From 79e0f98959344c2730af7e9428e4c2e6287b3391 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafael=20Fern=C3=A1ndez=20L=C3=B3pez?=
 <rfernandezl@vmware.com>
Date: Mon, 11 Sep 2023 12:48:55 +0200
Subject: [PATCH] feat: add Zig environment variables example

---
 docs/docs/features/environment-variables.md |  2 +-
 docs/docs/languages/zig.md                  |  2 +-
 examples/zig-envs/README.md                 | 33 +++++++++++++++++++++
 examples/zig-envs/build.zig                 | 26 ++++++++++++++++
 examples/zig-envs/src/envs.zig              | 25 ++++++++++++++++
 examples/zig-envs/zig-out/bin/envs.toml     |  5 ++++
 6 files changed, 91 insertions(+), 2 deletions(-)
 create mode 100644 examples/zig-envs/README.md
 create mode 100644 examples/zig-envs/build.zig
 create mode 100644 examples/zig-envs/src/envs.zig
 create mode 100644 examples/zig-envs/zig-out/bin/envs.toml

diff --git a/docs/docs/features/environment-variables.md b/docs/docs/features/environment-variables.md
index fea3fdfd..0f19bc83 100644
--- a/docs/docs/features/environment-variables.md
+++ b/docs/docs/features/environment-variables.md
@@ -50,4 +50,4 @@ This feature allows you to configure environment variables dynamically.
 | Go | ✅ |
 | Ruby | ✅ |
 | Python | ✅ |
-| Zig | ❌ |
+| Zig | ✅ |
diff --git a/docs/docs/languages/zig.md b/docs/docs/languages/zig.md
index c1a97eed..bab6a48c 100644
--- a/docs/docs/languages/zig.md
+++ b/docs/docs/languages/zig.md
@@ -342,4 +342,4 @@ The Zig kit was originally authored by Christoph Voigt ([@voigt](https://github.
 
 | [K/V Store](../features/key-value.md) | [Environment Variables](../features/environment-variables.md) | [Dynamic Routes](../features/dynamic-routes.md) | [Folders](../features/mount-folders.md) | [HTTP Requests](../features/http-requests.md) |
 | --- | --- | --- | --- | --- |
-|  ✅ | ❌ | ✅ | ❓ | ❌ |
+|  ✅ | ✅ | ✅ | ❓ | ❌ |
diff --git a/examples/zig-envs/README.md b/examples/zig-envs/README.md
new file mode 100644
index 00000000..cdbca6a9
--- /dev/null
+++ b/examples/zig-envs/README.md
@@ -0,0 +1,33 @@
+# Zig environment variables example
+
+Compile a Zig worker to WebAssembly and run it in Wasm Workers Server.
+
+## Prerequisites
+
+* Wasm Workers Server (wws):
+
+  ```shell-session
+  curl -fsSL https://workers.wasmlabs.dev/install | bash
+  ```
+
+* [Zig](https://ziglang.org/download/) `0.11.0`
+
+## Build
+
+All specific build configurations are in `build.zig` file.
+
+```shell-session
+zig build
+```
+
+## Run
+
+```shell-session
+wws ./zig-out/bin/
+```
+
+## Resources
+
+* [Environment variables](https://workers.wasmlabs.dev/docs/features/environment-variables)
+* [Zig documentation](https://workers.wasmlabs.dev/docs/languages/zig)
+* [Announcing Zig support for Wasm Workers Server](https://wasmlabs.dev/articles/Zig-support-on-wasm-workers-server/)
diff --git a/examples/zig-envs/build.zig b/examples/zig-envs/build.zig
new file mode 100644
index 00000000..67d8478a
--- /dev/null
+++ b/examples/zig-envs/build.zig
@@ -0,0 +1,26 @@
+const std = @import("std");
+
+const examples = [1][]const u8{ "envs" };
+
+pub fn build(b: *std.Build) !void {
+    const target = try std.zig.CrossTarget.parse(.{ .arch_os_abi = "wasm32-wasi" });
+    const optimize = b.standardOptimizeOption(.{});
+
+    const worker_module = b.createModule(.{
+        .source_file = .{ .path = "../../kits/zig/worker/src/worker.zig" },
+    });
+
+    inline for (examples) |example| {
+        const exe = b.addExecutable(.{
+            .name = example,
+            .root_source_file = .{ .path = "src/" ++ example ++ ".zig" },
+            .target = target,
+            .optimize = optimize,
+        });
+
+        exe.wasi_exec_model = .reactor;
+        exe.addModule("worker", worker_module);
+
+        b.installArtifact(exe);
+    }
+}
diff --git a/examples/zig-envs/src/envs.zig b/examples/zig-envs/src/envs.zig
new file mode 100644
index 00000000..6be4131e
--- /dev/null
+++ b/examples/zig-envs/src/envs.zig
@@ -0,0 +1,25 @@
+const std = @import("std");
+const worker = @import("worker");
+
+var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
+const allocator = arena.allocator();
+
+fn requestFn(resp: *worker.Response, r: *worker.Request) void {
+    _ = r;
+
+    const envvar = std.process.getEnvVarOwned(allocator, "MESSAGE") catch "";
+    defer allocator.free(envvar);
+
+    const s =
+        \\The environment variable value is: {s}
+    ;
+
+    var body = std.fmt.allocPrint(allocator, s, .{ envvar }) catch undefined; // add useragent
+
+    _ = &resp.headers.append("x-generated-by", "wasm-workers-server");
+    _ = &resp.writeAll(body);
+}
+
+pub fn main() !void {
+    worker.ServeFunc(requestFn);
+}
diff --git a/examples/zig-envs/zig-out/bin/envs.toml b/examples/zig-envs/zig-out/bin/envs.toml
new file mode 100644
index 00000000..4c90dfc5
--- /dev/null
+++ b/examples/zig-envs/zig-out/bin/envs.toml
@@ -0,0 +1,5 @@
+name = "envs"
+version = "1"
+
+[vars]
+MESSAGE = "Hello! This message comes from an environment variable"
\ No newline at end of file