Add custom SSH config when clone via SSH instead of HTTP

[sinlov]

Clear and concise description of the problem

Currently woodpecker clones the repositories via HTTP, but some git ssh config must use custom config.

• support custom git config as ssh_config
• support use different ssh clone config at different ssh clone pipline
• compatibility plugin-git/Add option to use SSH for cloning repo #75

Suggested solution

• workflow of this feature

1. create custom ssh config as file map

.
└── default
    ├── config
    ├── id_rsa
    └── known_hosts

2. setting woodpecker-agent arg WOODPECKER_CUSTOM_SSH_GROUP_ROOT

3. config

pipeline:
  clone:
    image: woodpeckerci/plugin-git
    settings:
      custom_ssh_group:
        name: default
        dryrun_host: host_name # optional

4. at clone step

• copy all file custom_ssh_group setting by name to woodpecker-agent path $HOME/.ssh/ for git ssh to use

Alternative

• custom ssh config at woodpecker agent as WOODPECKER_CUSTOM_SSH_GROUP_ROOT when $HOME/.ssh/config after workspace init. this path call custom_ssh_group_root.
  • for support use different key at different ssh clone pipline, WOODPECKER_CUSTOM_SSH_GROUP_ROOT can set from volume or local path
  • custom_ssh_group_root file map as

.
├── bar
│   ├── config
│   ├── id_rsa
│   └── known_hosts
├── default
│   ├── config
│   ├── id_rsa
│   └── known_hosts
└── foo
    ├── config
    ├── id_rsa
    └── known_hosts

• copy all file custom_ssh_group setting by name to woodpecker-agent path $HOME/.ssh/ for git ssh to use
• each config file format as ssh_config
• each known_hosts file is optional
• default folder is default ssh config, this is necessary，so less file map as

.
└── default
    ├── config
    ├── id_rsa
    └── known_hosts

• pipeline-syntax at clone can config by

pipeline:
  clone:
    image: woodpeckerci/plugin-git
    settings:
      custom_ssh_group:
        name: default
        dryrun_host: host_name # optional

beacuse settings. ssh_key args (type string) is change git config core.sshCommand ssh -i <key>, don not use at same time

• support settings.custom_ssh_group.dryrun_host as string can set ssh test host
  • will check config file when copy from WOODPECKER_CUSTOM_SSH_GROUP_ROOT and name set
  • copy succese, will run exec as ssh -vT <dryrun_host> for check ssh config

Additional context

No response

Validations

• Checked that the feature isn't part of the next version already [https://woodpecker-ci.org/faq#which-version-of-woodpecker-should-i-use]
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[qwerty287]

In 2.0.0, plugin-git supports ssh cloning. It must be enabled manually. Does this fix the issue? (See woodpecker-ci/plugin-git#75)

[sinlov]

@qwerty287 version 2.x

with local backend mode, support clone via SSH instead of HTTP can change git global config like this

git config --global url."git@git.xxx.com:".insteadOf "https://git.xxx.com/"

so, please close this issure