I am using ubuntu 18.04
I have docker-ce installed
I have a file named Dockerfile
I didn't have any other files
how can I start using this container
Firstly you need to build an image from Dockerfile. To do this:
Go to the directory containing Dockerfile
Run (change <image_name> to some meaningful name): docker build -t <image_name> .
After image is built we can finally run it: docker run -it <image_name>
There multiple options how the image can be run so I encourage you to read some docs.
Related
I have a Dockerfile based on apache/nifi:1.12.1 and want to expand it like this:
FROM apache/nifi:1.12.1
RUN mkdir -p /opt/nifi/nifi-current/conf/flow
Thing is that the folder isn't created when I'm building the image from Linux distros like Ubuntu and CentOS. Build succeeds, I run it with docker run -it -d --rm --name nifi nifi-test but when I enter the container through docker exec there's no flow dir.
Strange thing is, that the flow dir is being created normally when I'm building the image through Windows and Docker Desktop. I can't understand why is this happening.
I've tried things such as USER nifi or RUN chown ... but still...
For your convenience, this is the base image:
https://github.com/apache/nifi/blob/rel/nifi-1.12.1/nifi-docker/dockerhub/Dockerfile
Take a look at this as well:
This is what looks like at the CLI
Thanks in advance.
By taking a look at the dockerfile provided you can see the following volume definition
Then if you run
docker image inspect apache/nifi:1.12.1
As a result, when you execute the RUN command to create a folder under the conf directory it succeeds
BUT when you run the container the volumes are mounted and as a result they overwrite everything that is under the mountpoint /opt/nifi/nifi-current/conf
In your case the flow directory.
You can test this by editing your Dockerfile
FROM apache/nifi:1.12.1
# this will be overriden, by volumes
RUN mkdir -p /opt/nifi/nifi-current/conf/flow
# this will be available in the container environment
RUN mkdir -p /opt/nifi/nifi-current/flow
To tackle this you could
clone the Dockerfile of the image you use as base one (the one in
FROM) and remove the VOLUME directive manually. Then build it and
use in your FROM as base one.
You could try to avoid adding directories under the mount points specified in the Dockerfile
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 need to have an ubuntu image and then run a build process using that image. All is well until the build gets to the point of doing docker build etc.
Lets say I use the following to test this:
Dockerfile
FROM ubuntu:latest
I then build that - docker build -t ubuntudkr .
Next, I run it like:
docker run -ti -v /var/run/docker.sock:/var/run/docker.sock ubuntudkr
When I then run docker ps inside this container, I get the error bash: docker: command not found
All the examples I've found says I need to run:
docker run -v /var/run/docker.sock:/var/run/docker.sock \
-ti docker
They all use the docker image which contains the docker library. Is my answer then to install docker inside my base image to make it work? Does this then not go against what docker themselves says?
There are many other blog posts out there that gave the same advice, but my example does work. Where do I go wrong?
Replace the image ubuntu:latest in your dockerfile by the official docker:latest image wich contains docker binaries and does exactly what you want: https://hub.docker.com/_/docker
If you want to keep the Ubuntu image, you must install Docker tools following your error. By default, the Ubuntu image does not contain Docker binaries as a regular Ubuntu installation.
I'm a Docker beginner. I have pull and configured, installed Prestashop in my docker container.
I would like to build an image with this config.
How can I do?
Thanks.
To build a container you would have to run docker build -t myawsome_container:1.0.0 . (providing that you are in the directory where your Dockerfile is located)
Now to run your container you would want to run docker run myawsome_container:1.0.0
I am getting into Docker and am trying to better understand how it works out there in the "real world".
It occurs to me that, in practice:
You need a way to version Docker images
You need a way to tell the Docker engine (running on a VM) to stop/start/restart a particular container
You need a way to tell the Docker engine which version of a image to run
Does Docker ship with built-in commands for handling each of these? If not what tools/strategies are used for accomplishing them? Also, when I build a Docker image (via, say, docker build -t myapp .), what file type is produced and where is it located on the machine?
docker has all you need to build images and run containers. You can create your own image by writing a Dockerfile or by pulling it from the docker hub.
In the Dockerfile you specify another image as the basis for your image, run command install things. Images can have tags, for example the ubuntu image can have the latest or 12.04 tag, that can be specified with ubuntu:latest notation.
Once you have built the image with docker build -t image-name . you can create containers from that image with `docker run --name container-name image-name.
docker ps to see running containers
docker rm <container name/id> to remove containers
Suppose we have a docker file like bellow:
->Build from git without versioning:
sudo docker build https://github.com/lordash/mswpw.git#fecomments:comments
in here:
fecomments is branch name and comments is the folder name.
->building from git with tag and version:
sudo docker build https://github.com/lordash/mswpw.git#fecomments:comments -t lordash/comments:v1.0
->Now if you want to build from a directory: first go to comments directory the run command sudo docker build .
->if you want to add tag you can use -t or -tag flag to do that:
sudo docker build -t lordash . or sudo docker build -t lordash/comments .
-> Now you can version your image with the help of tag:
sudo docker build -t lordash/comments:v1.0 .
->you can also apply multiple tag to an image:
sudo docker build -t lordash/comments:latest -t lordash/comments:v1.0 .