move implementation to internal/ directory (#828)

internal/client/zfsabstractions_list.go

@@ -0,0 +1,100 @@
+package client
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"sync"
+
+	"github.com/fatih/color"
+	"github.com/pkg/errors"
+	"github.com/spf13/pflag"
+
+	"github.com/zrepl/zrepl/internal/cli"
+	"github.com/zrepl/zrepl/internal/endpoint"
+	"github.com/zrepl/zrepl/internal/util/chainlock"
+)
+
+var zabsListFlags struct {
+	Filter zabsFilterFlags
+	Json   bool
+}
+
+var zabsCmdList = &cli.Subcommand{
+	Use:             "list",
+	Short:           `list zrepl ZFS abstractions`,
+	Run:             doZabsList,
+	NoRequireConfig: true,
+	SetupFlags: func(f *pflag.FlagSet) {
+		zabsListFlags.Filter.registerZabsFilterFlags(f, "list")
+		f.BoolVar(&zabsListFlags.Json, "json", false, "emit JSON")
+	},
+}
+
+func doZabsList(ctx context.Context, sc *cli.Subcommand, args []string) error {
+	var err error
+
+	if len(args) > 0 {
+		return errors.New("this subcommand takes no positional arguments")
+	}
+
+	q, err := zabsListFlags.Filter.Query()
+	if err != nil {
+		return errors.Wrap(err, "invalid filter specification on command line")
+	}
+
+	abstractions, errors, drainDone, err := endpoint.ListAbstractionsStreamed(ctx, q)
+	if err != nil {
+		return err // context clear by invocation of command
+	}
+	defer drainDone()
+
+	var line chainlock.L
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	// print results
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		enc := json.NewEncoder(os.Stdout)
+		for a := range abstractions {
+			func() {
+				defer line.Lock().Unlock()
+				if zabsListFlags.Json {
+					enc.SetIndent("", "  ")
+					if err := enc.Encode(a); err != nil {
+						panic(err)
+					}
+					fmt.Println()
+				} else {
+					fmt.Println(a)
+				}
+			}()
+		}
+	}()
+
+	// print errors to stderr
+	errorColor := color.New(color.FgRed)
+	var errorsSlice []endpoint.ListAbstractionsError
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		for err := range errors {
+			func() {
+				defer line.Lock().Unlock()
+				errorsSlice = append(errorsSlice, err)
+				errorColor.Fprintf(os.Stderr, "%s\n", err)
+			}()
+		}
+	}()
+	wg.Wait()
+	if len(errorsSlice) > 0 {
+		errorColor.Add(color.Bold).Fprintf(os.Stderr, "there were errors in listing the abstractions")
+		return fmt.Errorf("")
+	} else {
+		return nil
+	}
+
+}