feat: implement list of available distros

distro/centos/centos.go

@@ -34,6 +34,10 @@ func (centos CentOS) ID() distro.ID {
 	return distro.CentOS
 }
 
+func (centos CentOS) Release() string {
+	return centos.release
+}
+
 func (centos CentOS) Equal(d distro.Distro) bool {
 	return centos.release == d.Release && distro.CentOS == d.ID
 }

distro/debian/debian.go

@@ -47,6 +47,10 @@ func (d Debian) ID() distro.ID {
 	return distro.Debian
 }
 
+func (d Debian) Release() string {
+	return d.release.String()
+}
+
 func (d Debian) Equal(dd distro.Distro) bool {
 	if dd.ID != distro.Debian {
 		return false

distro/distro.go

@@ -9,6 +9,7 @@ var distros []distribution
 
 type distribution interface {
 	ID() ID
+	Release() string
 	Equal(Distro) bool
 	Packages() (packages []string, err error)
 }
@@ -20,6 +21,20 @@ func Register(d distribution) {
 	distros = append(distros, d)
 }
 
+func List() (dds []Distro) {
+	mu.Lock()
+	defer mu.Unlock()
+
+	for _, dd := range distros {
+		dds = append(dds, Distro{
+			ID:      dd.ID(),
+			Release: dd.Release(),
+		})
+	}
+
+	return
+}
+
 type Distro struct {
 	ID      ID
 	Release string

distro/oraclelinux/oraclelinux.go

@@ -34,6 +34,10 @@ func (ol OracleLinux) ID() distro.ID {
 	return distro.OracleLinux
 }
 
+func (ol OracleLinux) Release() string {
+	return ol.release
+}
+
 func (ol OracleLinux) Equal(d distro.Distro) bool {
 	return ol.release == d.Release && distro.OracleLinux == d.ID
 }

distro/ubuntu/ubuntu.go

@@ -40,6 +40,10 @@ func (u Ubuntu) ID() distro.ID {
 	return distro.Ubuntu
 }
 
+func (u Ubuntu) Release() string {
+	return u.release
+}
+
 func (u Ubuntu) Equal(d distro.Distro) bool {
 	return u.release == d.Release && distro.Ubuntu == d.ID
 }