[Ubuntu] Add .NET SDK 6.0 (#4958)

Author: nikolai-frolov

images/linux/scripts/installers/dotnetcore-sdk.sh

@@ -32,12 +32,16 @@ for version in ${DOTNET_VERSIONS[@]}; do
     release_url="https://dotnetcli.blob.core.windows.net/dotnet/release-metadata/${version}/releases.json"
     download_with_retries "${release_url}" "." "${version}.json"
     releases=$(cat "./${version}.json")
-    sdks=("${sdks[@]}" $(echo "${releases}" | jq '.releases[]' | jq '.sdk.version'))
-    sdks=("${sdks[@]}" $(echo "${releases}" | jq '.releases[]' | jq '.sdks[]?' | jq '.version'))
+    if [[ $version == "6.0" ]]; then
+        sdks=("${sdks[@]}" $(echo "${releases}" | jq -r 'first(.releases[].sdks[]?.version | select(contains("preview") or contains("rc") | not))'))
+    else
+        sdks=("${sdks[@]}" $(echo "${releases}" | jq -r '.releases[].sdk.version | select(contains("preview") or contains("rc") | not)'))
+        sdks=("${sdks[@]}" $(echo "${releases}" | jq -r '.releases[].sdks[]?.version | select(contains("preview") or contains("rc") | not)'))
+    fi
     rm ./${version}.json
 done
 
-sortedSdks=$(echo ${sdks[@]} | tr ' ' '\n' | grep -v preview | grep -v rc | grep -v display | cut -d\" -f2 | sort -r | uniq -w 5)
+sortedSdks=$(echo ${sdks[@]} | tr ' ' '\n' | sort -r | uniq -w 5)
 
 extract_dotnet_sdk() {
     local ARCHIVE_NAME="$1"

images/linux/toolsets/toolset-1804.json

@@ -247,12 +247,14 @@
     "dotnet": {
         "aptPackages": [
             "dotnet-sdk-3.1",
-            "dotnet-sdk-5.0"
+            "dotnet-sdk-5.0",
+            "dotnet-sdk-6.0"
         ],
         "versions": [
             "2.1",
             "3.1",
-            "5.0"
+            "5.0",
+            "6.0"
         ],
         "tools": [
             { "name": "nbgv", "test": "nbgv --version", "getversion" : "nbgv --version" }

images/linux/toolsets/toolset-2004.json

@@ -247,12 +247,14 @@
     "dotnet": {
         "aptPackages": [
             "dotnet-sdk-3.1",
-            "dotnet-sdk-5.0"
+            "dotnet-sdk-5.0",
+            "dotnet-sdk-6.0"
         ],
         "versions": [
             "2.1",
             "3.1",
-            "5.0"
+            "5.0",
+            "6.0"
         ],
         "tools": [
             { "name": "nbgv", "test": "nbgv --version", "getversion" : "nbgv --version" }