Can't run Curl command inside my Docker Container

curl: command not found

is a big hint, you have to install it with :

apt-get update; apt-get install curl

Ran into this same issue while using the CURL command inside my Dockerfile. As Gilles pointed out, we have to install curl first. These are the commands to be added in the 'Dockerfile'.

FROM ubuntu:16.04

# Install prerequisites
RUN apt-get update && apt-get install -y \
curl
CMD /bin/bash

So I added curl AFTER my docker container was running.

(This was for debugging the container...I did not need a permanent addition)

I ran my image

docker run -d -p 8899:8080 my-image:latest

(the above makes my "app" available on my machine on port 8899) (not important to this question)

Then I listed and created terminal into the running container.

docker ps
docker exec -it my-container-id-here /bin/sh

If the exec command above does not work, check this SOF article:

Error: Cannot Start Container: stat /bin/sh: no such file or directory"

then I ran:

apk

just to prove it existed in the running container, then i ran:

apk add curl

and got the below:

apk add curl

fetch http://dl-cdn.alpinelinux.org/alpine/v3.8/main/x86_64/APKINDEX.tar.gz

fetch http://dl-cdn.alpinelinux.org/alpine/v3.8/community/x86_64/APKINDEX.tar.gz

(1/5) Installing ca-certificates (20171114-r3)

(2/5) Installing nghttp2-libs (1.32.0-r0)

(3/5) Installing libssh2 (1.8.0-r3)

(4/5) Installing libcurl (7.61.1-r1)

(5/5) Installing curl (7.61.1-r1)

Executing busybox-1.28.4-r2.trigger

Executing ca-certificates-20171114-r3.trigger

OK: 18 MiB in 35 packages

then i ran curl:

/ # curl
curl: try 'curl --help' or 'curl --manual' for more information
/ # 

Note, to get "out" of the drilled-in-terminal-window, I had to open a new terminal window and stop the running container:

docker ps
docker stop my-container-id-here

APPEND:

If you don't have "apk" (which depends on which base image you are using), then try to use "another" installer. From other answers here, you can try:

apt-get -qq update

apt-get -qq -y install curl