local-up-cluster changes: added help option, added error message for why docker ps fails and how to recover, added test to check if etcd is in your path to fail fast when not found.

from etcd.sh split the start process into validate fucntion + start function so that the validate piece can be reused elsewhere. the up-cluster script has been changed to remove duplicate docker logic to the one used in buid-tools/common.sh and the validate etcd function is now used here.

moved docker daemon check function to util.sh and made function name changes and upstream changes.

hack/lib/util.sh

@@ -575,5 +575,31 @@ EOF
 EOF
 }
 
+# Determines if docker can be run, failures may simply require that the user be added to the docker group.
+function kube::util::ensure_docker_daemon_connectivity {
+  DOCKER=(docker ${DOCKER_OPTS})
+  if ! "${DOCKER[@]}" info > /dev/null 2>&1 ; then
+    cat <<'EOF' >&2
+Can't connect to 'docker' daemon.  please fix and retry.
+
+Possible causes:
+  - Docker Daemon not started
+    - Linux: confirm via your init system
+    - macOS w/ docker-machine: run `docker-machine ls` and `docker-machine start <name>`
+    - macOS w/ Docker for Mac: Check the menu bar and start the Docker application
+  - DOCKER_HOST hasn't been set or is set incorrectly
+    - Linux: domain socket is used, DOCKER_* should be unset. In Bash run `unset ${!DOCKER_*}`
+    - macOS w/ docker-machine: run `eval "$(docker-machine env <name>)"`
+    - macOS w/ Docker for Mac: domain socket is used, DOCKER_* should be unset. In Bash run `unset ${!DOCKER_*}`
+  - Other things to check:
+    - Linux: User isn't in 'docker' group.  Add and relogin.
+      - Something like 'sudo usermod -a -G docker ${USER}'
+      - RHEL7 bug and workaround: https://bugzilla.redhat.com/show_bug.cgi?id=1119282#c8
+EOF
+    return 1
+  fi
+}
+
+
 
 # ex: ts=2 sw=2 et filetype=sh