Index

1. Homewok N3
2. Homewok N4
3. Homewok N5
4. Homewok N6
5. Homewok N7
6. Homewok N8
7. Homewok N9
8. Homewok N10
9. Homewok N11

Homework N3

Log in via command line

To log in to someinternalhost from working device via command line use the following command:

ssh -i ~/.ssh/appuser -A [email protected] -t ssh [email protected]

Log in via alias

To log in to someinternalhost from working device via alias

ssh someinternalhost

add to the file ~/.ssh/config the following configuration:

Host someinternalhost
	HostName 10.164.0.2
	User appuser
	IdentityFile ~/.ssh/appuser.pub
	ProxyCommand ssh -q -W %h:%p [email protected]

Data for bot connection

bastion_IP = 35.210.86.252 someinternalhost_IP = 10.164.0.2

Homework N4

Data for bot connection.

testapp_IP = 35.195.75.124 testapp_port = 9292

VM instance auto-deployment script. Option with local startup script file.

gcloud compute instances create reddit-app\
  --boot-disk-size=10GB \
  --image-family ubuntu-1604-lts \
  --image-project=ubuntu-os-cloud \
  --machine-type=g1-small \
  --tags puma-server \
  --restart-on-failure \
  --zone=europe-west1-b \
  --metadata-from-file startup-script=startup_script.sh

VM instance auto-deployment script. Option with script file located at GCP bucket.

gcloud compute instances create reddit-app\
  --boot-disk-size=10GB \
  --image-family ubuntu-1604-lts \
  --image-project=ubuntu-os-cloud \
  --machine-type=g1-small \
  --tags puma-server \
  --restart-on-failure \
  --zone=europe-west1-b \
  --metadata=startup-script-url='gs://otus-apas/startup_script.sh'

Firewall rule auto-deployment script.

gcloud compute firewall-rules create default-puma-server \
  --target-tags=puma-server \
  --source-ranges="0.0.0.0/0" \
  --allow tcp:9292 \
  --description="Allow from any to Puma-server"

Homework N5

This homework was devoted to the study of the Packer utility as a tool for creating images of virtual machines.

We made two teplates for fast images creation: packer/ubuntu16.json and packer/immutable.json. First template is used to implement "Fry" apporoach while second demonstated the "Bake" method. To use them first rename variables.json.exapmle to variables.json and make the appropriate variables change.

Then run the Packer tool like:

packer build -var-file=variables.json ubuntu16.json

or

packer build -var-file=variables.json immutable.json

File packer/config-scripts/create-reddit-vm.sh includes the example of usage of previously prepared Packer "bake" image to create virtual machine running Reddit application.

Homework N6

We developed basic parametrized Terraform configuration for Reddit application deployment from Packer base image. Examples of input variables can be found in terraform/terraform.tfvars.example.

To apply the configuration to GCP use and deplot the Reddit application:

cd terratorm
mv terraform.tfvars.example terraform.tfvars
terraform init
terraform plan
teffaform apply

Running application can we found at: http://app_external_ip:9292 The app_external_ip is the output variable of Terraform configuration.

Extra task1

Several public ssh keys were added to the project level. NOTE: In case of Terraform usage you can't mix manually added and Terraform applied ssh-keys. Terraform will delete any of manually added keys.

Extra task2

HTTP Load ballancer was added to Terraform configuration. Reddit application can be deployed in any number of instances with vm_instances_number variable. Running application can we found at: http://lb_external_ip The lb_external_ip is the IP-address of load balance, it is output variable of Terraform configuration.

Homework N7

This homework was devoted to decomposition of complex terraform configurations and code reuse.

• We learned how to import existing and running platfrom componets into terraform configuration with terraform init command.
• Examineted explicit and implicit resorces relationship in terraform configuration.
• Tried a simple way of decomposition of terraform configuration when one large file is splited into several smaller according to the logical entities.
• The we learned the advanced way of decompostion - terraform modules. They make terrafrom configuration easy to read and allow code reusage.
• And at the end we tested the official HashiCorp Terraform Register which includes code of terraform modules writen by other people.

Terraform module app

Parameter fw_app_port added which specifies the tcp port number wich will be opened at VCP firewall for the application access

Terraform module vcp

Parameter source_rangers added to specify the IP addresses which are allowed to connect to ssh port of any VM instance.

Output terraform variables

• app_external_ip - shows extarnal nat IP-address of app instance
• db_external_ip - shows extarnal nat IP-address of db instance
• vpc_source_ip_ranges - shows allowed IP-addresses for ssh connection to app and db instances.

New Packer images

packer/app.json and packer/db.json - two new templates which are used now instead of common ubuntu16.json

Current terraform configuratoins

• terraform/stage/main.tf - parametrized configuration with own variables for stage deployment
• terraform/prod/main.tf - parametrized configuration with own variables for prod deployment
• terraform/storage-bucket.tf - example of usage of terraform-google-storage-bucket HashiCorp module

Extra task 1

We moved stage and prod terrafrom backend from local disk to GCS buket. It allows us to store terraform state-file safely and makes available team-work with the same terraform configuration. Configuration is described in backend.tf files. official doc

Homework N8

First steps with Ansible automation tool.

• We installed Ansible tool with all necessary dependences.
• Configured Ansible to allow it to interract with our VM instances at GCP.
• We learned about different Ansible inventory formats: ini, yaml and dynamic.
• We tried to use Ansible modules: ping, command, shell, systemd, service, git.
• Finaly we wrote very basic Ansible playbook.

Usage of playbooks

ansible-playbook ansible/clone.yml

The Ansible will check if required changes are already made or not. If Ansible makes any changes on remote host then result message will include ok=2 changed=1, otherwise the output will be just ok=2.

Extra task

ansible all -i get-dynamic-inventory.sh -m ping

The following command will apply the dynamic configuration. Executable script git-dynamic-inventory.sh with --list argument will provide the JSON-structure with VM instances of Ansible tool. official doc

Homework N9

A continuation of work with Ansible automation tool. We implemented 3 version of the same task.

• Single playbook with single play ansible/reddit_app_one_play.yml
• Single playbook with 3 plays ansible/reddit_app_multiple_plays.yml
• 3 playbooks united with one main playbook ansible/site.yml
• In addition we updated packer provisioners with 2 playbooks ansible/packer_app.yml and ansible/packer_db.yml

To deploy Reddit-app in updated envitonment do the following.

First build new images:

packer build -var-file=packer/variables.json packer/db.json packer build -var-file=packer/variables.json packer/app.json

Then deploy stage environment in terrafrom:

cd terraform/stage terraform destroy terraform apply

Update app and db servers IPs at ansible/inventory and at last apply ansible playbook:

ansible-playbook -i ansible/inventory ansible/site.yml

Homework N10

Archiving more advanced stage of Ansible tool usage

• We created 2 Ansible roles by using ansible-galaxy utility, one for db server, another for app server.
• We made 2 independent environment for stage (default) and prod. Every environment has own set of variables but still using the same common roles: app and db.
• We uses Ansible Community role jdauphant.nginx to create reverse proxy for our application.
• Finaly we tested Ansible Vault feature to safely secrets of our project.

To deploy application in stage environment do the following:

From the dirrectory terraform/stage

terraform init terraform get terraform apply

From the dirrectory ansible

copy ip addresses of app and db servers to ansible/environment/stage/inventory ansible-playbook playbooks/site.yml

To deploy application in prod environment do the following:

From the dirrectory terraform/prod

terraform init terraform get terraform apply

From the dirrectory ansible

copy ip addresses of app and db servers to ansible/environment/prod/inventory ansible-playbook -i environments/prod/inventory playbooks/site.yml

Homework N11

Using of Vagrant to local development and using of Molecule for writing tests for Ansible roles.

• Vagrant can be used to deploy VMs localy without usage of real cloud.
• Vagrant VMs can be provisioned with Anslible roles.
• Ansible roles can be tested inside Vagrant with Molecule python package.

To run Vagrant test environment use

cd ansible vagrant up

To test DB role with Molecula test do the following

cd ansible/roles/db molecula create molecula verify