Mailing-List: contact dev-help@felix.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@felix.apache.org
From: Jan Willem Janssen <janwillem.janssen@luminis.eu>
To: "dev@felix.apache.org" <dev@felix.apache.org>
Subject: Re: [DISCUSS] Contribution of Bundle ARchive (BAR) installer
Thread-Topic: [DISCUSS] Contribution of Bundle ARchive (BAR) installer
Thread-Index: AQHTP4mrzKQqkvPCjkmod8kUcLYPHqLbOd6A
Date: Mon, 9 Oct 2017 08:56:20 +0000
Message-ID: <2D7EB410-A3EF-43C3-A06C-B8BE3E779130@luminis.eu>
References: <9F2D9F9C-0C17-4554-8D86-CC48DFF09C4F@paremus.com>
In-Reply-To: <9F2D9F9C-0C17-4554-8D86-CC48DFF09C4F@paremus.com>
Accept-Language: en-US, en-GB, nl-NL
Content-Language: en-US
received-spf: None (protection.outlook.com: luminis.eu does not designate
 permitted sender hosts)
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
Content-Type: multipart/signed;
	boundary="Apple-Mail=_3F7818AA-61C7-4C31-BBD8-FE065E23E1F8";
	protocol="application/pgp-signature"; micalg=pgp-sha256
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-originalarrivaltime: 09 Oct 2017 08:56:20.4347
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 92b1c82c-10a6-40ec-8b2e-1e63eeb29438
X-MS-Exchange-Transport-CrossTenantHeadersStamped: AMSPR03MB408
archived-at: Mon, 09 Oct 2017 08:56:35 -0000

--Apple-Mail=_3F7818AA-61C7-4C31-BBD8-FE065E23E1F8
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain;
	charset=utf-8


> On 7 Oct 2017, at 18:30, Neil Bartlett (Paremus) =
<neil.bartlett@paremus.com> wrote:
>=20
> Hello Felix developers,
>=20
> I would like to initiate a contribution of external code into Apache =
Felix. This code is being contributed on behalf of Intel Corporation, =
who funded development. The contribution is a plugin for File Install =
=E2=80=94 an implementation of the ArtifactInstaller service =E2=80=94 =
which handles Bundle ARchive (BAR) files. This is a proposed format for =
an aggregate of functionality represented as one or more OSGi bundles =
along with an OSGi index. It includes use of the OSGi resolver API to =
check consistency and permits overlapping resources from multiple =
installable units.
>=20
> A BAR file is physically a JAR file with some defined manifest headers =
to control the behaviour of the installer. It must contain an OSGi index =
(in the XML format specified by the Repository Service specification) =
and the index can reference bundles contained within the BAR, or =
optionally external bundles. Additionally the BAR manifest contains a =
set of requirements (a Require-Bundle and/or Require-Capability header) =
that define the root requirements to be resolved against that index.
>=20
> Dropping a BAR file into the File Install monitored directory does not =
immediately install its contents. Instead a resolution process is =
initiated to ensure that the contents of the BAR are complete and =
consistent. If that resolution process succeeds then the BAR contents =
become available for installation. The application or management agent =
is responsible for triggering the actual installation. Multiple BAR =
files can require the same resource transitively. We use a reference =
counting mechanism to ensure that BARs with overlapping requirements can =
be installed concurrently, and those resources are only uninstalled when =
the last BAR that references them is uninstalled.
>=20
> This differs from existing approaches in the following ways:
>=20
> 1. The OSGi Deployment Admin specification defines a similar file =
format for aggregates of bundles, but the contents of a Deployment =
Package cannot overlap with previously installed Deployment Packages. =
This limitation makes the specification unworkable in many practical =
scenarios.
>=20
> 2. Eclipse and Karaf both have a similar concept of =E2=80=9Cfeatures=E2=
=80=9D, but these are simply listings of bundles. The BAR Installer uses =
the OSGi resolver to ensure that the contents of the BAR can actually be =
installed cleanly in the current OSGi framework, and will never attempt =
to reinstall a bundle that is already in use.
>=20
> 3. The OSGi Subsystem Service specification has the ability to resolve =
the contents of a subsystem, but the resolved bundles are usually =
installed into an isolated =E2=80=9Cregion=E2=80=9D of the target OSGi =
framework. This creates a lot of complexity, and as a result the =
Subsystems chapter of the OSGi specification makes for a daunting read. =
BARs are installed into the flat OSGi framework without isolation, have =
a simpler lifecycle and are easier for developers to reason about.
>=20
> All sources are already Apache licensed, and were originally developed =
for the Open Security Controller project =
(https://www.opensecuritycontroller.org/ =
<https://www.opensecuritycontroller.org/>).

Nice work! I=E2=80=99ve glanced through the code and was wondering =
whether it is an idea to separate the file-install specifics from the =
more generic resolver/management parts. It would allow BARs to be =
installed by using different means (for example, a custom management =
agent) than
file install.

WDYT?

--
Met vriendelijke groeten | Kind regards

Jan Willem Janssen | Software Architect
+31 631 765 814


My world is something with Amdatu and Apache

Luminis Technologies
John F. Kennedylaan 32
7314 PS  Apeldoorn
+31 88 586 46 25

https://www.luminis.eu

KvK (CoC) 09 16 28 93
BTW (VAT) NL8170.94.441.B.01


--Apple-Mail=_3F7818AA-61C7-4C31-BBD8-FE065E23E1F8
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment; filename="signature.asc"
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: Message signed with OpenPGP

-----BEGIN PGP SIGNATURE-----
Comment: (JaWi)
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=QLsx
-----END PGP SIGNATURE-----

--Apple-Mail=_3F7818AA-61C7-4C31-BBD8-FE065E23E1F8--