Add option to read config value from stdin

Add --stdin option to the config set commands which reads the value to
set via stdin instead of on the command line.  This allows a more secure
way of entering values and avoids having to deal with multiple layers of
quoting and escapes for special characters.

packages/ctl/ctl.js

@@ -23,6 +23,7 @@ const libCommand = require("@clusterio/lib/command");
 const libSharedCommands = require("@clusterio/lib/shared_commands");
 const { ConsoleTransport, levels, logger } = require("@clusterio/lib/logging");
 const libLoggingUtils = require("@clusterio/lib/logging_utils");
+const libHelpers = require("@clusterio/lib/helpers");
 
 
 function print(...content) {
@@ -134,13 +135,21 @@ instanceConfigCommands.add(new libCommand.Command({
 }));
 
 instanceConfigCommands.add(new libCommand.Command({
-	definition: ["set <instance> <field> <value>", "Set field in instance config", (yargs) => {
+	definition: ["set <instance> <field> [value]", "Set field in instance config", (yargs) => {
 		yargs.positional("instance", { describe: "Instance to set config on", type: "string" });
 		yargs.positional("field", { describe: "Field to set", type: "string" });
 		yargs.positional("value", { describe: "Value to set", type: "string" });
+		yargs.options({
+			"stdin": { describe: "read value from stdin", nargs: 0, type: "boolean" },
+		});
 	}],
 	handler: async function(args, control) {
 		let instanceId = await libCommand.resolveInstance(control, args.instance);
+		if (args.stdin) {
+			args.value = (await libHelpers.readStream(process.stdin)).toString().replace(/\r?\n$/, "");
+		} else if (args.value === undefined) {
+			args.value = "";
+		}
 		await libLink.messages.setInstanceConfigField.send(control, {
 			instance_id: instanceId,
 			field: args.field,
@@ -155,9 +164,15 @@ instanceConfigCommands.add(new libCommand.Command({
 		yargs.positional("field", { describe: "Field to set", type: "string" });
 		yargs.positional("prop", { describe: "Property to set", type: "string" });
 		yargs.positional("value", { describe: "JSON parsed value to set", type: "string" });
+		yargs.options({
+			"stdin": { describe: "read value from stdin", nargs: 0, type: "boolean" },
+		});
 	}],
 	handler: async function(args, control) {
 		let instanceId = await libCommand.resolveInstance(control, args.instance);
+		if (args.stdin) {
+			args.value = (await libHelpers.readStream(process.stdin)).toString().replace(/\r?\n$/, "");
+		}
 		let request = {
 			instance_id: instanceId,
 			field: args.field,
@@ -168,8 +183,8 @@ instanceConfigCommands.add(new libCommand.Command({
 				request.value = JSON.parse(args.value);
 			}
 		} catch (err) {
-			// If this is looks like an array, object or string literal
-			// throw the parse error, otherwise assume this is a string.
+			// If this is from stdin or looks like an array, object or string
+			// literal throw the parse error, otherwise assume this is a string.
 			// The resoning behind this is that correctly quoting the string
 			// with the all the layers of quote removal at play is difficult.
 			// See the following table for how to pass "That's a \" quote" in
@@ -181,7 +196,7 @@ instanceConfigCommands.add(new libCommand.Command({
 			// bash             : '""That'\''s a \" quote""'
 			// bash + npx       : '""That'\''s a \" quote""'
 			// bash + npx -s sh : "'\"\"That'\\''s a \\\" quote\"\"'"
-			if (/^(\[.*]|{.*}|".*")$/.test(value)) {
+			if (args.stdin || /^(\[.*]|{.*}|".*")$/.test(args.value)) {
 				throw new libErrors.CommandError(`In parsing value '${args.value}': ${err.message}`);
 			}
 			request.value = args.value;

packages/lib/helpers.js

@@ -52,8 +52,32 @@ async function timeout(promise, time, timeoutResult) {
 	}
 }
 
+
+/**
+ * Read stream to the end and return its content
+ *
+ * Reads the stream given asynchronously until the end is reached and
+ * returns all the data which was read from the stream.
+ *
+ * @param {Readable} stream - byte stream to read to the end.
+ * @returns {Buffer} content of the stream.
+ */
+async function readStream(stream) {
+	let chunks = [];
+	for await (let chunk of stream) {
+		// Support using ^Z to end input on Windows
+		if (process.platform === "win32" && stream.isTTY && chunk.toString() === "\x1a\r\n") {
+			break;
+		}
+		chunks.push(chunk);
+	}
+	return Buffer.concat(chunks);
+}
+
+
 module.exports = {
 	basicType,
 	wait,
 	timeout,
+	readStream,
 };

packages/lib/shared_commands.js

@@ -8,6 +8,7 @@ const path = require("path");
 
 const libConfig = require("@clusterio/lib/config");
 const { logger } = require("@clusterio/lib/logging");
+const libHelpers = require("@clusterio/lib/helpers");
 
 
 function print(...content) {
@@ -100,7 +101,11 @@ async function handlePluginCommand(args, pluginList, pluginListPath) {
  */
 function configCommand(yargs) {
 	yargs
-		.command("set <field> [value]", "Set config field")
+		.command("set <field> [value]", "Set config field", yargs => {
+			yargs.options({
+				"stdin": { describe: "read value from stdin", nargs: 0, type: "boolean" },
+			});
+		})
 		.command("show <field>", "Show value of the given config field")
 		.command("list", "List all configuration fields and their values")
 		.demandCommand(1, "You need to specify a command to run")
@@ -141,7 +146,10 @@ async function handleConfigCommand(args, instance, configPath) {
 		}
 
 	} else if (command === "set") {
-		if (args.value === undefined) {
+		if (args.stdin) {
+			args.value = (await libHelpers.readStream(process.stdin)).toString().replace(/\r?\n$/, "");
+
+		} else if (args.value === undefined) {
 			args.value = null;
 		}