Merge pull request #29484 from ellieayla/artifact-list-json-output

feat: Add output format: podman artifact ls --format=json

cmd/podman/artifact/list.go

@@ -1,6 +1,7 @@
 package artifact
 
 import (
+	"encoding/json"
 	"fmt"
 	"os"
 	"time"
@@ -41,6 +42,7 @@ type artifactListOutput struct {
 	Digest       string
 	Repository   string
 	Size         string
+	sizeBytes    int64
 	Tag          string
 	created      time.Time
 	VirtualSize  string
@@ -84,13 +86,8 @@ func list(cmd *cobra.Command, _ []string) error {
 		return err
 	}
 
-	return outputTemplate(cmd, reports)
-}
-
-func outputTemplate(cmd *cobra.Command, lrs []*entities.ArtifactListReport) error {
-	var err error
 	artifacts := make([]artifactListOutput, 0)
-	for _, lr := range lrs {
+	for _, lr := range reports {
 		var tag string
 		artifactName, err := lr.Artifact.GetName()
 		if err != nil {
@@ -130,6 +127,7 @@ func outputTemplate(cmd *cobra.Command, lrs []*entities.ArtifactListReport) erro
 			Digest:       artifactHash,
 			Repository:   named.Name(),
 			Size:         units.HumanSize(float64(lr.Artifact.TotalSizeBytes())),
+			sizeBytes:    lr.Artifact.TotalSizeBytes(),
 			Tag:          tag,
 			created:      createdTime,
 			VirtualSize:  fmt.Sprintf("%d", lr.Artifact.TotalSizeBytes()),
@@ -137,6 +135,48 @@ func outputTemplate(cmd *cobra.Command, lrs []*entities.ArtifactListReport) erro
 		})
 	}
 
+	switch {
+	case report.IsJSON(listFlag.format):
+		return writeJSON(artifacts)
+	default:
+		return writeTemplate(cmd, artifacts)
+	}
+}
+
+func writeJSON(artifacts []artifactListOutput) error {
+	type artifact struct {
+		Repository string `json:"Repository,omitempty"`
+		CreatedAt  string
+		Size       int64
+		Tag        string `json:"Tag,omitempty"`
+		Digest     string
+	}
+
+	arti := make([]artifact, 0, len(artifacts))
+
+	for _, e := range artifacts {
+		var a artifact
+		a.Repository = e.Repository
+		a.CreatedAt = e.created.Format(time.RFC3339Nano)
+		a.Size = e.sizeBytes
+		a.Repository = e.Repository
+		a.Tag = e.Tag
+		a.Digest = e.Digest
+
+		arti = append(arti, a)
+	}
+
+	prettyJSON, err := json.MarshalIndent(arti, "", "    ")
+	if err != nil {
+		return err
+	}
+	fmt.Println(string(prettyJSON))
+	return nil
+}
+
+func writeTemplate(cmd *cobra.Command, artifacts []artifactListOutput) error {
+	var err error
+
 	headers := report.Headers(artifactListOutput{}, map[string]string{
 		"REPOSITORY": "REPOSITORY",
 		"Tag":        "TAG",

docs/source/markdown/podman-artifact-ls.1.md.in

@@ -62,6 +62,19 @@ ab609fad386d 2.097GB
 cd734b558ceb 12.58MB
 ```
 
+List artifact details in json format
+```
+$ podman artifact ls --format json"
+[
+    {
+        "Repository": "quay.io/artifact/foobar1",
+        "CreatedAt": "2026-06-16T00:00:57Z",
+        "Size": 12580000,
+        "Tag": "special",
+        "Digest": "cd734b558ceb"
+    }
+]
+```
 
 
 ## SEE ALSO

test/e2e/artifact_test.go

@@ -3,6 +3,7 @@
 package integration
 
 import (
+	"encoding/json"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -51,6 +52,24 @@ var _ = Describe("Podman artifact", func() {
 		Expect(output).To(ContainElement(artifact1Name))
 		Expect(output).To(ContainElement(artifact2Name))
 
+		// --format=json should work, produce valid json
+		listFormatJsonSession := podmanTest.PodmanExitCleanly("artifact", "ls", "--format", "json")
+		Expect(listFormatJsonSession).Should(ExitCleanly())
+		jsonOutput := listFormatJsonSession.OutputToString()
+		Expect(jsonOutput).To(BeValidJSON())
+
+		// --format=json should contain repository and tag fields
+		jsonArtifactsList := []map[string]any{}
+		jsonUnmarshalErr := json.Unmarshal([]byte(jsonOutput), &jsonArtifactsList)
+
+		Expect(jsonUnmarshalErr).ToNot(HaveOccurred())
+		Expect(jsonArtifactsList).ToNot(BeEmpty())
+
+		for _, image := range jsonArtifactsList {
+			Expect(image).To(HaveKey("Repository"))
+			Expect(image).To(HaveKey("Tag"))
+		}
+
 		// Check default digest length (should be 12)
 		defaultFormatSession := podmanTest.PodmanExitCleanly("artifact", "ls", "--format", "{{.Digest}}")
 		defaultOutput := defaultFormatSession.OutputToStringArray()[0]