Have most of the sim command handler, but to keep it pure while implementing
the rest will need some refactoring.
It seems likely that running the simulation itself will not be able to be
entirely pure. Preferred content evaluation runs in Annex after all.
Note that the somewhat awkward randomWords is because the i386ancient
build depends on a version of random too old to support generating a
random ByteString on its own.
updateRepoSize is only called on the UUID of a repository, not any
cluster it might be a node of. But overLocationLogs and overLocationLogsJournal
were inclusing cluster UUIDs. So it was inconsistent.
Currently I don't see any reason to calculate RepoSize for a cluster.
It's not even clear what it should mean, the total size of all nodes, or
the amount of information stored in the cluster in total?
This will be used to prime the RepoSizes database, which will always
contain values that correpond to information in the git-annex branch, so
without anything from journal files.
Factored out overJournalFileContents which will later be used to
update Annex.reposizes to include information from journal files.
This will be partitcularly important to support private UUIDs which only
ever get to journal files and not to the branch.
git-annex info was displaying a message that didn't make sense in
context.
In calcRepoSizes, it seems better to return the information from the
git-annex branch, rather than giving up. Especially since balanced
preferred content uses it, and we can't just give up evaluating a
preferred content expression if git-annex is to be usable in such a
readonly repo.
Commit 6d7ecd9e5d nobly wanted git-annex
to behave the same with such unmerged branches as it does when it can
merge them. But for the purposes of preferred content, it seems to me
there's a sense that such an unmerged branch is the same as a remote we
have not pulled from. The balanced preferred content will either way
operate under outdated information, and so make not the best choices.
This all works fine. But it doesn't check repository sizes yet, and
without repository size checking, once a repository gets full, there
will be no other repository that will want its files.
Use of sha2 seems unncessary, probably alder2 or md5 or crc would have
been enough. Possibly just summing up the bytes of the key mod the number
of repositories would have sufficed. But sha2 is there, and probably
hardware accellerated. I doubt very much there is any security benefit
to using it though. If someone wants to construct a key that will be
balanced onto a given repository, sha2 is certianly not going to stop
them.
There was no good reason for it to be using annexLocationsNonBare,
and exporttree=yes annexobjects=yes is going to use annexLocationsBare,
so this should as well for consistency.
Since all returned ExportLocations are tried when retrieving objects,
this won't break backwards compatability.
Refactored git-annex-shell code so this can use checkCanProxy'.
At this point all that remains is opening a proxy connection,
and using a proxy connection.
Added Maybe POSIXTime to SafeDropProof, which gets set when the proof is
based on a LockedCopy. If there are several LockedCopies, it uses the
closest expiry time. That is not optimal, it may be that the proof
expires based on one LockedCopy but another one has not expired. But
that seems unlikely to really happen, and anyway the user can just
re-run a drop if it fails due to expiry.
Pass the SafeDropProof to removeKey, which is responsible for checking
it for expiry in situations where that could be a problem. Which really
only means in Remote.Git.
Made Remote.Git check expiry when dropping from a local remote.
Checking expiry when dropping from a P2P remote is not yet implemented.
P2P.Protocol.remove has SafeDropProof plumbed through to it for that
purpose.
Fixing the remaining 2 build warnings should complete this work.
Note that the use of a POSIXTime here means that if the clock gets set
forward while git-annex is in the middle of a drop, it may say that
dropping took too long. That seems ok. Less ok is that if the clock gets
turned back a sufficient amount (eg 5 minutes), proof expiry won't be
noticed. It might be better to use the Monotonic clock, but that doesn't
advance when a laptop is suspended, and while there is the linux
Boottime clock, that is not available on other systems. Perhaps a
combination of POSIXTime and the Monotonic clock could detect laptop
suspension and also detect clock being turned back?
There is a potential future flag day where
p2pDefaultLockContentRetentionDuration is not assumed, but is probed
using the P2P protocol, and peers that don't support it can no longer
produce a LockedCopy. Until that happens, when git-annex is
communicating with older peers there is a risk of data loss when
a ssh connection closes during LOCKCONTENT.
Walking a tightrope between security and convenience here, because
git-annex-shell needs to only proxy for things when there has been
an explicit, local action to configure them.
In this case, the user has to have run `git-annex extendcluster`,
which now sets annex-cluster-gateway on the remote.
Note that any repositories that the gateway is recorded to
proxy for will be proxied onward. This is not limited to cluster nodes,
because checking the node log would not add any security; someone could
add any uuid to it. The gateway of course then does its own
checking to determine if it will allow proxying for the remote.
Works down to P2P protocol.
The question now is, how to handle protocol version negotiation for
clusters? Connecting to each node to find their protocol versions and
using the lowest would be too expensive with a lot of nodes. So it seems
that the cluster needs to pick its own protocol version to use with the
client.
Then it can either negotiate that same version with the nodes when
it comes time to use them, or it can translate between multiple protocol
versions. That seems complicated. Thinking it would be ok to refuse to
use a node if it is not able to negotiate the same protocol version with
it as with the client. That will mean that sometimes need nodes to be
upgraded when upgrading the cluster's proxy. But protocol versions
rarely change.
An oversight..
And with the work in progress proxy and cluster, there
can be additional remotes that are not listed in .git/config, but are
available. Making those more discoverable is another big benefit of
this.
This is to avoid inserting a cluster uuid into the location log when
only dead nodes in the cluster contain the content of a key.
One reason why this is necessary is Remote.keyLocations, which excludes
dead repositories from the list. But there are probably many more.
Implementing this was challenging, because Logs.Location importing
Logs.Cluster which imports Logs.Trust which imports Remote.List resulted
in an import cycle through several other modules.
Resorted to making Logs.Location not import Logs.Cluster, and instead
it assumes that Annex.clusters gets populated when necessary before it's
called.
That's done in Annex.Startup, which is run by the git-annex command
(but not other commands) at early startup in initialized repos. Or,
is run after initialization.
Note that is Remote.Git, it is unable to import Annex.Startup, because
Remote.Git importing Logs.Cluster leads the the same import cycle.
So ensureInitialized is not passed annexStartup in there.
Other commands, like git-annex-shell currently don't run annexStartup
either.
So there are cases where Logs.Location will not see clusters. So it won't add
any cluster UUIDs when loading the log. That's ok, the only reason to do
that is to make display of where objects are located include clusters,
and to make commands like git-annex get --from treat keys as being located
in a cluster. git-annex-shell certainly does not do anything like that,
and I'm pretty sure Remote.Git (and callers to Remote.Git.onLocalRepo)
don't either.
One benefit of this is that a typo in annex-cluster-node config won't
init a new cluster.
Also it gets the cluster description set and is consistent with
initremote.
connRepo is only used when relaying git upload-pack and receive-pack.
That's only supposed to be used when git-annex-remotedaemon is serving
git-remote-tor-annex connections over tor. But, it was always set, and
so could be used in other places possibly.
Fixed by making connRepo optional in the P2P protocol interface.
In Command.EnableTor, it's not needed, because it only speaks the
protocol in order to check that it's able to connect back to itself via
the hidden service. So changed that to pass Nothing rather than the git
repo.
In Remote.Helper.Ssh, it's connecting to git-annex-shell p2pstdio,
so is making the requests, so will never need connRepo.
In git-annex-shell p2pstdio, it was accepting git upload-pack and
receive-pack requests over the P2P protocol, even though nothing sent
them. This is arguably a security hole, particularly if the user has
set environment variables like GIT_ANNEX_SHELL_LIMITED to prevent
git push/pull via git-annex-shell.
For NotifyChanges and also for the fallthrough case where
git-annex-shell passes a command off to git-shell, proxying is currently
ignored. So every remote that is accessed via a proxy will be treated as
the same git repository.
Every other command listed in cmdsMap will need to check if
Annex.proxyremote is set, and if so handle the proxying appropriately.
Probably only P2PStdio will need to support proxying. For now,
everything else refuses to work when proxying.
The part of that I don't like is that there's the possibility a command
later gets added to the list that doesn't check proxying.
When proxying is not enabled, it's important that git-annex-shell not
leak information that it would not have exposed before. Such as the
names or uuids of remotes.
I decided that, in the case where a repository used to have proxying
enabled, but no longer supports any proxies, it's ok to give the user a
clear error message indicating that proxying is not configured, rather
than a confusing uuid mismatch message.
Similarly, if a repository has proxying enabled, but not for the
requested repository, give a clear error message.
A tricky thing here is how to handle the case where there is more than
one remote, with proxying enabled, with the specified uuid. One way to
handle that would be to plumb the proxyRemoteName all the way through
from the remote git-annex to git-annex-shell, eg as a field, and use
only a remote with the same name. That would be very intrusive though.
Instead, I decided to let the proxy pick which remote it uses to access
a given Remote. And so it picks the least expensive one.
The client after all doesn't necessarily know any details about the
proxy's configuration. This does mean though, that if the least
expensive remote is not accessible, but another remote would have
worked, an access via the proxy will fail.
Using the usual url download machinery even allows these urls to need
http basic auth, which is prompted for with git-credential. Which opens
the possibility for urls that contain a secret to be used, eg the cipher
for encryption=shared. Although the user is currently on their own
constructing such an url, I do think it would work.
Limited to httpalso for now, for security reasons. Since both httpalso
(and retrieving this very url) is limited by the usual
annex.security.allowed-ip-addresses configs, it's not possible for an
attacker to make one of these urls that sets up a httpalso url that
opens the garage door. Which is one class of attacks to keep in mind
with this thing.
It seems that there could be either a git-config that allows other types
of special remotes to be set up this way, or special remotes could
indicate when they are safe. I do worry that the git-config would
encourage users to set it without thinking through the security
implications. One remote config might be safe to access this way, but
another config, for one with the same type, might not be. This will need
further thought, and real-world examples to decide what to do.
This is just a good idea, I think. But it fixes this specific bug:
With buggy git version 2.45.1, git clone from an annex:: url, which has
a git-annex branch in it. Then in the repository, git fetch. That
left .git/annex/objects/ populated with bundles, since it did not clean
up. So later using git-annex failed to autoinit.
And use it to set annex-config-uuid in git config. This makes
using the origin special remote work after cloning.
Without the added Logs.Remote.configSet, instantiating the remote will
look at the annex-config-uuid's config in the remote log, which will be
empty, and so it will fail to find a special remote.
The added deletion of files in the alternatejournaldir is just to make
100% sure they don't get committed to the git-annex branch. Now that
they contain things that definitely should not be committed.
With the directory special remote, manifest objects uploaded by
git-remote-annex were mode 600. This prevented accessing them
from a httpalso special remote, for example.
The directory special remote just copies the file perms. Which is fine
except in this case the file perms were wrong.
An incremental push that gets converted to a full push due to this
config results in the inManifest having just one bundle in it, and the
outManifest listing every other bundle. So it actually takes up more
space on the special remote. But, it speeds up clone and fetch to not
have to download a long series of bundles for incremental pushes.
cleanupInitialization gets run when an exception is thrown, so needs to
avoid throwing exceptions itself, as that would hide the error message
that the user needs to see.
When exporttree=yes is also set. Probably it would also be possible to
support ones with only importtree=yes, by enabling exporttree=yes for
the remote only when using git-remote-annex, but let's keep this
simple... I'm not sure what gets recorded in .git/annex/ state
differently in the two cases that might cause a problem when doing that.
Note that the full annex:: urls generated and displayed for such a
remote omit the importree=yes. Which is ok, cloning from such an url
uses an exporttree=remote, but the git-annex branch doesn't get written
by this program, so once the real config is available from the git-annex
branch, it will still function as an importree=yes remote.
This git bug also broke git-lfs, and I am confident it will be reverted
in the next release.
For now, cloning from an annex:: url wastes some bandwidth on the next
pull by not caching bundles locally.
If git doesn't fix this in the next version, I'd be tempted to rethink
whether bundle objects need to be cached locally. It would be possible to
instead remember which bundles have been seen and their heads, and
respond to the list command with the heads, and avoid unbundling them
agian in fetch. This might even be a useful performance improvement in
the latter case. It would be quite a complication to a currently simple
implementation though.
This fixes pushing a new ref that is the same as something already
pushed. In findotherprereq, it compares two shas, which didn't work when
one is actually not a sha but a ref.
This is one of those cases where Sha being an alias for Ref makes it
hard to catch mistakes. One of these days those need to be
differentiated at the type level, but not today..
Locally record the manifest before uploading it or any bundles,
and read it on the next push. Any bundles from the push that are
not included in the currently being pushed manifest will get added
to the outManifest, and so eventually get deleted.
This deals with an interrupted push that is not resumed and instead
something else is pushed. And it deals with a push race that overwrites
the manifest.
Of course, this can't help if one of those situations is followed by
the local repo being deleted. But that's equivilant to doing a git-annex
copy of a new annexed file to a special remote and then deleting the
special repo w/o pushing. In either case the special remote ends up with
a object in it that git-annex doesn't know about.
