implement Executor pattern

Makefile

@@ -8,7 +8,7 @@ LDFLAGS=-ldflags "-X main.Version=${VERSION} -X main.BuildTime=${BUILD_TIME}"
 all: build-linux
 
 test:
-	go test ./...
+	go test -v ./...
 
 build-linux:
 	GOOS=linux GOARCH=amd64 go build ${LDFLAGS} -o bin/thanks ./cmd/thanks

internal/executor/executor.go

@@ -0,0 +1,11 @@
+package executor
+
+import (
+	"context"
+	"os/exec"
+)
+
+type Executor interface {
+	CombinedOutput(context.Context, string, ...string) ([]byte, error)
+	CommandContext(context.Context, string, ...string) *exec.Cmd
+}

internal/executor/local.go

@@ -0,0 +1,16 @@
+package executor
+
+import (
+	"context"
+	"os/exec"
+)
+
+type LocalExecutor struct{}
+
+func (l LocalExecutor) CombinedOutput(ctx context.Context, name string, arg ...string) ([]byte, error) {
+	return l.CommandContext(ctx, name, arg...).CombinedOutput()
+}
+
+func (l LocalExecutor) CommandContext(ctx context.Context, name string, arg ...string) *exec.Cmd {
+	return exec.CommandContext(ctx, name, arg...)
+}

internal/executor/ssh.go

@@ -0,0 +1,21 @@
+package executor
+
+import (
+	"context"
+	"os/exec"
+)
+
+type SSHExecutor struct {
+	SSHTarget string
+}
+
+func (s SSHExecutor) CombinedOutput(ctx context.Context, name string, arg ...string) ([]byte, error) {
+	return s.CommandContext(ctx, name, arg...).CombinedOutput()
+}
+
+func (s SSHExecutor) CommandContext(ctx context.Context, name string, arg ...string) *exec.Cmd {
+	newArg := append([]string{s.SSHTarget, name}, arg...)
+	cmd := exec.CommandContext(ctx, "ssh", newArg...)
+
+	return cmd
+}

internal/jobs/jobs.go

@@ -7,12 +7,26 @@ import (
 	"context"
 	"fmt"
 	"log"
+	"os"
+	"os/exec"
 	"strings"
 	"time"
 
+	"git.gentoo.party/sam/thanks/internal/executor"
 	"git.gentoo.party/sam/thanks/internal/zfs"
 )
 
+type BackupHookCommand struct {
+	Command string   `yaml:"command"`
+	Args    []string `yaml:"args"`
+	Env     []string `yaml:"env"`
+}
+
+type BackupHooks struct {
+	Completed BackupHookCommand `yaml:"completed"` // called upon successful completion of a backup job
+	Error     BackupHookCommand `yaml:"error"`
+}
+
 type BackupJob struct {
 	Source     string        `yaml:"source"`     // the source dataset (e.g., zroot)
 	TargetHost string        `yaml:"targetHost"` // SSH-compatible host
@@ -21,15 +35,14 @@ type BackupJob struct {
 	MaxAge     time.Duration `yaml:"maxAge"`     // age at which to delete snapshot (if Keep is met)
 	Recursive  bool          `yaml:"recursive"`  // create recursive snapshots
 	Prefix     string        `yaml:"prefix"`     // name each snapshot with this prefix
+	Hooks      BackupHooks   `yaml:"hooks"`      // external programs (libnotify, sendmail, etc) to call
+
+	localExecutor  executor.Executor
+	remoteExecutor executor.Executor
 }
 
-//	func (j *BackupJob) getBaseSnap() {
-//		params := "zfs get -j -d 1 -t snapshot guid,creation %s"
-//		srcCmd := fmt.Sprintf(params, j.Source)
-//		dstCmd := fmt.Sprintf(params, j.Target)
-//	}
 func (j *BackupJob) listSnapshots(ctx context.Context) ([]zfs.Snapshot, error) {
-	allSnaps, err := zfs.Snapshots(ctx, j.Source)
+	allSnaps, err := zfs.Snapshots(ctx, j.localExecutor, j.Source)
 	if err != nil {
 		return nil, err
 	}
@@ -46,7 +59,6 @@ func (j *BackupJob) listSnapshots(ctx context.Context) ([]zfs.Snapshot, error) {
 }
 
 func (j *BackupJob) snapName() string {
-	// ts := time.Now().Format(time.RFC3339)
 	ts := time.Now().UnixMicro()
 	if j.Prefix == "" {
 		return fmt.Sprintf("%d", ts)
@@ -58,20 +70,16 @@ func (j *BackupJob) snapName() string {
 func (j *BackupJob) Snapshot(ctx context.Context) (string, error) {
 	snapName := j.snapName()
 	snap := fmt.Sprintf("%s@%s", j.Source, snapName)
-
+	err := zfs.CreateSnapshot(
-	out, err := zfs.Cmd(
 		ctx,
-		"zfs snapshot %s",
+		j.localExecutor,
-		snap,
+		j.Source,
+		snapName,
 	)
-	if err != nil {
-		log.Printf("zfs-snapshot: error: %s", out)
-		return snapName, nil
-	}
 	return snap, err
 }
 
-func (j *BackupJob) FullSend(ctx context.Context, snap string) {
+func (j *BackupJob) FullSend(ctx context.Context, snap string) error {
 	out, err := zfs.FullSend(
 		ctx,
 		snap,
@@ -79,8 +87,9 @@ func (j *BackupJob) FullSend(ctx context.Context, snap string) {
 		j.Target,
 	)
 	if err != nil {
-		log.Fatalf("zfs-send: error: %s", out)
+		return fmt.Errorf("zfs-send: error: %s - %s", err.Error(), out)
 	}
+	return nil
 }
 
 func (j *BackupJob) IncrementalSend(ctx context.Context, prevSnap *zfs.Snapshot, newSnap string) ([]byte, error) {
@@ -122,10 +131,40 @@ func (j *BackupJob) Retain(ctx context.Context) error {
 	return nil
 }
 
-func (j *BackupJob) Do(ctx context.Context) {
+func (j *BackupJob) findCommonAnscestor(ctx context.Context) {
+	localSnapshots, err := j.listSnapshots(ctx)
+}
+
+type HookErr struct {
+	message string
+}
+
+func (e *HookErr) Error() string {
+	return fmt.Sprintf("error while running hook: %s", e.message)
+}
+
+func (j *BackupJob) Do(ctx context.Context) error {
+	err := j.do(ctx)
+	if err != nil {
+		log.Print("job encountered error, running error hook\n")
+		err = j.runHookError(ctx, err)
+		if err != nil {
+			log.Printf("error running hook! %s", err.Error())
+		}
+		return &HookErr{message: err.Error()}
+
+	} else {
+		err = j.runHookCompleted(ctx)
+		return &HookErr{message: err.Error()}
+	}
+
+	return err
+}
+
+func (j *BackupJob) do(ctx context.Context) error {
 	currentSnaps, err := j.listSnapshots(ctx)
 	if err != nil {
-		log.Fatal("failed to list existing snapshots")
+		return fmt.Errorf("failed to list existing snapshots: %s", err.Error())
 	}
 	var prev *zfs.Snapshot
 
@@ -135,14 +174,70 @@ func (j *BackupJob) Do(ctx context.Context) {
 
 	newSnapshot, err := j.Snapshot(ctx)
 	if err != nil {
-		log.Fatalf("error creating new snapshot: %s", err.Error())
+		return fmt.Errorf("error creating new snapshot: %s", err.Error())
 	}
 
+	var sendErr error
 	if prev == nil {
 		// Full Send
-		j.FullSend(ctx, newSnapshot)
+		sendErr = j.FullSend(ctx, newSnapshot)
 	} else {
 		// Inc send
-		j.IncrementalSend(ctx, prev, newSnapshot)
+		_, sendErr = j.IncrementalSend(ctx, prev, newSnapshot)
 	}
+
+	if sendErr != nil {
+		return fmt.Errorf("error sending backup: %s", sendErr.Error())
+	}
+
+	return nil
+}
+
+func (j *BackupJob) runHookCompleted(ctx context.Context) error {
+	cmdDef := j.Hooks.Completed
+	if cmdDef.Command == "" {
+		return nil
+	}
+
+	timeoutCtx, cancel := context.WithTimeout(
+		ctx,
+		time.Second*3,
+	)
+	cmd := exec.CommandContext(timeoutCtx, cmdDef.Command, cmdDef.Args...)
+	defer cancel()
+	cmd.Env = []string{
+		fmt.Sprintf("THANKS_JOB_SOURCE=%s", j.Source),
+		fmt.Sprintf("THANKS_JOB_TARGET=%s", j.Target),
+	}
+	return cmd.Run()
+}
+
+func (j *BackupJob) runHookError(ctx context.Context, err error) error {
+	cmdDef := j.Hooks.Error
+	if cmdDef.Command == "" {
+		return nil
+	}
+
+	timeoutCtx, cancel := context.WithTimeout(
+		ctx,
+		time.Second*3,
+	)
+	cmd := exec.CommandContext(timeoutCtx, cmdDef.Command, cmdDef.Args...)
+	defer cancel()
+	cmd.Env = append(
+		[]string{
+			fmt.Sprintf("THANKS_JOB_SOURCE=%s", j.Source),
+			fmt.Sprintf("THANKS_JOB_TARGET=%s", j.Target),
+			fmt.Sprintf("THANKS_JOB_ERROR=%s", err.Error()),
+			fmt.Sprintf("DISPLAY=%s", os.Getenv("DISPLAY")),
+		},
+		cmdDef.Env...,
+	)
+
+	out, runErr := cmd.CombinedOutput()
+	if runErr != nil {
+		log.Printf("%s", out)
+	}
+
+	return runErr
 }

internal/jobs/jobs_test.go

@@ -0,0 +1,36 @@
+package jobs_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"git.gentoo.party/sam/thanks/internal/jobs"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_JobHookError(t *testing.T) {
+	job := jobs.BackupJob{
+		Target:     "znothing/nothing",
+		TargetHost: "devnull",
+		Source:     "zempty/empty",
+		Keep:       1,
+		MaxAge:     1 * time.Second,
+		Recursive:  false,
+		Hooks: jobs.BackupHooks{
+			Error: jobs.BackupHookCommand{
+				Command: "/usr/bin/notify-send",
+				Args:    []string{"--app-name=thanks", "--urgency=CRITICAL", "Backup Failure", "Backup failed"},
+				Env: []string{
+					"XDG_RUNTIME_DIR=/run/user/1000/",
+				},
+			},
+		},
+	}
+
+	var hookErr *jobs.HookErr
+
+	err := job.Do(context.Background())
+	assert.NotNil(t, err, "expected job to produce an error")
+	assert.NotErrorAsf(t, err, &hookErr, "expected a non-hook error, got %w", err)
+}

internal/zfs/zfs.go

@@ -11,6 +11,7 @@ import (
 	"strings"
 	"time"
 
+	"git.gentoo.party/sam/thanks/internal/executor"
 	"git.gentoo.party/sam/thanks/internal/runner"
 )
 
@@ -37,6 +38,20 @@ func Cmd(ctx context.Context, arg string, a ...any) ([]byte, error) {
 	return out, err
 }
 
+func CreateSnapshot(ctx context.Context, e executor.Executor, dataset, name string) error {
+	_, err := e.CombinedOutput(
+		ctx,
+		"zfs",
+		"snapshot",
+		fmt.Sprintf("%s@%s", dataset, name),
+	)
+	if err != nil {
+		return fmt.Errorf("zfs-snapshot error: %w", err)
+	}
+
+	return nil
+}
+
 func ParseSnapshots(reader io.Reader) ([]Snapshot, error) {
 	scanner := bufio.NewScanner(reader)
 
@@ -78,8 +93,8 @@ func ParseSnapshots(reader io.Reader) ([]Snapshot, error) {
 	return snaps, nil
 }
 
-func Snapshots(ctx context.Context, target string) ([]Snapshot, error) {
+func Snapshots(ctx context.Context, e executor.Executor, target string) ([]Snapshot, error) {
-	cmd := exec.CommandContext(
+	cmd := e.CommandContext(
 		ctx,
 		"zfs",
 		"list",
@@ -157,7 +172,6 @@ func IncrementalSend(ctx context.Context, prevSnapName, newSnapName, sshTarget,
 	)
 }
 
-func Destroy(ctx context.Context, target string) ([]byte, error) {
+func Destroy(ctx context.Context, e executor.Executor, target string) ([]byte, error) {
-	cmd := exec.CommandContext(ctx, "zfs", "destroy", target)
+	return e.CombinedOutput(ctx, "zfs", target)
-	return cmd.CombinedOutput()
 }

thanks.yaml.example

@@ -0,0 +1,14 @@
+jobs:
+  - source: "zroot/home/sam/thanks"
+    target: "zrust/backup/weller/thanks"
+    targetHost: "backup@woodford.gentoo.party"
+    keep: 30
+    prefix: "thanks-"
+    recursive: false
+    hooks:
+      completed: 
+        cmd: "backup-success.sh" 
+        args: []
+      error:
+        cmd: "backup-error.sh" 
+        args: []