this is my container running the folder /app copied from the folder express present in my image
this is my image containing the folder express
after dockerising my express app folder I deleted it from my desktop but I still have the image now I need that folder how can I get it from my image
You can run the docker cp command (documentation: https://docs.docker.com/engine/reference/commandline/cp/). The way how to use is the following:
docker cp <container_id_or_name>:/path/in/container /path/in/host
In order to do that, you just need to run a container from the image you have, and then run the docker cp command:
# run a container as deamon
docker run -d --name my-container fahrazzzgb91/merns bash
# from your host, copy the files from the container to the host
docker cp my-container:/path/to/copy .
Related
I want to make sure I understand correctly docker: when i build an image from the current directory I run:
docker build -t imgfile .
What happens when i change the content of a file in the directory AFTER the image is built? From what i've tried it seems it changes the content of the docker image also dynamically.
I thought the docker image was like a zip file that could only be changed with docker commands or logging into the image and running commands.
The dockerfile is :
FROM lambci/lambda:build-python3.8
WORKDIR /var/task
EXPOSE 8000
RUN echo 'export PS1="\[\e[36m\]zappashell>\[\e[m\] "' >> /root/.bashrc
CMD ["bash"]
And the docker run command is :
docker run -ti -p 8000:8000 -e AWS_PROFILE=zappa -v "$(pwd):/var/task" -v ~/.aws/:/root/.aws --rm zappa-docker-image
Thank you
Best,
Your docker run command isn't really running your image at all. The docker run -v $(pwd):/var/task syntax overwrites what was in /var/task in the image with a bind mount to the current directory on the host. So when you edit a file on your host, the container has the same host directory (and not the content from the image) and you see the changes inside the container as well.
You're right that the image is immutable. The image you show doesn't really contain anything, beyond a .bashrc file that won't usually be used. You can try running the image without the -v options to see:
docker run --rm zappa-docker-image ls -al
# just shows `.` and `..` directories
I'd recommend making sure you COPY your application into the image, setting its CMD to actually run the application, and removing the -v option that overwrites its main directory. If your goal is to run host code against host files with host supporting data like your AWS credentials, you're not really getting much benefit from introducing Docker in between your application and every single file it uses.
i have creted a docker volume with such command
docker run -ti --rm -v TestVolume1:/testvolume1 ubuntu
then i created a file there, called TestFile.txt and added text to it
Also i have a simple "Hello world" .net core app with Dockerfile
FROM mcr.microsoft.com/dotnet/aspnet:6.0
COPY bin/Release/net6.0/publish/ ShareFileTestInstance1/
WORKDIR /ShareFileTestInstance1
ENTRYPOINT ["dotnet", "ShareFileTestInstance1.dll"]
I published it using
dotnet publish -c Release
then ran
docker build -t counter-image -f Dockerfile .
And finally executed
docker run -it --rm --name=counter-container counter-image -v TestVolume1:/testvolume1 ubuntu
to run my app with a docker volume
So what i want to achive to access a file which is in a volume("TestFile.txt" in my case) from a code in the container.
for example
Console.WriteLine(File.Exists("WHAT FILE PATH HAS TO BE HERE") ? "File exists." : "File does not exist.");
Is it also possible to combine all this stuff in a Dockerfile? I want to add one more container next and connect to the volume to save data there.
The parameters for docker run can be either for docker or for the program running in the docker container. Parameters for docker go before the image name and parameters for the program in the container go after the image name.
The volume mapping is a parameter for docker, so it should go before the image name. So instead of
docker run -it --rm --name=counter-container counter-image -v TestVolume1:/testvolume1 ubuntu
you should do
docker run -it --rm --name=counter-container -v TestVolume1:/testvolume1 counter-image
When you do that, your file should be accessible for your program at /testvolume1/TestFile.txt.
It's not possible to do the mapping in the Dockerfile as you ask. Mappings may vary from docker host to docker host, so they need to be specified at run-time.
I have created a customised-docker image which runs some code after creating a container.
But I want to attach a config file at the time of deployment and our config file is saved on the local machine.
docker run -d -ti -v /home/logs/:/home/logs/ --name "ContainerName" "ImageName" /bin/bash
I want to attach file at the place of volume.
How can I attach a config file to the container at runtime?
the docker run options doesnt really let you mess with the image. for that you have the Dockerfile - so you can build an inage of your own, or in this case- kinda like extending the base one:
on your project root directory:
copy the logs you need to sit inside your project (so the dockerfile can access them)
create a Dockerfile:
#Dockerfile
FROM <image_name>
COPY ./logs /home/logs
build your own image: ( you can also push it to a repo)
docker build . -t <new_image_name>
run the container:
docker run -d -ti --name "ContainerName" <new_image_name> /bin/bash
I try to copy the content of a folder (on my server) to my container:
docker cp sonatype-work-backup/* nexus:/sonatype-work/
So I want the content of sonatype-work in my /sonatype-work/ of nexus. But it doesn't work with the * and without the star it's copying the directory sonatype-work-backup inside my sonatype-work directory. I can't perform mv after that.
you could just mount that directory in your container at run
docker run -v /sonatype-work-backup:/mnt --name nexus nexus-image
then
docker exec -it nexus bash
and just cp from /mnt to your desired folder
I pulled official Docker image for Tomcat by running this command.
docker run -it --rm tomcat:8.0
By using this as base image I need to build new image that contains my war file in the tomcat webapps folder. I created Dockerfile like this.
From tomcat8
ADD warfile /usr/local/tomcat
When I run this Dockerfile by building image I am not able to see Tomcat front page.
Can anybody tell me how to add my warfile to official Tomcat images webapp folder.
Reading from the documentation of the repo you would do something like that
FROM tomcat
MAINTAINER xyz
ADD your.war /usr/local/tomcat/webapps/
CMD ["catalina.sh", "run"]
Then build your image with docker build -t yourName <path-to-dockerfile>
And run it with:
docker run --rm -it -p 8080:8080 yourName
--rm removes the container as soon as you stop it
-p forwards the port to your host (or if you use boot2docker to this IP)
-it allows interactive mode, so you see if something get's deployed
Building on #daniel's answer, if you want to deploy your WAR to the root of tomcat, I did this:
FROM tomcat:7-jre7
MAINTAINER xyz
RUN ["rm", "-fr", "/usr/local/tomcat/webapps/ROOT"]
COPY ./target/your-webapp-1.0-SNAPSHOT.war /usr/local/tomcat/webapps/ROOT.war
CMD ["catalina.sh", "run"]
It deletes the existing root webapp, copies your WAR to the ROOT.war filename then executes tomcat.
docker run -it --rm --name MYTOMCAT -p 8080:8080 -v .../wars:/usr/local/tomcat/webapps/ tomcat:8.0
where wars folder contains war to deploy
How do you check the webapps folder?
The webapps folder is within the docker container.
If you want to access your webapps container you could mount a host directory within your container to use it as webapps folder. That way you can access files without accessing docker.
Details see here
To access your logs you could do that when you run your container e.g.
docker run -rm -it -p 8080:8080 **IMAGE_NAME** /path/to/tomcat/bin/catalina.sh && tail -f /path/to/tomcat/logs
or you start your docker container and then do something like:
docker exec -it **CONTAINER_ID** tail -f /path/to/tomcat/logs
If you are using spring mvc project then you require server to run your application suppose you use tomcat then you need base image of tomcat that your application uses which you can specify through FROM command.
You can set environment variable using ENV command.
You can additionally use RUN command which executes during Docker Image buiding.
eg to give read write execute permissions to webapps folder for tomcat to unzip war file
RUN chmod -R 777 $CATALINA_HOME/webapps
And one more command is CMD. Whatever you specifying in CMD command it will execute at a time of container running. You can specify options in CMD command using double quotes(" ") seperated by comma(,).
eg
CMD ["catalina.sh","start"]
(NOTE : Remember RUN command execute at a time of image building and CMD execute at a time of running container this is confusing for new users).
This is my Dockerfile -
FROM tomcat:9.0.27-jdk8-openjdk
VOLUME /tmp
RUN chmod -R 777 $CATALINA_HOME/webapps
ENV CATALINA_HOME /usr/local/tomcat
COPY target/*.war $CATALINA_HOME/webapps/myapp.war
EXPOSE 8080
CMD ["catalina.sh","run"]
Build your image using command
docker build -t imageName <path_of_Dockerfile>
check your docker image using command
docker images
Run image using command
docker run -p 9999:8080 imageName
here 8080 is tomcat port and application can access on 9999 port
Try accessing your application on
localhost:9999/myapp/