Fix a regression where we accidentally started treating non-AWS
environments as AWS environments, resulting in bad networking settings.
Two factors some at play:
First, in [1], we accidentally switched the ultimate AWS test from
checking `ami-id` to `instance-id`. This means that nomad started
treating more environments as AWS; e.g. Hetzner implements `instance-id`
but not `ami-id`.
Second, some of these environments return empty values instead of
errors! Hetzner returns empty 200 response for `local-ipv4`, resulting
into bad networking configuration.
This change fix the situation by restoring the check to `ami-id` and
ensuring that we only set network configuration when the ip address is
not-empty. Also, be more defensive around response whitespace input.
[1] https://github.com/hashicorp/nomad/pull/6779
Previously, Nomad used hand rolled HTTP requests to interact with the
EC2 metadata API. Recently however, we switched to using the AWS SDK for
this fingerprinting.
The default behaviour of the AWS SDK is to perform retries with
exponential backoff when a request fails. This is problematic for Nomad,
because interacting with the EC2 API is in our client start path.
Here we revert to our pre-existing behaviour of not performing retries
in the fast path, as if the metadata service is unavailable, it's likely
that nomad is not running in AWS.
Some code cleanup:
* Use a field for setting EC2 metadata instead of env-vars in testing;
but keep environment variables for backward compatibility reasons
* Update tests to use testify
This removes a cyclical dependency when importing client/structs from
dependencies of the plugin_loader, specifically, drivers. Due to
client/config also depending on the plugin_loader.
It also better reflects the ownership of fingerprint structs, as they
are fairly internal to the fingerprint manager.
Certain environments use WARN for serious logging; however, it's very
possible to have machines without some of the fingerprinted keys
(public-ipv4 and public-hostname specifcally). Setting log level to
INFO seems more consistent with this possibility.
This PR:
* Makes AWS network speeds more granular
* Makes `network_speed` an override and not a default
* Adds a default of 1000 MBits if no network link speed is detected.
Fixes#1985
Fix URL. It was printing an error message on startup:
```
2015/11/13 15:49:21 [ERR] fingerprint.env_aws: Error querying AWS Metadata URL, skipping
```
By the way is it safe to use latest? Is there a chance that Amazon decides to change the format of the metadata? It could be safer to use something like `http://169.254.169.254/2014-11-05/meta-data`
GCE and AWS both expose metadata servers, and GCE's 404 response
includes the URL in the content, which maatches the regex. So,
check the response code as well and if a 4xx code comes back,
take that to meanit's not AWS.
Mahmood Ali