feature(storage): config support for generate section

doc/auto_storage.md

@@ -5,10 +5,10 @@ installation.
 
 ## Agama and AutoYaST
 
-AutoYaST profiles can be used with Agama offering a 100% backward compatibility.
-
-The `legacyAutoyastStorage` section of the Agama profile is a 1:1 representation of the XML
-specification of AutoYaST. No JSON validation will be performed for it.
+The Agama profile has a special `legacyAutoyastStorage` section which is a 1:1 representation of the
+XML AutoYaST profile. This section supports everything offered by the *partitioning* AutoYaST
+section. Note that Agama does not validate this special section, so be careful to provide valid
+AutoYaST options.
 
 ~~~json
 {
@@ -21,21 +21,6 @@ specification of AutoYaST. No JSON validation will be performed for it.
 }
 ~~~
 
-### Implementation Considerations for AutoYaST Specification
-
-In principle, implementing the legacy AutoYaST module is as simple as converting the corresponding
-section of the profile into a `Y2Storage::PartitioningSection` object and use
-`Y2Storage::AutoInstProposal` to calculate the result.
-
-But there are some special cases in which AutoYaST fallbacks to read some settings from the YaST
-settings or to use some YaST mechanisms. Those cases should be taken into account during the
-implementation.
-
-For example, AutoYaST relies on the traditional YaST proposal settings when "auto" is used to
-specify the size of a partition or to determine the default list of subvolumes when Btrfs is used.
-See also the sections "Automatic Partitioning" and "Guided Partitioning" at the AutoYaST
-documentation for situations in which AutoYaST uses the standard YaST `GuidedProposal` as fallback.
-
 ### Problems with the AutoYaST Schema
 
 The AutoYaST schema is far from ideal and it presents some problems.
@@ -166,6 +151,21 @@ going to be used by.
 
 It would be more natural to indicate the used devices directly in the RAID or logical volume drive.
 
+### Implementation Considerations for AutoYaST Specification
+
+In principle, implementing the legacy AutoYaST module is as simple as converting the corresponding
+section of the profile into a `Y2Storage::PartitioningSection` object and use
+`Y2Storage::AutoInstProposal` to calculate the result.
+
+But there are some special cases in which AutoYaST fallbacks to read some settings from the YaST
+settings or to use some YaST mechanisms. Those cases should be taken into account during the
+implementation.
+
+For example, AutoYaST relies on the traditional YaST proposal settings when "auto" is used to
+specify the size of a partition or to determine the default list of subvolumes when Btrfs is used.
+See also the sections "Automatic Partitioning" and "Guided Partitioning" at the AutoYaST
+documentation for situations in which AutoYaST uses the standard YaST `GuidedProposal` as fallback.
+
 ## The New Storage Schema
 
 Agama offers its own storage schema which is more semantic, comprehensive and flexible than the
@@ -240,7 +240,7 @@ VolumeGroup
   alias [<string>]
   name [<string>]
   peSize [<number>]
-  physicalVolumes [<<string|Search>[]>]
+  physicalVolumes [<string|Search>[]>]
   logicalVolumes [<LogicalVolume[]>]
   delete [<boolean=false>]
 
@@ -855,6 +855,95 @@ space first by shrinking the partitions and deleting them only if shrinking is n
 }
 ```
 
+### Generating Default Volumes
+
+Every product provides a configuration which defines the storage volumes (e.g., feasible file
+systems for root, default partitions to create, etc). The default or mandatory product volumes can
+be automatically generated by using a *generate* section in the *partitions* or *logicalVolumes*
+sections.
+
+```json
+"storage": {
+  "drives": [
+    {
+      "partitions": [
+        { "generate": "default" }
+      ]
+    }
+  ]
+}
+
+```
+
+The *generate* section allows creating the product volumes without explicitly writing all of them.
+The config above would be equivalent to something like this:
+
+```json
+"storage": {
+  "drives": [
+    {
+      "partitions": [
+        { "filesystem": { "path": "/" } },
+        { "filesystem": { "path": "/home" } },
+        { "filesystem": { "path": "swap" } }
+      ]
+    }
+  ]
+}
+
+```
+
+If any path is explicitly defined, then the *generate* section will not generate a volume for it.
+For example, with the following config only root and swap would be automatically added:
+
+```json
+"storage": {
+  "drives": [
+    {
+      "partitions": [
+        { "generate": "default" },
+        { "filesystem": { "path": "/home" } }
+      ]
+    }
+  ]
+}
+```
+
+The auto-generated volumes can be also configured. For example, for encrypting the partitions:
+
+```json
+"storage": {
+  "drives": [
+    {
+      "partitions": [
+        {
+          "generate": {
+            "partitions": "default",
+            "encryption": {
+              "luks1": { "password": "12345" }
+            }
+          }
+        }
+      ]
+    }
+  ]
+}
+```
+
+The *mandatory* keyword can be used for only generating the mandatory partitions or logical volumes:
+
+```json
+"storage": {
+  "volumeGroups": [
+    {
+      "logicalVolumes": [
+        { "generate": "mandatory" }
+      ]
+    }
+  ]
+}
+```
+
 ### Using the Automatic Proposal
 
 On the first implementations, Agama can rely on the process known as Guided Proposal to calculate

rust/agama-lib/share/examples/storage/generate_lvs.json

@@ -0,0 +1,24 @@
+{
+  "storage": {
+    "drives": [
+      {
+        "partitions": [
+          {
+            "alias": "pv1",
+            "id": "lvm",
+            "size": { "min": "10 GiB" }
+          }
+        ]
+      }
+    ],
+    "volumeGroups": [
+      {
+        "name": "system",
+        "physicalVolumes": ["pv1"],
+        "logicalVolumes": [
+          { "generate": "default" }
+        ]
+      }
+    ]
+  }
+}

rust/agama-lib/share/examples/storage/generate_lvs_extended.json

@@ -0,0 +1,43 @@
+{
+  "storage": {
+    "drives": [
+      {
+        "partitions": [
+          {
+            "alias": "pv1",
+            "id": "lvm",
+            "size": { "min": "10 GiB" }
+          }
+        ]
+      }
+    ],
+    "volumeGroups": [
+      {
+        "name": "system",
+        "physicalVolumes": ["pv1"],
+        "logicalVolumes": [
+          {
+            "generate": {
+              "logicalVolumes": "mandatory",
+              "encryption": {
+                "luks2": {
+                  "password": "12345"
+                }
+              },
+              "stripes": 10,
+              "stripeSize": "4 KiB"
+            }
+          },
+          {
+            "name": "data",
+            "size": "5 GiB",
+            "filesystem": {
+              "path": "/data",
+              "type": "xfs"
+            }
+          }
+        ]
+      }
+    ]
+  }
+}

rust/agama-lib/share/examples/storage/generate_partitions.json

@@ -0,0 +1,13 @@
+{
+  "storage": {
+    "drives": [
+      {
+        "partitions": [
+          {
+            "generate": "mandatory"
+          }
+        ]
+      }
+    ]
+  }
+}

rust/agama-lib/share/examples/storage/generate_partitions_extended.json

@@ -0,0 +1,26 @@
+{
+  "storage": {
+    "drives": [
+      {
+        "partitions": [
+          {
+            "size": "10 GiB",
+            "filesystem": {
+              "type": "vfat"
+            }
+          },
+          {
+            "generate": {
+              "partitions": "default",
+              "encryption": {
+                "luks2": {
+                  "password": "12345"
+                }
+              }
+            }
+          }
+        ]
+      }
+    ]
+  }
+}