libpod: Move platform-specific bind mounts to a per-platform method

This adds a new per-platform method makePlatformBindMounts and moves the
/etc/hostname mount. This file is only needed on Linux.

[NO NEW TESTS NEEDED]

Signed-off-by: Doug Rabson <dfr@rabson.org>

libpod/container_internal_common.go

@@ -1766,16 +1766,6 @@ func (c *Container) makeBindMounts() error {
 		}
 	}
 
-	// Make /etc/hostname
-	// This should never change, so no need to recreate if it exists
-	if _, ok := c.state.BindMounts["/etc/hostname"]; !ok {
-		hostnamePath, err := c.writeStringToRundir("hostname", c.Hostname())
-		if err != nil {
-			return fmt.Errorf("creating hostname file for container %s: %w", c.ID(), err)
-		}
-		c.state.BindMounts["/etc/hostname"] = hostnamePath
-	}
-
 	// Make /etc/localtime
 	ctrTimezone := c.Timezone()
 	if ctrTimezone != "" {
@@ -1879,7 +1869,7 @@ rootless=%d
 		}
 	}
 
-	return nil
+	return c.makePlatformBindMounts()
 }
 
 // generateResolvConf generates a containers resolv.conf

libpod/container_internal_freebsd.go

@@ -283,3 +283,7 @@ func setVolumeAtime(mountPoint string, st os.FileInfo) error {
 	}
 	return nil
 }
+
+func (c *Container) makePlatformBindMounts() error {
+	return nil
+}

libpod/container_internal_linux.go

@@ -652,3 +652,16 @@ func setVolumeAtime(mountPoint string, st os.FileInfo) error {
 	}
 	return nil
 }
+
+func (c *Container) makePlatformBindMounts() error {
+	// Make /etc/hostname
+	// This should never change, so no need to recreate if it exists
+	if _, ok := c.state.BindMounts["/etc/hostname"]; !ok {
+		hostnamePath, err := c.writeStringToRundir("hostname", c.Hostname())
+		if err != nil {
+			return fmt.Errorf("creating hostname file for container %s: %w", c.ID(), err)
+		}
+		c.state.BindMounts["/etc/hostname"] = hostnamePath
+	}
+	return nil
+}