Please stay healthy!
Remote Lectures
All Meetings
Schedule here:
High Quality Work!
Self-Motivation!
Despite the chaos:
Revised Project Proposals
Feedback this week!
Lecture 17
Hands-on Day! (C++ Functions and Classes)
// part 3
class SingletonConverter
{
public:
static SingletonConverter* getInstance( ) {
static SingletonConverter* instance;
return instance;
};
~SingletonConverter( );
float fromFtoC(float temp) {
return ((temp-32)/1.8);
};
private:
SingletonConverter( );
}; //... in main
SingletonConverter *c = SingletonConverter::getInstance()
float convertedTemp = c->fromFtC(temp);
//...Lazy Loading!
But does it work?
#include <iostream>
//
// Singleton Converter w/ Lazy Loading
//
class SingletonConverter
{
public:
static SingletonConverter* getInstance( ) {
static SingletonConverter* instance;
return instance;
};
~SingletonConverter( );
float fromFtoC(float temp) {
return ((temp-32)/1.8);
};
private:
SingletonConverter( );
};
int main()
{
SingletonConverter* i1 = SingletonConverter::getInstance();
SingletonConverter* i2 = SingletonConverter::getInstance();
SingletonConverter* i3 = SingletonConverter::getInstance();
if (i1 == i2) {
std::cout << "yes";
}
if (i1 == i3) {
std::cout << "yes";
}
}Pointer arithmetic!
int carton[10];int carton[10] = { };int carton[10] = { 1, 3, 7 };Array
#include <vector>
// ...
std::vector<float> allTemps;
std::cout << allTemps.size();
while(1) {
std::string temp;
std::cout << "Please enter a temperature or x to stop.";
std::cin >> temp;
if (temp == "x") {
break;
}
allTemps.push_back( std::stof(temp) );
}Vector
Dynamic containers..
Templates!
Developer
IT Operations
Software Developer
SysAdmins / IT Ops
should know a little bit of both!
Deployment
Delivery to Client or Customer
Make Software Accessible
Containers
Virtual Machines
Docker
All other platforms..
$ docker run --detach httpd
$ docker ps
$ docker inspect ID
$ docker pause ID
$ docker unpause ID
$ docker kill ID
$ docker run -it python:2.7
We can never know it all.
But we can be curious.
alias docker=podman
MicroVMs for AWS
No daemon required
# A basic apache server. To use either add or bind mount content under /var/www
FROM ubuntu:12.04
MAINTAINER Kimbro Staken version: 0.1
RUN apt-get update && apt-get install -y apache2 && apt-get clean && rm -rf /var/lib/apt/lists/*
ENV APACHE_RUN_USER www-data
ENV APACHE_RUN_GROUP www-data
ENV APACHE_LOG_DIR /var/log/apache2
EXPOSE 80
CMD ["/usr/sbin/apache2", "-D", "FOREGROUND"]Dockerfile
Base Docker
Author and version
Install Commands
Environment Variables
Open Ports
Executable Commands
This command can be overwritten when starting the container!
ENTRYPOINT ["/bin/bash"]Fixed Command!
We will now create our own
Dockerfile
to specify a container
that downloads C++ code from Github,
compiles it,
and then runs it!
We will deploy the container using
This time just watch!
We will do it later together..
1. Create repository and clone it.
2. Add C++ code.
3. Create Dockerfile.
4. Build and tag Docker container.
5. Push container to !
6. Modify C++ code.
7. And see what happens...
#include <iostream>
#include <vector>
class SingletonConverter
{
public:
static SingletonConverter* getInstance( ) {
static SingletonConverter* instance;
return instance;
};
~SingletonConverter( );
float fromFtoC(float temp) {
return ((temp-32)/1.8);
};
private:
SingletonConverter( );
};
int main()
{
std::vector<float> allTemps;
while(1) {
std::string temp;
std::cout << "Please enter a temperature or x to stop entering temperatures.\n";
std::cin >> temp;
if (temp == "x") {
break;
}
std::cout << "Stored " << temp << "!\n";
allTemps.push_back(std::stof(temp));
}
std::cout << allTemps.size() << " temperatures stored!\n";
float averageTemp = 0;
for (int i=0; i<allTemps.size(); i++) {
averageTemp += allTemps[i];
}
averageTemp /= allTemps.size();
std::cout << "The average temperature is: " << averageTemp << "\n";
std::cout << "Converted to Celsius, this temperature is " << SingletonConverter::getInstance()->fromFtoC(averageTemp) << "!\n";
}
converter.cc
FROM ubuntu:18.04
MAINTAINER Daniel Haehn version: 0.1
ADD converter.cc converter.cc
RUN apt-get update
RUN apt-get install -y g++
RUN g++ -o converter converter.cc
ENTRYPOINT ["./converter"]
Dockerfile
Docker commands we used today:
# build the container from the Dockerfile
docker build -t TAG .
# run the container interactively
docker run -it TAG
# login to DockerHub
docker login
# deploy the container
docker push TAG:latestContainer Orchestration
Run many containers on a cluster
Scalability
Docker Swarm
Kubernetes
easy
complex
