Improve logging from resolve-key

The resolve-key function now logs first resolve attempt as a debug
statement. For usual INFO-level logging this will effectively turn off
logging of the first key resolve attempt which covers most resolve
calls.

If the key is not found the clj-jwt library will log the error with
error level before throwing the exception. This might help with
debugging when encountering problems with token validation.
Signed-off-by: Snorre Magnus Davøen <snorre.davoen@nsd.no>

README.md

@@ -5,7 +5,7 @@
 A Clojure library to handle validation of JWTs.
 
 ```clojure
-[no.nsd/clj-jwt "0.2.0"]
+[no.nsd/clj-jwt "0.2.1"]
 ```
 
 The library exposes functions to handle validation of JSON web tokens. It wraps

project.clj

-(defproject no.nsd/clj-jwt "0.2.0"
+(defproject no.nsd/clj-jwt "0.2.1"
   :description "A Clojure library to fetch json web keys and validate json web tokens. Wraps Buddy."
   :url "https://gitlab.nsd.no/clojure/clj-jwt"
   :license {:name "Eclipse Public License"

src/no/nsd/clj_jwt.clj

@@ -118,7 +118,7 @@
   "Returns java.security.PublicKey given jwks-url and :kid in jwt-header.
   If no key is found refreshes"
   [jwks-url jwt-header]
-  (log/info "Resolving key " jwt-header " from " jwks-url)
+  (log/debug "Resolving key " jwt-header " from " jwks-url)
   (let [key-fn (fn [] (get @public-keys (:kid jwt-header)))]
     (if-let [key (key-fn)]
       key
@@ -126,8 +126,10 @@
           (reset! public-keys (or (fetch-keys jwks-url) @public-keys))
           (if-let [key (key-fn)]
             key
-            (throw (ex-info (str "Could not locate public key corresponding to jwt header's kid: " (:kid jwt-header))
-                            {:type :validation :cause :unknown-key})))))))
+            (do
+              (log/error "Could not locate public key corresponding to jwt header's kid: " (:kid jwt-header))
+              (throw (ex-info (str "Could not locate public key corresponding to jwt header's kid: " (:kid jwt-header))
+                              {:type :validation :cause :unknown-key}))))))))
 
 
 (s/fdef unsign