This topic describes Garden, the component that VMware Tanzu Application Service for VMs (TAS for VMs) uses to create and manage isolated environments called containers. Each instance of an app deployed to TAS for VMs runs within a container. For more information about how containers work, see Container Mechanics in Container Security.
Garden has pluggable back ends for different platforms and runtimes, and specifies a set of interfaces that each platform-specific back end must implement. These interfaces contain methods to perform the following actions:
STDERRdata out of containers
For more information, see the Garden repository on GitHub.
TAS for VMs currently uses the Garden-runC back end, a Linux-specific implementation of the Garden interface using the Open Container Interface (OCI) standard. Previous versions of TAS for VMs used the Garden-Linux back end. For more information, see the Garden-Linux repository on GitHub.
Note: PAS v1.8.8 and later use Garden-runC instead of Garden-Linux.
Garden-runC has the following features:
Uses the same OCI low-level container execution code as Docker and Kubernetes, so container images run identically across all three platforms
AppArmor is configured and enforced by default for all unprivileged containers
Seccomp allowlisting restricts the set of system calls a container can access, reducing the risk of container breakout
Allows pluggable networking and rootfs management
For more information, see the Garden-runC repository on GitHub.
Garden manages container filesystems through a plugin interface. TAS for VMs uses the GrootFS plugin for this task. GrootFS is a Linux-specific implementation of the Garden volume plugin interface.
GrootFS performs the following actions:
For more information, see GrootFS Disk Usage and the GrootFS repository on GitHub.