cpp-exercises

In this repository I host some implementations of C++ exercises.

Each file in /src corresponds to an exercise. A task description is given in each file. There are unit tests in /test which verify a correct implementation. They are based on GoogleTest. The testing process is automated in CI fashion by Jenkins.

Requirements

Developed and tested on the following setup:

Debian 11.2
Docker 20.10
Jenkins 2.341
cmake 3.21.4

Build

Run following commands on your host to compile the project:

mkdir build
cd build
cmake ..
make

Or build the project in a container:

docker build -t cpp-exercises .

Test

Run the unit tests from your build environment:

cd build
ctest

Or run the container:

docker run --rm cpp-exercises cpp-exercises-test

Continuous Testing

The following instructions explain how to set up a containerized Jenkins environment.

Create a bridge network for Docker containers:

docker network create jenkins

Create a container which runs a Docker daemon:

docker run \
  --name jenkins-docker --detach \
  --privileged --network jenkins --network-alias docker \
  --env DOCKER_TLS_CERTDIR=/certs \
  --volume jenkins-certs:/certs/client \
  --volume jenkins-data:/var/jenkins_home \
  --publish 2376:2376 \
  docker:dind --storage-driver overlay2

Create a container which runs a Jenkins server:

docker run \
  --name jenkins-server --detach \
  --network jenkins --env DOCKER_HOST=tcp://docker:2376 \
  --env DOCKER_CERT_PATH=/certs/client --env DOCKER_TLS_VERIFY=1 \
  --publish 8000:8080 --publish 50000:50000 \
  --volume jenkins-data:/var/jenkins_home \
  --volume jenkins-certs:/certs/client:ro \
  jenkins/jenkins:latest

Retrieve the password to authenticate with the Jenkins server in the last step:

docker logs jenkins-server

Start a shell inside the Jenkins server:

docker exec -it -u root jenkins-server bash

Run following instructions to complete the setup of the Jenkins server:

curl -fsSLo /usr/share/keyrings/docker-keyring.asc https://download.docker.com/linux/debian/gpg
echo "deb [arch=amd64 \
  signed-by=/usr/share/keyrings/docker-keyring.asc] \
  https://download.docker.com/linux/debian \
  bullseye stable" > /etc/apt/sources.list.d/docker.list
apt-get update
apt-get upgrade
apt-get install -y docker-ce-cli nano cmake gcc g++ cppcheck
jenkins-plugin-cli --plugins docker-plugin:1.2.6
jenkins-plugin-cli --plugins docker-workflow:1.28
jenkins-plugin-cli --plugins docker-commons:1.19
jenkins-plugin-cli --plugins docker-java-api:3.1.5.2
jenkins-plugin-cli --plugins cmakebuilder:4.1.1
jenkins-plugin-cli --plugins xunit:3.0.6
jenkins-plugin-cli --plugins cppcheck:1.25
echo "alias c='clear'" > /var/jenkins_home/.bashrc && source /var/jenkins_home/.bashrc
exit

Open http://localhost:8000, enter the authentication password and finish the setup.

Create Pipeline

After the setup for the Jenkins server is done, you need to create a Jenkins pipeline.

Select Pipeline script from SCM in the options, so Jenkins will use the Jenkinsfile provided in this repository.

Activate Webhook

Jenkins shall trigger a pipeline run, whenever a new commit is pushed to the repository.

Use ngrok on your host to expose the Jenkins server to the Internet:

ngrok http 8000

Take note of the resulting address, and add a webhook with a push-event in the settings section of your repository:

https://<subdomain>.ngrok.io/github-webhook/

Activate the checkbox for GitHub hook trigger for GITScm polling in the options of your Jenkins pipeline.

Known Issues

The Jenkins plugin cppcheck 1.25 is incompatible with JDK11. When you perform a pipeline run, you may encounter following error in the Console Output:

[Cppcheck] Parsing throws exceptions. javax.xml.bind.JAXBException: Implementation of JAXB-API has not been found on module path or classpath.

You can resolve this issue by implementing the pull request #56.

Follow these steps to build the plugin including patch:

git clone -b jdk11 https://github.com/xnYi9wRezm/cppcheck-plugin.git
cd cppcheck-plugin
mvn verify
mvn hpi:hpi
cp target/cppcheck.hpi /var/jenkins_home/plugins

Install the plugin by restarting the Jenkins server.

cfanatic / cpp-exercises