* Accept temp creds in AWS secret backend acceptance tests
The AWS secret backend acceptance tests implicitly accepted long-lived
AWS credentials (i.e., AWS IAM user and/or root credentials) in two
ways:
1. It expected credentials to be passed in via the AWS_ACCESS_KEY_ID and
AWS_SECRET_ACCESS_KEY environment variables. By not accepting
AWS_SESSION_TOKEN or AWS_SECURITY_TOKEN, temporary credentials could
not be passed in. (This also forced all credentials to be passed in
via environment variables, which is a bit ugly).
2. The AWS sts:GetFederationToken call is only allowed from long-term
credentials. This is called by the Vault code which the acceptance
tests exercise.
1 is solved by deleting explicit references to credentials, which allows
the SDK to do one of the things it does best -- find credentials via the
default chain.
2 is a little more complicated. Rather than pass in whatever creds the
acceptance test was run under to the backend, the acceptance test now
creates a new IAM user and gets an access key from it, then passes the
IAM user's creds back to the backend so that it can call
sts:GetFederationToken (and then tries to clean up afterwards).
* Fix Travis build failure
The Travis build was failing because the user creation was happening
regardless of whether it was running in acceptance test mode or not.
This moves the user creation into the acceptance test precheck, which
requires lazily evaluating the credentials when configuring the backend
in the STS accetpance test, and so moving that to a PreFlight closure.
* Reduce blind sleeps in AWS secret backend acceptance tests
This removes a blind "sleep 10 seconds and then attempt to reuse the
credential" codepath and instead just keeps attemtping to reuse the
credential for 10 seconds and fails if there aren't any successful uses
after 10 seconds. This adds a few seconds speedup of acceptance test
runs from my experiments.
Support use cases where you want to provision STS tokens
using Vault, but, you need to call AWS APIs that are blocked
for federated tokens. For example, STS federated tokens cannot
invoke IAM APIs, such as Terraform scripts containing
`aws_iam_*` resources.
The secretAccessKeysRevoke revoke function now asserts that it is
not dealing with STS keys by checking a new internal data flag. Defaults
to IAM when the flag is not found.
Factored out genUsername into its own function to share between STS and
IAM secret creation functions.
Fixed bad call to "WriteOperation" instead of "UpdateOperation" in
aws/backend_test
This strips out http.DefaultClient everywhere I could immediately find
it. Too many things use it and then modify it in incompatible ways.
Fixes#700, I believe.
