incus-simplestreams: Simplify and add documentation

cmd/incus-simplestreams/main_remove.go

@@ -65,55 +65,41 @@ func (c *cmdRemove) Run(cmd *cobra.Command, args []string) error {
 		}
 
 		for kVersion, version := range product.Versions {
-			// Find the incus.tar.xz and figure out what to delete.
-			var deleteDisk bool
-			var deleteSquashfs bool
-			var metadataPath string
-
-			for _, item := range version.Items {
-				if item.FileType != "incus.tar.xz" {
-					continue
-				}
-
-				metadataPath = item.Path
-
-				if item.CombinedSha256DiskKvmImg == image.Fingerprint {
-					deleteDisk = true
-					break
-				}
-
-				if item.CombinedSha256SquashFs == image.Fingerprint {
-					deleteSquashfs = true
-					break
-				}
+			// Get the metadata entry.
+			metaEntry, ok := version.Items["incus.tar.xz"]
+			if !ok {
+				// Image isn't using our normal structure.
+				continue
 			}
 
-			// Delete the entry and associated files.
-			for kItem, item := range version.Items {
-				if deleteDisk && item.FileType == "disk-kvm.img" {
-					err = os.Remove(item.Path)
-					if err != nil && !os.IsNotExist(err) {
-						return err
-					}
-
-					delete(version.Items, kItem)
-					break
+			if metaEntry.CombinedSha256DiskKvmImg == image.Fingerprint {
+				// Deleting a VM image.
+				err = os.Remove(version.Items["disk-kvm.img"].Path)
+				if err != nil && !os.IsNotExist(err) {
+					return err
 				}
 
-				if deleteSquashfs && item.FileType == "squashfs" {
-					err = os.Remove(item.Path)
-					if err != nil && !os.IsNotExist(err) {
-						return err
-					}
-
-					delete(version.Items, kItem)
-					break
+				delete(version.Items, "disk-kvm.img")
+				metaEntry.CombinedSha256DiskKvmImg = ""
+			} else if metaEntry.CombinedSha256SquashFs == image.Fingerprint {
+				// Deleting a container image.
+				err = os.Remove(version.Items["squashfs"].Path)
+				if err != nil && !os.IsNotExist(err) {
+					return err
 				}
+
+				delete(version.Items, "squashfs")
+				metaEntry.CombinedSha256SquashFs = ""
+			} else {
+				continue
 			}
 
+			// Update the metadata entry.
+			version.Items["incus.tar.xz"] = metaEntry
+
 			// Delete the version if it's now empty.
 			if len(version.Items) == 1 {
-				err = os.Remove(metadataPath)
+				err = os.Remove(metaEntry.Path)
 				if err != nil && !os.IsNotExist(err) {
 					return err
 				}

doc/images.md

@@ -10,6 +10,6 @@ Manage images <howto/images_manage>
 Copy and import images <howto/images_copy>
 Create images <howto/images_create>
 Associate profiles <howto/images_profiles>
-reference/remote_image_servers
 reference/image_format
+reference/image_servers
 ```

doc/reference/remote_image_servers.md → doc/reference/image_servers.md

@@ -1,22 +1,25 @@
-(remote-image-servers)=
-# Remote image servers
+(image-servers)=
+# Default image server
 
-The [`incus`](incus.md) CLI command comes pre-configured with the following default remote image servers:
+The [`incus`](incus.md) CLI command comes pre-configured with the following default remote image server:
 
 `images:`
 : This server provides unofficial images for a variety of Linux distributions.
   The images are maintained by the [Linux Containers](https://linuxcontainers.org/) team and are built to be compact and minimal.
 
   See [`images.linuxcontainers.org`](https://images.linuxcontainers.org) for an overview of available images.
 
-(remote-image-server-types)=
-## Remote server types
+Additional image servers can be added through `incus remote add`.
+
+(image-server-types)=
+## Image server types
 
 Incus supports the following types of remote image servers:
 
 Simple streams servers
 : Pure image servers that use the [simple streams format](https://git.launchpad.net/simplestreams/tree/).
-  The default image servers are simple streams servers.
+  No special software is required to run such a server as it's only made of static files.
+  The default `images:` server uses simplestreams.
 
 Public Incus servers
 : Incus servers that are used solely to serve images and do not run instances themselves.
@@ -29,3 +32,16 @@ Incus servers
 
   For security reasons, you should restrict the access to the remote API and configure an authentication method to control access.
   See {ref}`server-expose` and {ref}`authentication` for more information.
+
+(image-server-tooling)=
+## Tooling to manage a simplestreams server
+Incus includes a tool called `incus-simplestreams` which can be used to manage a file system tree using the Simple streams format.
+
+It supports importing either a container (`squashfs`) or virtual-machine (`qcow2`) image
+with `incus-simplestreams add`, list all images available as well as their fingerprints
+with `incus-simplestreams list` and remove images from the server with `incus-simplestreams remove`.
+
+That file system tree must then be placed on a regular web server which supports HTTPS with a valid certificate.
+
+When importing an image that doesn't come with an Incus metadata tarball, the `incus-simplestreams generate-metadata` command
+can be used to generate a new basic metadata tarball from a few questions.