The system scheduler should leave allocs on draining nodes as-is, but
stop node stop allocs on nodes that are no longer part of the job
datacenters.
Previously, the scheduler did not make the distinction and left system
job allocs intact if they are already running.
I've added a failing test first, which you can see in https://app.circleci.com/jobs/github/hashicorp/nomad/179661 .
Fixes https://github.com/hashicorp/nomad/issues/11373
Pick up https://github.com/golang/snappy/pull/56 to handle arm64 architectures to fix panics. tldr; Golang 1.16 changed `memmove` implementation for arm64 requiring additional cpu registers that snappy wasn't preserving in its assembly implementation.
Other projects have experienced this issue as well, searching for `encode_arm64.s:666` on your favorite search engine will reveal some. Vault updated the dependency earlier this August: https://github.com/hashicorp/vault/pull/12371 .
I believe this issue affects Nomad 1.2.x and 1.1.x. Nomad 1.0.x use Golang 1.15 and isn't affected. However, backporting the change to 1.0.x should be harmless.
Fixed https://github.com/hashicorp/nomad/issues/11385 .
Fix a bug where the scheduler may panic when preemption is enabled. The conditions are a bit complicated:
A job with higher priority that schedule multiple allocations that preempt other multiple allocations on the same node, due to port/network/device assignments.
The cause of the bug is incidental mutation of internal cached data. `RankedNode` computes and cache proposed allocations in https://github.com/hashicorp/nomad/blob/v1.1.6/scheduler/rank.go#L42-L53 . But scheduler then mutates the list to remove pre-emptable allocs in https://github.com/hashicorp/nomad/blob/v1.1.6/scheduler/rank.go#L293-L294, and `RemoveAllocs` mutates and sets the tail of cached slice with `nil`s triggering a nil-pointer derefencing case.
I fixed the issue by avoiding the mutation in `RemoveAllocs` - the micro-optimization there doesn't seem necessary.
Fixes https://github.com/hashicorp/nomad/issues/11342
Fixes#2522
Skip embedding client.alloc_dir when building chroot. If a user
configures a Nomad client agent so that the chroot_env will embed the
client.alloc_dir, Nomad will happily infinitely recurse while building
the chroot until something horrible happens. The best case scenario is
the filesystem's path length limit is hit. The worst case scenario is
disk space is exhausted.
A bad agent configuration will look something like this:
```hcl
data_dir = "/tmp/nomad-badagent"
client {
enabled = true
chroot_env {
# Note that the source matches the data_dir
"/tmp/nomad-badagent" = "/ohno"
# ...
}
}
```
Note that `/ohno/client` (the state_dir) will still be created but not
`/ohno/alloc` (the alloc_dir).
While I cannot think of a good reason why someone would want to embed
Nomad's client (and possibly server) directories in chroots, there
should be no cause for harm. chroots are only built when Nomad runs as
root, and Nomad disables running exec jobs as root by default. Therefore
even if client state is copied into chroots, it will be inaccessible to
tasks.
Skipping the `data_dir` and `{client,server}.state_dir` is possible, but
this PR attempts to implement the minimum viable solution to reduce risk
of unintended side effects or bugs.
When running tests as root in a vm without the fix, the following error
occurs:
```
=== RUN TestAllocDir_SkipAllocDir
alloc_dir_test.go:520:
Error Trace: alloc_dir_test.go:520
Error: Received unexpected error:
Couldn't create destination file /tmp/TestAllocDir_SkipAllocDir1457747331/001/nomad/test/testtask/nomad/test/testtask/.../nomad/test/testtask/secrets/.nomad-mount: open /tmp/TestAllocDir_SkipAllocDir1457747331/001/nomad/test/.../testtask/secrets/.nomad-mount: file name too long
Test: TestAllocDir_SkipAllocDir
--- FAIL: TestAllocDir_SkipAllocDir (22.76s)
```
Also removed unused Copy methods on AllocDir and TaskDir structs.
Thanks to @eveld for not letting me forget about this!
Meant for development purposes only, so one can compile binary on a
macos host then start a Docker container or scp the binary to a linux
host easily.
The resulting binary is statically linked and has very subtle
differences. e.g. static binaries use go native network stack that
honor /etc/hosts and /etc/resolve differently from the glibc
implementation. In development environment, I don't expect these to
materially change our experience.
