Plan:

terraform apply -var-file="secret.tfvars"

Each of these commands includes the secret.tfvars containing the sensitive variables needed to connect to the different resources as described in the previous section.

Results

You will see 5 virtual machines created with static IP addresses in vSphere, each running an Apache Web Server, and all 5 appearing in the AppDynamics controller.