feat(examples): Introduce HTTP C application (#3)

Approved-by: Alexander Jung <[email protected]>
unikraft · Oct 27, 2023 · 8d5ee80 · 8d5ee80
2 parents f53b665 + a90109b
commit 8d5ee80
Show file tree

Hide file tree

Showing 4 changed files with 177 additions and 0 deletions.
diff --git a/examples/http-c/Kraftfile b/examples/http-c/Kraftfile
@@ -0,0 +1,28 @@
+spec: v0.6
+
+name: http-c
+
+unikraft:
+  version: stable
+  kconfig:
+    CONFIG_LIBUKBUS: 'y'
+
+targets:
+- qemu/x86_64
+- qemu/arm64
+- fc/x86_64
+- xen/x86_64
+- linuxu/x86_64
+- linuxu/arm64
+
+libraries:
+  lwip:
+    version: stable
+    kconfig:
+      CONFIG_LWIP_UKNETDEV: 'y'
+      CONFIG_LWIP_TCP: 'y'
+      CONFIG_LWIP_THREADS: 'y'
+      CONFIG_LWIP_SOCKET: 'y'
+      CONFIG_LWIP_AUTOIFACE: 'y'
+      CONFIG_LWIP_IPV4: 'y'
+      CONFIG_LWIP_DHCP: 'y'
diff --git a/examples/http-c/Makefile.uk b/examples/http-c/Makefile.uk
@@ -0,0 +1,3 @@
+$(eval $(call addlib,apphttpreply))
+
+APPHTTPREPLY_SRCS-y += $(APPHTTPREPLY_BASE)/main.c
diff --git a/examples/http-c/README.md b/examples/http-c/README.md
@@ -0,0 +1,34 @@
+# Simple HTTP C Server on Unikraft
+
+This directory contains a simple HTTP server written in C running with Unikraft.
+The image opens up a simple HTTP server and provides a simple HTML response for each request.
+
+To run this example, [install Unikraft's companion command-line toolchain `kraft`](https://unikraft.org/docs/cli).
+
+Then, clone this repository and `cd` into this directory.
+You can then build the project with:
+
+```console
+kraft build
+```
+
+In the above command, `kraft build` will prompt you with the target you wish to compile for.
+If you are unsure, select `qemu/` and your host's architecture, e.g. `qemu/x86_64`.
+
+Once built, you can execute the unikernel via:
+
+```console
+kraft run -p 8080:8080
+```
+
+Once executed, query the simple HTTP server:
+
+```console
+curl localhost:8080
+```
+
+## Learn more
+
+- [How to build unikernels](https://unikraft.org/docs/cli/building)
+- [How to run unikernels locally](https://unikraft.org/docs/cli/running)
+- [The `Kraftfile` specification](https://unikraft.org/docs/cli/reference/kraftfile/latest)
diff --git a/examples/http-c/main.c b/examples/http-c/main.c
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Authors: Simon Kuenzer <[email protected]>
+ *
+ * Copyright (c) 2019, NEC Laboratories Europe GmbH, NEC Corporation.
+ *                     All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <errno.h>
+
+#define LISTEN_PORT 8080
+static const char reply[] = "HTTP/1.1 200 OK\r\n" \
+			    "Content-type: text/html\r\n" \
+			    "Connection: close\r\n" \
+			    "\r\n" \
+			    "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">" \
+			    "<html>" \
+			    "<head><title>It works!</title></head>" \
+			    "<body><h1>It works!</h1><p>This is only a test.</p></body>" \
+			    "</html>\n";
+
+#define BUFLEN 2048
+static char recvbuf[BUFLEN];
+
+int main(int argc __attribute__((unused)),
+	 char *argv[] __attribute__((unused)))
+{
+	int rc = 0;
+	int srv, client;
+	ssize_t n;
+	struct sockaddr_in srv_addr;
+
+	srv = socket(AF_INET, SOCK_STREAM, 0);
+	if (srv < 0) {
+		fprintf(stderr, "Failed to create socket: %d\n", errno);
+		goto out;
+	}
+
+	srv_addr.sin_family = AF_INET;
+	srv_addr.sin_addr.s_addr = INADDR_ANY;
+	srv_addr.sin_port = htons(LISTEN_PORT);
+
+	rc = bind(srv, (struct sockaddr *) &srv_addr, sizeof(srv_addr));
+	if (rc < 0) {
+		fprintf(stderr, "Failed to bind socket: %d\n", errno);
+		goto out;
+	}
+
+	/* Accept one simultaneous connection */
+	rc = listen(srv, 1);
+	if (rc < 0) {
+		fprintf(stderr, "Failed to listen on socket: %d\n", errno);
+		goto out;
+	}
+
+	printf("Listening on port %d...\n", LISTEN_PORT);
+	while (1) {
+		client = accept(srv, NULL, 0);
+		if (client < 0) {
+			fprintf(stderr,
+				"Failed to accept incoming connection: %d\n",
+				errno);
+			goto out;
+		}
+
+		/* Receive some bytes (ignore errors) */
+		read(client, recvbuf, BUFLEN);
+
+		/* Send reply */
+		n = write(client, reply, sizeof(reply) - 1);
+		if (n < 0)
+			fprintf(stderr, "Failed to send a reply\n");
+		else
+			printf("Sent a reply\n");
+
+		/* Close connection */
+		close(client);
+	}
+
+out:
+	return rc;
+}
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		$(eval $(call addlib,apphttpreply))

		APPHTTPREPLY_SRCS-y += $(APPHTTPREPLY_BASE)/main.c