In my blueprint, I need to execute a command on Prism Central VM. The command will be a script on Prism Central VM. My blueprint uses the existing Prism Central VM as the substrate. I tried different ways to execute the command but none of them worked. Could you please advise how I could do it? The script I need to run doesn’t have an API counterpart. I can run PC API from the blueprint without problems. Here are the different ways I tried and how they failed.
# SSH Endpoint
PCSSHEndpoint = Endpoint.Linux.ip(
["@@{calm_pc_ip}@@"],
name="PC_SSH_Endpoint",
port=22,
cred=SSHCredential,
)
# ============================================================================
# METHOD 1: SSH Endpoint with Target Reference
# ============================================================================
class Method1_SSHEndpointService(Service):
"""
Method 1: Using SSH endpoint with explicit target reference
Pros: Proper SSH connection setup
Cons: Failed with "Machine and credential are required for script execution"
and "ssh: subsystem request failed" errors
"""
@action
def RunCommand(name="Method 1 SSH Endpoint"):
"""Execute command via SSH endpoint"""
Task.Exec.ssh(
name="SSHWithEndpoint",
script='echo "=== Method 1: SSH Endpoint ===" \nncli cluster version',
target=ref(PCSSHEndpoint),
cred=ref(SSHCredential),
)
# ============================================================================
# METHOD 2: SSH Without Endpoint (Local Execution)
# ============================================================================
class Method2_SSHLocalService(Service):
"""
Method 2: SSH task without endpoint (attempting local execution)
Pros: Simpler syntax
Cons: Still tried to use SSH subsystem, failed with "subsystem request failed"
"""
@action
def RunCommand(name="Method 2 SSH Local"):
"""Execute command locally via SSH task"""
Task.Exec.ssh(
name="SSHLocal",
script='#!/bin/bash\necho "=== Method 2: SSH Local ==="\nncli cluster version',
)
# ============================================================================
# METHOD 3: Escript with Subprocess
# ============================================================================
class Method3_SubprocessService(Service):
"""
Method 3: Using Python subprocess module in escript
Pros: Standard Python approach for running commands
Cons: subprocess module not available in Calm escript environment
Error: "No module named 'subprocess'"
"""
@action
def RunCommand(name="Method 3 Subprocess"):
"""Execute command using subprocess"""
Task.Exec.escript(
name="SubprocessExec",
script='import subprocess\n\nprint("=== Method 3: Subprocess ===")\nresult = subprocess.run(["ncli", "cluster", "version"], capture_output=True, text=True)\nprint(result.stdout)',
)
# ============================================================================
# METHOD 4: Escript with Paramiko
# ============================================================================
class Method4_ParamikoService(Service):
"""
Method 4: Using paramiko library for SSH in escript
Pros: Full-featured SSH library
Cons: paramiko not available in Calm escript environment
Error: "No module named 'paramiko'"
"""
@action
def RunCommand(name="Method 4 Paramiko"):
"""Execute command using paramiko"""
Task.Exec.escript(
name="ParamikoExec",
script='import paramiko\n\nprint("=== Method 4: Paramiko ===")\nssh = paramiko.SSHClient()\nssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())\nssh.connect("@@{calm_pc_ip}@@", username="admin", password="Delluser@123")\nstdin, stdout, stderr = ssh.exec_command("ncli cluster version")\nprint(stdout.read().decode())\nssh.close()',
)
# ============================================================================
# METHOD 5: Escript with os.system()
# ============================================================================
class Method5_OsSystemService(Service):
"""
Method 5: Using os.system() for direct command execution
Pros: Simple, built-in Python function
Cons: os module not available in Calm escript environment
Error: "No module named 'os'" or similar restriction
"""
@action
def RunCommand(name="Method 5 os_system"):
"""Execute command using os.system()"""
Task.Exec.escript(
name="OsSystemExec",
script='import os\n\nprint("=== Method 5: os.system() ===")\nos.system("ncli cluster version")\nos.system("cluster status")',
)
# ============================================================================
# METHOD 6: Shell Script with Task.Exec.ssh()
# ============================================================================
class Method6_ShellScriptService(Service):
"""
Method 6: Pure bash script using Task.Exec.ssh() without target
Pros: No Python dependencies, native shell execution
Cons: Still uses SSH subsystem, failed with "subsystem request failed"
"""
@action
def RunCommand(name="Method 6 Shell Script"):
"""Execute bash script"""
Task.Exec.ssh(
name="ShellScript",
script='#!/bin/bash\necho "=== Method 6: Shell Script ==="\nncli cluster version\nncli cluster info\ncluster status',
)