Nella  Brown

Nella Brown

1620336120

Let’s Do DevOps: Terraform AWS Ec2 Module (Required)

Hey all!

Terraform has this great concept of “modules” which have a ton of uses. One of the most common is to have a resource-specific module that builds a resource with the required security and operational settings your org has standardized on. That lets your module receive just the bare minimum of values (making life easier for developers), and still building things appropriately and securely.

Terraform’s behavior with most resources and calls works well in this way, but interestingly, AWS EC2 is not in that list. There is a significant bug with how Terraform (and the AWS API) handles building ec2 modules. Here’s the GitHub bug report (opened fully 3.5 years ago at time of this blog’s publication):

Inline EBS block device modification on AWS instance not working · Issue #2709 ·…

The problem arises when a user attempts to update a non-root EBS volume, which is the way AWS manages additional disks for your hosts. Rather than supporting an uptime change (like the AWS console does), Terraform requires you to destroy the host and rebuild from scratch.

#devops #aws #terraform

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Buddha Community

Let’s Do DevOps: Terraform AWS Ec2 Module (Required)
Nella  Brown

Nella Brown

1620336120

Let’s Do DevOps: Terraform AWS Ec2 Module (Required)

Hey all!

Terraform has this great concept of “modules” which have a ton of uses. One of the most common is to have a resource-specific module that builds a resource with the required security and operational settings your org has standardized on. That lets your module receive just the bare minimum of values (making life easier for developers), and still building things appropriately and securely.

Terraform’s behavior with most resources and calls works well in this way, but interestingly, AWS EC2 is not in that list. There is a significant bug with how Terraform (and the AWS API) handles building ec2 modules. Here’s the GitHub bug report (opened fully 3.5 years ago at time of this blog’s publication):

Inline EBS block device modification on AWS instance not working · Issue #2709 ·…

The problem arises when a user attempts to update a non-root EBS volume, which is the way AWS manages additional disks for your hosts. Rather than supporting an uptime change (like the AWS console does), Terraform requires you to destroy the host and rebuild from scratch.

#devops #aws #terraform

Kole  Haag

Kole Haag

1604005200

Creating an EC2 Module That Filters for the Latest Windows Server AMI in Terraform

Alrighty peeps lets get right into it. Let’s assume that you have an EC2 instance that you want to automatically look up the latest windows ami for.

Your EC2 instance code might look something like this

resource "aws_instance" "example" {
     ami = "some ami here"
     instance_type = "t2.micro"
     availability_zone = var.availability_zone
}

Creating the Data and Filter

Now what we are going to do is update it to use a data source for the ami, then that data source will use a filter. Here is what our data code will look like

data "aws_ami" "windows" {
     most_recent = true     

filter {
       name   = "name"
       values = ["Windows_Server-2019-English-Full-Base-*"]  
  }     
filter {
       name   = "virtualization-type"
       values = ["hvm"]  
  }     
owners = ["801119661308"] ## Canonical
}

The argument most_recent is set to true. This means that it will grab the most recent AMI that fits the criteria that we specify in our filter.

Next you will notice that in the name we set the value to *Windows_Server-2019-English-Full-Base- **with the star at the end. This lets Terraform know we don’t care about what text comes after that point and it was done because the standard format puts the date there. If we set the date the ami was created and set the most_recent argument to true it would not do us any good.

After that we set the virtualization-type to hvm. I am not going to go into a lot of detail here. Just know this is a good idea and do some additional research on hvm vs pv.

Last we set **owners **to 801119661308.

Now I am sure you are asking… how the heck do I actually get this information? Well you are going to have to run a quick command with the AWS cli.

First, login to AWS and get the ami you want to grab the information for. Here is an example:

Image for post

Image for post

Image for post

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If you click on launch instance you can do a search.

After that you want to copy the ami id and run this command

aws ec2 describe-images — owners amazon — image-ids ami-0eb7fbcc77e5e6ec6

Make sure you replace my ami id with your own.

After running the command there will be a lot of output. In the last block you will see something that looks like this

Image for post

Image for post

Here you can see the Name and the **Owner ID **(which we use for ‘owner’). You can copy these values to use in your own AMI filter!

Also, you can now see what I was talking about with the date. At the end of the Name you can see that the date is used. Make sure you remove that and add a * if you want the most recent ami to always be used.

Updating the Instance Code

As you remember our instance code looked something like this

resource "aws_instance" "example" {
     ami = "some ami here"
     instance_type = "t2.micro"
     availability_zone = var.availability_zone
}

Now we are just going to update the resource addressing to get the id of the ami from the data source. (changes in bold)

resource "aws_instance" "example" {
     ami = data.aws_ami.windows.id
     instance_type = "t2.micro"
     availability_zone = var.availability_zone
}

Now if you are in a scenario where you don’t want the ami changing you may want to add in an argument to ignore lifecycle changes, but for something more ephemeral this will do! Here is an example of how to ignore ami changes.

#terraform-modules #hashicorp #terraform #aws-ec2 #devops

Kole  Haag

Kole Haag

1603213200

Using Terraform to Create an EC2 Instance With Cloudwatch Alarm Metrics

Hey guys! I wanted to do a quick tutorial on how I created an EC2 module for Terraform. If you want to see the repository it is located in check it out here. This module will do a few things:

  1. Create an EC2 Instance
  2. Automatically look up the latest Windows Server 2019 AMI for the EC2 instance.
  3. Create and attach a additional drive.
  4. Create a Cloudwatch Alarm Metric to monitor CPU.

The folder structure looks like this:

Image for post

First things first… I created the main.tf file which contains all of my configuration except for the variables and outputs. The main.tf has a few parts to it.

AWS Instance Code

The first section is the instance resource code

#AWS Instance

resource "aws_instance" "example" {
     ami = data.aws_ami.windows.id
     instance_type = "t2.micro"
     availability_zone = var.availability_zone
}

You will notice a few things here.

  1. The instance type is set in the module to t2.micro
  2. availability_zone is set using a variable
  3. ami is set using data

We will get the the availability zone piece in just a bit, first we are going to tackle the data used for the ami argument.

Data for AMI Using a Filter

The next bit of code for the filter looks like this

#AMI Filter for Windows Server 2019 Base

data "aws_ami" "windows" {
     most_recent = true
     filter {
       name   = "name"
       values = ["Windows_Server-2019-English-Full-Base-*"]
  }
     filter {
       name   = "virtualization-type"
       values = ["hvm"]
  }
     owners = ["801119661308"] ## Canonical
}

The argument most_recent is set to true. This means that it will grab the most recent AMI that fits the criteria that we specify in our filter.

Next you will notice that in the name we set the value to *Windows_Server-2019-English-Full-Base- **with the star at the end. This lets Terraform know we don’t care about what text comes after that point and it was done because the standard format puts the date there. If we set the date the ami was created and set the most_recent argument to true it would not do us any good.

After that we set the virtualization-type to hvm. I am not going to go into a lot of detail here. Just know this is a good idea and do some additional research on hvm vs pv.

Last we set **owners **to 801119661308.

Now I am sure you are asking… how the heck do I actually get this information? Well you are going to have to run a quick command with the AWS cli.

First, login to AWS and get the ami you want to grab the information for. Here is an example:

Image for post

If you click on launch instance you can do a search.

#aws-ec2 #hashicorp-terraform #aws-cloudwatch #terraform-modules #terraform

Rory  West

Rory West

1619263860

Why Terraform? How to Getting Started with Terraform Using AWS

Terraform is a tool for building, changing, and versioning infrastructure safely and efficiently. Terraform can manage existing and popular service providers as well as custom in-house solutions.

Traditional Infrastructure vs Modern Infrastructure

Traditional Infrastructure

  • Mutable
  • Operational Complexity
  • No Central Control on Infrastructure

Modern Infrastructure

  • Immutable
  • Less Operational Complexity
  • Faster time to the market
  • single point for state management

#terraform-aws #terraform #aws #aws-ec2

Mike  Kozey

Mike Kozey

1656151740

Test_cov_console: Flutter Console Coverage Test

Flutter Console Coverage Test

This small dart tools is used to generate Flutter Coverage Test report to console

How to install

Add a line like this to your package's pubspec.yaml (and run an implicit flutter pub get):

dev_dependencies:
  test_cov_console: ^0.2.2

How to run

run the following command to make sure all flutter library is up-to-date

flutter pub get
Running "flutter pub get" in coverage...                            0.5s

run the following command to generate lcov.info on coverage directory

flutter test --coverage
00:02 +1: All tests passed!

run the tool to generate report from lcov.info

flutter pub run test_cov_console
---------------------------------------------|---------|---------|---------|-------------------|
File                                         |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
 print_cov_constants.dart                    |    0.00 |    0.00 |    0.00 |    no unit testing|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|

Optional parameter

If not given a FILE, "coverage/lcov.info" will be used.
-f, --file=<FILE>                      The target lcov.info file to be reported
-e, --exclude=<STRING1,STRING2,...>    A list of contains string for files without unit testing
                                       to be excluded from report
-l, --line                             It will print Lines & Uncovered Lines only
                                       Branch & Functions coverage percentage will not be printed
-i, --ignore                           It will not print any file without unit testing
-m, --multi                            Report from multiple lcov.info files
-c, --csv                              Output to CSV file
-o, --output=<CSV-FILE>                Full path of output CSV file
                                       If not given, "coverage/test_cov_console.csv" will be used
-t, --total                            Print only the total coverage
                                       Note: it will ignore all other option (if any), except -m
-p, --pass=<MINIMUM>                   Print only the whether total coverage is passed MINIMUM value or not
                                       If the value >= MINIMUM, it will print PASSED, otherwise FAILED
                                       Note: it will ignore all other option (if any), except -m
-h, --help                             Show this help

example run the tool with parameters

flutter pub run test_cov_console --file=coverage/lcov.info --exclude=_constants,_mock
---------------------------------------------|---------|---------|---------|-------------------|
File                                         |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|

report for multiple lcov.info files (-m, --multi)

It support to run for multiple lcov.info files with the followings directory structures:
1. No root module
<root>/<module_a>
<root>/<module_a>/coverage/lcov.info
<root>/<module_a>/lib/src
<root>/<module_b>
<root>/<module_b>/coverage/lcov.info
<root>/<module_b>/lib/src
...
2. With root module
<root>/coverage/lcov.info
<root>/lib/src
<root>/<module_a>
<root>/<module_a>/coverage/lcov.info
<root>/<module_a>/lib/src
<root>/<module_b>
<root>/<module_b>/coverage/lcov.info
<root>/<module_b>/lib/src
...
You must run test_cov_console on <root> dir, and the report would be grouped by module, here is
the sample output for directory structure 'with root module':
flutter pub run test_cov_console --file=coverage/lcov.info --exclude=_constants,_mock --multi
---------------------------------------------|---------|---------|---------|-------------------|
File                                         |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|
---------------------------------------------|---------|---------|---------|-------------------|
File - module_a -                            |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|
---------------------------------------------|---------|---------|---------|-------------------|
File - module_b -                            |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|

Output to CSV file (-c, --csv, -o, --output)

flutter pub run test_cov_console -c --output=coverage/test_coverage.csv

#### sample CSV output file:
File,% Branch,% Funcs,% Lines,Uncovered Line #s
lib/,,,,
test_cov_console.dart,0.00,0.00,0.00,no unit testing
lib/src/,,,,
parser.dart,100.00,100.00,97.22,"97"
parser_constants.dart,100.00,100.00,100.00,""
print_cov.dart,100.00,100.00,82.91,"29,49,51,52,171,174,177,180,183,184,185,186,187,188,279,324,325,387,388,389,390,391,392,393,394,395,398"
print_cov_constants.dart,0.00,0.00,0.00,no unit testing
All files with unit testing,100.00,100.00,86.07,""

Installing

Use this package as an executable

Install it

You can install the package from the command line:

dart pub global activate test_cov_console

Use it

The package has the following executables:

$ test_cov_console

Use this package as a library

Depend on it

Run this command:

With Dart:

 $ dart pub add test_cov_console

With Flutter:

 $ flutter pub add test_cov_console

This will add a line like this to your package's pubspec.yaml (and run an implicit dart pub get):

dependencies:
  test_cov_console: ^0.2.2

Alternatively, your editor might support dart pub get or flutter pub get. Check the docs for your editor to learn more.

Import it

Now in your Dart code, you can use:

import 'package:test_cov_console/test_cov_console.dart';

example/lib/main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
        // This makes the visual density adapt to the platform that you run
        // the app on. For desktop platforms, the controls will be smaller and
        // closer together (more dense) than on mobile platforms.
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

Author: DigitalKatalis
Source Code: https://github.com/DigitalKatalis/test_cov_console 
License: BSD-3-Clause license

#flutter #dart #test