Add flag validation diskspace and set false(skip) step by default (#909)

* flag validation diskspace

* display Available disk space

* update image.CI

* add image.CI flag

* update env RUN_VALIDATION_FLAG

images/linux/scripts/installers/validate-disk-space.sh

@@ -8,6 +8,12 @@ availableSpaceMB=$(df / -hm | sed 1d | awk '{ print $4}')
 minimumFreeSpaceMB=17800
 
 echo "Available disk space: $availableSpaceMB MB"
+
+if [ $RUN_VALIDATION != "true" ]; then
+    echo "Skipping validation disk space..."
+    exit 0
+fi
+
 if [ $availableSpaceMB -le $minimumFreeSpaceMB ]; then
     echo "Not enough disk space on the image (minimum available space: $minimumFreeSpaceMB MB)"
     exit 1

images/linux/ubuntu1604.json

@@ -24,6 +24,7 @@
         "image_version": "dev",
         "image_os": "ubuntu16",
         "github_feed_token": null,
+        "run_validation_diskspace": "false",
         "go_default": "1.14",
         "go_versions": "1.11 1.12 1.13 1.14"
     },
@@ -344,6 +345,9 @@
             "type": "shell",
             "scripts":[
                 "{{template_dir}}/scripts/installers/validate-disk-space.sh"
+            ],
+            "environment_vars": [
+                "RUN_VALIDATION={{user `run_validation_diskspace`}}"
             ]
         },
         {

images/linux/ubuntu1804.json

@@ -24,6 +24,7 @@
         "image_version": "dev",
         "image_os": "ubuntu18",
         "github_feed_token": null,
+        "run_validation_diskspace": "false",
         "go_default": "1.14",
         "go_versions": "1.11 1.12 1.13 1.14"
     },
@@ -348,6 +349,9 @@
             "type": "shell",
             "scripts":[
                 "{{template_dir}}/scripts/installers/validate-disk-space.sh"
+            ],
+            "environment_vars": [
+                "RUN_VALIDATION={{user `run_validation_diskspace`}}"
             ]
         },
         {