challenge 3

challenge_3/README.md

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+# Challenge 1
+
+## Instructions
+
+A Web application has been reported by a customer as broken and this has been escalated to the team. You're job is to investigate, troubleshoot and resolve the problem, returning the web app to normal service.
+
+You will be provided with an individual url for the site.
+
+[source code](./trubble/trubble.js), [documentation](./trubble/README.md) and [deployment code](./trubble/ansible/deploy.yml) is in the [trubble directory](./trubble/)
+
+1. in advance, please generate a new, unique SSH keypair and send us the **public** key. You may follow [these](https://docs.github.com/en/authentication/connecting-to-github-with-ssh/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent#generating-a-new-ssh-key) instructions.
+
+2. You will recieve a url from us.
+
+3. Using SSH log in to the instance the web app is hosted on (the address is the same as the url the username is `ubuntu`).
+
+4. Document your troubleshooting process while you restore normal operation.
+
+5. Provide a permanent solution or work-around to the issue.
+
+## Solution Submission
+
+Please host your solution as a **private** repository and invite your interviewer as a collaborator.

challenge_3/trubble/.gitignore

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+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+.pnpm-debug.log*
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+*.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# Snowpack dependency directory (https://snowpack.dev/)
+web_modules/
+
+# TypeScript cache
+*.tsbuildinfo
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional stylelint cache
+.stylelintcache
+
+# Microbundle cache
+.rpt2_cache/
+.rts2_cache_cjs/
+.rts2_cache_es/
+.rts2_cache_umd/
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variable files
+.env
+.env.development.local
+.env.test.local
+.env.production.local
+.env.local
+
+# parcel-bundler cache (https://parceljs.org/)
+.cache
+.parcel-cache
+
+# Next.js build output
+.next
+out
+
+# Nuxt.js build / generate output
+.nuxt
+dist
+
+# Gatsby files
+.cache/
+# Comment in the public line in if your project uses Gatsby and not Next.js
+# https://nextjs.org/blog/next-9-1#public-directory-support
+# public
+
+# vuepress build output
+.vuepress/dist
+
+# vuepress v2.x temp and cache directory
+.temp
+.cache
+
+# Docusaurus cache and generated files
+.docusaurus
+
+# Serverless directories
+.serverless/
+
+# FuseBox cache
+.fusebox/
+
+# DynamoDB Local files
+.dynamodb/
+
+# TernJS port file
+.tern-port
+
+# Stores VSCode versions used for testing VSCode extensions
+.vscode-test
+
+# yarn v2
+.yarn/cache
+.yarn/unplugged
+.yarn/build-state.yml
+.yarn/install-state.gz
+.pnp.*
+
+# Local .terraform directories
+**/.terraform/*
+
+# .tfstate files
+*.tfstate
+*.tfstate.*
+
+# Crash log files
+crash.log
+crash.*.log
+
+# Exclude all .tfvars files, which are likely to contain sensitive data, such as
+# password, private keys, and other secrets. These should not be part of version 
+# control as they are data points which are potentially sensitive and subject 
+# to change depending on the environment.
+*.tfvars
+*.tfvars.json
+
+# Ignore override files as they are usually used to override resources locally and so
+# are not checked in
+override.tf
+override.tf.json
+*_override.tf
+*_override.tf.json
+
+# Include override files you do wish to add to version control using negated pattern
+# !example_override.tf
+
+# Include tfplan files to ignore the plan output of command: terraform plan -out=tfplan
+# example: *tfplan*
+
+# Ignore CLI configuration files
+.terraformrc
+terraform.rc
+
+# Ansible retry files
+*.retry
+
+dist

challenge_3/trubble/.node-version

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+14.17.6

challenge_3/trubble/README.md

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+# Trubble
+
+A web application built using Node.js and Express. It serves a simple web page at the root URL. There is only a single route `/` which searches for a random entity from [pokeapi](https://pokeapi.co/) and presents the encounter as plain text.
+
+## Prerequisites
+
+Before running the app, make sure you have the following installed:
+
+- Node.js version 14 (https://nodejs.org/en/download)
+- NPM (Node Package Manager)
+
+## Configuration
+
+The web app can be configured using environment variables. Create a `.env` file in the root directory of the project with the following variables:
+- `NODE_ENV` (optional): The environment the app will run in.
+- `PORT` (optional): The port number the app will listen on. Defaults to `3000`.
+- `IMPORTANT_VALUE` (required): A boolean value that must be set to `true` for the app to run. If this value is not set or is set to anything other than `true`, the app will log an error message and exit.
+
+## Logging
+
+The application will log to an `app.log` file in `logs` directory.
+In production logging will also be handled by systemd and will log to `/var/logs/syslog`. check the below systemd file for details.
+
+## Running the App in Development
+
+To run the app, follow these steps:
+
+1. Install dependencies by running `npm install`.
+2. Start the app by running `npm start`.
+3. Access the app by navigating to `http://localhost:3000` (or whichever port you specified in the `PORT` environment variable).
+
+## Testing
+
+Open a web browser and navigate to `http://localhost:3000/`.
+
+## Building the app for production
+
+1. Install dependencies by running `npm install`.
+2. Build the application with `npm run build`
+
+## Installing the app in Production
+
+Creation of the instance, install and managment of the application is by ansible. the playbook is in the [ansible directory](./ansible/deploy.yml).
+Instructions on how to use the ansible playbook can be found in the [ansible directory](./ansible/README.md).
+Ansible should be used to ensure the application is installed and configured correctly.
+
+The [playbook](./ansible/deploy.yml) reads as the documentation however the install steps can be summarised as:
+
+1. Ensure the App is built in the `dist` directory.
+1. Create a new Linux instance.
+2. Ensure nodejs is installed on the system.
+3. Ensure nginx is installed and configured correctly.
+4. Copy the contents of the local `dist` directory to the remote machine at the `/opt/` directory
+5. Use systemd (example below) to keep the app running
+
+
+## Systemd Unit File
+
+To run the app as a systemd service on Linux, create a file as a root user `/etc/systemd/system/trubble.service` with the following content:
+
+```
+[Unit]
+Description=trubble
+After=network.target
+
+[Service]
+Environment="NODE_ENV=production"
+User=root
+WorkingDirectory=/opt
+ExecStart=/usr/bin/node index.js
+Restart=always
+StandardOutput=syslog
+StandardError=syslog
+SyslogIdentifier=trubble
+
+[Install]
+WantedBy=multi-user.target
+```
+
+Then run the following commands:
+
+```
+sudo systemctl daemon-reload
+sudo systemctl enable trubble
+sudo systemctl start trubble
+```
+
+The app will now start automatically on boot and can be managed using the `systemctl` command.

challenge_3/trubble/ansible/README.md

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+# Deploy Trubble
+
+A playbook to create an AWS EC2 instance and install The trubble nodejs application.
+
+## Prerequisites
+
+- python 3.9+
+- python pip
+
+## Setup
+
+Install dependencies
+
+```
+python3 -m pip install -r requirements.txt
+ansible-galaxy install -f -r requirements.yml
+ansible-galaxy collection install -f -r requirements.yml
+```
+
+Setup AWS credentials
+
+```
+export AWS_ACCESS_KEY_ID="xxxxx"
+export AWS_SECRET_ACCESS_KEY="xxxxx"
+export AWS_SESSION_TOKEN="xxxxx"
+```
+
+To only manage existing running application instances run:
+
+ansible-playbook deploy.yml  --extra-vars='\{"users": \[user1,user2,user3\]\}' --skip-tags='create'
+
+where `users` var is an array of users to create instances for.
+
+Run the full playbook and create a new instance:
+
+```
+ansible-playbook deploy.yml  --extra-vars='\{"users": \[user1,user2,user3\]\}'
+```

challenge_3/trubble/ansible/ansible.cfg

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+
+[defaults]
+ansible_python_interpreter=/usr/bin/python3
+inventory=aws_ec2.yaml
+
+[inventory]
+enable_plugins = aws_ec2

challenge_3/trubble/ansible/aws_ec2.yaml

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+---
+plugin: aws_ec2
+filters:
+  tag:Env: dev
+keyed_groups:
+  - key: tags
+    prefix: tag
+regions:
+  - us-east-1