Update Container Scanning documentation

doc/ci/examples/container_scanning.md

@@ -31,6 +31,9 @@ sast:container:
     - chmod +x clair-scanner
     - touch clair-whitelist.yml
     - while( ! wget -q -O /dev/null http://docker:6060/v1/namespaces ) ; do sleep 1 ; done
+    - retries=0
+    - echo "Waiting for clair daemon to start"
+    - while( ! wget -T 10 -q -O /dev/null http://docker:6060/v1/namespaces ) ; do sleep 1 ; echo -n "." ; if [ $retries -eq 10 ] ; then echo " Timeout, aborting." ; exit 1 ; fi ; retries=$(($retries+1)) ; done
     - ./clair-scanner -c http://docker:6060 --ip $(hostname -i) -r gl-sast-container-report.json -l clair.log -w clair-whitelist.yml ${CI_APPLICATION_REPOSITORY}:${CI_APPLICATION_TAG} || true
   artifacts:
     paths: [gl-sast-container-report.json]