Table of Contents

How to use Dockerfile


Table of Contents


Reference


How to write Dockerfile

FROM Source image FROM name/web:ver1.0
MAINTAINER
ENV Environment variable ENV KEY=VALUE
RUN Execute the specified command RUN yum -y install httpd
ADD Add file to image ADD index.html /var/www/html/index.htm
EXPOSE Specify port number EXPOSE 80
CMD Command executed when container starts CMD [“service”,“httpd”,“start”]
ENTRYPOINT ENTRYPOINT [“/usr/sbin/httpd”, “-DFOREGROUND”]
WORKDIR Specify current directory WORKDIR /var/www/html
VOLUME Volume specification VOLUME /var/log/httpd


Example1

How to make a Dockerfile

# mkdir test
# cd test
# vi Dockerfile

FROM centos

RUN yum update -y \
    && yum install httpd -y \
    && echo "hello world from dockerfile" > /var/www/html/index2.html \
    && yum clean all

ADD ./httpd/www/index.html /var/www/html/

EXPOSE 80

ENTRYPOINT ["/usr/sbin/httpd", "-DFOREGROUND"]

How to create a Docker image from Dockerfile

# docker build . -t mycentos_with_httpd_from_dockerfile
# docker images

How to start a container based on the created image

# docker run -d --rm -p 8080:80 mycentos_with_httpd_from_dockerfile

http://x.x.x.x/index.html
http://x.x.x.x/index2.html


Dockerfile Examples

PHP + Apache

FROM php:7.0-apache

COPY ./etc_apache2_conf-enabled_docker-php.conf /etc/apache2/conf-enabled/docker-php.conf
COPY ./var_www_html_index.php /var/www/html/

# docker build --tag php70-apache ./
# docker run -d --name php70-apache  -p 8080:80 php70-apache

# docker container exec -ti php70-apache bash
# docker ps --filter name=php70-apache
# docker logs [ContainerID] 
# docker stop [ContainerID] 
# docker rm [ContainerID] 
# docker images php70-apache
# docker rmi [ImageID]