fst: improve config

The config struct more or less "grew" to what it is today. This change moves things around to make more sense and fixes nonsensical comments describing obsolete behaviour.

Signed-off-by: Ophestra <cat@gensokyo.uk>

fst/container.go

@@ -0,0 +1,59 @@
+package fst
+
+import (
+	"git.gensokyo.uk/security/fortify/sandbox/seccomp"
+)
+
+type (
+	// ContainerConfig describes the container configuration baseline to which the app implementation adds upon.
+	ContainerConfig struct {
+		// container hostname
+		Hostname string `json:"hostname,omitempty"`
+
+		// extra seccomp flags
+		Seccomp seccomp.FilterOpts `json:"seccomp"`
+		// allow ptrace and friends
+		Devel bool `json:"devel,omitempty"`
+		// allow userns creation in container
+		Userns bool `json:"userns,omitempty"`
+		// share host net namespace
+		Net bool `json:"net,omitempty"`
+		// allow dangerous terminal I/O
+		Tty bool `json:"tty,omitempty"`
+		// allow multiarch
+		Multiarch bool `json:"multiarch,omitempty"`
+
+		// initial process environment variables
+		Env map[string]string `json:"env"`
+		// map target user uid to privileged user uid in the user namespace
+		MapRealUID bool `json:"map_real_uid"`
+
+		// pass through all devices
+		Device bool `json:"device,omitempty"`
+		// container host filesystem bind mounts
+		Filesystem []*FilesystemConfig `json:"filesystem"`
+		// create symlinks inside container filesystem
+		Link [][2]string `json:"symlink"`
+
+		// read-only /etc directory
+		Etc string `json:"etc,omitempty"`
+		// automatically set up /etc symlinks
+		AutoEtc bool `json:"auto_etc"`
+		// cover these paths or create them if they do not already exist
+		Cover []string `json:"cover"`
+	}
+
+	// FilesystemConfig is an abstract representation of a bind mount.
+	FilesystemConfig struct {
+		// mount point in container, same as src if empty
+		Dst string `json:"dst,omitempty"`
+		// host filesystem path to make available to the container
+		Src string `json:"src"`
+		// do not mount filesystem read-only
+		Write bool `json:"write,omitempty"`
+		// do not disable device files
+		Device bool `json:"dev,omitempty"`
+		// fail if the bind mount cannot be established for any reason
+		Must bool `json:"require,omitempty"`
+	}
+)