How to run bash function in Dockerfile

Question

I have a bash function nvm defined in /root/.profile. docker build failed to find that function when I call it in RUN step.

RUN apt-get install -y curl build-essential libssl-dev && \
    curl https://raw.githubusercontent.com/creationix/nvm/v0.16.1/install.sh | sh
RUN nvm install 0.12 && \
    nvm alias default 0.12 && \
    nvm use 0.12

The error is

Step 5 : RUN nvm install 0.12
 ---> Running in b639c2bf60c0
/bin/sh: nvm: command not found

I managed to call nvm by wrapping it with bash -ic, which will load /root/.profile.

RUN bash -ic "nvm install 0.12" && \
    bash -ic "nvm alias default 0.12" && \
    bash -ic "nvm use 0.12"

The above method works fine, but it has a warning

bash: cannot set terminal process group (1): Inappropriate ioctl for device
bash: no job control in this shell

And I want to know is there a easier and cleaner way to call the bash function directly as it's normal binary without the bash -ic wrapping? Maybe something like

RUN load_functions && \
    nvm install 0.12 && \
    nvm alias default 0.12 && \
    nvm use 0.12

RUN bash -c 'nvm install 0.12 && nvm alias default 0.12 && nvm use 0.12' should do the trick. Does it work for you? (I'm not 100% sure because I don't know how your container is looking in detail) — hek2mgl
– hek2mgl, Commented Sep 22, 2015 at 3:24
Ok, check my answer. A shell script is the cleanest way to do it. — hek2mgl
– hek2mgl, Commented Sep 22, 2015 at 3:32
You've not accepted my answer so far. What do you mean with a better solution? — hek2mgl
– hek2mgl, Commented Sep 22, 2015 at 5:02
NVM is not designed for Docker. Do you really want two Node.js in a single container? — Franklin Yu
– Franklin Yu, Commented Nov 8, 2016 at 5:39

hek2mgl · Accepted Answer · 2015-09-22 03:31:51Z

19

Docker's RUN doesn't start the command in a shell. That's why shell functions and shell syntax (like cmd1 && cmd2) cannot being used out of the box. You need to call the shell explicitly:

RUN bash -c 'nvm install 0.12 && nvm alias default 0.12 && nvm use 0.12'

If you are afraid of that long command line, put those commands into a shell script and call the script with RUN:

script.sh

#!/bin/bash

nvm install 0.12 && \
nvm alias default 0.12 && \
nvm use 0.12

and make it executable:

chmod +x script.sh

In Dockerfile put:

RUN /path/to/script.sh

answered Sep 22, 2015 at 3:31

hek2mgl

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8 Comments

Quanlong Over a year ago

I need run nvm in some different steps. And I think the right quote of bash -c is hard to control when commands are formatted as multiple lines.

hek2mgl Over a year ago

That's why I've suggested to use a shell script.

hek2mgl Over a year ago

I don't get why you need multiple scripts. Can you elaborate on that? Once I got it I may suggest something.

Franklin Yu Over a year ago

This is not what I got from documentation: "RUN <command> (shell form, the command is run in a shell, which by default is /bin/sh -c on Linux or cmd /S /C on Windows)".

Alexander Mills Over a year ago

yeah I am not sure this answer is right...I was under the impression that each RUN command executed its contents in a subshell.

|

civicus030 · Accepted Answer · 2024-03-26 14:46:59Z

0

In the very specific case of nvm, I use the following:

ADD --link  https://github.com/nvm-sh/nvm.git#${NVM_VERSION} $NVM_DIR

RUN /bin/bash -c "\
    source ${NVM_DIR}/nvm.sh \
    && nvm install -b --no-progress $NODE_VERSION \
    && nvm alias default $NODE_VERSION \
    && nvm use default \
    "

The first command (ADD --link ...) will install NVM from GitHub into the container (you need to either define the ARGs NVM_DIR and NODE_VERSION or just replace the placeholders in the snippet). ADD will avoid having to install Git into the container itself.

The second command will instantiate a Bash shell and import & use the function definitions from nvm.sh.

answered Mar 26, 2024 at 14:46

civicus030

212 bronze badges

1 Comment

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