Merge pull request 'jpictl: introduce --config-file/-f as alternative to scanning m/' (#19)

Reviewed-on: #19

cmd/jpictl/config.go

@@ -1,11 +1,25 @@
 package main
 
-import "git.jpi.io/amery/jpictl/pkg/cluster"
+import (
+	"os"
+
+	"darvaza.org/core"
+
+	"git.jpi.io/amery/jpictl/pkg/cluster"
+)
+
+const (
+	// DefaultConfigFile is read if -f/--config-file isn't specified.
+	// If it doesn't exist, m/ will be scanned
+	DefaultConfigFile = "cloud.yaml"
+)
 
 // Config describes the repository
 type Config struct {
 	Base   string
 	Domain string
+
+	ConfigFile string
 }
 
 var cfg = &Config{
@@ -14,9 +28,32 @@ var cfg = &Config{
 }
 
 // LoadZones loads all zones and machines in the config directory
+// or file
 func (cfg *Config) LoadZones(resolve bool) (*cluster.Cluster, error) {
+	// try config file first
+	zones, err := cluster.NewFromConfig(cfg.ConfigFile,
+		cluster.ResolvePublicAddresses(resolve),
+		cluster.WithLogger(log),
+	)
+
+	switch {
+	case err == nil:
+		// file was good
+		return zones, nil
+	case !os.IsNotExist(err) || cfg.ConfigFile != DefaultConfigFile:
+		// file was bad
+		return nil, core.Wrapf(err, "NewFromConfig(%q)", cfg.ConfigFile)
+	}
+
+	// default file doesn't exist. scan instead.
 	return cluster.NewFromDirectory(cfg.Base, cfg.Domain,
 		cluster.ResolvePublicAddresses(resolve),
 		cluster.WithLogger(log),
 	)
 }
+
+func init() {
+	rootCmd.PersistentFlags().
+		StringVarP(&cfg.ConfigFile, "config-file", "f",
+			DefaultConfigFile, "config file (JSON or YAML)")
+}

pkg/cluster/cluster_fs.go

@@ -0,0 +1,25 @@
+package cluster
+
+import (
+	"io/fs"
+	"path/filepath"
+
+	"github.com/hack-pad/hackpadfs/os"
+)
+
+// DirFS returns a file system (an [fs.FS]) for the tree
+// of files rooted at the directory dir.
+func DirFS(dir string) (fs.FS, error) {
+	dir = filepath.Clean(dir)
+	fullPath, err := filepath.Abs(dir)
+	if err != nil {
+		return nil, err
+	}
+
+	sub, err := os.NewFS().Sub(fullPath[1:])
+	if err != nil {
+		return nil, err
+	}
+
+	return sub, nil
+}

pkg/cluster/cluster_import.go

@@ -0,0 +1,137 @@
+package cluster
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+
+	"gopkg.in/yaml.v3"
+)
+
+func (m *Cluster) init(opts *ScanOptions) error {
+	for _, fn := range []func(*ScanOptions) error{
+		m.initZones,
+		m.scanZoneIDs,
+		m.scanSort,
+		m.scanGateways,
+	} {
+		if err := fn(opts); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (m *Cluster) initZones(opts *ScanOptions) error {
+	var err error
+
+	sub, err := DirFS(m.BaseDir)
+	if err != nil {
+		return err
+	}
+
+	m.dir = sub
+
+	m.ForEachZone(func(z *Zone) bool {
+		err = m.initZone(z, opts)
+		return err != nil
+	})
+
+	return err
+}
+
+func (m *Cluster) initZone(z *Zone, _ *ScanOptions) error {
+	var hasMissing bool
+	var lastMachineID int
+
+	z.zones = m
+	z.logger = m
+
+	z.ForEachMachine(func(p *Machine) bool {
+		p.zone = z
+		p.logger = z
+
+		switch {
+		case p.ID == 0:
+			hasMissing = true
+		case p.ID > lastMachineID:
+			lastMachineID = z.ID
+		}
+
+		return false
+	})
+
+	if hasMissing {
+		next := lastMachineID + 1
+
+		z.ForEachMachine(func(p *Machine) bool {
+			if p.ID == 0 {
+				p.ID, next = next, next+1
+			}
+
+			return false
+		})
+	}
+
+	z.ForEachMachine(func(p *Machine) bool {
+		p.Name = fmt.Sprintf("%s-%v", z.Name, p.ID)
+		return false
+	})
+
+	return nil
+}
+
+func decodeConfigData(data []byte) (out *Cluster, err error) {
+	// try JSON first
+	out = new(Cluster)
+	err = json.Unmarshal(data, out)
+	if err == nil {
+		// good json
+		return out, nil
+	} else if _, ok := err.(*json.SyntaxError); !ok {
+		// bad json
+		return nil, err
+	}
+
+	out = new(Cluster)
+	err = yaml.Unmarshal(data, out)
+	if err != nil {
+		// bad yaml too
+		return nil, err
+	}
+
+	// good yaml
+	return out, nil
+}
+
+// NewFromConfig loads the cluster data from the given file
+func NewFromConfig(filename string, opts ...ScanOption) (*Cluster, error) {
+	var scanOptions ScanOptions
+
+	data, err := os.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	m, err := decodeConfigData(data)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, opt := range opts {
+		if err = opt(m, &scanOptions); err != nil {
+			return nil, err
+		}
+	}
+
+	if err = m.setScanDefaults(&scanOptions); err != nil {
+		return nil, err
+	}
+
+	if err := m.init(&scanOptions); err != nil {
+		return nil, err
+	}
+
+	return m, nil
+}

pkg/cluster/cluster_scan_options.go

@@ -6,7 +6,6 @@ import (
 
 	"darvaza.org/resolver"
 	"darvaza.org/slog"
-	"github.com/hack-pad/hackpadfs/os"
 )
 
 // A ScanOption pre-configures the Zones before scanning
@@ -101,7 +100,7 @@ func NewFromDirectory(dir, domain string, opts ...ScanOption) (*Cluster, error)
 		return nil, err
 	}
 
-	sub, err := os.NewFS().Sub(fullPath[1:])
+	sub, err := DirFS(dir)
 	if err != nil {
 		return nil, err
 	}