fix: IPv6 addresses double-wrapped in brackets

[clarsen]

Description

removed ipv6 address wrapping code because golang net.JoinHostPort already wraps ipv6 addresses in '[' and ']'. double wrapping causes ssh communicator to fail.

Resolved Issues

If your PR resolves any open issue(s), please indicate them like this so they will be closed when your PR is merged:

This reverts the fix #406 for this issue #333 (comment)

Logs before this PR

2025/10/13 23:00:23 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:00:23 VM IP acquired: 2620:83:8008:161::17
2025/10/13 23:00:23 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:00:23 VM IP is still the same: 2620:83:8008:161::17
...
2025/10/13 23:00:28 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:00:28 VM IP seems stable enough: [2620:83:8008:161::17]
2025/10/13 23:00:28 ui: ==> vsphere-iso: IP address: [2620:83:8008:161::17]
2025/10/13 23:00:28 ui: ==> vsphere-iso: Using SSH communicator to connect: [2620:83:8008:161::17]
2025/10/13 23:00:28 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:00:28 [INFO] Waiting for SSH, up to timeout: 30m0s
2025/10/13 23:00:28 ui: ==> vsphere-iso: Waiting for SSH to become available...
2025/10/13 23:00:28 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:00:28 [DEBUG] TCP connection to SSH ip/port failed: dial tcp: address [[2620:83:8008:161::17]]:22: missing port in address
...
and so on in a loop.

Logs after this PR

2025/10/13 23:09:33 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:09:33 VM IP acquired:
2025/10/13 23:09:33 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:09:33 VM IP acquired: 2620:83:8008:161::17
2025/10/13 23:09:33 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:09:33 VM IP is still the same: 2620:83:8008:161::17
...
2025/10/13 23:09:38 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:09:38 VM IP seems stable enough: 2620:83:8008:161::17
2025/10/13 23:09:38 ui: ==> vsphere-iso: Using SSH communicator to connect: 2620:83:8008:161::17
2025/10/13 23:09:38 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:09:38 [INFO] Waiting for SSH, up to timeout: 30m0s
2025/10/13 23:09:38 ui: ==> vsphere-iso: Waiting for SSH to become available...
2025/10/13 23:09:38 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:09:38 [INFO] Attempting SSH connection to [2620:83:8008:161::17]:22...
2025/10/13 23:09:38 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:09:38 [DEBUG] reconnecting to TCP connection for SSH
2025/10/13 23:09:38 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:09:38 [DEBUG] handshaking with SSH
2025/10/13 23:09:42 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:09:42 [DEBUG] SSH handshake err: ssh: handshake failed: ssh: unable to authenticate, attempted methods [none password], no supported methods remain
2025/10/13 23:09:42 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:09:42 [DEBUG] Detected authentication error. Increasing handshake attempts.
...
2025/10/13 23:13:27 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:13:27 [INFO] Attempting SSH connection to [2620:83:8008:161::17]:22...
2025/10/13 23:13:27 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:13:27 [DEBUG] reconnecting to TCP connection for SSH
2025/10/13 23:13:27 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:13:27 [DEBUG] handshaking with SSH
2025/10/13 23:13:33 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:13:33 [DEBUG] handshake complete!
2025/10/13 23:13:33 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:13:33 [DEBUG] Opening new ssh session
2025/10/13 23:13:34 packer-plugin-vsphere_v2.1.0-dev_x5.0_linux_amd64 plugin: 2025/10/13 23:13:34 [INFO] agent forwarding enabled
2025/10/13 23:13:34 ui: ==> vsphere-iso: Connected to SSH!

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[tenthirtyam]

Marking as draft for the time being.

• CLA Issue
• Tests not passing (unused import).
• Please use conventional cmmmmits.

[Copilot]

Pull Request Overview

This PR fixes a bug where IPv6 addresses were being double-wrapped in brackets, causing SSH connection failures. The code was manually wrapping IPv6 addresses in brackets, but Go's net.JoinHostPort function already handles this, resulting in malformed addresses like [[IPv6]]:port.

• Removed manual IPv6 bracket wrapping logic
• Added documentation explaining why the wrapping was removed
• Fixed SSH communicator failures with IPv6 addresses

---

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[tenthirtyam]

Marking as draft for the time being.

• CLA Issue
• Tests not passing (unused import).
• Please use conventional cmmmmits.

I've amended and addressed the above.

[tenthirtyam]

LGTM

[clarsen]

Marking as draft for the time being.

• CLA Issue
• Tests not passing (unused import).
• Please use conventional cmmmmits.

I've amended and addressed the above.

thanks for taking care of the code/commit comment issues.
I did sign the CLA with my primary github email and the email listed in the commit has been added to my profile as an alternate email...

[tenthirtyam]

thanks for taking care of the code/commit comment issues. I did sign the CLA with my primary github email and the email listed in the commit has been added to my profile as an alternate email...

You're welcome! @kp2099 will review this one along with a few others this week. Depending on the payload we may consider a minor patch for this issue and one other ahead of v2.1.0.