Initial attempt to add userinfo endpoint

Author: michaeljcollinsuk

src/etc/nginx/nginx.conf.template

@@ -299,4 +299,23 @@ http {
       proxy_read_timeout 20d;
     }
   }
+
+  # Userinfo
+  server {
+    listen PROXY_USERINFO_LISTEN_ADDRESS:PROXY_USERINFO_LISTEN_PORT;
+
+    error_log /var/log/nginx/error.log ERROR_LOG_LEVEL;
+
+    location /userinfo {
+
+      set_by_lua $analytical_platform_tool 'return "ANALYTICAL_PLATFORM_TOOL"';
+      set_by_lua $auth0_client_id          'return "AUTH0_CLIENT_ID"';
+      set_by_lua $auth0_client_secret      'return "AUTH0_CLIENT_SECRET"';
+      set_by_lua $auth0_tenant_domain      'return "AUTH0_TENANT_DOMAIN"';
+      set_by_lua $username                 'return "USERNAME"';
+
+      content_by_lua_file /opt/lua-scripts/userinfo-api.lua;
+    }
+  }
+
 }

src/opt/lua-scripts/userinfo-api.lua

@@ -0,0 +1,67 @@
+local http = require("resty.http")
+local httpc = http.new()
+local cjson = require("cjson")
+
+
+local function get_access_token()
+  local endpoint = "https://" .. ngx.var.auth0_tenant_domain .. "/oauth/token"
+  local headers = {
+    ["Content-Type"] = "application/x-www-form-urlencoded"
+  }
+
+  local body = {
+    client_id = ngx.var.auth0_client_id,
+    client_secret = ngx.var.auth0_client_secret,
+    audience = "https://" .. ngx.var.auth0_tenant_domain .. "/api/v2/",
+    grant_type = "client_credentials"
+  }
+
+  local res, err = httpc:request_uri(endpoint,  {
+    method = "POST",
+    body = ngx.encode_args(body),
+    headers = headers,
+  })
+  ngx.log(ngx.NOTICE, ngx.var.auth0_tenant_domain)
+  if not res then
+    ngx.log(ngx.NOTICE, err)
+    return false, nil, err
+  else
+    return true, cjson.decode(res.body).access_token, nil
+  end
+end
+
+local function get_user_info(access_token)
+  local user_endpoint = "https://" .. ngx.var.auth0_tenant_domain .. "/api/v2/users"
+  local user_info_headers = {
+    ["Content-Type"] = "application/json",
+    ["Authorization"] = "Bearer " .. access_token
+  }
+
+  local search_params = {
+    q = "nickname: " .. ngx.var.username,
+    search_engine = "v2"
+  }
+
+  local user_res, err = httpc:request_uri(user_endpoint,  {
+    method = "GET",
+    query = search_params,
+    headers = user_info_headers,
+  })
+
+  local found_user = cjson.decode(user_res.body)[1]
+  if not found_user then
+    return '{"error": 404, "message": "Not found"}'
+  else
+    return cjson.encode(found_user)
+  end
+end
+
+-- Main entry
+local succeeded, access_token, err = get_access_token()
+
+if succeeded then
+  ngx.say(get_user_info(access_token))
+else
+  ngx.status = 400
+  ngx.say(err)
+end