Docker Compose is a tool that you will use to define and share multi-container applications. This means you can run a project with multiple containers using a single source, you will need to create a YAML file to define the services you need and run with a single command.
docker-compose.yml
services:simplecore.api:container_name:simplecoreapi.from.docker.composed#image: bindplus.api.v2 # will use imageimage:${DOCKER_REGISTRY-}simplecoreapi:1.0.0# will use Dockerfilebuild:context:.# ASP-NET-Core-Simple-API replace with the actual name of your project, docker file locationdockerfile:ASP-NET-Core-Simple-API/Dockerfileports:-49195:80#[targer port]:[docker file port]
The docker-compose.override.yml is the configuration file where you can override existing settings from the docker-compose.yml or can even add completely new services.
Create docker image using this command: docker build -t [image name] [docker file location]
Example:
dockerbuild-t simplecoreapi:1.0.0.
Step 4: Docker Container
Create docker container using this command: docker run -d -p [port]:[exposed port] –name [container name] [image name] Example: (Note it will return the container id)
Note: exposed port should be the same as the exposed port in the docker file.
Step 5: Let’s test it!
Testing our container using Postman:
Accessing the files in the container
The snap shot below is from Docker desktop, you can see that the files generated by the api are stored in the payloads-default folder, which is configure in the appsettings.json:
Docker Container Shell
We can also access the files saved using the docker container shell, here I will show you, take note I switched to my windows machine, here’s what I did:
We need to get the container Id using the command: docker ps
Run bash inside the container using the command: docker exec -it 1653 sh //1653 is the first 4 character of the container id
inside the shell, change the directory to payloads-default to list the files created.
In the excerpt of the saved payload below, notice that the values of the Environment and LogJsonPath are from the environment passed.
Note:
· “LogJson__Path=Payloads” is the same as in appsettings.json: “LogJson”: { “Path”: ” payloads” }
· Will work if not assigned/declared in appsettings.json
· Overriding appsettings file
· To override environment variables, remove them from the appsettings file
Docker Volumes
Volumes are a mechanism for storing data outside containers. All volumes are managed by Docker and stored in a dedicated directory on your host, usually /app for Macbook systems.
Volumes are mounted to filesystem paths in your containers. When containers write to a path beneath a volume mount point, the changes will be applied to the volume instead of the container’s writable image layer.
