CUA Env vars

Windows

"ProgramFiles" - if unset, logs an error
"WINDIR" - if unset, logs an error

Linux

"HOST_PROC" - returns "/proc" if unset.
"HOST_MOUNT_PREFIX" - plugins/inputs/system/ps used for host volume mounts

Universal

"ENABLE_DEFAULT_PLUGINS" - if set to "false", disables default plugins
"CUA_CONFIG_PATH" - if set, overrides any other config file
"ECS_CONTAINER_METADATA_URI" - if set, enables ecs v3 endpoint. if unset, v2 is used.
"DOCKER_HOST" - if unset, defaults to "localhost"