Add default image for cloudchamber create

Add a default image when using "wrangler cloudchamber create". This
image is docker.io/cloudflare/hello-world which is a simple HTTP server
that runs on Cloudflare's container platform.

This commit also augments validation to both the `cloudchamber create`
and `cloudchamber modify` commands to ensure the provided image contains
a tag and adheres to the format in the OCI specification.

.changeset/six-apes-pull.md

@@ -0,0 +1,5 @@
+---
+"wrangler": minor
+---
+
+Add a default image for cloudchamber create and modify commands

packages/wrangler/src/__tests__/cloudchamber/common.test.ts

@@ -0,0 +1,62 @@
+import { parseImageName } from "../../cloudchamber/common";
+
+describe("parseImageName", () => {
+	it("works", () => {
+		type TestCase = [
+			input: string,
+			expected: { name?: string; tag?: string; digest?: string; err?: boolean },
+		];
+		const cases: TestCase[] = [
+			// Multiple domains
+			[
+				"docker.io/cloudflare/hello-world:1.0",
+				{ name: "docker.io/cloudflare/hello-world", tag: "1.0" },
+			],
+
+			// Domain with port
+			[
+				"localhost:7777/web:local",
+				{ name: "localhost:7777/web", tag: "local" },
+			],
+
+			// No domain
+			["hello-world:1.0", { name: "hello-world", tag: "1.0" }],
+
+			// With sha256 digest
+			[
+				"hello/world:1.0@sha256:abcdef0123456789",
+				{ name: "hello/world", tag: "1.0", digest: "abcdef0123456789" },
+			],
+
+			// sha256 digest but no tag
+			[
+				"hello/world@sha256:abcdef0123456789",
+				{ name: "hello/world", digest: "sha256:abcdef0123456789" },
+			],
+
+			// Invalid name
+			["bad image name:1", { err: true }],
+
+			// Missing tag
+			["no-tag", { err: true }],
+			["no-tag:", { err: true }],
+
+			// Invalid tag
+			["no-tag::", { err: true }],
+
+			// latest tag
+			["name:latest", { err: true }],
+
+			// Too many colons
+			["registry.com:1234/foobar:4444/image:sometag", { err: true }],
+		];
+
+		for (const c of cases) {
+			const [input, expected] = c;
+			const result = parseImageName(input);
+			expect(result.name).toEqual(expected.name);
+			expect(result.tag).toEqual(expected.tag);
+			expect(result.err !== undefined).toEqual(expected.err === true);
+		}
+	});
+});

packages/wrangler/src/__tests__/cloudchamber/create.test.ts

@@ -116,6 +116,22 @@ describe("cloudchamber create", () => {
 		);
 	});
 
+	it("should fail with a nice message when image is invalid", async () => {
+		setIsTTY(false);
+		setWranglerConfig({});
+		await expect(
+			runWrangler("cloudchamber create --image hello:latest --location sfo06")
+		).rejects.toThrowErrorMatchingInlineSnapshot(
+			`[Error: "latest" tag is not allowed]`
+		);
+
+		await expect(
+			runWrangler("cloudchamber create --image hello --location sfo06")
+		).rejects.toThrowErrorMatchingInlineSnapshot(
+			`[Error: Invalid image format: expected NAME:TAG[@DIGEST] or NAME@DIGEST]`
+		);
+	});
+
 	it("should fail with a nice message when parameters are mistyped", async () => {
 		setIsTTY(false);
 		fs.writeFileSync(

packages/wrangler/src/cloudchamber/common.ts

@@ -40,6 +40,50 @@ import type { Arg } from "@cloudflare/cli/interactive";
 
 export type CommonCloudchamberConfiguration = { json: boolean };
 
+/**
+ * Regular expression for matching an image name.
+ *
+ * See: https://github.com/opencontainers/distribution-spec/blob/v1.1.0/spec.md#pulling-manifests
+ */
+const imageRe = (() => {
+	const alphaNumeric = "[a-z0-9]+";
+	const separator = "(?:\\.|_|__|-+)";
+	const port = ":[0-9]+";
+	const domain = `${alphaNumeric}(?:${separator}${alphaNumeric})*`;
+	const name = `(?:${domain}(?:${port})?/)?(?:${domain}/)*(?:${domain})`;
+	const tag = ":(?<tag>[a-zA-Z0-9_][a-zA-Z0-9._-]{0,127})";
+	const digest = "@(?<digest>sha256:[A-Fa-f0-9]+)";
+	const reference = `(?:${tag}|${digest}|${tag}${digest})`;
+	return new RegExp(`^(?<name>${name})${reference}$`);
+})();
+
+/**
+ * Parse a container image name.
+ */
+export function parseImageName(value: string): {
+	name?: string;
+	tag?: string;
+	digest?: string;
+	err?: string;
+} {
+	const matches = value.match(imageRe);
+	if (matches === null || matches.groups === undefined) {
+		return {
+			err: "Invalid image format: expected NAME:TAG[@DIGEST] or NAME@DIGEST",
+		};
+	}
+
+	if (matches.groups.tag === "latest") {
+		return { err: '"latest" tag is not allowed' };
+	}
+
+	return {
+		name: matches.groups.name,
+		tag: matches.groups.tag,
+		digest: matches.groups.digest,
+	};
+}
+
 /**
  * Wrapper that parses wrangler configuration and authentication.
  * It also wraps exceptions and checks if they are from the RestAPI.

packages/wrangler/src/cloudchamber/create.ts

@@ -17,6 +17,7 @@ import {
 	collectLabels,
 	interactWithUser,
 	loadAccountSpinner,
+	parseImageName,
 	promptForEnvironmentVariables,
 	promptForLabels,
 	renderDeploymentConfiguration,
@@ -34,6 +35,8 @@ import type {
 import type { EnvironmentVariable, Label, SSHPublicKeyID } from "./client";
 import type { Arg } from "@cloudflare/cli/interactive";
 
+const defaultContainerImage = "docker.io/cloudflare/hello-world:1.0";
+
 export function createCommandOptionalYargs(yargs: CommonYargsArgvJSON) {
 	return yargs
 		.option("image", {
@@ -123,6 +126,12 @@ export async function createCommand(
 		}
 
 		const body = checkEverythingIsSet(args, ["image", "location"]);
+
+		const { err } = parseImageName(body.image);
+		if (err !== undefined) {
+			throw new Error(err);
+		}
+
 		const keysToAdd = args.allSshKeys
 			? (await pollSSHKeysUntilCondition(() => true)).map((key) => key.id)
 			: [];
@@ -239,18 +248,19 @@ async function handleCreateCommand(
 		label: "image",
 		validate: (value) => {
 			if (typeof value !== "string") {
-				return "unknown error";
+				return "Unknown error";
 			}
 			if (value.length === 0) {
-				return "you should fill this input";
-			}
-			if (value.endsWith(":latest")) {
-				return "we don't allow :latest tags";
+				// validate is called before defaultValue is
+				// applied, so we must set it ourselves
+				value = defaultContainerImage;
 			}
+
+			const { err } = parseImageName(value);
+			return err;
 		},
-		defaultValue: givenImage ?? "",
-		initialValue: givenImage ?? "",
-		helpText: 'i.e. "docker.io/org/app:1.2", :latest tags are not allowed!',
+		defaultValue: givenImage ?? defaultContainerImage,
+		helpText: 'NAME:TAG ("latest" tag is not allowed)',
 		type: "text",
 	});
 
@@ -323,4 +333,4 @@ async function handleCreateCommand(
 	await waitForPlacement(deployment);
 }
 
-const whichImageQuestion = "Which image url should we use for your container?";
+const whichImageQuestion = "Which image should we use for your container?";

packages/wrangler/src/cloudchamber/modify.ts

@@ -10,6 +10,7 @@ import {
 	collectLabels,
 	interactWithUser,
 	loadAccountSpinner,
+	parseImageName,
 	promptForEnvironmentVariables,
 	promptForLabels,
 	renderDeploymentConfiguration,
@@ -192,15 +193,14 @@ async function handleModifyCommand(
 		label: "",
 		validate: (value) => {
 			if (typeof value !== "string") {
-				return "unknown error";
-			}
-			if (value.endsWith(":latest")) {
-				return "we don't allow :latest tags";
+				return "Unknown error";
 			}
+			const { err } = parseImageName(value);
+			return err;
 		},
 		defaultValue: givenImage ?? deployment.image,
 		initialValue: givenImage ?? deployment.image,
-		helpText: "Press Return to leave unchanged",
+		helpText: "press Return to leave unchanged",
 		type: "text",
 	});