add iam and deploy build steps

This requires aws cli v2 version 2.2.43 or higher. We force-build the
bootstrap executable as arm 64 to take advantage of Graviton2.
Also we are using an arm strip executable if found. This might
only work on debian x86_64 linux systems. Note that I am running
into timeout issues invoking from the command line that does
not manifest when invoking from the test console. But, the
goo seems to work otherwise, so I am deferring this issue for the
moment

build.zig

@@ -1,29 +1,147 @@
+const builtin = @import("builtin");
 const std = @import("std");
 const pkgs = @import("deps.zig").pkgs;
 
-pub fn build(b: *std.build.Builder) void {
+pub fn build(b: *std.build.Builder) !void {
     // Standard target options allows the person running `zig build` to choose
     // what target to build for. Here we do not override the defaults, which
     // means any target is allowed, and the default is native. Other options
     // for restricting supported target set are available.
-    const target = b.standardTargetOptions(.{});
+    // We want the target to be aarch64-linux for deploys
+    const target = std.zig.CrossTarget{
+        .cpu_arch = .aarch64,
+        .os_tag = .linux,
+    };
 
     // Standard release options allow the person running `zig build` to select
     // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall.
-    const mode = b.standardReleaseOptions();
+    // const mode = b.standardReleaseOptions();
 
     const exe = b.addExecutable("bootstrap", "src/main.zig");
     pkgs.addAllTo(exe);
     exe.setTarget(target);
-    exe.setBuildMode(mode);
+    exe.setBuildMode(.ReleaseSafe);
+    exe.strip = true;
     exe.install();
 
-    const run_cmd = exe.run();
+    // TODO: We can cross-compile of course, but stripping and zip commands
-    run_cmd.step.dependOn(b.getInstallStep());
+    // may vary
+    if (std.builtin.os.tag == .linux) {
+        // Package step
+        const package_step = b.step("package", "Package the function");
+        package_step.dependOn(b.getInstallStep());
+        // strip may not be installed or work for the target arch
+        // TODO: make this much less fragile
+        const strip = try std.fmt.allocPrint(b.allocator, "[ -x /usr/aarch64-linux-gnu/bin/strip ] && /usr/aarch64-linux-gnu/bin/strip {s}", .{b.getInstallPath(exe.install_step.?.dest_dir, exe.install_step.?.artifact.out_filename)});
+        defer b.allocator.free(strip);
+        package_step.dependOn(&b.addSystemCommand(&.{ "/bin/sh", "-c", strip }).step);
+        const function_zip = b.getInstallPath(exe.install_step.?.dest_dir, "function.zip");
+        const zip = try std.fmt.allocPrint(b.allocator, "zip -qj9 {s} {s}", .{ function_zip, b.getInstallPath(exe.install_step.?.dest_dir, exe.install_step.?.artifact.out_filename) });
+        defer b.allocator.free(zip);
+        package_step.dependOn(&b.addSystemCommand(&.{ "/bin/sh", "-c", zip }).step);
+
+        // Deployment
+        const deploy_step = b.step("deploy", "Deploy the function");
+        var deal_with_iam = true;
+        if (b.args) |args| {
+            for (args) |arg| {
+                if (std.mem.eql(u8, "--role", arg)) {
+                    deal_with_iam = false;
+                    break;
+                }
+            }
+        }
+        var iam_role: []u8 = &.{};
+        const iam_step = b.step("iam", "Create/Get IAM role for function");
+        deploy_step.dependOn(iam_step); // iam_step will either be a noop or all the stuff below
+        if (deal_with_iam) {
+            // if someone adds '-- --role arn...' to the command line, we don't
+            // need to do anything with the iam role. Otherwise, we'll create/
+            // get the IAM role and stick the name in a file in our destination
+            // directory to be used later
+            const iam_role_name_file = b.getInstallPath(exe.install_step.?.dest_dir, "iam_role_name");
+            iam_role = try std.fmt.allocPrint(b.allocator, "--role $(cat {s})", .{iam_role_name_file});
+
+            // Role get/creation command
+            const ifstatement_fmt =
+                \\ if aws iam get-role --role-name lambda_basic_execution 2>&1 |grep -q NoSuchEntity; then aws iam create-role --output text --query Role.Arn --role-name lambda_basic_execution --assume-role-policy-document '{
+                \\ "Version": "2012-10-17",
+                \\ "Statement": [
+                \\   {
+                \\     "Sid": "",
+                \\     "Effect": "Allow",
+                \\     "Principal": {
+                \\       "Service": "lambda.amazonaws.com"
+                \\     },
+                \\     "Action": "sts:AssumeRole"
+                \\   }
+                \\ ]}' > /dev/null; fi && \
+                \\ aws iam attach-role-policy --policy-arn arn:aws:iam::aws:policy/AWSLambdaExecute --role-name lambda_basic_execution && \
+                \\ aws iam get-role --role-name lambda_basic_execution --query Role.Arn --output text > 
+            ;
+
+            const ifstatement = try std.mem.concat(b.allocator, u8, &[_][]const u8{ ifstatement_fmt, iam_role_name_file });
+            defer b.allocator.free(ifstatement);
+            iam_step.dependOn(&b.addSystemCommand(&.{ "/bin/sh", "-c", ifstatement }).step);
+        }
+        const function_name = b.option([]const u8, "function-name", "Function name for Lambda [zig-fn]") orelse "zig-fn";
+        const ifstatement = "if aws lambda get-function --function-name {s} 2>&1 |grep -q ResourceNotFoundException; then echo not found > /dev/null; {s}; else echo found > /dev/null; {s}; fi";
+        // The architectures option was introduced in 2.2.43 released 2021-10-01
+        // We want to use arm64 here because it is both faster and cheaper for most
+        // Amazon Linux 2 is the only arm64 supported option
+        const not_found = "aws lambda create-function --architectures arm64 --runtime provided.al2 --function-name {s} --zip-file fileb://{s} --handler not_applicable {s}";
+        const not_found_fmt = try std.fmt.allocPrint(b.allocator, not_found, .{ function_name, function_zip, iam_role });
+        defer b.allocator.free(not_found_fmt);
+        const found = "aws lambda update-function-code --function-name {s} --zip-file fileb://{s}";
+        const found_fmt = try std.fmt.allocPrint(b.allocator, found, .{ function_name, function_zip });
+        defer b.allocator.free(found_fmt);
+        var found_final: []const u8 = undefined;
+        var not_found_final: []const u8 = undefined;
+        if (b.args) |args| {
+            found_final = try addArgs(b.allocator, found_fmt, args);
+            not_found_final = try addArgs(b.allocator, not_found_fmt, args);
+        } else {
+            found_final = found_fmt;
+            not_found_final = not_found_fmt;
+        }
+        const cmd = try std.fmt.allocPrint(b.allocator, ifstatement, .{ function_name, not_found_fmt, found_fmt });
+        defer b.allocator.free(cmd);
+
+        // std.debug.print("{s}\n", .{cmd});
+        deploy_step.dependOn(package_step);
+        deploy_step.dependOn(&b.addSystemCommand(&.{ "/bin/sh", "-c", cmd }).step);
+
+        const payload =
+            \\ {"foo": "bar"}"
+        ;
+        const run_script =
+            \\ f=$(mktemp) && \
+            \\ logs=$(aws lambda invoke \
+            \\          --function-name {s} \
+            \\          --payload $(echo '{s}'|base64) \
+            \\          --log-type Tail \
+            \\          --query LogResult \
+            \\          --output text "$f"  |base64 -d) && \
+            \\  cat "$f" && rm "$f" && \
+            \\  echo && echo && echo "$logs"
+        ;
+        const run_script_fmt = try std.fmt.allocPrint(b.allocator, run_script, .{ function_name, payload });
+        defer b.allocator.free(run_script_fmt);
+        const run_cmd = b.addSystemCommand(&.{ "/bin/sh", "-c", run_script_fmt });
+        run_cmd.step.dependOn(deploy_step);
         if (b.args) |args| {
             run_cmd.addArgs(args);
         }
 
         const run_step = b.step("run", "Run the app");
         run_step.dependOn(&run_cmd.step);
+    }
+}
+
+fn addArgs(allocator: *std.mem.Allocator, original: []const u8, args: [][]const u8) ![]const u8 {
+    var rc = original;
+    for (args) |arg| {
+        rc = try std.mem.concat(allocator, u8, &.{ rc, " ", arg });
+    }
+    return rc;
 }