The OAuth2/OIDC server accepted its signing key via a file path
(key-file), while every other PEM key in the probod config (SAML
private key, ACME account key) is embedded inline. Switch the
field to a private-key string so the convention is uniform.
The signing key is operator-supplied material that must outlive
any process restart, so the bootstrap builder now treats
OAUTH2_SERVER_SIGNING_KEY as required and refuses to start
without one; silently minting a fresh key per boot would break
token validation across rollouts. The OAUTH2_SERVER_* env vars
otherwise flow through builder.Build like the existing SAML
block so the new OAuth2Server section is populated end-to-end.
Rework the e2e harness to render its config via bootstrap at
test setup, which removes the static
e2e/console/testdata/config.yaml and the previously generated
test-only PEM file. A per-run RSA key is minted via
bootstrap.GenerateOAuth2SigningKey (kept public for test
tooling) and injected through the builder env map. CI now
passes ACME_ROOT_CA inline instead of mutating a YAML on disk.
Signed-off-by: Bryan Frimin <bryan@getprobo.com>
