Docker - Ubuntu - bash: ping: command not found

Question

I've got a Docker container running Ubuntu which I did as follows:

docker run -it ubuntu /bin/bash

however it doesn't seem to have ping. E.g.

bash: ping: command not found

Do I need to install that?

Seems a pretty basic command to be missing. I tried whereis ping which doesn't report anything.

Answer 1

This is the Docker Hub page for Ubuntu and this is how it is created. It only has (somewhat) bare minimum packages installed, thus if you need anything extra you need to install it yourself.

apt-get update && apt-get install -y iputils-ping

However usually you'd create a "Dockerfile" and build it:

mkdir ubuntu_with_ping
cat >ubuntu_with_ping/Dockerfile <<'EOF'
FROM ubuntu
RUN apt-get update && apt-get install -y iputils-ping
CMD bash
EOF
docker build -t ubuntu_with_ping ubuntu_with_ping
docker run -it ubuntu_with_ping

Please use Google to find tutorials and browse existing Dockerfiles to see how they usually do things :) For example image size should be minimized by running apt-get clean && rm -rf /var/lib/apt/lists/* after apt-get install commands.

Answer 2

Alternatively you can use a Docker image which already has ping installed, e.g. busybox:

docker run --rm busybox ping SERVER_NAME -c 2

Answer 3

Docker images are pretty minimal, But you can install ping in your official ubuntu docker image via:

apt-get update
apt-get install iputils-ping

Chances are you dont need ping your image, and just want to use it for testing purposes. Above example will help you out.

But if you need ping to exist on your image, you can create a Dockerfile or commit the container you ran the above commands in to a new image.

Commit:

docker commit -m "Installed iputils-ping" --author "Your Name <[e-mail]>" ContainerNameOrId yourrepository/imagename:tag

Dockerfile:

FROM ubuntu
RUN apt-get update && apt-get install -y iputils-ping
CMD bash

Please note there are best practices on creating docker images, Like clearing apt cache files after and etc.

Answer 4

Generally people pull the official image of Ubuntu/CentOS but they don't realize that these images are minimal and doesn't have any thing on the top of that.

For Ubuntu, this image is built from official rootfs tarballs provided by Canonical. Given that it is a minimal install of Ubuntu, this image only includes the C, C.UTF-8, and POSIX locales by default.

One can install net-tools (includes ifconfig, netstat), ip-utils(includes ping) andy other likes curl etc on container and can create image from container or can write Dockerfile that will install these tool while creating image.

Below is Dockerfile example, while creating image from this it will include these tools:

FROM vkitpro/ubuntu16.04
RUN     apt-get  update -y \
&& apt-get upgrade -y \
&& apt-get install iputils-ping -y \
&& apt-get install net-tools -y \
CMD bash

or launch container from base image and install these utilities on container and then commit to image. docker commit -m "any descriptive message" container_id image_name:lattest

That image will have all thing installed.