claircore: add JSON marshaling for Alias type

alias.go

@@ -1,6 +1,7 @@
 package claircore
 
 import (
+	"encoding/json"
 	"strings"
 	"unique"
 )
@@ -49,3 +50,33 @@ func (a Alias) Equal(b Alias) bool {
 func (a Alias) Valid() bool {
 	return a.Space != unique.Handle[string]{} && a.Space.Value() != "" && a.Name != ""
 }
+
+type aliasJSON struct {
+	Space string `json:"space"`
+	Name  string `json:"name"`
+}
+
+// MarshalJSON implements [json.Marshaler].
+func (a Alias) MarshalJSON() ([]byte, error) {
+	var space string
+	if a.Space != (unique.Handle[string]{}) {
+		space = a.Space.Value()
+	}
+	return json.Marshal(aliasJSON{
+		Space: space,
+		Name:  a.Name,
+	})
+}
+
+// UnmarshalJSON implements [json.Unmarshaler].
+func (a *Alias) UnmarshalJSON(data []byte) error {
+	var v aliasJSON
+	if err := json.Unmarshal(data, &v); err != nil {
+		return err
+	}
+	if v.Space != "" {
+		a.Space = unique.Make(v.Space)
+	}
+	a.Name = v.Name
+	return nil
+}

alias_test.go

@@ -1,6 +1,7 @@
 package claircore
 
 import (
+	"encoding/json"
 	"fmt"
 	"testing"
 	"unique"
@@ -71,4 +72,44 @@ func TestAlias(t *testing.T) {
 			}
 		})
 	})
+
+	t.Run("JSON", func(t *testing.T) {
+		a := Alias{Space: unique.Make("CVE"), Name: "2024-24786"}
+		data, err := json.Marshal(a)
+		if err != nil {
+			t.Fatal(err)
+		}
+		want := `{"space":"CVE","name":"2024-24786"}`
+		if got := string(data); got != want {
+			t.Fatalf("marshal: got %s, want %s", got, want)
+		}
+
+		var b Alias
+		if err := json.Unmarshal(data, &b); err != nil {
+			t.Fatal(err)
+		}
+		if !a.Equal(b) {
+			t.Errorf("unmarshal: got %v, want %v", b, a)
+		}
+	})
+
+	t.Run("JSONZero", func(t *testing.T) {
+		a := Alias{}
+		data, err := json.Marshal(a)
+		if err != nil {
+			t.Fatal(err)
+		}
+		want := `{"space":"","name":""}`
+		if got := string(data); got != want {
+			t.Errorf("marshal: got %s, want %s", got, want)
+		}
+
+		var b Alias
+		if err := json.Unmarshal(data, &b); err != nil {
+			t.Fatal(err)
+		}
+		if b.Valid() {
+			t.Errorf("unmarshal zero: expected invalid alias, got valid: %v", b)
+		}
+	})
 }

datastore/postgres/get.go

@@ -6,6 +6,7 @@ import (
 	"log/slog"
 	"strconv"
 	"time"
+	"unique"
 
 	"github.com/jackc/pgx/v5"
 	"github.com/prometheus/client_golang/prometheus"
@@ -172,8 +173,101 @@ func (s *MatcherStore) Get(ctx context.Context, records []*claircore.IndexRecord
 	getVulnerabilitiesCounter.WithLabelValues("query_batch").Add(1)
 	getVulnerabilitiesDuration.WithLabelValues("query_batch").Observe(time.Since(start).Seconds())
 
+	if err := populateAliases(ctx, tx, results); err != nil {
+		return nil, fmt.Errorf("populating aliases: %w", err)
+	}
+
 	if err := tx.Commit(ctx); err != nil {
 		return nil, fmt.Errorf("failed to commit tx: %v", err)
 	}
 	return results, nil
 }
+
+// populateAliases fetches aliases and self references for all vulnerabilities
+// in the results map and populates the Aliases and Self fields.
+func populateAliases(ctx context.Context, tx pgx.Tx, results map[string][]*claircore.Vulnerability) error {
+	vulnByID := make(map[string]*claircore.Vulnerability)
+	for _, vulns := range results {
+		for _, v := range vulns {
+			vulnByID[v.ID] = v
+		}
+	}
+	if len(vulnByID) == 0 {
+		return nil
+	}
+
+	ids := make([]int64, 0, len(vulnByID))
+	for id := range vulnByID {
+		n, err := strconv.ParseInt(id, 10, 64)
+		if err != nil {
+			continue
+		}
+		ids = append(ids, n)
+	}
+
+	const aliasQuery = `
+		SELECT va.vulnerability, ns.namespace, a.name
+		FROM vulnerability_alias va
+		JOIN alias a ON va.alias = a.id
+		JOIN alias_namespace ns ON a.namespace = ns.id
+		WHERE va.vulnerability = ANY($1)
+	`
+	aliasRows, err := tx.Query(ctx, aliasQuery, ids)
+	if err != nil {
+		return fmt.Errorf("querying aliases: %w", err)
+	}
+	defer aliasRows.Close()
+
+	for aliasRows.Next() {
+		var vulnID int64
+		var namespace, name string
+		if err := aliasRows.Scan(&vulnID, &namespace, &name); err != nil {
+			return fmt.Errorf("scanning alias row: %w", err)
+		}
+		v := vulnByID[strconv.FormatInt(vulnID, 10)]
+		if v == nil {
+			continue
+		}
+		v.Aliases = append(v.Aliases, claircore.Alias{
+			Space: unique.Make(namespace),
+			Name:  name,
+		})
+	}
+	if err := aliasRows.Err(); err != nil {
+		return fmt.Errorf("iterating alias rows: %w", err)
+	}
+
+	const selfQuery = `
+		SELECT vs.vulnerability, ns.namespace, a.name
+		FROM vulnerability_self vs
+		JOIN alias a ON vs.self = a.id
+		JOIN alias_namespace ns ON a.namespace = ns.id
+		WHERE vs.vulnerability = ANY($1)
+	`
+	selfRows, err := tx.Query(ctx, selfQuery, ids)
+	if err != nil {
+		return fmt.Errorf("querying self aliases: %w", err)
+	}
+	defer selfRows.Close()
+
+	for selfRows.Next() {
+		var vulnID int64
+		var namespace, name string
+		if err := selfRows.Scan(&vulnID, &namespace, &name); err != nil {
+			return fmt.Errorf("scanning self row: %w", err)
+		}
+		v := vulnByID[strconv.FormatInt(vulnID, 10)]
+		if v == nil {
+			continue
+		}
+		v.Self = claircore.Alias{
+			Space: unique.Make(namespace),
+			Name:  name,
+		}
+	}
+	if err := selfRows.Err(); err != nil {
+		return fmt.Errorf("iterating self rows: %w", err)
+	}
+
+	return nil
+}