I am learning Docker
docker build -t mm/cowsay .
Should I go to cowsay folder or should I run it from my home mm directory?
I have registered on Docker hub.
The docker build command follows instructions specified in a given Dockerfile, and outputs an image.
Syntax:
docker build \
-t <tag-of-output-image> \
-f <path-to-dockerfile>
If you use . instead of -f <path-to-dockerfile>, you are telling the Docker Engine to use the Dockerfile in the current directory.
So you need to run your command from where the Dockerfile exists.
Related
I m trying to write a shell script that builds/runs containers and then copies files from docker container to host.
docker build . -t container:latest
docker run -t -d container /bin/bash
docker cp container_id:/xyz/xyz.txt /tmp
How can I capture the container id from the build and then use it within the shell script? Thanks for your help.
The first option would be to simply store the container ID in a variable.
docker build . -t container:latest
container_id="$(docker run -t -d container /bin/bash)"
docker cp "$container_id":/xyz/xyz.txt /tmp
Docker also allows you to specify a container name.
docker build . -t container:latest
docker run -t --name NAME -d container /bin/bash
docker cp NAME:/xyz/xyz.txt /tmp
Following this post -- docker: "build" requires 1 argument. See 'docker build --help', I'm trying to build my docker image using a file with a non-traditional name ("local.Dockerfile") on Mac 10.13.6. I tried the below
localhost:mydir davea$ docker build -t mycontainer -f local.Dockerfile
"docker build" requires exactly 1 argument.
See 'docker build --help'.
Usage: docker build [OPTIONS] PATH | URL | -
Build an image from a Dockerfile
But docker is choking on me. I'm running version 19.03.5.
Basic command to build docker image:
docker build -t <image_tag> -f <Dockerfile_name> <Path_of_Dockerfile>
So you are missing to specify the path of your local.Dockerfile (which is mandatory). If your dockerfile is in the current directory from where you are running the command, then run below command, else update the path accordingly:
docker build -t mycontainer -f local.Dockerfile .
Note: You can specify the Path_of_Dockerfile in any way: relative path or absolute path, whichever way you feel comfortable.
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.
I'm learning how to use docker.
I want to deploy a microservice for swagger. I can do
docker pull schickling/swagger-ui
docker run -p 80:8080 -e API_URL=http://myapiurl/api.json swaggerapi/swagger-ui
To deploy it, I need a dockerfile i can run.
How do i generate the dockerfile in a way I can run it with docker build ?
The original question asks for a Dockerfile, perhaps for some CI/CD workflow, so this answer addresses that requirement:
Create a very simple Dockerfile beginning with
FROM schickling/swagger-ui
Then from that directory run
$ docker build -t mycontainername .
Which can then be run:
$ docker run -p 80:8080 -e API_URL=http://myapiurl/api.json mycontainername
Usually the docker pull pulls the Dockerfile. The Dockerfile for swagger is on the docker repo for it if you wanted to edit it or customize it.
(https://hub.docker.com/r/schickling/swagger-ui/~/dockerfile/)
That one should work with the build command. The build command builds the image, the run command turns the image into a container. The docker pull command should pull the image in. You don't need to run docker build for it as you should already have the image from the pull. You only need to do docker run.
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 .