Added support for spiget to download Spigot/Bukkit/Paper plugins

#808

README.md

@@ -462,6 +462,8 @@ You can build spigot from source by adding `-e BUILD_FROM_SOURCE=true`
 
 If you have attached a host directory to the `/data` volume, then you can install plugins within the `plugins` subdirectory. You can also [attach a `/plugins` volume](#deploying-plugins-from-attached-volume). If you add plugins while the container is running, you'll need to restart it to pick those up.
 
+[You can also auto-download plugins using `SPIGET_RESOURCES`.](#auto-downloading-spigotmcbukkitpapermc-plugins)
+
 > NOTE some of the `VERSION` values are not as intuitive as you would think, so make sure to click into the version entry to find the **exact** version needed for the download. For example, "1.8" is not sufficient since their download naming expects `1.8-R0.1-SNAPSHOT-latest` exactly.
 
 ## Running a Paper server
@@ -484,6 +486,8 @@ An example compose file is provided at
 
 If you have attached a host directory to the `/data` volume, then you can install plugins via the `plugins` subdirectory. You can also [attach a `/plugins` volume](#deploying-plugins-from-attached-volume). If you add plugins while the container is running, you'll need to restart it to pick those up.
 
+[You can also auto-download plugins using `SPIGET_RESOURCES`.](#auto-downloading-spigotmcbukkitpapermc-plugins)
+
 ## Running a Tuinity server
 
 A [Tuinity](https://github.com/Spottedleaf/Tuinity) server, which is a fork of Paper aimed at improving server performance at high playercounts.
@@ -705,6 +709,19 @@ There is one additional volume that can be mounted; `/plugins`. Any files in thi
 
 This works well if you want to have a common set of plugins in a separate location, but still have multiple worlds with different server requirements in either persistent volumes or a downloadable archive.
 
+## Auto-downloading SpigotMC/Bukkit/PaperMC plugins
+
+The `SPIGET_RESOURCES` variable can be set with a comma-separated list of SpigotMC resource IDs to automatically download [SpigotMC resources/plugins](https://www.spigotmc.org/resources/) using [the spiget API](https://spiget.org/). Resources that are zip files will be expanded into the plugins directory and resources that are simply jar files will be moved there.
+
+The **resource ID** can be located from the numerical part of the URL after the shortname and a dot. For example, the ID is **9089** from
+
+    https://www.spigotmc.org/resources/essentialsx.9089/
+                                                   ====
+
+For example, the following will auto-download the [EssentialsX](https://www.spigotmc.org/resources/essentialsx.9089/) and [Vault](https://www.spigotmc.org/resources/vault.34315/) plugins:
+
+    -e SPIGET_RESOURCES=9089,34315
+
 ## Running with a custom server JAR
 
 If you would like to run a custom server JAR, set `-e TYPE=CUSTOM` and pass the custom server

start-deployBukkitSpigot

@@ -125,5 +125,4 @@ fi
 export TYPE=SPIGOT
 export SKIP_LOG4J_CONFIG=true
 
-# Continue to Final Setup
+exec ${SCRIPTS:-/}start-spiget "$@"
-exec ${SCRIPTS:-/}start-finalSetupWorld $@

start-deployPaper

@@ -76,5 +76,4 @@ fi
 export TYPE=SPIGOT
 export SKIP_LOG4J_CONFIG=true
 
-# Continue to Final Setup
+exec ${SCRIPTS:-/}start-spiget "$@"
-exec ${SCRIPTS:-/}start-finalSetupWorld "$@"

start-spiget

@@ -0,0 +1,58 @@
+#!/bin/bash
+set -euo pipefail
+IFS=$'\n\t'
+
+. ${SCRIPTS:-/}start-utils
+handleDebugMode
+
+: ${SPIGET_RESOURCES:=}
+
+containsJars() {
+  file=${1?}
+
+  pat='\.jar$'
+
+  while read -r line; do
+    if [[ $line =~ $pat ]]; then
+      return 0
+    fi
+  done <<< $(unzip -l "$file")
+
+  return 1
+}
+
+getResourceFromSpiget() {
+  resource=${1?}
+
+  log "Downloading resource ${resource} ..."
+
+  tmpfile="/tmp/${resource}.zip"
+  url="https://api.spiget.org/v2/resources/${resource}/download"
+  if ! curl -o "${tmpfile}" -fsSL -H "User-Agent: itzg/minecraft-server" "${extraCurlArgs[@]}" "${url}"; then
+    log "ERROR failed to download resource '${resource}' from ${url}"
+    exit 2
+  fi
+
+  mkdir -p /data/plugins
+  if containsJars "${tmpfile}"; then
+    log "Extracting contents of resource ${resource} into plugins"
+    unzip -o -q -d /data/plugins "${tmpfile}"
+    rm "${tmpfile}"
+  else
+    log "Moving resource ${resource} into plugins"
+    mv "${tmpfile}" "/data/plugins/${resource}.jar"
+  fi
+
+}
+
+if [[ ${SPIGET_RESOURCES} ]]; then
+  log "Getting plugins via Spiget"
+  IFS=',' read -r -a resources <<< "${SPIGET_RESOURCES}"
+  for resource in "${resources[@]}"
+  do
+    getResourceFromSpiget "${resource}"
+  done
+fi
+
+# Continue to Final Setup
+exec ${SCRIPTS:-/}start-finalSetupWorld $@

start-utils

@@ -57,13 +57,20 @@ function isTrue() {
 }
 
 function isDebugging() {
-  if [[ -v DEBUG ]] && [[ ${DEBUG^^} == TRUE ]]; then
+  if isTrue "${DEBUG:-false}"; then
     return 0
   else
     return 1
   fi
 }
 
+function handleDebugMode() {
+  if isDebugging; then
+    set -x
+    extraCurlArgs=(-v)
+  fi
+}
+
 function debug() {
   if isDebugging; then
     log "DEBUG: $*"