Add .drone.jsonnnet

.drone.jsonnet

@@ -0,0 +1,51 @@
+# Copyright 2022 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# https://www.boost.org/LICENSE_1_0.txt
+
+local triggers =
+{
+	branch: [ "master", "develop", "feature/*" ]
+};
+
+local linux_pipeline(name, image, environment, arch = "amd64", sources = "", packages = "") =
+{
+	name: name,
+    kind: "pipeline",
+    type: "docker",
+    trigger: triggers,
+    platform:
+    {
+		os: "linux",
+		arch: arch
+    },
+    steps:
+    [
+		{
+			"name": "everything",
+			"image": image,
+			"environment": environment,
+			"commands":
+			[
+				"uname -a",
+				if sources != "" then "apt-add-repository " + sources else "",
+				if packages != "" then "apt-get install " + packages else "",
+			]
+		}
+    ]
+};
+
+local macos_pipeline =
+{
+};
+
+local windows_pipeline =
+{
+};
+
+[
+	linux_pipeline(
+		"Linux 20.04 GCC 9",
+		"cppalliance/droneubuntu2004:1",
+		{ TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a', ADDRMD: '32,64' }
+	),
+]