Kubernetes - Share single file between containers (within the same pod)
One of the simplest approaches is to use emptyDir: https://kubernetes.io/docs/concepts/storage/volumes/#emptydir
In your container that generates the file that needs to be shared, mount emptyDir volume with write access and copy the file there. In your sidecar that needs to read the file, mount the same volume as read only and read the file.With this pattern, all containers in the pod can have access to the same file system with read / write as needed.