Merge ubiquity:bump-swap into ubiquity:master

[Dimitri John Ledkov]

Implement dynamic swap support

This is just a draft, did not test-build nor test install yet. This is a draft that at least hopes to cover all install cases and scenarios that need to work correctly.

Unmerged commits

982dd15... by Dimitri John Ledkov on 2022-06-27

Ensure minimum available amount of memory available

Attempt to ensure that total available memory is at least 8GB
(preseedable value). Adjust partman-auto memory capping to result in
more swap, when available ram is under 6GB. Also set the calculated
value, such that partman-swapfile / zsys-setup can consume it.

Due to increased swap file size, also allow larger disk usage
percentage for swap. Small RAM machines, are likely to have less disk
space as well (2GB/128GB dual-boot scenario), and it seems reasonable
to continue to support them.

LP: #1979997

diff --git a/d-i/source/partman-auto/debian/partman-auto.templates b/d-i/source/partman-auto/debian/partman-auto.templates
index 7d7ee98..60dedd7 100644
--- a/d-i/source/partman-auto/debian/partman-auto.templates
+++ b/d-i/source/partman-auto/debian/partman-auto.templates
@@ -51,11 +51,39 @@ Type: string
 Default: 1024
 Description: for internal use; can be preseeded
  Cap RAM size to specified size in MB, when calculating the swap
- partition size. Defaults to 1024, meaning 1GB, and since swap is
- maximum 200% of RAM in the default recipes, it results in swap
- partitions to be capped at 2GB. To revert to previous behaviour of
- uncapped swap size with respect to available ram, pressed this key to
- any string, e.g. partman-auto/cap-ram=false
+ partition size. Defaults to 1024, meaning 1GB, and since swap is 200%
+ of RAM in the default recipes, it results in swap partitions to be
+ capped at 2GB. To revert to previous behaviour of uncapped swap size
+ with respect to available ram, preseed this key to any string,
+ e.g. partman-auto/cap-ram=false
+
+Template: partman-auto/cap-ram-percentage
+Type: string
+Default: 10
+Description: for internal use; can be preseeded
+ Cap RAM size such that resulting swap does not take up more than the
+ given percentage of free disk space. Defaults to 10%.
+
+Template: partman-auto/ensure-min-mem
+Type: string
+Default: 8192
+Description: for internal use; can be preseeded
+ Ensure minimum amount of total available memory available (RAM+swap)
+ in MB. Achieve this by reverse calculating what declared memory size
+ needs to be, to ensure that double of that will result in enough swap
+ in default recipes to reach minimum required memory. This will raise
+ parman-auto/cap-ram for machines with less than 6GB of RAM to
+ increase the amount of calculated SWAP. To revert to previous
+ behaviour of not raising swap size with respect to low ram, preseed
+ this key to any string, e.g. partman-auto/ensure-min-mem=false.
+
+Template: partman-auto/desired-swap
+Type: string
+Description: for internal use; automatically set
+
+Template: partman-auto/cap-ram-free-size
+Type: string
+Description: for internal use; automatically set
 
 Template: partman-auto/automatically_partition
 Type: select
diff --git a/d-i/source/partman-auto/lib/recipes.sh b/d-i/source/partman-auto/lib/recipes.sh
index 024c199..b47afed 100644
--- a/d-i/source/partman-auto/lib/recipes.sh
+++ b/d-i/source/partman-auto/lib/recipes.sh
@@ -40,15 +40,44 @@ find_method () {
 }
 
 cap_ram () {
-    local ram
+    local ram min_ram limit
     ram="$1"
+    min_ram="0"
+
+    db_get partman-auto/ensure-min-mem
+    # test that return string is all numbers, otherwise do not raise
+    if [ $(expr "x$RET" : "x[0-9]*$") -gt 1 ]; then
+	if [ "$ram" -lt "$RET" ]; then
+            min_ram=$(expr \( "$RET" - "$ram" \) / 2)
+        fi
+    fi
+
     db_get partman-auto/cap-ram
     # test that return string is all numbers, otherwise do not cap
     if [ $(expr "x$RET" : "x[0-9]*$") -gt 1 ]; then
-	if [ $ram -gt "$RET" ]; then
+	if [ "$ram" -gt "$RET" ]; then
 	    ram=$RET
 	fi
     fi
+
+    if [ "$min_ram" -gt "$ram" ]; then
+        ram=$min_ram
+    fi
+
+    db_get partman-auto/cap-ram-free-size
+    limit=$((RET//100))
+
+    db_get partman-auto/cap-ram-percentage
+    limit=$((limit*RET))
+
+    limit=$((limit/2))
+
+    if [ "$ram" -gt "$limit" ]; then
+        ram=$limit
+    fi
+
+    db_set partman-auto/desired-swap $((ram*2))
+
     echo "$ram"
 }
 
@@ -377,6 +406,9 @@ choose_recipe () {
 	target="$2"
 	free_size=$3
 
+	# Export free_size for cap_ram calculation
+	db_set partman-auto/cap-ram-free-size $free_size
+
 	# Preseeding of recipes
 	db_get partman-auto/expert_recipe
 	if [ -n "$RET" ]; then
diff --git a/d-i/source/partman-swapfile/debian/partman-swapfile.templates b/d-i/source/partman-swapfile/debian/partman-swapfile.templates
index 0954dda..a36ffbd 100644
--- a/d-i/source/partman-swapfile/debian/partman-swapfile.templates
+++ b/d-i/source/partman-swapfile/debian/partman-swapfile.templates
@@ -4,14 +4,20 @@ Default: 2048
 # :sl3:
 _Description: Maximum size of swapfile
  Please enter the absolute maximum size of swapfile in MiB.
+ .
+ Please note partman-auto/cap-ram partman-auto/cap-ram-percentage
+ partman-auto/ensure-min-mem will take precedence over this value.
 
 Template: partman-swapfile/percentage
 Type: string
-Default: 5
+Default: 10
 # :sl3:
 _Description: Maximum percentage of free space to use for swapfile
  Please enter the maximum percentage of free space on root filesystem to
  use for swapfile.
+ .
+ Please note partman-auto/cap-ram partman-auto/cap-ram-percentage
+ partman-auto/ensure-min-mem will take precedence over this value.
 
 Template: partman-swapfile/progress_swap_formatting
 Type: text
diff --git a/d-i/source/partman-swapfile/finish.d/create_swapfile b/d-i/source/partman-swapfile/finish.d/create_swapfile
index f1f97f0..1d31881 100755
--- a/d-i/source/partman-swapfile/finish.d/create_swapfile
+++ b/d-i/source/partman-swapfile/finish.d/create_swapfile
@@ -80,6 +80,12 @@ then
     size=$limit
 fi
 
+# Allow partman-auto to override
+db_get partman-auto/desired-swap
+if [ -n "$RET" ]; then
+    size="$RET"
+fi
+
 # No swapfile if limits are 0MB or 0%
 if [ $size = 0 ]
 then