reynir/albatross
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

[ci skip] minor rewording

Browse source
This commit is contained in:
Hannes Mehnert 2020-03-31 21:18:09 +02:00
parent 14f861b945
commit 59212bdca9
1 changed files with 43 additions and 28 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

71
README.md
View file

@ -3,25 +3,38 @@
[![Build Status](https://travis-ci.org/hannesm/albatross.svg?branch=master)](https://travis-ci.org/hannesm/albatross)
The goal of albatross is robust deployment of [MirageOS](https://mirage.io)
unikernels using [Solo5](https://github.com/solo5/solo5), including precise
error handling of failures. The code running under superuser privileges is
minimimal. Albatross is supposed to be run on a machine in the dom0, next to the
hypervisor. Albatross keeps track of unikernel resource usage (memory, CPUs,
bridges, block storage and active block devices). Policies restricting these
resources for administrative domains are available. Local and remote deployments
are supported, remote ones are authenticated and encrypted via a mutually
authenticated TLS connection using X.509 client certificates. Multi-tenancy
deployments are possible, tenants do not need any other access to the machine:
console output and statistics gathered by the host are accessible via TLS.
Albatross keeps the information of running unikernels persistently, and starts
these unikernels when the albatross daemon is started. This means that whenever
a unikernel was started, it keeps running until it crashes or an explicit
destroy command is issued.
unikernels using [Solo5](https://github.com/solo5/solo5). Resources managed
by albatross are network interfaces of kind `tap`, which are connected to
already existing bridges, block devices, memory, and CPU. Each unikernel is
pinned (`cpuset` / `taskset`) to a specific core.
The administrative domain is similar to DNS: each unikernel has a name (e.g.
`foo.hello`), which consists of labels separated by dots. Policies and
access is done on a name basis - if access to `foo` is granted, `foo.hello`,
`foo.bar.hello`, etc. can be accessed, but not `bar` or `bar.hello`.
Albatross allows remote management, to deploy or destroy a unikernel, no shell
access is necessary. The remote channel is a mutually authenticated (with X.509
certificates) TLS connection. Console output of the unikernels is stored in
memory in a ring buffer, and accessible from remote. Monitoring data (CPU and
memory usage) of the unikernels can be collected as well, and pushed into a
Influx time series database.
Albatross consists of multiple processes, each running with the least
privileges. Albatross can be run next to other orchestration systems, it does
not assume to be the single instance on a dom0 which creates and destroys
virtual machines. Resource policies can be dynamically configured for each
administrative domain (similar to DNS, a hierarchical naming scheme), and is
statically checked (to decrease while going down the tree) and dynamically when
a new unikernel is to be deployed.
When a unikernel was deployed on albatross, it tries the best to keep this
running, even when the physical hardware reboots, or albatross is restarted.
When the unikernel exits, depending on configuration and its exit code, it is
re-started. The current set of running unikernels is persisted on disk, though
there is no dependency or order how to restart them.
The scope of albatross is to provide a minimal orchestration system that avoids
the need of shell access on the dom0. This leads to mostly immutable - or only
mutable via albatross which writes a log for every administrative change -
infrastructure. Further dissemination of albatross into virtual machines, and
a communication interface for deploying and destroying unikernels, is being
researched on.
## Components
@ -31,8 +44,7 @@ request-response style over Unix domain sockets, are run in the host system:
- `albatross_console`: reads the console output of unikernels
- `albatross_log`: event log
- `albatross_stats`: statistics gathering (rusage, ifstat, BHyve debug counters)
- `albatross_tls_endpoint`: remote deployment via TLS with client certificate, and proxies to local daemons
- `albatross_tls_inetd`: remote deployment via TLS and inetd (alternative to `albatross_tls_endpoint`)
- `albatross_tls_inetd`: remote deployment via TLS and inetd (an alternative is `albatross_tls_endpoint`)
- `albatross_influx`: statistic reporting from `albatross_stats` to influx
The main daemon is the privileged `albatrossd`, which supervises unikernels. It opens
@ -55,11 +67,13 @@ write their standard output to.
`Albatross_stats` gathers periodically statistics (memory, CPU, network, hypervisor)
from all running unikernels.
`Albatross_tls_endpoint` and `albatross_tls_inetd` listen on a TCP port, and proxy requests from
remote clients to the respective daemons described above. They enforce client
authentication, and use the commen names of the client certificate chain as
administrative domain. The policies are embedded in CA certificates, the command
is embedded in the leaf certificate.
`Albatross_tls_inetd` is executed via inetd (socket activation), and proxy
requests from remote clients to the respective daemons described above. It
enforce client authentication, and use the commen names of the client
certificate chain as administrative domain. The policies are embedded in CA
certificates, the command is embedded in the leaf certificate. The
`albatross_tls_endpoint` is an alternative, which listen on a TCP port and
executes an asynchronous task for each incoming request.
The following command-line applications for local and remote management are provided:
- `albatross_client_local`: sends a command locally to the Unix domain sockets
@ -73,9 +87,10 @@ The following command-line applications for local and remote management are prov
To install Albatross, run `opam pin add albatross
https://github.com/hannesm/albatross`.
Init scripts for FreeBSD are provided in the `packaging/rc.d` subdirectory.
TODO: from here on, this documentation is not up to date.
Init scripts for FreeBSD are provided in the `packaging/FreeBSD/rc.d`
subdirectory, and a script to create a FreeBSD package
`packaging/FreeBSD/create_package.sh`.
For Linux, systemd service scripts are available in `packaging/Linux`.
It may help to read [the _outdated_ blog article](https://hannes.nqsb.io/Posts/VMM)
for motivation of albatross and an overview over its functionality.