General Info

Asserts

• Examples:
  • Testing for the ability to read a file can also be done.

    1	assertTrue 'test failed' "[ -r /some/non-existant/file' ]"

  • Testing using and (-a), or (-o)

    1	assertTrue 'test failed' '[ 1 -eq 1 -a 2 -eq 2 ]'

Failures

Setup/Teardown

Skipping

Suites

Advanced

Constants

• Predefined

  Constant	Value
  SHUNIT_TRUE	Standard shell true value (the integer value 0)
  SHUNIT_FALSE	Standard shell false value (the integer value 1)
  SHUNIT_ERROR	The integer value 2
  SHUNIT_TMPDIR	Path to temporary directory that will be automatically cleaned up upon exit of shUnit2
  SHUNIT_VERSION	The version of shUnit2 you are running

• User defined

  Constant	Value
  SHUNIT_CMD_EXPR	Override which expr command is used. By default expr is used, except on BSD systems where gexpr is used
  SHUNIT_COLOR	Enable colorized output. Options are ‘auto’, ‘always’, or ‘none’, with ‘auto’ being the default
  SHUNIT_PARENT	The filename of the shell script containing the tests. This is needed specifically for Zsh support
  SHUNIT_TEST_PREFIX	Define this variable to add a prefix in front of each test name that is output in the test report

Error handling

• The constants values SHUNIT_TRUE, SHUNIT_FALSE, and SHUNIT_ERROR are returned from nearly every function to indicate the success or failure of the function
• The variable flags_error is filled with a detailed error message if any function returns with a SHUNIT_ERROR value

Test skipping

• File

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  # file: examples/math.inc. add_generic() { num_a=$1 num_b=$2 expr $1 + $2 } add_bash() { num_a=$1 num_b=$2 echo $(($1 + $2)) }

• Test file

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  #! /bin/sh # file: examples/math_test.sh testAdding() { result=`add_generic 1 2` assertEquals \ "the result of '${result}' was wrong" \ 3 "${result}" # Disable non-generic tests. [ -z "${BASH_VERSION:-}" ] && startSkipping result=`add_bash 1 2` assertEquals \ "the result of '${result}' was wrong" \ 3 "${result}" } oneTimeSetUp() { # Load include to test. . ./math.inc } # Load and run shUnit2. . ./shunit2

Run specific test

• Simply run script

  1	test-script.sh -- testOne testTwo otherFunction

• Clarifying, with shunit2 call

  1	shunit2 test-script.sh testOne testTwo otherFunction

Introduction to shUnit2

Unit tests for Bash with shUnit2

shUnit2 is a xUnit unit test framework for Bourne based shell scripts, and it is designed to work in a similar manner to JUnit, PyUnit, etc..

Setup

• Install

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  # Manjaro yum -y install shunit2 # You may also just download shunit2 and make sure it's on your path.

• Quickstart

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  #! /bin/sh # file: examples/party_test.sh testEquality() { assertEquals 1 1 } # load shunit2 . /usr/share/shunit2/shunit2

Tests structure

• 3 sections:
  • set up section
    • setUp and tearDown functions
    • define mocks
  • test cases section
  • call to the shunit2 test runner (. shunit2.)

Example

• File to test

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  #!/usr/bin/env bash cidr="$1" usage() { [ ! -z "$1" ] && echo $1 cat <<EOF Print all IPs in a CIDR range, similar to the Ubuntu prips utility. This script assumes that the Red Hat version of ipcalc is available. Usage: $0 <cidr> [-h] Example: $0 192.168.0.3/28 EOF exit 1 } [ -h == "$1" ] && usage [ ! -z "$2" ] && usage 'You may only pass one CIDR' [ -z "$cidr" ] && usage 'You must pass a CIDR' echo $cidr | egrep -q "^(?:[0-9]+\.){3}[0-9]+/[0-9]+$" || \ usage "$cidr is not a valid CIDR" # range is bounded by network (-n) & broadcast (-b) addresses. lo=$(ipcalc -n $cidr | cut -f2 -d=) hi=$(ipcalc -b $cidr | cut -f2 -d=) IFS=. read a b c d <<< "$lo" IFS=. read e f g h <<< "$hi" eval "echo {$a..$e}.{$b..$f}.{$c..$g}.{$d..$h}"

• The test cases (White-box testing)

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  #!/usr/bin/env bash # Mock the output of the ipcalc. ipcalc() { case "$*" in "-n 192.168.0.2/28") echo NETWORK=192.168.0.0 ;; "-b 192.168.0.2/28") echo BROADCAST=192.168.0.15 ;; "-n 10.45.0.0/16") echo NETWORK=10.45.0.0 ;; "-b 10.45.0.0/16") echo BROADCAST=10.45.255.255 esac } # test cases test_minus_h() { first_line=$(. ./prips.sh -h | head -1) assertEquals "Print all IPs in a CIDR range, similar to the Ubuntu \ prips utility." "$first_line" } test_missing_args() { first_line=$(. ./prips.sh | head -1) assertEquals 'You must pass a CIDR' "$first_line" } test_too_many_args() { first_line=$(. ./prips.sh 192.168.0.2/28 192.168.0.2/30 | head -1) assertEquals 'You may only pass one CIDR' "$first_line" } test_bad_input() { first_line=$(. ./prips.sh bad_input | head -1) assertEquals 'bad_input is not a valid CIDR' "$first_line" } test_a_little_cidr() { response=$(. ./prips.sh 192.168.0.2/28) expected="192.168.0.0 192.168.0.1 192.168.0.2 192.168.0.3 192.168.0.4 \ 192.168.0.5 192.168.0.6 192.168.0.7 192.168.0.8 192.168.0.9 192.168.0.10 \ 192.168.0.11 192.168.0.12 192.168.0.13 192.168.0.14 192.168.0.15" assertEquals "$expected" "$response" } test_a_big_cidr() { number_of_ips=$(. ./prips.sh 10.45.0.0/16 | wc -w) assertEquals 65536 "$number_of_ips" } . shunit2

• Run tests

  1	bash examples/test_prips.sh

Setup

• Install Container Structure Test

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  curl -LO https://storage.googleapis.com/container-structure-test/latest/container-structure-test-linux-amd64 && \ chmod +x container-structure-test-linux-amd64 && \ sudo mv container-structure-test-linux-amd64 /usr/local/bin/container-structure-test

• Select test options:
  • Command Tests: execute a command in your image and check the output
  • File Existence Tests: check if a file is, or isn’t, present in the image
  • File Content Tests: check the content of a file
  • Metadata Test: check if a container metadata is correct

Write unit tests

Prerequisites

• a Dockerfile
• a .yaml or .json file that contains your test cases

Example

• Pre-existing code
  • Dockerfile

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    FROM ubuntu:bionic RUN apt-get update \ && apt-get install -y curl gnupg \ && curl -fsSL https://bazel.build/bazel-release.pub.gpg | gpg --dearmor > bazel.gpg \ && mv bazel.gpg /etc/apt/trusted.gpg.d/ \ && echo "deb [arch=amd64] https://storage.googleapis.com/bazel-apt stable jdk1.8" > /etc/apt/sources.list.d/bazel.list \ && apt-get update \ && apt-get install -y bazel \ && rm -rf /var/lib/apt/lists/* RUN groupadd -g 1000 user \ && useradd -d /home/user -m -u 1000 -g 1000 user \ && chown -R user:user /home/user \ && mkdir -p /bazel/cache \ && chown -R user:user /bazel RUN echo "build --repository_cache=/bazel/cache">/home/user/.bazelrc

  • Build dockerfile

    1	docker build -t docker-unit-test .

• Unit Test code
  • unit-test.yaml

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    schemaVersion: '2.0.0' fileExistenceTests: - name: 'Check bazel cache folder exists and is owned by the non-root user' path: '/bazel/cache' shouldExist: true uid: 1000 gid: 1000 isExecutableBy: 'group' fileContentTests: - name: 'Validate cache folder config' path: '/home/user/.bazelrc' expectedContents: ['.*build --repository_cache=/bazel/cache.*']

  • Run the tests

    1	container-structure-test test --image docker-unit-test --config unit-test.yaml

Automate testing

• Automation with Ansible

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  - name: unit test Docker Image shell: | container-structure-test test --image {{ docker_image }} --config {{ test_file }} if $? then echo "Test Failed" exit 1 else echo "Test Succeeded" exit 0 fi

General parameters

List and search

List

Show

Search

Install, Freeze and uninstall

Install

Freeze

Uninstall

Definition

• Temporary adjustment to how Python runs code.
• It is not a virtual machine, nor a container.
• It manipulates the environment variables of your shell so that you can execute one known version of Python using a local set of modules.

Creation

Activation

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# no virtual environment
$ python --version
Python 2.7.17

# virtual environment
$ python3 -m venv myvirtualenv
#creates a virtual environment called myvirtualenv
$ source ./venv/bin/activate
# activates the virtual environment
(myvirtualenv)$ python --version
Python 3.7
# check we have python 3 active
(myvirtualenv)$ deactivate

# no virtual environment
$ python --version
Python 2.7.17

Using modules

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# no virtual environment
$ python3
>>> import flask
ModuleNotFoundError: No module named 'flask'

# virtual environment
(venv)$ python -m pip install flask
[...]
(venv) bash-4.3$ python -m pip install flask
Collecting flask
  Downloading [...]
Successfully installed [...]
(venv)$ python
>>> from flask import Flask
>>> app = Flask(__name__)
(venv)$ deactivate

# no virtual environment again
$ python3
>>> import flask
ModuleNotFoundError: No module named 'flask'

Storing a Virtual Environment configuration

Get the installed packages list and pipe it into the requirements.txt file.

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pip freeze > requirements.txt

Restoring a Virtual Environment

The virtual environment system encourages you to keep track of the modules you’re using in a requirements.txt file within your project directory.
You can process requirements.txt with pip to handle automated installs of all dependencies:

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$ cd myproject
$ source ./venv/bin/activate
(venv)$ python -m pip install -r requirements.txt
Installed [...]
$ python
>>> from flask import Flask
>>> import examplepymod

Cheatsheet