From the MirageOS 3.0 release announcement:
MirageOS applications can be compiled to run as self-contained virtual machines (a few MB in size) on Xen or KVM hosts, FreeBSD’s bhyve, or even as regular Unix processes (allowing access to regular debugging tools). The system libraries themselves can be reused in traditional applications, just like any other software library.
MirageOS unikernels are written in OCaml and can be run directly on top of Muen
via the Solo5 platform. Support for Muen was
merged into Solo5 with pull-request
#190. The port includes an implementation of
muennet, thus networking is
|Since IncludeOS v0.11 was ported to run on Solo5, it should be possible to run it as subject on Muen as well. (We even got a mention in one of their blog posts).|
|According to the authors plans HalVM 3.0 will include a port to Solo5, which would enable Haskell subjects on Muen.|
MirageOS heavily depends on the OCaml Package Manager
(OPAM) as its build system. Follow the installation
instructions here to setup OPAM on your system.
However, do not yet install
mirage until after the next step.
These instructions have been tested with version 4.05.0 of the compiler. If you are not already using this compiler, you can create a new switch as follows:
$ opam switch 4.05.0
Then make sure you update the environment:
$ eval `opam config env`
The version 4.05.0 should be marked as the current version:
$ opam switch list ... -- C 4.05.0 Official 4.05.0 release ...
Until new versions of MirageOS packages with Muen-specific extensions are released and included in the OPAM repository they must be pinned to specific versions:
$ opam pin add ocaml-freestanding -n --dev-repo $ opam pin add mirage -n --kind git https://github.com/codelabs-ch/mirage#muen $ opam pin add solo5-kernel-muen -n -y --kind git https://github.com/solo5/solo5
|These pins will be unnecessary as soon as Solo5 issue #194 has been closed.|
After successfully adding the necessary pins, install the depext module. It handles external/system dependencies for opam packages.
$ opam install depext
Then install the mirage tool:
$ opam install -y mirage
The Solo5 repository includes simple test cases, some of which can be executed on Muen in Bochs:
$ git clone https://github.com/solo5/solo5 $ cd solo5 $ make
Copy the generated binary to the Muen policy object directory:
$ objcopy -O binary tests/test_hello/test_hello.muen path/to/muen/policy/obj/unikernel
Finally, emulate the system:
$ make SYSTEM=xml/mirage-solo5.xml emulate
The unikernel does not produce any VGA output but you should see the following messages in the log:
$ cat emulate/serial.out | tools/scripts/mulog-subject.py 3
Solo5: Console: Muen Channel @ 0xffff00000, size 0x20000, epoch 0x26341161 | ___| __| _ \ | _ \ __ \ \__ \ ( | | ( | ) | ____/\___/ _|\___/____/ Solo5: Memory map: 512 MB addressable: Solo5: unused @ (0x0 - 0xfffff) Solo5: text @ (0x100000 - 0x107fff) Solo5: rodata @ (0x108000 - 0x109fff) Solo5: data @ (0x10a000 - 0x10efff) Solo5: heap >= 0x10f000 < stack < 0x20000000 Solo5: Clock source: Muen PV clock, TSC frequency 50000000 Hz Solo5: Net: No output channel **** Solo5 standalone test_hello **** Hello, World Command line is: ''
$ git clone -b mirage-dev https://github.com/mirage/mirage-skeleton
Currently there is a build issue on the master branch so make sure to be
$ cd mirage-skeleton/applications/static_website_tls
The content that will be served can be found in the
htdocs directory. You can
replace it with something more interesting, e.g. the Muen project website.
To build the unikernel using the mirage tool issue the following commands:
$ mirage configure -t muen $ make depend $ make
If all goes well an unikernel image called
https.muen should be present in
the current directory.
Copy it over to the Muen policy object directory:
$ objcopy -O binary https.muen path/to/muen/policy/obj/unikernel
Build and deploy the system to hardware:
$ make SYSTEM=xml/mirage-solo5-net.xml deploy
|The following commands must be executed in the NIC Linux of the deployed Muen system.|
Once the deployed system is booted, disable the standard muennet interface in NIC Linux and setup networking for MirageOS:
$ /etc/init.d/S51muennet stop $ /usr/bin/mirage-net
|The following commands must be executed on the development/host computer.|
By default, the unikernel is listening on 10.0.0.2. So in order to make it reachable from the host computer add a route:
$ sudo ip route add 10.0.0.0/24 via 192.168.254.2
You should be able to ping the NIC Linux and the unikernel:
$ ping 10.0.0.1 PING 10.0.0.1 (10.0.0.1) 56(84) bytes of data. 64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=1.30 ms .. $ ping 10.0.0.2 PING 10.0.0.2 (10.0.0.2) 56(84) bytes of data. 64 bytes from 10.0.0.2: icmp_seq=1 ttl=37 time=3.52 ms
Finally you can point your browser to
https://10.0.0.2:4433/ and after
accepting the certificate warnings you should see the static website served by
Instead of a routed connection, the muennet interface used by the unikernel can be bridged with the physical interface. This way the unikernel can talk directly to the local network.
Which IP address the unikernel is supposed to use is configured via the
--ipv4* options that can either be passed as unikernel configure parameters
or as boot parameters in the subject policy of the unikernel subject
To serve the website from 192.168.254.10, rebuild the static_website_tls unikernel by issuing the following commands:
$ mirage configure -t muen --ipv4=192.168.254.10/24 --ipv4-gateway=192.168.254.1 $ make depend $ make $ objcopy -O binary https.muen path/to/muen/policy/obj/unikernel
Then rebuild and deploy the system to hardware.
On the NIC Linux, use the
mirage-net-bridge script to setup the bridging:
$ /etc/init.d/S51muennet stop $ /usr/bin/mirage-net-bridge
If all goes well, the MirageOS unikernel should be reachable via the configured IP address.
While the previous MirageOS Unikernels article described how to build and deploy MirageOS/Solo5 unikernels as subjects on Muen in general, this article focuses on a practical use-case of the technology.
The following graph gives an overview of the muen.sk system image build process:
In order to be able to serve the page via the TLS stack provided by MirageOS, up to date SSL/TLS certificates are required. We use Letsencrypt certificates for that purpose.
Therefore, the first step in the build process is to check whether the currently deployed certificates are still valid. This is done using openssl:
openssl x509 -checkend 2592000 -noout -in certs/live/muen.sk/cert.pem
The command checks whether the certificate expires within 30 days. If renewal is required, a new certificate is requested via the standalone feature of the Letsencrypt’s certbot client. The certificate files are then added as content of stage one in the multi-stage Docker build.
The complete Muen system image build consists of three Docker images:
These images can be found on our Docker
Hub page. The key is to import artifacts from the previous build stage into
the next one using the
COPY --from syntax. The following command gives an
example how to copy the generated site content from the website to the
FROM codelabsch/muen-website:latest as website-content # generate website content FROM codelabsch/muen-mirageos:latest as unikernel COPY --from=website-content /home/writer/website-muen.sk/_site htdocs
The assembled Muen system image containing the unikernel subject serving the generated website content is copied out of the final Docker container. Because we want the target system to only boot cryptographically verified images, the image is signed using the following command (as described by the iPXE homepage):
openssl cms -sign -binary -noattr -in $IMAGE -signer $SIGN_CERT \ -inkey $SIGN_KEY -certfile $CA -outform DER -out $SIG
Then the image and associated signature is uploaded to a webserver which is reachable by the target system.
In order to support image signature verification, the iPXE bootloader must be
compiled with the
IMAGE_TRUST_CMD option enabled:
diff --git a/src/config/general.h b/src/config/general.h index 3c14a2cd..0c67a39d 100644 --- a/src/config/general.h +++ b/src/config/general.h @@ -144,7 +144,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); //#define PXE_CMD /* PXE commands */ //#define REBOOT_CMD /* Reboot command */ //#define POWEROFF_CMD /* Power off command */ -//#define IMAGE_TRUST_CMD /* Image trust management commands */ +#define IMAGE_TRUST_CMD /* Image trust management commands */ //#define PCI_CMD /* PCI commands */ //#define PARAM_CMD /* Form parameter commands */ //#define NEIGHBOUR_CMD /* Neighbour management commands */
The following script instructs iPXE to only boot images which are deemed
trusted (i.e. which have a valid signature). Besides the general networking
setup steps, it fetches the Muen system image containing our MirageOS webserver
subject from a given URL and then verifies the associated signature. The
imgstat command is for debugging purposes and displays the current image
state before booting into the verified Muen system.
#!ipxe imgtrust --permanent ifopen net0 set net0/ip 192.168.199.4 set net0/netmask 255.255.255.0 set net0/gateway 192.168.199.1 set dns 192.168.199.1 imgfetch http://192.168.199.2/muen.img imgverify muen.img http://192.168.199.2/muen.img.sig imgstat boot muen.img
The image is signed using a certificate issued by our own private CA. In order
for iPXE to successfully verify such a signature, we need to embed and trust
the appropriate certificates. The
TRUST environment variables can
be used for this:
make bin/ipxe.usb -j5 EMBED=muen.ipxe.website \ DEBUG=open,x509 \ CERT=ipxe-sign.crt,ca.crt \ TRUST=ca.crt
This command compiles a bootable iPXE image which can be dumped onto an USB
stick. The certificates specified via
CERT are embedded into the image. Since
embedded certificates are not automatically trusted, our CA must be specified
explicitly via the
DEBUG option is very helpful during initial testing if the image fetching
or signature verification step fails for some reason.
The last step of the build process is to trigger a restart of the target system via Intel AMT functionality. The target system restarts and performs the steps depicted in the following graph:
Your minimal, unikernel-based website should now be served at the configured IP after system start.
In order to easily perform updates of the static Muen website with minimal downtime, the whole aforementioned process is scripted.