This type of information/metadata is not passed into the container by default. There are 2 reasons for this. if every metadata about the container was passed into the container, it could potentially pose a security risk when someone breaks into it container shouldn’t need this kind of information anyway The reason why you can get … Read more
In Linux host: Run the container in privileged mode (–privileged) Add all capabilities (–cap-add=ALL) mount host /lib/modules into the container (-v /lib/modules:/lib/modules) docker run –name container_name \ –privileged \ –cap-add=ALL -d \ -v /dev:/dev \ -v /lib/modules:/lib/modules \ image_id Caution: Here all Linux capabilities are added so capabilities can be refined. Few words about Linux … Read more
Each Dockerfile RUN step runs a new container and a new shell. If you try to set an environment variable in one shell, it will not be visible later on. For example, you might experiment with this Dockerfile: FROM busybox ENV FOO=foo1 RUN export FOO=foo2 RUN export BAR=bar CMD echo FOO is $FOO, BAR is … Read more
when we pull ubuntu image then it have different kernel No it does not: it does not have the kernel part: it relies on the kernel of the host (the one running docker engine) for all system calls. As mentioned in “Docker vs Virtualization“: Initially Docker was built as an abstraction layer on top of … Read more
Use the alias “db” that you have defined in file to refer to the database host name. Containers for the linked service will be reachable at a hostname identical to the alias, or the service name if no alias was specified. Source: https://docs.docker.com/compose/compose-file/compose-file-v2/#links
Since nginx 1.19 you can now use environment variables in your configuration with docker-compose. I used the following setup: # file: docker/nginx/templates/default.conf.conf upstream api-upstream { server ${API_HOST}; } # file: docker-compose.yml services: nginx: image: nginx:1.19-alpine volumes: – “./docker/nginx/templates:/etc/nginx/templates/” environment: NGINX_ENVSUBST_TEMPLATE_SUFFIX: “.conf” API_HOST: api.example.com I’m going off script a little from the example in the documentation. … Read more
Dockerfiles are meant to be portable and shared. The host-dir volume is something 100% host dependent and will break on any other machine, which is a little bit off the Docker idea. Because of this, it is only possible to use portable instructions within a Dockerfile. If you need a host-dir volume, you need to … Read more
My colleague came up with this and it works with our company network drive and it might help someone out there. We start by creating a docker volume named mydockervolume. docker volume create –driver local –opt type=cifs –opt device=//networkdrive-ip/Folder –opt o=user=yourusername,domain=yourdomain,password=yourpassword mydockervolume –driver specifies the volume driver name –opt Sets driver specific options. I guess … Read more
After countless hours of research, I decided to extend my image with the following Dockerfile: FROM sphinxsearch VOLUME /usr/local/sphinx/etc VOLUME /usr/local/sphinx/var RUN mkdir -p /sphinx && cd /sphinx && cp -avr /usr/local/sphinx/etc . && cp -avr /usr/local/sphinx/var . ADD docker-entrypoint.sh / RUN chmod +x /docker-entrypoint.sh ENTRYPOINT [“/docker-entrypoint.sh”] Extending it benefited it me in that I … Read more
That is actively requested in docker/machine issue 1709 I want to be able to specify the IP address of a VM (i.e. the value that’s listed under “URL” in docker-machine ls) when I create it with docker-machine create. I want this because I’ve been relying on boot2docker’s default address of 192.168.59.103, but now it varies … Read more