Document containers.conf settings for remote connections

Currently we don't document which end of the podman-remote client server
operations uses the containers.conf.  This PR begins documenting this
and then testing to make sure the defaults follow the rules.

Fixes: https://github.com/containers/podman/issues/7657

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

4 files changed, 206 insertions, 54 deletions

diff --git a/pkg/specgen/generate/container_create.go b/pkg/specgen/generate/container_create.go
index c049e64cf..45a374216 100644
--- a/pkg/specgen/generate/container_create.go
+++ b/pkg/specgen/generate/container_create.go
@@ -111,7 +111,7 @@ func MakeContainer(ctx context.Context, rt *libpod.Runtime, s *specgen.SpecGener
 		return nil, errors.Wrap(err, "invalid config provided")
 	}
 
-	finalMounts, finalVolumes, err := finalizeMounts(ctx, s, rt, rtc, newImage)
+	finalMounts, finalVolumes, finalOverlays, err := finalizeMounts(ctx, s, rt, rtc, newImage)
 	if err != nil {
 		return nil, err
 	}
@@ -121,7 +121,7 @@ func MakeContainer(ctx context.Context, rt *libpod.Runtime, s *specgen.SpecGener
 		return nil, err
 	}
 
-	opts, err := createContainerOptions(ctx, rt, s, pod, finalVolumes, newImage, command)
+	opts, err := createContainerOptions(ctx, rt, s, pod, finalVolumes, finalOverlays, newImage, command)
 	if err != nil {
 		return nil, err
 	}
@@ -144,7 +144,7 @@ func MakeContainer(ctx context.Context, rt *libpod.Runtime, s *specgen.SpecGener
 	return rt.NewContainer(ctx, runtimeSpec, options...)
 }
 
-func createContainerOptions(ctx context.Context, rt *libpod.Runtime, s *specgen.SpecGenerator, pod *libpod.Pod, volumes []*specgen.NamedVolume, img *image.Image, command []string) ([]libpod.CtrCreateOption, error) {
+func createContainerOptions(ctx context.Context, rt *libpod.Runtime, s *specgen.SpecGenerator, pod *libpod.Pod, volumes []*specgen.NamedVolume, overlays []*specgen.OverlayVolume, img *image.Image, command []string) ([]libpod.CtrCreateOption, error) {
 	var options []libpod.CtrCreateOption
 	var err error
 
@@ -224,7 +224,7 @@ func createContainerOptions(ctx context.Context, rt *libpod.Runtime, s *specgen.
 	for _, volume := range volumes {
 		destinations = append(destinations, volume.Dest)
 	}
-	for _, overlayVolume := range s.OverlayVolumes {
+	for _, overlayVolume := range overlays {
 		destinations = append(destinations, overlayVolume.Destination)
 	}
 	for _, imageVolume := range s.ImageVolumes {
@@ -244,9 +244,9 @@ func createContainerOptions(ctx context.Context, rt *libpod.Runtime, s *specgen.
 		options = append(options, libpod.WithNamedVolumes(vols))
 	}
 
-	if len(s.OverlayVolumes) != 0 {
+	if len(overlays) != 0 {
 		var vols []*libpod.ContainerOverlayVolume
-		for _, v := range s.OverlayVolumes {
+		for _, v := range overlays {
 			vols = append(vols, &libpod.ContainerOverlayVolume{
 				Dest:   v.Destination,
 				Source: v.Source,
diff --git a/pkg/specgen/generate/storage.go b/pkg/specgen/generate/storage.go
index b225f79ee..331a5c5bf 100644
--- a/pkg/specgen/generate/storage.go
+++ b/pkg/specgen/generate/storage.go
@@ -33,17 +33,17 @@ var (
 )
 
 // Produce final mounts and named volumes for a container
-func finalizeMounts(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.Runtime, rtc *config.Config, img *image.Image) ([]spec.Mount, []*specgen.NamedVolume, error) {
+func finalizeMounts(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.Runtime, rtc *config.Config, img *image.Image) ([]spec.Mount, []*specgen.NamedVolume, []*specgen.OverlayVolume, error) {
 	// Get image volumes
 	baseMounts, baseVolumes, err := getImageVolumes(ctx, img, s)
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, nil, err
 	}
 
 	// Get volumes-from mounts
 	volFromMounts, volFromVolumes, err := getVolumesFrom(s.VolumesFrom, rt)
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, nil, err
 	}
 
 	// Supersede from --volumes-from.
@@ -57,19 +57,53 @@ func finalizeMounts(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.Ru
 	// Need to make map forms of specgen mounts/volumes.
 	unifiedMounts := map[string]spec.Mount{}
 	unifiedVolumes := map[string]*specgen.NamedVolume{}
+	unifiedOverlays := map[string]*specgen.OverlayVolume{}
+
+	// Need to make map forms of specgen mounts/volumes.
+	commonMounts, commonVolumes, commonOverlayVolumes, err := specgen.GenVolumeMounts(rtc.Volumes())
+	if err != nil {
+		return nil, nil, nil, err
+	}
+
 	for _, m := range s.Mounts {
 		if _, ok := unifiedMounts[m.Destination]; ok {
-			return nil, nil, errors.Wrapf(errDuplicateDest, "conflict in specified mounts - multiple mounts at %q", m.Destination)
+			return nil, nil, nil, errors.Wrapf(errDuplicateDest, "conflict in specified mounts - multiple mounts at %q", m.Destination)
 		}
 		unifiedMounts[m.Destination] = m
 	}
+
+	for _, m := range commonMounts {
+		if _, ok := unifiedMounts[m.Destination]; !ok {
+			unifiedMounts[m.Destination] = m
+		}
+	}
+
 	for _, v := range s.Volumes {
 		if _, ok := unifiedVolumes[v.Dest]; ok {
-			return nil, nil, errors.Wrapf(errDuplicateDest, "conflict in specified volumes - multiple volumes at %q", v.Dest)
+			return nil, nil, nil, errors.Wrapf(errDuplicateDest, "conflict in specified volumes - multiple volumes at %q", v.Dest)
 		}
 		unifiedVolumes[v.Dest] = v
 	}
 
+	for _, v := range commonVolumes {
+		if _, ok := unifiedVolumes[v.Dest]; !ok {
+			unifiedVolumes[v.Dest] = v
+		}
+	}
+
+	for _, v := range s.OverlayVolumes {
+		if _, ok := unifiedOverlays[v.Destination]; ok {
+			return nil, nil, nil, errors.Wrapf(errDuplicateDest, "conflict in specified volumes - multiple volumes at %q", v.Destination)
+		}
+		unifiedOverlays[v.Destination] = v
+	}
+
+	for _, v := range commonOverlayVolumes {
+		if _, ok := unifiedOverlays[v.Destination]; ok {
+			unifiedOverlays[v.Destination] = v
+		}
+	}
+
 	// If requested, add container init binary
 	if s.Init {
 		initPath := s.InitPath
@@ -78,10 +112,10 @@ func finalizeMounts(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.Ru
 		}
 		initMount, err := addContainerInitBinary(s, initPath)
 		if err != nil {
-			return nil, nil, err
+			return nil, nil, nil, err
 		}
 		if _, ok := unifiedMounts[initMount.Destination]; ok {
-			return nil, nil, errors.Wrapf(errDuplicateDest, "conflict with mount added by --init to %q", initMount.Destination)
+			return nil, nil, nil, errors.Wrapf(errDuplicateDest, "conflict with mount added by --init to %q", initMount.Destination)
 		}
 		unifiedMounts[initMount.Destination] = initMount
 	}
@@ -115,12 +149,12 @@ func finalizeMounts(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.Ru
 	// Check for conflicts between named volumes and mounts
 	for dest := range baseMounts {
 		if _, ok := baseVolumes[dest]; ok {
-			return nil, nil, errors.Wrapf(errDuplicateDest, "conflict at mount destination %v", dest)
+			return nil, nil, nil, errors.Wrapf(errDuplicateDest, "conflict at mount destination %v", dest)
 		}
 	}
 	for dest := range baseVolumes {
 		if _, ok := baseMounts[dest]; ok {
-			return nil, nil, errors.Wrapf(errDuplicateDest, "conflict at mount destination %v", dest)
+			return nil, nil, nil, errors.Wrapf(errDuplicateDest, "conflict at mount destination %v", dest)
 		}
 	}
 	// Final step: maps to arrays
@@ -129,7 +163,7 @@ func finalizeMounts(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.Ru
 		if mount.Type == TypeBind {
 			absSrc, err := filepath.Abs(mount.Source)
 			if err != nil {
-				return nil, nil, errors.Wrapf(err, "error getting absolute path of %s", mount.Source)
+				return nil, nil, nil, errors.Wrapf(err, "error getting absolute path of %s", mount.Source)
 			}
 			mount.Source = absSrc
 		}
@@ -140,7 +174,12 @@ func finalizeMounts(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.Ru
 		finalVolumes = append(finalVolumes, volume)
 	}
 
-	return finalMounts, finalVolumes, nil
+	finalOverlays := make([]*specgen.OverlayVolume, 0, len(unifiedOverlays))
+	for _, volume := range unifiedOverlays {
+		finalOverlays = append(finalOverlays, volume)
+	}
+
+	return finalMounts, finalVolumes, finalOverlays, nil
 }
 
 // Get image volumes from the given image
diff --git a/pkg/specgen/specgen.go b/pkg/specgen/specgen.go
index 0a9a16ea7..fad2406e5 100644
--- a/pkg/specgen/specgen.go
+++ b/pkg/specgen/specgen.go
@@ -1,13 +1,13 @@
 package specgen
 
 import (
-	"errors"
 	"net"
 	"syscall"
 
 	"github.com/containers/image/v5/manifest"
 	"github.com/containers/storage"
 	spec "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
 )
 
 //  LogConfig describes the logging characteristics for a container
@@ -459,42 +459,6 @@ type SpecGenerator struct {
 	ContainerHealthCheckConfig
 }
 
-// NamedVolume holds information about a named volume that will be mounted into
-// the container.
-type NamedVolume struct {
-	// Name is the name of the named volume to be mounted. May be empty.
-	// If empty, a new named volume with a pseudorandomly generated name
-	// will be mounted at the given destination.
-	Name string
-	// Destination to mount the named volume within the container. Must be
-	// an absolute path. Path will be created if it does not exist.
-	Dest string
-	// Options are options that the named volume will be mounted with.
-	Options []string
-}
-
-// OverlayVolume holds information about a overlay volume that will be mounted into
-// the container.
-type OverlayVolume struct {
-	// Destination is the absolute path where the mount will be placed in the container.
-	Destination string `json:"destination"`
-	// Source specifies the source path of the mount.
-	Source string `json:"source,omitempty"`
-}
-
-// ImageVolume is a volume based on a container image.  The container image is
-// first mounted on the host and is then bind-mounted into the container.  An
-// ImageVolume is always mounted read only.
-type ImageVolume struct {
-	// Source is the source of the image volume.  The image can be referred
-	// to by name and by ID.
-	Source string
-	// Destination is the absolute path of the mount in the container.
-	Destination string
-	// ReadWrite sets the volume writable.
-	ReadWrite bool
-}
-
 // PortMapping is one or more ports that will be mapped into the container.
 type PortMapping struct {
 	// HostIP is the IP that we will bind to on the host.
diff --git a/pkg/specgen/volumes.go b/pkg/specgen/volumes.go
new file mode 100644
index 000000000..1178f9960
--- /dev/null
+++ b/pkg/specgen/volumes.go
@@ -0,0 +1,149 @@
+package specgen
+
+import (
+	"path/filepath"
+	"strings"
+
+	"github.com/containers/buildah/pkg/parse"
+	spec "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+// NamedVolume holds information about a named volume that will be mounted into
+// the container.
+type NamedVolume struct {
+	// Name is the name of the named volume to be mounted. May be empty.
+	// If empty, a new named volume with a pseudorandomly generated name
+	// will be mounted at the given destination.
+	Name string
+	// Destination to mount the named volume within the container. Must be
+	// an absolute path. Path will be created if it does not exist.
+	Dest string
+	// Options are options that the named volume will be mounted with.
+	Options []string
+}
+
+// OverlayVolume holds information about a overlay volume that will be mounted into
+// the container.
+type OverlayVolume struct {
+	// Destination is the absolute path where the mount will be placed in the container.
+	Destination string `json:"destination"`
+	// Source specifies the source path of the mount.
+	Source string `json:"source,omitempty"`
+}
+
+// ImageVolume is a volume based on a container image.  The container image is
+// first mounted on the host and is then bind-mounted into the container.  An
+// ImageVolume is always mounted read only.
+type ImageVolume struct {
+	// Source is the source of the image volume.  The image can be referred
+	// to by name and by ID.
+	Source string
+	// Destination is the absolute path of the mount in the container.
+	Destination string
+	// ReadWrite sets the volume writable.
+	ReadWrite bool
+}
+
+// GenVolumeMounts parses user input into mounts, volumes and overlay volumes
+func GenVolumeMounts(volumeFlag []string) (map[string]spec.Mount, map[string]*NamedVolume, map[string]*OverlayVolume, error) {
+	errDuplicateDest := errors.Errorf("duplicate mount destination")
+
+	mounts := make(map[string]spec.Mount)
+	volumes := make(map[string]*NamedVolume)
+	overlayVolumes := make(map[string]*OverlayVolume)
+
+	volumeFormatErr := errors.Errorf("incorrect volume format, should be [host-dir:]ctr-dir[:option]")
+
+	for _, vol := range volumeFlag {
+		var (
+			options []string
+			src     string
+			dest    string
+			err     error
+		)
+
+		splitVol := strings.Split(vol, ":")
+		if len(splitVol) > 3 {
+			return nil, nil, nil, errors.Wrapf(volumeFormatErr, vol)
+		}
+
+		src = splitVol[0]
+		if len(splitVol) == 1 {
+			// This is an anonymous named volume. Only thing given
+			// is destination.
+			// Name/source will be blank, and populated by libpod.
+			src = ""
+			dest = splitVol[0]
+		} else if len(splitVol) > 1 {
+			dest = splitVol[1]
+		}
+		if len(splitVol) > 2 {
+			if options, err = parse.ValidateVolumeOpts(strings.Split(splitVol[2], ",")); err != nil {
+				return nil, nil, nil, err
+			}
+		}
+
+		// Do not check source dir for anonymous volumes
+		if len(splitVol) > 1 {
+			if err := parse.ValidateVolumeHostDir(src); err != nil {
+				return nil, nil, nil, err
+			}
+		}
+		if err := parse.ValidateVolumeCtrDir(dest); err != nil {
+			return nil, nil, nil, err
+		}
+
+		cleanDest := filepath.Clean(dest)
+
+		if strings.HasPrefix(src, "/") || strings.HasPrefix(src, ".") {
+			// This is not a named volume
+			overlayFlag := false
+			for _, o := range options {
+				if o == "O" {
+					overlayFlag = true
+					if len(options) > 1 {
+						return nil, nil, nil, errors.New("can't use 'O' with other options")
+					}
+				}
+			}
+			if overlayFlag {
+				// This is a overlay volume
+				newOverlayVol := new(OverlayVolume)
+				newOverlayVol.Destination = cleanDest
+				newOverlayVol.Source = src
+				if _, ok := overlayVolumes[newOverlayVol.Destination]; ok {
+					return nil, nil, nil, errors.Wrapf(errDuplicateDest, newOverlayVol.Destination)
+				}
+				overlayVolumes[newOverlayVol.Destination] = newOverlayVol
+			} else {
+				newMount := spec.Mount{
+					Destination: cleanDest,
+					Type:        "bind",
+					Source:      src,
+					Options:     options,
+				}
+				if _, ok := mounts[newMount.Destination]; ok {
+					return nil, nil, nil, errors.Wrapf(errDuplicateDest, newMount.Destination)
+				}
+				mounts[newMount.Destination] = newMount
+			}
+		} else {
+			// This is a named volume
+			newNamedVol := new(NamedVolume)
+			newNamedVol.Name = src
+			newNamedVol.Dest = cleanDest
+			newNamedVol.Options = options
+
+			if _, ok := volumes[newNamedVol.Dest]; ok {
+				return nil, nil, nil, errors.Wrapf(errDuplicateDest, newNamedVol.Dest)
+			}
+			volumes[newNamedVol.Dest] = newNamedVol
+		}
+
+		logrus.Debugf("User mount %s:%s options %v", src, dest, options)
+	}
+
+	return mounts, volumes, overlayVolumes, nil
+}