lmbench is a bit outdated tool to do OS performance analysis. The
upcoming neotest SR will use lat_tcp from this packages to measure TCP
round-trip-time latency.

We use a bit patched version with fixes to lat_tcp for errors not to go
unnoticed and also lat_tcp.go added to see how using Go compares to
plain lat_tcp.c for latencies.

In the upcoming neotest SR both lat_tcp C & Go versions will be used to
automatically benchmark TCP round-trip-times over network link in between
2 machines.

This tool can be used to measure disk IO latency for various workloads
(random read, sequential read, direct or cached, write, ...).

We use a bit patched version shows not only avg latency but also its
distribution. (the patches are currently dirty/not very robust and not
yet sent to upstream).

In the upcoming neotest SR ioping will be used to automatically
benchmark underlying disk characteristics.

ethtool can be used to adjust NIC settings, such as e.g. interrupt
coalescing and various others. It usually requires root to do so.

However regular users can query NIC settings via ethtool just ok.

This way upcoming neotest SR will use it to query/display NIC setting
which are essential to get good networked latency and automatically
produce warnings if it is not.

Starting from this version zodbtools requires zodburi to open ZODB
storages by URL (see nexedi/zodbtools@db3b84ec
and nexedi/zodbtools@82b06413)

zodburi in turn requires ZEO (maybe we might patch it to only optionally
depend on it), so we move ZEO requirement from stack/ERP5 to the place
where it is actually first needed.

In Go world development workflow is organized around so-called workspace
where multiple packages can be installed / worked on etc. The following
page describes Go workspaces:

https://golang.org/doc/code.html

A new [gowork] section and infrastructure around it is introduced.
Quoting code:

    # gowork is a top-level section representing workspace
    #
    # users should add `install` field to [gowork] to describe packages they want to
    # be installed (+ automatically their dependencies are installed too). e.g.
    #
    #   [gowork]
    #   install =
    #       lab.nexedi.com/kirr/neo/go/...  \
    #       github.com/pkg/profile          \
    #       golang.org/x/perf/cmd/benchstat

The way it all works inside is:

- gowork organizes to create go.work/ directory in buildout root
- inside it creates env.sh which when sources in shell adjusts all paths
  so that appropriate go compiler is in path, GOPATH is also set
  appropriately, etc - in other words everything needs for using/working
  on this workspace is setup in the environment.
- in actual user software profile the list of Go projects which needs to
  be installed by SlapOS has to be listed. The [gowork] machinery takes
  care about git-cloning these projects and `go install`s them after.
- by SlapOS design builds have to be reproducible and so every component
  state/version has to be fixed.

  A convenient helper (gowork-snapshot) to get snapshot of git go
  packages installed with their exact revisions is added. This should be
  used to automatically (re-)generate list of go git repositories &
  their pinning for a workspace.

For a new Go project that needs to be slaposified the workflow should be:

- first get a project into working state via any convenient way (`go get`, etc.)
- generate list of go packages & their pinning with gowork-snapshot
- extend golang/buildout.cfg and in project software profile add

	[gowork]
  	install = your-top-level-packages

  as it was outlined above.

P.S.

[golang] is removed because

1. it is not used anywhere in slapos.git tree, and
2. the canonical way to work on go projects from now on will be to use
   [gowork]. There latest go version is preconfigured, but users can
   override it to some particular other version in their projects as they
   need.

/reviewed-on	 !242
/also-needed-for !243

This reverts merge request !243

The first proof of concept  of Caddy in Slapos. 

For now, everything is inside software/caddy but in the next merge request we will move to stack. 

@rafael @romain 


/reviewed-on !243

WIP

  Environment requires new lines instead spaces

   This is required got the usage of git

  MD5SUM update was missing.

Experimental. Not automatically executed.

Restores given backup, configures service as a slave to given master,
starts replication.

Like for "normal" backup restoration, any running mariadb is killed,
started with backup-restoration-friendly parameters, and killed again once
restored.

As there is AFAIK no way to ask supervisor to start even one of our own
services, this script unfortunately leaves the partition in a
not-immediately useful state.

Nothing references this section otherwise.

This value is supposed to come from configuration file, which is already
implicitly provided inside used wrapper.

Back-porting a patch from upstream's github repository.

This reverts commit 18c4c3e2.