feat: allow for multiple channel inputs

src/julia/devcontainer-feature.json

@@ -1,7 +1,7 @@
 {
     "name": "Julia (via Juliaup)",
     "id": "julia",
-    "version": "1.1.1",
+    "version": "1.2.0",
     "description": "Install the Julia programming language",
     "documentationURL": "https://github.com/JuliaLang/devcontainer-features/tree/main/src/julia",
     "options": {
@@ -13,6 +13,11 @@
             ],
             "default": "release",
             "description": "Select a Juliaup channel"
+        },
+        "additionalChannels": {
+            "type": "string",
+            "default": "",
+            "description": "Additional Juliaup channels to install, separated by commas (e.g., 'nightly,1.10')"
         }
     },
     "installsAfter": [

src/julia/install.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 CHANNEL=${CHANNEL:-"release"}
-
+IFS=',' read -ra channels <<< ${ADDITIONALCHANNELS:-""}
 USERNAME=${USERNAME:-${_REMOTE_USER:-"automatic"}}
 
 set -e
@@ -28,6 +28,13 @@ elif [ "${USERNAME}" = "none" ] || ! id -u "${USERNAME}" >/dev/null 2>&1; then
     USERNAME=root
 fi
 
+# Determine the home directory of the user
+if [ "${USERNAME}" = "root" ]; then
+    REMOTE_USER_HOME=${_REMOTE_USER_HOME:-"/root"}
+else
+    REMOTE_USER_HOME=${_REMOTE_USER_HOME:-"/home/${USERNAME}"}
+fi
+
 cleanup_apt() {
     # shellcheck source=/dev/null
     source /etc/os-release
@@ -52,7 +59,15 @@ export DEBIAN_FRONTEND=noninteractive
 cleanup_apt
 check_packages curl ca-certificates
 
-su "${USERNAME}" -c "curl -fsSL https://install.julialang.org | sh -s -- --yes --default-channel ${CHANNEL}"
+su ${USERNAME} -c "curl -fsSL https://install.julialang.org | sh -s -- --yes --default-channel ${CHANNEL}"
+
+for channel in "${channels[@]}"; do
+    # if channel is not empty and not equal to the default channel...
+    if [ "${channel}" != "" ] && [ "${channel}" != "${CHANNEL}" ]; then
+        echo "Adding additional Julia channel: ${channel}";
+        su ${USERNAME} -c "${REMOTE_USER_HOME}/.juliaup/bin/juliaup add ${channel}";
+    fi
+done
 
 # Clean up
 cleanup_apt

test/julia/multiple.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+set -e
+
+# shellcheck source=/dev/null
+source dev-container-features-test-lib
+
+# helper function (lts and release should be installed)
+check_version_count() {
+  local count
+  count=$(juliaup status | awk 'NR > 2 { print $(NF-1) }' | wc -l)
+  [ "$count" -eq 4 ] # matches number in scenarios.json
+}
+
+# Feature-specific tests
+check "version" julia --version
+check "version-count" check_version_count
+
+
+# Report result
+reportResults

test/julia/scenarios.json

@@ -38,5 +38,14 @@
 				"channel": "lts"
 			}
 		}
+	},
+	"multiple": {
+		"image": "debian:stable-slim",
+		"features": {
+			"julia": {
+				"channel": "lts",
+				"additionalChannels": "1.6, 1.7,1.8"
+			}
+		}
 	}
-}
+}