Add Leaf support (#3470)

Co-authored-by: Geoff Bourne <itzgeoff@gmail.com>

docs/types-and-platforms/server-types/paper.md

@@ -85,6 +85,23 @@ Extra variables:
 - `USE_FLARE_FLAGS=false` : set to true to add appropriate flags for the built-in [Flare](https://blog.airplane.gg/flare) profiler
 - `PURPUR_DOWNLOAD_URL=<url>` : set URL to download Purpur from custom URL.
 
+### Leaf
+
+A [Leaf server](https://www.leafmc.one/) is a Paper fork focused on performance improvements and low-level optimizations for smoother gameplay.
+
+To use a Leaf server, set the environment variable `TYPE` to `"LEAF"`.
+
+    -e TYPE=LEAF
+
+!!! note
+
+    The `VERSION` variable is used to select the Minecraft version to run.  
+    To specify a particular Leaf build, use `LEAF_BUILD`.  
+
+By default the latest build will be used; however, a specific build number can be selected by setting `LEAF_BUILD`, such as
+
+    -e VERSION=1.21.4 -e LEAF_BUILD=441
+
 ### Folia
 
 A [Folia server](https://papermc.io/software/folia) can be used by setting the environment variable `TYPE` to "FOLIA".

scripts/start-configuration

@@ -278,6 +278,10 @@ case "${TYPE^^}" in
     exec "${SCRIPTS:-/}start-deployCrucible" "$@"
   ;;
 
+  LEAF)
+    exec "${SCRIPTS:-/}start-deployLeaf" "$@"
+  ;;
+
   *)
       logError "Invalid TYPE: '$TYPE'"
       logError "Must be: VANILLA, FORGE, BUKKIT, SPIGOT, PAPER, FOLIA, PURPUR, FABRIC, QUILT,"
@@ -286,4 +290,4 @@ case "${TYPE^^}" in
       exit 1
   ;;
 
-esac
+esac

scripts/start-deployLeaf

@@ -0,0 +1,51 @@
+#!/bin/bash
+
+# shellcheck source=start-utils
+. "${SCRIPTS:-$(dirname "$0")}/start-utils"
+set -o pipefail
+set -e
+isDebugging && set -x
+
+resolveVersion
+: "${LEAF_BUILD:=LATEST}"
+
+# Docs at https://api.leafmc.one/docs/swagger-ui/index.html
+leafApiUrl="https://api.leafmc.one/v2/projects/leaf"
+leafDownloadsPage="https://www.leafmc.one/download"
+
+if ! get --exists "${leafApiUrl}/versions/${VERSION}/builds"; then
+  logError "Leaf builds do not exist for ${VERSION}"
+  logError "       check ${leafDownloadsPage} for available versions"
+  logError "       and set VERSION accordingly"
+  exit 1
+fi
+
+if [[ "${LEAF_BUILD^^}" == "LATEST" ]]; then
+  # Get the latest build number from the API, which will be the last object in the builds array
+  if ! buildNumber=$(
+    get --json-path '$.builds[-1].build' "${leafApiUrl}/versions/${VERSION}/builds"
+  ); then
+    logError "failed to list Leaf builds for ${VERSION}"
+    exit 1
+  fi
+  LEAF_BUILD="${buildNumber}"
+fi
+
+if ! filename=$(
+  get --json-path='$.downloads.primary.name' --json-value-when-missing="" "${leafApiUrl}/versions/${VERSION}/builds/${LEAF_BUILD}"
+); then
+  logError "Failed to retrieve download filename"
+  exit 1
+fi
+
+SERVER="/data/$filename"
+
+if ! get --skip-existing --log-progress-each -o "${SERVER}" "${leafApiUrl}/versions/${VERSION}/builds/${LEAF_BUILD}/downloads/${filename}"; then
+  logError "Failed to download"
+  exit 1
+fi
+
+export FAMILY=SPIGOT
+export SERVER
+
+exec "${SCRIPTS:-/}start-spiget" "$@"