Add local attach support

go.mod

@@ -3,7 +3,6 @@ module github.com/kraken-hpc/imageapi
 go 1.15
 
 require (
-	github.com/u-root/u-root v7.0.0+incompatible
 	github.com/asaskevich/govalidator v0.0.0-20210307081110-f21760c49a8d // indirect
 	github.com/bensallen/rbd v0.0.0-20210224155049-baf486eceefa
 	github.com/go-openapi/errors v0.20.0
@@ -19,11 +18,12 @@ require (
 	github.com/kraken-hpc/uinit v0.1.1
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/sirupsen/logrus v1.8.1
+	github.com/u-root/u-root v7.0.0+incompatible
 	golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2 // indirect
 	golang.org/x/mod v0.4.2 // indirect
 	golang.org/x/net v0.0.0-20210331060903-cb1fcc7394e5
 	golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44
 	google.golang.org/genproto v0.0.0-20200825200019-8632dd797987 // indirect
 )
 
-replace github.com/u-root/u-root v7.0.0+incompatible => github.com/u-root/u-root v1.0.1-0.20201119150355-04f343dd1922
+replace github.com/u-root/u-root v7.0.0+incompatible => github.com/u-root/u-root v1.0.1-0.20201119150355-04f343dd1922

go.sum

@@ -352,8 +352,6 @@ github.com/u-root/iscsinl v0.1.0/go.mod h1:UGTrNqGTX3vAz6y/VmHC7pY8FLqoigybttGad
 github.com/u-root/u-root v1.0.1-0.20201119150355-04f343dd1922 h1:t9B62nb5RYgZNwrK+gaF//CDcJnYSt1HqE+MAROggM0=
 github.com/u-root/u-root v1.0.1-0.20201119150355-04f343dd1922/go.mod h1:c7G35Qvc1z58PWx/p1R9ROyiSuBc0ckqMU74klQ5g/s=
 github.com/u-root/u-root v6.0.1-0.20200118052101-6bcd1cda5996+incompatible/go.mod h1:RYkpo8pTHrNjW08opNd/U6p/RJE7K0D8fXO0d47+3YY=
-github.com/u-root/u-root v7.0.0+incompatible h1:u+KSS04pSxJGI5E7WE4Bs9+Zd75QjFv+REkjy/aoAc8=
-github.com/u-root/u-root v7.0.0+incompatible/go.mod h1:RYkpo8pTHrNjW08opNd/U6p/RJE7K0D8fXO0d47+3YY=
 github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
 github.com/ulikunitz/xz v0.5.8/go.mod h1:nbz6k7qbPmH4IRqmfOplQw/tblSgqTqBwxkY0oWt/14=
 github.com/vektah/gqlparser v1.1.2/go.mod h1:1ycwN7Ij5njmMkPPAOaRFY4rET2Enx7IkVv3vaXspKw=

internal/api/attach_local.go

@@ -0,0 +1,62 @@
+package api
+
+import (
+	"os"
+
+	"github.com/kraken-hpc/imageapi/models"
+	"github.com/sirupsen/logrus"
+)
+
+func init() {
+	AttachDrivers[models.AttachKindLocal] = &AttachDriverLocal{}
+}
+
+type AttachDriverLocal struct {
+	log *logrus.Entry
+}
+
+func (a *AttachDriverLocal) Init(log *logrus.Entry) {
+	a.log = log
+	a.log.Trace("initialized")
+}
+
+func (a *AttachDriverLocal) Attach(att *Attach) (ret *Attach, err error) {
+	// sanity check
+	l := a.log.WithField("operation", "attach")
+	if att.Local == nil {
+		l.Trace("attempted to attach local with no local definition")
+		return nil, ERRINVALDAT
+	}
+	l = l.WithField("path", *att.Local.Path)
+
+	finfo, err := os.Stat(*att.Local.Path)
+	if err != nil {
+		l.WithError(err).Debug("failed to stat device file")
+		return nil, ERRFAIL
+	}
+
+	if finfo.Mode()&os.ModeDevice == 0 {
+		l.Trace("path is not a device file")
+		return nil, ERRINVALDAT
+	}
+
+	if finfo.Mode()&os.ModeCharDevice != 0 {
+		l.Trace("path points to character device")
+		return nil, ERRINVALDAT
+	}
+	att.DeviceFile = *att.Local.Path
+
+	l.Info("successfully attached")
+	return att, nil
+}
+
+func (a *AttachDriverLocal) Detach(att *Attach) (ret *Attach, err error) {
+	// this is a dummy operation
+	l := a.log.WithFields(logrus.Fields{
+		"operation": "detach",
+		"id":        att.ID,
+		"path":      *att.Local.Path,
+	})
+	l.Info("successfully detached")
+	return att, nil
+}

internal/api/attach_loopback.go

@@ -1,7 +1,5 @@
 package api
 
-// API operations on rbd maps
-
 import (
 	"os"
 	"path"
@@ -32,8 +30,8 @@ func (a *AttachDriverLoopback) Attach(att *Attach) (ret *Attach, err error) {
 		return nil, ERRINVALDAT
 	}
 	l = l.WithFields(logrus.Fields{
-		"path": att.Loopback.Path,
-		"base": att.Loopback.Base,
+		"path": *att.Loopback.Path,
+		"base": *att.Loopback.Base,
 	})
 
 	base := "/"
@@ -85,8 +83,8 @@ func (a *AttachDriverLoopback) Detach(att *Attach) (ret *Attach, err error) {
 	l := a.log.WithFields(logrus.Fields{
 		"operation": "unmap",
 		"id":        att.ID,
-		"path":      att.Loopback.Path,
-		"base":      att.Loopback.Base,
+		"path":      *att.Loopback.Path,
+		"base":      *att.Loopback.Base,
 	})
 	if err = loop.ClearFile(att.DeviceFile); err != nil {
 		l.Debug("failed to clear loopback association")

internal/api/mount_nfs.go

@@ -68,8 +68,8 @@ func (m *MountDriverNFS) Unmount(mnt *Mount) (ret *Mount, err error) {
 	l := m.log.WithFields(logrus.Fields{
 		"operation": "unmount",
 		"id":        mnt.ID,
-		"host":      mnt.Nfs.Host,
-		"path":      mnt.Nfs.Path,
+		"host":      *mnt.Nfs.Host,
+		"path":      *mnt.Nfs.Path,
 	})
 
 	// always lazy unmount.  Good idea?

swagger.yaml

@@ -166,6 +166,21 @@ definitions:
       mount:
         $ref: "#/definitions/mount"
 
+  attach_local:
+    description: |
+      `attach_local` describes a block device that is locally present.
+      This can be used to get a reference to a local disk, for instance.
+
+      Local only supports finding device files on the local (root) system.
+      It only takes one parameter: the path to the device file.
+    type: object
+    required:
+      - path
+    properties:
+      path:
+        type: string
+        description: A unix-formatted filesystem path pointing to a block device file.
+
   attach:
     description: |
       Generically address attachments.  Attachments are objects that ultimately provide a block device file.    
@@ -197,6 +212,8 @@ definitions:
         readOnly: true
       rbd:
         $ref: "#/definitions/attach_rbd"
+      local:
+        $ref: "#/definitions/attach_local"
       loopback:
         $ref: "#/definitions/attach_loopback"