Simplify allocDir.Build() function to avoid depending on client/structs,
and remove a parameter that's always set to `false`.
The motivation here is to avoid a dependency cycle between
drivers/cstructs and alloc_dir.
* Stopping an alloc is implemented via Updates but update hooks are
*not* run.
* Destroying an alloc is a best effort cleanup.
* AllocRunner destroy hooks implemented.
* Disk migration and blocking on a previous allocation exiting moved to
its own package to avoid cycles. Now only depends on alloc broadcaster
instead of also using a waitch.
* AllocBroadcaster now only drops stale allocations and always keeps the
latest version.
* Made AllocDir safe for concurrent use
Lots of internal contexts that are currently unused. Unsure if they
should be used or removed.
If an alloc dir is being GC'd (removed) during snapshotting the walk
func will be passed an error. Previously we didn't check for an error so
a panic would occur when we'd try to use a nil `fileInfo`.
interface has 3 implementations:
1. local for blocking and moving data locally
2. remote for blocking and moving data from another node
3. noop for allocs that don't need to block
Fixes#2478#2474#1995#2294
The new client only handles agent and task service advertisement. Server
discovery is mostly unchanged.
The Nomad client agent now handles all Consul operations instead of the
executor handling task related operations. When upgrading from an
earlier version of Nomad existing executors will be told to deregister
from Consul so that the Nomad agent can re-register the task's services
and checks.
Drivers - other than qemu - now support an Exec method for executing
abritrary commands in a task's environment. This is used to implement
script checks.
Interfaces are used extensively to avoid interacting with Consul in
tests that don't assert any Consul related behavior.
Fixes an issue where the Ruby runtime expects the sticky bit to be set
on the temp directory. The sticky bit is commonly set on the temp
directory since it is usually shared by many users. This change brings
ours in line with that assumption.
This commit adds Solaris versions of the following functions:
- `linkDir`
- `unlinkDir`
- `createSecretDir`
- `removeSecretDir`
I believe this requires Go 1.8 in order to compile, as the unlink
syscall was previously missing.
A change in the behavior of `os.Rename` in Go 1.8 brought to light a
difference in the logic between `{Alloc,Task}Runner` and this test:
AllocRunner builds the alloc dir, moves dirs if necessary, and then lets
TaskRunner call TaskDir.Build().
This test called `TaskDir.Build` *before* `AllocDir.Move`, so in Go 1.8
it failed to `os.Rename over` the empty {data,local} dirs.
I updated the test to behave like the real code, but I defensively added
`os.Remove` calls as a subtle change in call order shouldn't break this
code. `os.Remove` won't remove a non-empty directory, so it's still
safe.
Fixes#2178 and allows using Docker and other image based drivers even
when nomad is run as a non-root user.
`client/allocdir` tests can be run as a non-root user to ensure this
behavior and tests that rely on root or non-root users properly detect
their effective user and skip instead of fail.
