Needed to prompt for a connection or sudo password (host: 10.10.1.10), but abort-on-prompts was set to True',) - fabric

Question

I am trying to use cloudify fabric plugin to run a simple command. When I install the blueprint I am getting following error.
Task failed 'fabric_plugin.tasks.run_commands' -> RecoverableError('FabricTaskError: Needed to prompt for a connection or sudo password (host: 10.10.1.10), but abort-on-prompts was set to True',)
Below is my entire blueprint file.
tosca_definitions_version: cloudify_dsl_1_0
imports:
- http://www.getcloudify.org/spec/cloudify/3.2/types.yaml
- http://www.getcloudify.org/spec/fabric-plugin/1.2/plugin.yaml
inputs:
host_ip:
description: >
The ip of the host the application will be deployed on
agent_user:
description: >
Agent User.
agent_private_key_path:
description: >
agent key path
node_templates:
host:
type: cloudify.nodes.Compute
properties:
ip: { get_input: host_ip }
install_agent:
default: false
cloudify_agent:
user: { get_input: agent_user }
key: { get_input: agent_private_key_path }
example_node:
type: cloudify.nodes.WebServer
interfaces:
cloudify.interfaces.lifecycle:
start:
implementation: fabric.fabric_plugin.tasks.run_commands
inputs:
commands:
- ls -lh > ~/list-of-files.txt
relationships:
- type: cloudify.relationships.contained_in
target: host
My inputs.yaml is
agent_private_key_path: /root/.ssh/id_rsa
agent_user: vagrant
host_ip: 10.10.1.10
When I update my blueprint to use following then it works. But is this necessary? I mean this information is already specified in the host. Why do I need to give it again with the fabric plugin.
fabric_env:
host_string: { get_input: host_ip }
user: { get_input: agent_user }
key_filename: { get_input: agent_private_key_path }
Is there anything I am doing wrong. I am just the beginner in this area, so any help will be appreciated.

Answer 1

Fabric can fail due to many reasons, like missing key file, or wrong key file...
generally speaking, you'll be seeing this kind of errors when there are issues SSHing into the application VMs , where the authentication using the private keypair fails (because its missing or because its a wrong one), in which case there will be a fallback to user/password authentication.
I can't give a more detailed answer without information regarding which Cloudify version you have installed and OS (Ubuntu, Centos, etc).