在 docker 容器中的 bash 命令提示符上添加 git 分支名称

Question

In my local bash, I could add git branch name on the bash command prompt by adding below code in ~/.bashrc

parse_git_branch() {
     git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ (\1)/'
}
export PS1="\u@\h \[\033[32m\]\w\[\033[33m\]\$(parse_git_branch)\[\033[00m\] $ "

I add the same code to docker container ~/.bashrc when making docker image. However, it only colored the current directory but not showing branch name like below

user@server /workspace/mydir ()

what I expect was like below. The yellow bracket indicates which branch that I'm using.

user@server /workspace/mydir (master)

Answer 1

This is how I had to do in my Dockerfile where <<USERNAME>> should be replaced with the user that your docker is run as:

### Setup git branch view in CLI ############
RUN echo "parse_git_branch() {" >> /home/<<USERNAME>>/.bashrc \
    && echo "    git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ (\\\1)/'" >> /home/<<USERNAME>>/.bashrc \
    && echo "}" >> /home/<<USERNAME>>/.bashrc \
    && echo "export PS1='\u@\h \[\033[32m\]\w\[\033[33m\]\$(parse_git_branch)\[\033[00m\] $ '" >> /home/<<USERNAME>>/.basic

The part that took me so long to figure this out is the three backslashes needed before the 1 in the grep of the sed command.

My troubleshooting consisted of my looking at my.bashrc file inside of my Docker instance. That is where I saw that the (\1) was being replaced with just () . So, if you're having this issue and my fix doesn't work for you, check your.bashrc file to see what it did do.