A version 2 file could share a container’s volumes with volumes_from, which is how the data-container pattern worked. Version 3 removes it, because a scheduler placing containers on…
A container without a memory limit can take the host down. A container with one gets its process killed by the kernel, which from inside looks like the…
Since 1.12 the engine has had orchestration built in — docker swarm init and a cluster exists. It is genuinely simple and almost nobody is running it, which…
depends_on controls start order and nothing else. The database container being started is not the database accepting connections, so the application starts, fails to connect, and exits. Version…
Building assets inside the runtime image drags a compiler toolchain into production, and deleting it afterwards does nothing because layers are additive. Until May the workaround was two…
The two commands look like alternatives and do different things. exec runs a process inside a container that is already up; run starts a new container from the…
Deploying by rsync on a Friday afternoon, and what replaced it: lint, test, build, stage, promote — with a rollback that is the same mechanism rather than a…
A containerised application writing to /var/log/app.log has written to a filesystem that disappears with the container, and nothing outside can see it. The convention is that a container…