How to install git on a docker ubuntu image?
This Dockerfile works for me FROM ubuntu:18.04 RUN apt update RUN apt install -y git Inside the container $ which git /usr/bin/git
containers
How do I mount a Docker volume while using a Windows host?
It is possible the / is interpreted as an option by the CMD Windows shell. Try first a docker-machine ssh default, in order to open an ssh session in your VM. From there try the docker run again: docker run -v /c/Users/phisch/dev/htdocs:/var/www phisch:dev As commented by thaJeztah in issue 18290: You could consider using docker-compose; … Read more
c++ template class; function with arbitrary container type, how to define it?
Traits solution. Generalize not more than needed, and not less. In some cases that solution might not be enough as it will match any template with such signature (e.g. shared_ptr), in which case you could make use of type_traits, very much like duck-typing (templates are duck typed in general). #include <type_traits> // Helper to determine … Read more
Start service using systemctl inside docker container
When you do docker run with bash as the command, the init system (e.g. SystemD) doesn’t get started (nor does your start script, since the command you pass overrides the CMD in the Dockerfile). Try to change the command you use to /sbin/init, start the container in daemon mode with -d, and then look around … Read more
When do you prefer using std::list instead of std::vector?
So my question is: when exactly do you prefer std::list over std::vector? When I need a sequential container in a performance-sensitive area and profiling shows std::list is faster. So far, this has never happened to me. (I might be tempted to try std::list first when I would have to store very big objects with lots … Read more
How does Debian differ from Debian-Slim? [closed]
You can compare the git repos used to build the images (rootfs.manifest is useful). Or you can run each image and see what they show is different: $ docker run –rm debian:stable dpkg –get-selections >debian-stable-pkgs.txt $ docker run –rm debian:stable-slim dpkg –get-selections >debian-stable-slim-pkgs.txt $ diff debian-stable-pkgs.txt debian-stable-slim-pkgs.txt 23,24d22 < iproute2 install < iputils-ping install 35,36d32 … Read more
Ulimits in Docker host vs container
The real limit will be 1048576. Have a look at the right part of this image, which shows that containers are basically just isolated processes, running on the same operating system: As every system call in the container will be handled directly by the host OS, the ulimit that is displayed (1048576) comes directly from … Read more
What is the purpose of std::scoped_allocator_adaptor?
If you want a container of strings and want to use the same allocator for the container and its elements (so they are all allocated in the same arena, as TemplateRex describes) then you can do that manually: template<typename T> using Allocator = SomeFancyAllocator<T>; using String = std::basic_string<char, std::char_traits<char>, Allocator<char>>; using Vector = std::vector<String, Allocator<String>>; … Read more
How to create WPF usercontrol which contains placeholders for later usage
ContentControls & ItemsControls are good for this, you can bind them to a property of your UserControl or expose them. Using a ContentControl (for placeholders in multiple disconnected places): <UserControl x:Class=”Test.UserControls.MyUserControl2″ xmlns=”http://schemas.microsoft.com/winfx/2006/xaml/presentation” xmlns:x=”http://schemas.microsoft.com/winfx/2006/xaml” xmlns:mc=”http://schemas.openxmlformats.org/markup-compatibility/2006″ xmlns:d=”http://schemas.microsoft.com/expression/blend/2008″ Name=”control”> <Grid> <Button>Just a button</Button> <ContentControl Content=”{Binding PlaceHolder1, ElementName=control}”/> </Grid> </UserControl> public partial class MyUserControl2 : UserControl { public static … Read more
Understanding servlet container
A servlet is a class that you will use to receive HTTP requests as methods and reply back with stuff (usually HTML). A servlet container is a server program which provides everything else; the opening of the socket, the transformation framework to turn HTTP into Java API calls, and a number of interfaces which allow … Read more