Add deployment automation steps

The settings file can now specify an optional list of steps.
After creating a bunch of instances, the steps are then
automatically executed. This helps since virtually all
deployments will be a sequence of 'start + deploy + otheractions'.

It also helps to automatically excecute steps like webssh
and tailhist (since I tend to forget them often).

prepare-vms/lib/commands.sh

@@ -339,7 +339,7 @@ _cmd_maketag() {
     if [ -z $USER ]; then
         export USER=anonymous
     fi
-    MS=$(($(date +%N)/1000000))
+    MS=$(($(date +%N | tr -d 0)/1000000))
     date +%Y-%m-%d-%H-%M-$MS-$USER
 }
 
@@ -493,6 +493,7 @@ _cmd_start() {
         --settings) SETTINGS=$2; shift 2;;
         --count) COUNT=$2; shift 2;;
         --tag) TAG=$2; shift 2;;
+        --students) STUDENTS=$2; shift 2;;
         *) die "Unrecognized parameter: $1."
         esac
     done
@@ -504,8 +505,14 @@ _cmd_start() {
         die "Please add --settings flag to specify which settings file to use."
     fi
     if [ -z "$COUNT" ]; then
-        COUNT=$(awk '/^clustersize:/ {print $2}' $SETTINGS)
-        warning "No --count option was specified. Using value from settings file ($COUNT)."
+        CLUSTERSIZE=$(awk '/^clustersize:/ {print $2}' $SETTINGS)
+        if [ -z "$STUDENTS" ]; then
+            warning "Neither --count nor --students was specified."
+            warning "According to the settings file, the cluster size is $CLUSTERSIZE."
+            warning "Deploying one cluster of $CLUSTERSIZE nodes."
+            STUDENTS=1
+        fi
+        COUNT=$(($STUDENTS*$CLUSTERSIZE))
     fi
 
     # Check that the specified settings and infrastructure are valid.
@@ -523,11 +530,41 @@ _cmd_start() {
     infra_start $COUNT
     sep
     info "Successfully created $COUNT instances with tag $TAG"
-    sep
     echo created > tags/$TAG/status
 
-    info "To deploy Docker on these instances, you can run:"
-    info "$0 deploy $TAG"
+    # If the settings.yaml file has a "steps" field,
+    # automatically execute all the actions listed in that field.
+    # If an action fails, retry it up to 10 times.
+    python -c 'if True: # hack to deal with indentation
+        import sys, yaml
+        settings = yaml.safe_load(sys.stdin)
+        print ("\n".join(settings.get("steps", [])))
+        ' < tags/$TAG/settings.yaml \
+    | while read step; do
+        if [ -z "$step" ]; then
+            break
+        fi
+        sep
+        info "Automatically executing step '$step'."
+        TRY=1
+        MAXTRY=10
+        while ! $0 $step $TAG ; do
+            TRY=$(($TRY+1))
+            if [ $TRY -gt $MAXTRY ]; then
+                error "This step ($step) failed after $MAXTRY attempts."
+                info "You can troubleshoot the situation manually, or terminate these instances with:"
+                info "$0 stop $TAG"
+                die "Giving up."
+            else
+                sep
+                info "Step '$step' failed. Let's wait 10 seconds and try again."
+                info "(Attempt $TRY out of $MAXTRY.)"
+                sleep 10
+            fi
+        done
+    done
+    sep
+    info "Deployment successful."
     info "To terminate these instances, you can run:"
     info "$0 stop $TAG"
 }

prepare-vms/settings/fundamentals.yaml

@@ -21,3 +21,9 @@ machine_version: 0.15.0
 
 # Password used to connect with the "docker user"
 docker_user_password: training
+
+steps:
+  - deploy
+  - webssh
+  - tailhist
+  - cards

prepare-vms/settings/jerome.yaml

@@ -20,3 +20,10 @@ machine_version: 0.14.0
 # Password used to connect with the "docker user"
 docker_user_password: training
 
+steps:
+  - deploy
+  - webssh
+  - tailhist
+  - kube
+  - cards
+  - kubetest