feat: initial public version

config/config.go

@@ -0,0 +1,165 @@
+// Package config reads application config.
+package config
+
+import (
+	"encoding/json"
+	"sort"
+)
+
+// A Config describes application cofig.
+type Config struct {
+	PoolSize int   `json:"pool_size"`
+	Verbose  bool  `json:"verbose"`
+	Box      *Box  `json:"box"`
+	Step     *Step `json:"step"`
+	HTTP     *HTTP `json:"http"`
+
+	// These are the available containers ("boxes").
+	Boxes map[string]*Box `json:"boxes"`
+
+	// These are the "sandboxes". Each sandbox can contain
+	// multiple commands, and each command can contain
+	// multiple steps. Each step is executed in a specific box.
+	Commands map[string]SandboxCommands `json:"commands"`
+}
+
+// BoxNames returns configured box names.
+func (cfg *Config) BoxNames() []string {
+	names := make([]string, 0, len(cfg.Boxes))
+	for name := range cfg.Boxes {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	return names
+}
+
+// CommandNames returns configured command names.
+func (cfg *Config) CommandNames() []string {
+	names := make([]string, 0, len(cfg.Commands))
+	for name := range cfg.Commands {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	return names
+}
+
+// ToJSON returns JSON-encoded config with indentation.
+func (cfg *Config) ToJSON() string {
+	data, _ := json.MarshalIndent(cfg, "", "  ")
+	return string(data)
+}
+
+// A Box describes a specific container.
+// There is an important difference between a "sandbox" and a "box".
+// A box is a single container. A sandbox is an environment in which we run commands.
+// A sandbox command can contain multiple steps, each of which runs in a separate box.
+// So the relation sandbox -> box is 1 -> 1+.
+type Box struct {
+	Image   string `json:"image"`
+	Runtime string `json:"runtime"`
+	Host
+
+	Files []string `json:"files"`
+}
+
+// A Host describes container Host attributes.
+type Host struct {
+	CPU      int      `json:"cpu"`
+	Memory   int      `json:"memory"`
+	Storage  string   `json:"storage"`
+	Network  string   `json:"network"`
+	Writable bool     `json:"writable"`
+	Volume   string   `json:"volume"`
+	Tmpfs    []string `json:"tmpfs"`
+	CapAdd   []string `json:"cap_add"`
+	CapDrop  []string `json:"cap_drop"`
+	Ulimit   []string `json:"ulimit"`
+	// do not use the ulimit nproc because it is
+	// a per-user setting, not a per-container setting
+	NProc int `json:"nproc"`
+}
+
+// SandboxCommands describes all commands available for a sandbox.
+// command name : command
+type SandboxCommands map[string]*Command
+
+// A Command describes a specific set of actions to take
+// when executing a command in a sandbox.
+type Command struct {
+	Engine string  `json:"engine"`
+	Entry  string  `json:"entry"`
+	Before *Step   `json:"before"`
+	Steps  []*Step `json:"steps"`
+	After  *Step   `json:"after"`
+}
+
+// A Step describes a single step of a command.
+type Step struct {
+	Box     string   `json:"box"`
+	User    string   `json:"user"`
+	Action  string   `json:"action"`
+	Stdin   bool     `json:"stdin"`
+	Command []string `json:"command"`
+	Timeout int      `json:"timeout"`
+	NOutput int      `json:"noutput"`
+}
+
+// An HTTP describes HTTP engine settings.
+type HTTP struct {
+	Hosts map[string]string `json:"hosts"`
+}
+
+// setBoxDefaults sets default box properties
+// instead of zero values.
+func setBoxDefaults(box, defs *Box) {
+	if box.Runtime == "" {
+		box.Runtime = defs.Runtime
+	}
+	if box.CPU == 0 {
+		box.CPU = defs.CPU
+	}
+	if box.Memory == 0 {
+		box.Memory = defs.Memory
+	}
+	if box.Storage == "" {
+		box.Storage = defs.Storage
+	}
+	if box.Network == "" {
+		box.Network = defs.Network
+	}
+	if box.Volume == "" {
+		box.Volume = defs.Volume
+	}
+	if box.Tmpfs == nil {
+		box.Tmpfs = defs.Tmpfs
+	}
+	if box.CapAdd == nil {
+		box.CapAdd = defs.CapAdd
+	}
+	if box.CapDrop == nil {
+		box.CapDrop = defs.CapDrop
+	}
+	if box.Ulimit == nil {
+		box.Ulimit = defs.Ulimit
+	}
+	if box.NProc == 0 {
+		box.NProc = defs.NProc
+	}
+}
+
+// setStepDefaults sets default command step
+// properties instead of zero values.
+func setStepDefaults(step, defs *Step) {
+	if step.User == "" {
+		step.User = defs.User
+	}
+	if step.Action == "" {
+		step.Action = defs.Action
+	}
+	if step.Timeout == 0 {
+		step.Timeout = defs.Timeout
+	}
+	if step.NOutput == 0 {
+		step.NOutput = defs.NOutput
+	}
+}