stack status cmd - add columns for image build date and VCS reference

When dealing with snapshot builds that are constantly updated, it's difficult to know what
build of a service is really running. When viewing historic build logs from CI this information
is important to know.

This adds information about the service to the output of `elastic-package stack status`. The data
is read from http://label-schema.org/rc1/ labels. It uses the org.label-schema.build-date and
org.label-schema.vcs-ref labels.

```
BEFORE:
╭──────────────────┬─────────────────┬─────────────────────╮
│ SERVICE          │ VERSION         │ STATUS              │
├──────────────────┼─────────────────┼─────────────────────┤
│ elastic-agent    │ 8.16.0-SNAPSHOT │ running (unhealthy) │
│ elasticsearch    │ 8.16.0-SNAPSHOT │ running (healthy)   │
│ fleet-server     │ 8.16.0-SNAPSHOT │ running (healthy)   │
│ kibana           │ 8.16.0-SNAPSHOT │ running (healthy)   │
│ package-registry │ latest          │ running (healthy)   │
╰──────────────────┴─────────────────┴─────────────────────╯
```

```
AFTER:
╭──────────────────┬─────────────────┬─────────────────────┬───────────────────┬────────────╮
│ SERVICE          │ VERSION         │ STATUS              │ IMAGE BUILD DATE  │ VCS REF    │
├──────────────────┼─────────────────┼─────────────────────┼───────────────────┼────────────┤
│ elastic-agent    │ 8.16.0-SNAPSHOT │ running (unhealthy) │ 2024-08-22T02:44Z │ b96a4ca8fa │
│ elasticsearch    │ 8.16.0-SNAPSHOT │ running (healthy)   │ 2024-08-22T13:26Z │ 1362d56865 │
│ fleet-server     │ 8.16.0-SNAPSHOT │ running (healthy)   │ 2024-08-22T02:44Z │ b96a4ca8fa │
│ kibana           │ 8.16.0-SNAPSHOT │ running (healthy)   │ 2024-08-22T11:09Z │ cdcdfddd3f │
│ package-registry │ latest          │ running (healthy)   │                   │            │
╰──────────────────┴─────────────────┴─────────────────────┴───────────────────┴────────────╯
```

cmd/stack.go

@@ -7,6 +7,7 @@ package cmd
 import (
 	"fmt"
 	"strings"
+	"time"
 
 	"github.com/jedib0t/go-pretty/table"
 
@@ -350,11 +351,28 @@ func printStatus(cmd *cobra.Command, servicesStatus []stack.ServiceStatus) {
 		return
 	}
 	t := table.NewWriter()
-	t.AppendHeader(table.Row{"Service", "Version", "Status"})
+	t.AppendHeader(table.Row{"Service", "Version", "Status", "Image Build Date", "VCS Ref"})
 
 	for _, service := range servicesStatus {
-		t.AppendRow(table.Row{service.Name, service.Version, service.Status})
+		t.AppendRow(table.Row{service.Name, service.Version, service.Status, formatTime(service.Labels.BuildDate), truncate(service.Labels.VCSRef, 10)})
 	}
 	t.SetStyle(table.StyleRounded)
 	cmd.Println(t.Render())
 }
+
+// formatTime returns the given RFC3339 time formated as 2006-01-02T15:04Z.
+// If the value is not in RFC3339 format, then it is returned as-is.
+func formatTime(maybeRFC3339Time string) string {
+	if t, err := time.Parse(time.RFC3339, maybeRFC3339Time); err == nil {
+		return t.UTC().Format("2006-01-02T15:04Z")
+	}
+	return maybeRFC3339Time
+}
+
+// truncate truncates text if it longer than maxLength.
+func truncate(text string, maxLength int) string {
+	if len(text) > maxLength {
+		return text[:maxLength]
+	}
+	return text
+}

internal/docker/docker.go

@@ -49,6 +49,10 @@ type ConfigLabels struct {
 	ComposeProject string `json:"com.docker.compose.project"`
 	ComposeService string `json:"com.docker.compose.service"`
 	ComposeVersion string `json:"com.docker.compose.version"`
+
+	// http://label-schema.org/rc1/ Labels
+	BuildDate string `json:"org.label-schema.build-date,omitempty"` // This label contains the Date/Time the image was built. The value SHOULD be formatted according to RFC 3339.
+	VCSRef    string `json:"org.label-schema.vcs-ref,omitempty"`    // Identifier for the version of the source code from which this image was built. For example if the version control system is git this is the SHA.
 }
 
 // String function dumps string representation of the container description.

internal/stack/compose.go

@@ -18,6 +18,7 @@ type ServiceStatus struct {
 	Name    string
 	Status  string
 	Version string
+	Labels  *docker.ConfigLabels // Container labels.
 }
 
 const readyServicesSuffix = "is_ready"
@@ -214,6 +215,7 @@ func newServiceStatus(description *docker.ContainerDescription) (*ServiceStatus,
 		Name:    description.Config.Labels.ComposeService,
 		Status:  description.State.Status,
 		Version: getVersionFromDockerImage(description.Config.Image),
+		Labels:  &description.Config.Labels,
 	}
 	if description.State.Status == "running" {
 		healthStatus := "unknown health"

internal/stack/compose_test.go

@@ -78,6 +78,7 @@ func TestNewServiceStatus(t *testing.T) {
 				Name:    "myservice",
 				Status:  "running (healthy)",
 				Version: "1.42.0",
+				Labels:  &docker.ConfigLabels{ComposeService: "myservice"},
 			},
 		},
 		{
@@ -112,6 +113,7 @@ func TestNewServiceStatus(t *testing.T) {
 				Name:    "myservice",
 				Status:  "exited (128)",
 				Version: "1.42.0",
+				Labels:  &docker.ConfigLabels{ComposeService: "myservice"},
 			},
 		},
 		{
@@ -155,6 +157,7 @@ func TestNewServiceStatus(t *testing.T) {
 				Name:    "myservice",
 				Status:  "running (starting)",
 				Version: "1.42.0",
+				Labels:  &docker.ConfigLabels{ComposeService: "myservice"},
 			},
 		},
 	}