Calling OCI APIs from Postman

Oracle’s Cloud Infrastructure has been designed in an API-first manner, which is awesome for all sorts of infrastructure automation tasks. It also implements an interesting API security model, in which all requests must be signed using a private key, associated with a public key which has already been configured in OCI (here, the developers are showing their infrastructure roots, as this echoes how SSH Auth is normally handled). The documentation of this model provides sample code in a number of languages, which is perfect if you are writing automation scripts, but is a little inflexible for ad-hoc testing. Typically I much prefer to use a rich graphical REST client, such a Postman, so that I can easily tweak my parameters and try out different types of calls before I write any code. Unfortunately while Postman is well equipped for Basic and Token based Auth, HTTP-Signature is not natively implemented, and rather than abandon Postman for a new tool, I set out to implement it using Postman’s powerful scripting capabilities. In this blog post I provide the result of this, which is a downloadable collection which provides all of the required scripts, and discuss the approach used.

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