Fix numerous go-getter security issues:
- Add timeouts to http, git, and hg operations to prevent DoS
- Add size limit to http to prevent resource exhaustion
- Disable following symlinks in both artifacts and `job run`
- Stop performing initial HEAD request to avoid file corruption on
retries and DoS opportunities.
**Approach**
Since Nomad has no ability to differentiate a DoS-via-large-artifact vs
a legitimate workload, all of the new limits are configurable at the
client agent level.
The max size of HTTP downloads is also exposed as a node attribute so
that if some workloads have large artifacts they can specify a high
limit in their jobspecs.
In the future all of this plumbing could be extended to enable/disable
specific getters or artifact downloading entirely on a per-node basis.
* cli: add -json flag to support job commands
While the CLI has always supported running JSON jobs, its support has
been via HCLv2's JSON parsing. I have no idea what format it expects the
job to be in, but it's absolutely not in the same format as the API
expects.
So I ignored that and added a new -json flag to explicitly support *API*
style JSON jobspecs.
The jobspecs can even have the wrapping {"Job": {...}} envelope or not!
* docs: fix example for `nomad job validate`
We haven't been able to validate inside driver config stanzas ever since
the move to task driver plugins. 😭
Fixes a bug where if a command flag parsing errors, the resulting error
and help usage messages get interleaved in unexpected and non-user
friendly way.
The reason is that we have flag parsing library effectively writes to
ui.Error in a goroutine. This is problematic: first, we lose the sequencing between help
usage and error message; second, cli.Ui methods are not concurrent safe.
Here, we introduce a custom error writer that buffers result and calls
ui.Error() in the write method and in the same goroutine.
For context, we need to wrap ui.Error because it's line-oriented, while
flags library expects a io.Writer which is bytes oriented.
This change updates the formatTime CLI helper function to return
an ISO_8601 time format which will make CLI time usage more
consistent and easier. Previosuly the time format was in US style
format which was somewhat confusing to non US users.
Closes#3806
This PR fixes our vet script and fixes all the missed vet changes.
It also fixes pointers being printed in `nomad stop <job>` and `nomad
node-status <node>`.
