Re: [OSSTEST PATCH 1/9] README.dev: Document the blessings

[Ian Campbell <ian.campbell@citrix.com>]

On Thu, 2015-12-17 at 17:06 +0000, Ian Jackson wrote:
> Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
> ---
>  README.dev |  101
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 101 insertions(+)
> 
> diff --git a/README.dev b/README.dev
> index 65ec111..879af60 100644
> --- a/README.dev
> +++ b/README.dev
> @@ -232,3 +232,104 @@ probably are after a reboot) by looking for
> processes relating to the
>  lists flight,job combinations and then:
>  
>  $ ./mg-hosts previoustasks --clear
> +
> +
> +Flight blessings and the blessed-* host flags
> +=============================================
> +
> +Both flights and hosts have a `blessing'.
> +
> +Blessings are used:
> +
> + * To avoid accidentally tools operating on flights which are in the
> +   wrong phase of their existence.
> +
> + * To control which automatic archaeologists will look at which
> +   flights.  (Archeaology tools take arguments to control which

                 Archaeology

> +   blessings they will consider.)
> +
> + * To control which hosts are considered suitable for use with which
> +   flight.  (Flights with blessing `foo' use only hosts which have
> +   flag `blessed-foo'.)
> +
> +Each flight has a `blessing' and an `intended blessing'.  The
> +`intended blessing' is what the flight is going to be blessed as when
> +its execution has completed.  The intended blessing controls host
> +allocation.

I think this could also usefully mention that `blessing' is the current
blessing, which may go through several phases during the life of the
flight, hopefully culminating in being set to `intended blessing' if the
flight is successful and that the archaeology tools only look at `blessing'
and never `intended blessing'

> +(Normally the `intended blessing' is the same as the bless argument to
> +sg-execute-flight aka the -B argument to mg-execute-flight.)

How does this interact with the intended blessing passed to cs-flight-
create?

> + * `real-bisect' and `adhoc-bisect': These are found only as the
> +   blessing of finished flights.  (This is achieved by passing *-adhoc
> +   to sg-execute-flight.)  This allows the archaeologist tools to
> +   distinguish full flights from bisection steps.

I don't follow the reference to *-adhoc here, since it matches neither
`real-bisect' nor `adhoc-bisect'.

> +There is a special exception to the tools' flight status checks: any
> +flight whose blessing contains `play' can be operated on out of order.
> +
> +Flights blessings can be manually changed with cs-flight-bless.  Eg
> +  ./cs-flight-bless FLIGHT broken-real real
> +updates FLIGHT to be marked `broken' rather than `real'.  This can be

The example says `broken-real' but the text says `broken' (if the text
didn't quote the `broken' it probably wouldn't matter.

Maybe mention the need to pass the current blessing as a safety catch,
since it is part of the example command?

Ian.

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