mgsh/README.md

# mgsh — git shell

A small interactive shell / command-line wrapper around a self-hosted bare git
server reachable over ssh. It manages a flat set of projects living under a base
directory. Go port of the original Perl `mgsh` (`mgsh.perl`).

## Contents

- [Build](#build) · [Usage](#usage) · [Commands](#commands) · [Aliases](#aliases)
- [Overview](#overview) · [Credential check](#credential-check)
- [Public mirror (`pushremote`)](#public-mirror-pushremote) ·
  [Releases](#releases)
- [Configuration](#configuration) · [Settings reference](#settings-reference) ·
  [Per-project configuration](#per-project-configuration)
- [Git server layout](#git-server-layout)

## Build

```sh
./build.sh          # builds ./mgsh and bumps the patch version by 0.0.1
go build -o mgsh .  # plain build, keeps the default version
```

`build.sh` reads `version.txt`, increments the patch component, injects it via
`-ldflags -X main.VERSION`, and writes it back — so `version.txt` always holds
the version of the binary just built. Dependencies are fetched via Go modules
(`go.mod` / `go.sum`) on first build.

Run the tests with `go test ./...`.

## Usage

Launch `mgsh` for the interactive shell, or run a single command directly from a
project directory, e.g. `mgsh push "message"`, `mgsh status`, `mgsh log`.

In command-line mode the project is taken from the working directory: anywhere
below `<base>/myproject` — however deep — the active project is `myproject`, and
the command applies to the whole project, not the subdirectory you happen to
stand in. Outside `base` no project is selected. `mgsh <project>` starts the
interactive shell with that project preselected.

The commands available directly from the shell are `clone`, `init`, `log`,
`push`, `pushremote`, `release`, `list`, `tag`, `archive`, `show`, `open`,
`pull`, `fetch`, `status`, `diff`, `overview`, `config`, `count`, `login` and
`cloneall`; every other command is interactive-only.

The interactive prompt is colored (Catppuccin Mocha) and shows the active
project, its git branch and a `*` dirty marker:

```
< src/myproject (master*) >
```

Features: command history (`~/.mgsh_history`), Tab completion (commands, local
projects for `cd`/`open`, server repos for `clone`/`show`, branches/tags for
`checkout`/`tag`, mirror targets for `pushremote`, filesystem paths for `dist`),
and colored `list`/`log`/error output.

The server repository list is fetched once per session on the first Tab that
needs it; `rescan` refreshes it (and reloads the configuration).

Exit with `quit`, `exit`, `Ctrl-D`, or `Ctrl-C` on an empty line.

### Shell escape

Unknown commands are **not** forwarded to a shell. To run a shell command,
prefix it with `!`:

```
< src/myproject > !ls -la
```

### Commands

Run `help` for the full list. Highlights:

| command                   | description                                    |
|---------------------------|------------------------------------------------|
| `cd [project]`            | change project (no argument: back to the base) |
| `push [comment]`          | commit everything and push to the server       |
| `pushremote [desc]`       | mirror the repo to a public server (gitea/github/gitlab) |
| `pull` / `fetch`          | pull / fetch from the server                   |
| `status [-a]` / `diff`    | short git status (`-a`: overview of all projects) |
| `overview`                | inventory of all projects, local and on the server |
| `log`                     | show the project log                           |
| `edit [n]`                | interactive rebase of the last n commits       |
| `clone [-a] <repo>`       | clone a repository (or archive) from the server |
| `list [-a] [pattern]`     | list repositories on the server (`-a`: archives, with sizes) |
| `show <repo>`             | show a repository log directly on the server   |
| `archive [comment]`       | snapshot the server-side repo into `./archive` |
| `init`                    | make a new repository from the current directory |
| `tag [add/checkout/delete]` | manage tags (`tag add v1.0 "why"` annotates) |
| `release [@name] <tag> [notes]` | tag and publish a release on the mirrors |
| `alias [name [cmd]]`      | list, show or define a command alias           |
| `unalias <name>`          | remove a command alias                         |
| `config [-k]`             | show the effective configuration and its sources |
| `rescan`                  | reload the config, refresh the cached repo list |
| `!<command>`              | run `<command>` in the shell                   |

Commands that touch a repository (`push`, `pull`, `log`, `diff`, `tag`, `dist`,
`checkout`, `edit`, …) require an active project with a `.git`; they refuse to
run rather than silently operating on the base directory. `checkout` and `diff`
forward their arguments to git unchanged, so `checkout -b topic` works.

`config` is the quickest way to see what mgsh actually resolved — which server,
which mirror targets, and which of them came from the project's own `.mgshrc`:

```
< src/myproject > config
global  /Users/me/.mgshrc
project /Users/me/src/myproject/.mgshrc

  base          /Users/me/src
  githost       git.example.com
  gitport       22
  gituser       git
  gitpath       /home/git
  editor        code  (.mgshrc)
  remotes       hub  (.mgshrc)
  clone url     ssh://git@git.example.com:22/home/git

pushremote targets (in push order):
  @hub          https://github.com  github (detected), public, key gh***************xk
```

Tokens are masked, so the output is safe to paste into a bug report.
`config -k` prints just the setting names, one per line.

### Listing the server

`list` shows what is on the git server, name first and aligned, ordered by
modification time — `push` touches the bare repository, so the most recently
worked-on project sits closest to the prompt:

```
< src > list
  Betaflight3.0.0  Sep 28  2016     181M
  website          Mar  3  2024     2.1M
  notes            Jan  3 14:32     876K
3 repositories · 184M
```

The size is the repository's real disk usage on the server, asked of `du` in
the same round trip as the listing — a long listing reports the inode size for
a directory, which is the same number for every repository and says nothing. If
the server produces no usable sizes the column is left out rather than filled
with zeroes.

`list -a` lists the archives instead, whose sizes come from the listing itself;
a pattern filters by name (`list note`).

### Overview

`overview` (or `status -a`) is the one view that needs mgsh: it is the only
thing that sees the local base directory *and* the git server at once.

```
< src > overview
  notes           * ↑2  laptop        3h
  website         * ✓   desktop       2d  → hub
  Betaflight3.0.0   ✓   workstation  20d  → gitea hub
  scratch (wip)     –   laptop        1h
4 projects · 2 dirty · 2 in sync
  not on the server (init)  experiments, sandbox
```

Every field sits in its own column, so the eye can go down one instead of
hunting along each line. The projects that need something done come first;
within a group the order stays alphabetical, so positions do not jump around.

| column | meaning |
|---|---|
| name | the project, with its branch appended when it is not `master`/`main` |
| `*` | uncommitted changes |
| `↑n` `↓n` | commits ahead of / behind the upstream (`↑2↓1` when both) |
| `✓` | in sync with the upstream |
| `–` | the branch tracks nothing — never pushed |
| host, age | who last committed and when, from the `[user@host]` stamp |
| `→` | mirror targets this repository has a remote for |

The host and age come from the commit itself — `push` writes `[user@host]` into
every message, so `overview` can say where a project was last worked on without
storing anything. On a setup spanning a laptop and a workstation that is usually
the piece of information you actually wanted.

The line at the end is the join no git command can do: the local projects the
git server has never seen, which are the ones `init` is for. If the server
cannot be reached, mgsh says so instead of claiming everything is missing. The
other direction — repositories on the server that are not here — is what `list`
shows.

### Credential check

`push` runs `git add --all .`, so anything lying in the project gets committed —
and with `mirror = true` it reaches a public server in the same breath. That is
the only action in mgsh that cannot be undone: a deleted server repository comes
back from an archive, a published credential does not.

So before anything is committed, the staged diff is checked for private keys,
GitHub/GitLab/Slack/AWS/PyPI tokens and credential-shaped assignments:

```
< src/notes > push new notes
2 possible credential(s) in what is about to be committed:
  .env:3  credential assignment
    API_KEY="<the offending line is shown in full here>"
  deploy_key:1  private key
    <the BEGIN … PRIVATE KEY header is shown here>
  (set 'secretscan = off' to skip this check)
push anyway? y/N ?
```

Declining stops the push with nothing committed; the changes stay staged, so
`git restore --staged <file>` and a `.gitignore` entry are all it takes.

For a line that only *looks* like a credential and is meant to stay, put
`mgsh:allow` in it — a comment on that line is enough. That is better than
turning the whole check off for one false positive.

This is not a complete secret scanner and does not try to be one. It aims for a
high hit rate on what actually leaks, with few enough false alarms that the
prompt still means something: values that are plainly environment references,
constants, template slots (`<token>`, `${VAR}`) or masked stand-ins are ignored —
a test checks that mgsh's own README and `mgshrc.example`, both full of
credential-shaped text, stay quiet. Switch it off with `secretscan = off`.

### Aliases

`alias <name> '<command>'` defines a reusable shortcut, persisted to
`~/.mgshrc` and reloaded on every start. The expansion is itself a mgsh
command line and may reference the alias arguments:

| placeholder | meaning                          |
|-------------|----------------------------------|
| `$1` … `$N` | the Nth argument (empty if unset)|
| `$*` / `$@` | all arguments, space-joined      |

When the expansion contains no placeholder, the arguments are appended (classic
shell-alias behaviour). Because unknown commands are **not** forwarded to a
shell, a shell command inside an alias needs the `!` prefix:

```
alias co 'checkout $1'    # co v2         -> checkout v2   (builtin)
alias p  'push $*'        # p fixed bug   -> push fixed bug (builtin)
alias ec '!echo $1'       # ec hello      -> echo hello    (shell)
```

`alias` with no arguments lists all aliases, `alias <name>` shows one, and
`unalias <name>` removes it. Aliases cannot shadow builtin commands.

### Public mirror (`pushremote`)

Besides the internal ssh git server, `pushremote` mirrors the active project to
one or more public hosting servers (Gitea, GitHub or GitLab) over their REST
API. A single server is configured flat:

```ini
remoteurl        = https://git.example.com   # base URL of the server
remotekey        = <personal-access-token>   # API token
# remotetype     = gitea                     # optional; auto-detected from remoteurl
# remotevisibility = private                 # visibility of created repos (default private)
# mirror         = true                      # `push` also mirrors via pushremote
```

Several servers get one `remote.<name>.*` block each:

```ini
remote.gitea.url      = https://git.example.com
remote.gitea.key      = <personal-access-token>

remote.hub.url        = https://github.com
remote.hub.key        = <personal-access-token>
remote.hub.visibility = public

# remotes             = gitea, hub           # optional: restrict and order the set
```

| command                | pushes to                                     |
|------------------------|-----------------------------------------------|
| `pushremote`           | every configured target, in order              |
| `pushremote @hub`      | only `hub`                                     |
| `pushremote @hub @gitea` | those two                                    |
| `pushremote a fix`     | every target, description "a fix"              |

Each target owns a git remote of the same name in the repository (the flat form
uses `public`, as before), so `git push hub` keeps working outside mgsh. A
target that fails does not stop the others; with more than one target
`pushremote` prints an `n/m remotes updated` summary. `remotes = …` restricts
and orders the set, which is mostly useful in a project `.mgshrc` — see below.

`pushremote` authenticates with the token, creates the repository (named after
the current project) if it does not exist yet, adds the credential-free remote,
and pushes all branches and tags. New repositories are **private** unless
`visibility = public`; any words after the command (and after any `@name`) are
set as the repository description on creation.
The token is sent as a one-shot HTTP auth header: it is never written into the
repo's git config, and it reaches git through the environment rather than the
command line, so it does not show up in the process table. Because `~/.mgshrc`
then holds a credential, mgsh creates it mode `600` and warns at startup if an
existing file is readable by others. The provider is auto-detected from `remoteurl` (`github.com` →
GitHub, `gitlab*` → GitLab, otherwise Gitea) and can be forced with
`remotetype`. Set `mirror = true` to have every `push` mirror automatically.

### Releases

`release` turns a commit into a published release on the mirror servers, in one
step — creating the tag, getting it onto the internal server, and then onto each
mirror as a release object:

```
release [@name ...] <tag> [notes]
```

```
< src/mgsh > release v4.1.0 first public build
remote hub released https://github.com/mike/mgsh.git
```

Without `@name` it releases to every configured mirror target, exactly like
`pushremote`. Everything after the tag becomes the release notes *and* the tag's
annotation.

**Notes are generated when you do not write any**: the tag's own annotation if
it has a real one, otherwise the commit subjects since the previous tag
(`- <subject>` per line, at most 50). So a plain `release v4.1.0` already
produces a usable changelog.

A tag ending in `-rc`, `-alpha`, `-beta` or `-pre` (optionally with digits) is
marked as a **pre-release** on Gitea and GitHub; GitLab has no such flag.

Releasing the same tag twice updates the existing release rather than failing.
But a tag that already exists **on a different commit** stops the command —
moving a published tag is how one version quietly comes to mean different things
on different servers. `release` also refuses when the repository is not on the
mirror yet and tells you to run `pushremote` first, rather than creating it as a
side effect.

**No binary assets.** The three providers handle uploads in three incompatible
ways — Gitea attaches them to the release, GitHub uses a separate upload host,
and GitLab does not host them at all but expects a link into its package
registry. mgsh publishes source releases with notes; if you need binaries,
upload them with the provider's own tooling.

## Configuration

mgsh has **no built-in defaults**. Settings are resolved in three steps, each
overriding the one before:

```
~/.mgshrc   ->   <project>/.mgshrc   ->   MGSH_* environment variables
```

On first run mgsh writes a blank, annotated `~/.mgshrc` template (migrating any
aliases from a pre-4.x `~/.mgsh_aliases`) and then exits with an error until the
required settings — `base`, `githost`, `gitport`, `gituser`, `gitpath` — are
filled in. The global file must be complete on its own: mgsh has to work outside
any project, so a project file can only refine it, never complete it.

It uses simple `key = value` (or `key: value`) lines; a `#` preceded by
whitespace starts a comment, so a value may still contain a literal `#` (quote
the value to keep a trailing comment-like part). Alias definitions live in the
same file:

```ini
# --- required ---
base        = /Users/me/src
githost     = git.example.com
gitport     = 22
gituser     = git
gitpath     = /home/git

# --- optional ---
gitname     = Your Name
gitemail    = you@example.com
pushdefault = matching
editor      = code            # fallback opener for `open`

alias co 'checkout $1'
```

`config` shows the resolved result at any time.

### Settings reference

Every setting can also be given as an environment variable named `MGSH_<KEY>`
(e.g. `MGSH_GITHOST`), which wins over both files. "Scope" says whether a
project `.mgshrc` may override the setting.

| setting | scope | meaning |
|---|---|---|
| `base` | global | directory holding the projects — **required** |
| `githost` | project | git server host — **required** |
| `gitport` | project | ssh port — **required** |
| `gituser` | project | ssh user on the git server — **required** |
| `gitpath` | project | path of the bare repositories on the server — **required** |
| `gitkey` | project | ssh identity for the git server: a bare name is looked up in `~/.ssh`, a path is used as given. Applies to mgsh's own ssh calls and to git's ssh transport. Unset = normal ssh/`~/.ssh/config` behaviour |
| `gitname` | global | `user.name` written to the **global** git config at startup |
| `gitemail` | global | `user.email` written to the global git config |
| `pushdefault` | global | `push.default` written to the global git config |
| `editor` | project | opener used by `open`/`view` when the project has no Xcode workspace (default `coda`) |
| `remoteurl` | project | base URL of a single mirror server (target name `public`) |
| `remotekey` | project | API token for `remoteurl` |
| `remotetype` | project | `gitea`\|`github`\|`gitlab`; auto-detected from the URL when unset |
| `remotevisibility` | project | `private` (default) or `public` for repositories created by `pushremote` |
| `remote.<name>.url` | project | base URL of the named mirror target |
| `remote.<name>.key` | project | API token for that target |
| `remote.<name>.type` | project | provider override for that target |
| `remote.<name>.visibility` | project | visibility for that target |
| `remotes` | project | comma- or space-separated list restricting and ordering the mirror targets |
| `mirror` | project | truthy (`1`/`true`/`yes`/`on`) → every `push` also mirrors |
| `secretscan` | project | `off` disables the credential check `push` runs before committing (on by default; only an explicit `off` disables it) |

The three settings written to the global git config are applied at startup, and
only when they actually differ, so a plain `mgsh status` does not rewrite
`~/.gitconfig`.

### Per-project configuration

A project may carry its own `.mgshrc`, which overrides the global settings while
that project is active — a project on a different git server, with a different
editor, or mirrored to a different place:

```ini
# ~/src/myproject/.mgshrc
githost = other.example.com
remotes = hub                 # mirror this project to github only
mirror  = true
```

It is read when you `cd` into the project and applies to every command that
follows. `base`, `gitname`, `gitemail` and `pushdefault` stay global — `base`
defines where projects live, and the identity keys are written to your *global*
git config, which should not change as you move between projects. mgsh says so
when a project file sets one of them. Aliases also remain global; `alias` always
writes to `~/.mgshrc`.

`rescan` re-reads both files, so an edit takes effect without restarting. A
reload that would leave the global config incomplete is refused, and a changed
`base` needs a restart — mgsh says so rather than half-applying it.

A project `.mgshrc` is a normal file in the working tree, and `push` commits
everything: **keep API tokens out of it** unless it is git-ignored. mgsh warns
when a project config holds a token that git is not ignoring — including before
`init`, since that first commit would publish it too.

See `mgshrc.example` for an annotated template.

## Git server layout

mgsh expects nothing more than a user with ssh access whose **login directory is
`gitpath`** — every remote command runs there without a `cd`. Bare repositories
live directly in it, snapshots in an `archive/` subdirectory:

```
/home/git/                 <- gitpath, and the login directory of gituser
├── myproject.git          <- created by `init`, cloned by `clone`
├── notes.git
└── archive/               <- created by hand; needed by `archive` and `clone -a`
    └── myproject_170126.1432_before_rewrite.git.tar.gz
```

Setting this up once:

```sh
ssh git@git.example.com 'mkdir -p /home/git/archive'
```

Ownership does not matter — `list` reads whatever `ls -ltr` reports, whichever
user or group owns the repositories. Everything mgsh runs there is plain
`ls`/`mkdir`/`cp`/`tar`/`rm` plus `git --bare init`, with all names shell-quoted,
so a restricted shell that allows those commands is enough.

`archive` copies the *server-side* repository (not the working tree) to
`archive/<project>_DDMMYY.HHMM[_comment].git.tar.gz`; `clone -a <name>` unpacks
one and clones it back. `list -a` lists them.