cli/command/system: fix "docker events" not supporting --format=json

Before this patch: docker events --format=json json json json ^C With this patch: docker events --format=json {"status":"create","id":"4ac3bba8abd68961e627540fed81ad16d55b88e45629d7cdb792126d09b6488d","from":"hello-world","Type":"container","Action":"create","Actor":{"ID":"4ac3bba8abd68961e627540fed81ad16d55b88e45629d7cdb792126d09b6488d","Attributes":{"image":"hello-world","name":"dreamy_goldstine"}},"scope":"local","time":1693168508,"timeNano":1693168508190136885} {"status":"attach","id":"4ac3bba8abd68961e627540fed81ad16d55b88e45629d7cdb792126d09b6488d","from":"hello-world","Type":"container","Action":"attach","Actor":{"ID":"4ac3bba8abd68961e627540fed81ad16d55b88e45629d7cdb792126d09b6488d","Attributes":{"image":"hello-world","name":"dreamy_goldstine"}},"scope":"local","time":1693168508,"timeNano":1693168508192851593} {"Type":"network","Action":"connect","Actor":{"ID":"c54920dd5074a73e28bea62007e0334d81cc040a90372be311cf16806403d350","Attributes":{"container":"4ac3bba8abd68961e627540fed81ad16d55b88e45629d7cdb792126d09b6488d","name":"bridge","type":"bridge"}},"scope":"local","time":1693168508,"timeNano":1693168508212398802} {"status":"start","id":"4ac3bba8abd68961e627540fed81ad16d55b88e45629d7cdb792126d09b6488d","from":"hello-world","Type":"container","Action":"start","Actor":{"ID":"4ac3bba8abd68961e627540fed81ad16d55b88e45629d7cdb792126d09b6488d","Attributes":{"image":"hello-world","name":"dreamy_goldstine"}},"scope":"local","time":1693168508,"timeNano":1693168508312969843} ^C Signed-off-by: Sebastiaan van Stijn <[email protected]>
docker · Aug 27, 2023 · 3a6f3d4 · 3a6f3d4
1 parent 6f80b0b
commit 3a6f3d4
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Showing 7 changed files with 111 additions and 9 deletions.
diff --git a/cli/command/system/client_test.go b/cli/command/system/client_test.go
@@ -2,8 +2,10 @@ package system
 
 import (
 	"context"
+	"io"
 
 	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/events"
 	"github.com/docker/docker/client"
 )
 
@@ -12,6 +14,7 @@ type fakeClient struct {
 
 	version       string
 	serverVersion func(ctx context.Context) (types.Version, error)
+	events        []events.Message
 }
 
 func (cli *fakeClient) ServerVersion(ctx context.Context) (types.Version, error) {
@@ -21,3 +24,17 @@ func (cli *fakeClient) ServerVersion(ctx context.Context) (types.Version, error)
 func (cli *fakeClient) ClientVersion() string {
 	return cli.version
 }
+
+func (cli *fakeClient) Events(ctx context.Context, options types.EventsOptions) (<-chan events.Message, <-chan error) {
+	messages := make(chan events.Message)
+	errs := make(chan error, 1)
+	go func() {
+		for _, msg := range cli.events {
+			messages <- msg
+		}
+		errs <- io.EOF
+		close(messages)
+		close(errs)
+	}()
+	return messages, errs
+}
diff --git a/cli/command/system/events.go b/cli/command/system/events.go
@@ -12,6 +12,7 @@ import (
 	"github.com/docker/cli/cli"
 	"github.com/docker/cli/cli/command"
 	"github.com/docker/cli/cli/command/completion"
+	"github.com/docker/cli/cli/command/formatter"
 	"github.com/docker/cli/opts"
 	"github.com/docker/cli/templates"
 	"github.com/docker/docker/api/types"
@@ -33,7 +34,7 @@ func NewEventsCommand(dockerCli command.Cli) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "events [OPTIONS]",
 		Short: "Get real time events from the server",
-		Args:  cli.NoArgs,
+		// Args:  cli.NoArgs,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			return runEvents(dockerCli, &options)
 		},
@@ -60,14 +61,12 @@ func runEvents(dockerCli command.Cli, options *eventsOptions) error {
 			Status:     "Error parsing format: " + err.Error(),
 		}
 	}
-	eventOptions := types.EventsOptions{
+	ctx, cancel := context.WithCancel(context.Background())
+	events, errs := dockerCli.Client().Events(ctx, types.EventsOptions{
 		Since:   options.since,
 		Until:   options.until,
 		Filters: options.filter.Value(),
-	}
-
-	ctx, cancel := context.WithCancel(context.Background())
-	events, errs := dockerCli.Client().Events(ctx, eventOptions)
+	})
 	defer cancel()
 
 	out := dockerCli.Out()
@@ -96,15 +95,18 @@ func handleEvent(out io.Writer, event eventtypes.Message, tmpl *template.Templat
 }
 
 func makeTemplate(format string) (*template.Template, error) {
-	if format == "" {
+	switch format {
+	case "":
 		return nil, nil
+	case formatter.JSONFormatKey:
+		format = formatter.JSONFormat
 	}
 	tmpl, err := templates.Parse(format)
 	if err != nil {
 		return tmpl, err
 	}
-	// we execute the template for an empty message, so as to validate
-	// a bad template like "{{.badFieldString}}"
+	// execute the template on an empty message to validate a bad
+	// template like "{{.badFieldString}}"
 	return tmpl, tmpl.Execute(io.Discard, &eventtypes.Message{})
 }
 

diff --git a/cli/command/system/events_test.go b/cli/command/system/events_test.go
@@ -0,0 +1,67 @@
+package system
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/docker/cli/internal/test"
+	"github.com/docker/docker/api/types/events"
+	"gotest.tools/v3/assert"
+	"gotest.tools/v3/golden"
+)
+
+func TestEventsFormat(t *testing.T) {
+	var evts []events.Message
+	for i, action := range []string{"create", "start", "attach", "die"} {
+		evts = append(evts, events.Message{
+			Status: action,
+			ID:     "abc123",
+			From:   "ubuntu:latest",
+			Type:   events.ContainerEventType,
+			Action: action,
+			Actor: events.Actor{
+				ID:         "abc123",
+				Attributes: map[string]string{"image": "ubuntu:latest"},
+			},
+			Scope:    "local",
+			Time:     int64(time.Second) * int64(i+1),
+			TimeNano: int64(time.Second) * int64(i+1),
+		})
+	}
+	tests := []struct {
+		name, format string
+	}{
+		{
+			name: "default",
+		},
+		{
+			name:   "json",
+			format: "json",
+		},
+		{
+			name:   "json template",
+			format: "{{ json . }}",
+		},
+		{
+			name:   "json action",
+			format: "{{ json .Action }}",
+		},
+	}
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			cli := test.NewFakeCli(&fakeClient{events: evts})
+			cmd := NewEventsCommand(cli)
+			if tc.format != "" {
+				cmd.Flags().Set("format", tc.format)
+			}
+			assert.Check(t, cmd.Execute())
+			out := cli.OutBuffer().String()
+			assert.Check(t, golden.String(out, fmt.Sprintf("docker-events-%s.golden", strings.ReplaceAll(tc.name, " ", "-"))))
+			cli.OutBuffer().Reset()
+		})
+	}
+}
diff --git a/cli/command/system/testdata/docker-events-default.golden b/cli/command/system/testdata/docker-events-default.golden
@@ -0,0 +1,4 @@
+1970-01-01T01:00:01.000000000+01:00 container create abc123 (image=ubuntu:latest)
+1970-01-01T01:00:02.000000000+01:00 container start abc123 (image=ubuntu:latest)
+1970-01-01T01:00:03.000000000+01:00 container attach abc123 (image=ubuntu:latest)
+1970-01-01T01:00:04.000000000+01:00 container die abc123 (image=ubuntu:latest)
diff --git a/cli/command/system/testdata/docker-events-json-action.golden b/cli/command/system/testdata/docker-events-json-action.golden
@@ -0,0 +1,4 @@
+"create"
+"start"
+"attach"
+"die"
diff --git a/cli/command/system/testdata/docker-events-json-template.golden b/cli/command/system/testdata/docker-events-json-template.golden
@@ -0,0 +1,4 @@
+{"status":"create","id":"abc123","from":"ubuntu:latest","Type":"container","Action":"create","Actor":{"ID":"abc123","Attributes":{"image":"ubuntu:latest"}},"scope":"local","time":1000000000,"timeNano":1000000000}
+{"status":"start","id":"abc123","from":"ubuntu:latest","Type":"container","Action":"start","Actor":{"ID":"abc123","Attributes":{"image":"ubuntu:latest"}},"scope":"local","time":2000000000,"timeNano":2000000000}
+{"status":"attach","id":"abc123","from":"ubuntu:latest","Type":"container","Action":"attach","Actor":{"ID":"abc123","Attributes":{"image":"ubuntu:latest"}},"scope":"local","time":3000000000,"timeNano":3000000000}
+{"status":"die","id":"abc123","from":"ubuntu:latest","Type":"container","Action":"die","Actor":{"ID":"abc123","Attributes":{"image":"ubuntu:latest"}},"scope":"local","time":4000000000,"timeNano":4000000000}
diff --git a/cli/command/system/testdata/docker-events-json.golden b/cli/command/system/testdata/docker-events-json.golden
@@ -0,0 +1,4 @@
+{"status":"create","id":"abc123","from":"ubuntu:latest","Type":"container","Action":"create","Actor":{"ID":"abc123","Attributes":{"image":"ubuntu:latest"}},"scope":"local","time":1000000000,"timeNano":1000000000}
+{"status":"start","id":"abc123","from":"ubuntu:latest","Type":"container","Action":"start","Actor":{"ID":"abc123","Attributes":{"image":"ubuntu:latest"}},"scope":"local","time":2000000000,"timeNano":2000000000}
+{"status":"attach","id":"abc123","from":"ubuntu:latest","Type":"container","Action":"attach","Actor":{"ID":"abc123","Attributes":{"image":"ubuntu:latest"}},"scope":"local","time":3000000000,"timeNano":3000000000}
+{"status":"die","id":"abc123","from":"ubuntu:latest","Type":"container","Action":"die","Actor":{"ID":"abc123","Attributes":{"image":"ubuntu:latest"}},"scope":"local","time":4000000000,"timeNano":4000000000}