Add default retention policy

Remove images that are not visited in last 7 days
Add a build method in policy models.go

Signed-off-by: stonezdj <stonezdj@gmail.com>

src/core/api/project.go

@@ -17,6 +17,7 @@ package api
 import (
 	"context"
 	"fmt"
+	"github.com/goharbor/harbor/src/pkg/retention/policy"
 	"net/http"
 	"regexp"
 	"strconv"
@@ -56,6 +57,7 @@ type ProjectAPI struct {
 const projectNameMaxLen int = 255
 const projectNameMinLen int = 1
 const restrictedNameChars = `[a-z0-9]+(?:[._-][a-z0-9]+)*`
+const defaultDaysToRetention = 7
 
 // Prepare validates the URL and the user
 func (p *ProjectAPI) Prepare() {
@@ -241,6 +243,14 @@ func (p *ProjectAPI) Post() {
 		}
 	}
 
+	// create a default retention policy for proxy project
+	if pro.RegistryID > 0 {
+		if err := p.addRetentionPolicyForProxy(projectID); err != nil {
+			p.SendInternalServerError(fmt.Errorf("failed to add tag retention policy for project: %v", err))
+			return
+		}
+	}
+
 	// fire event
 	evt.BuildAndPublish(&metadata.CreateProjectEventMetadata{
 		ProjectID: projectID,
@@ -251,6 +261,18 @@ func (p *ProjectAPI) Post() {
 	p.Redirect(http.StatusCreated, strconv.FormatInt(projectID, 10))
 }
 
+func (p *ProjectAPI) addRetentionPolicyForProxy(projID int64) error {
+	plc := policy.WithNDaysSinceLastPull(projID, defaultDaysToRetention)
+	retID, err := retentionController.CreateRetention(plc)
+	if err != nil {
+		return err
+	}
+	if err := p.ProjectMgr.GetMetadataManager().Add(projID, map[string]string{"retention_id": strconv.FormatInt(retID, 10)}); err != nil {
+		return err
+	}
+	return nil
+}
+
 // Head ...
 func (p *ProjectAPI) Head() {
 

src/pkg/retention/policy/models.go

@@ -16,6 +16,7 @@ package policy
 
 import (
 	"github.com/astaxie/beego/validation"
+	"github.com/goharbor/harbor/src/lib/selector/selectors/doublestar"
 	"github.com/goharbor/harbor/src/pkg/retention/policy/rule"
 	"github.com/goharbor/harbor/src/pkg/retention/policy/rule/index"
 )
@@ -112,3 +113,47 @@ type Scope struct {
 	// 0 for 'system', project ID for 'project' and repo ID for 'repository'
 	Reference int64 `json:"ref" valid:"Required"`
 }
+
+// WithNDaysSinceLastPull build a retention rule to keep images n days to since last pull
+func WithNDaysSinceLastPull(projID int64, n int) *Metadata {
+	return &Metadata{
+		Algorithm: "or",
+		Rules: []rule.Metadata{
+			{
+				ID:       1,
+				Priority: 1,
+				Action:   "retain",
+				Template: "nDaysSinceLastPull",
+				TagSelectors: []*rule.Selector{
+					{
+						Kind:       doublestar.Kind,
+						Decoration: doublestar.Matches,
+						Pattern:    "**",
+					},
+				},
+				ScopeSelectors: map[string][]*rule.Selector{
+					"repository": {
+						{
+							Kind:       doublestar.Kind,
+							Decoration: doublestar.RepoMatches,
+							Pattern:    "**",
+						},
+					},
+				},
+				Parameters: rule.Parameters{
+					"nDaysSinceLastPull": n,
+				},
+			},
+		},
+		Trigger: &Trigger{
+			Kind: "Schedule",
+			Settings: map[string]interface{}{
+				"cron": "0 0 0 * * *",
+			},
+		},
+		Scope: &Scope{
+			Level:     "project",
+			Reference: projID,
+		},
+	}
+}