Gomote.md

# Using gomote

## Installing

```
$ go get -u golang.org/x/build/cmd/gomote
```

## Using

TODO: examples. For now:

```
The gomote command is a client for the Go builder infrastructure. It's a
remote control for remote Go builder machines.

See https://golang.org/wiki/Gomote

Usage:

    gomote [global-flags] cmd [cmd-flags]

    For example,
    $ gomote create openbsd-amd64-60
    user-username-openbsd-amd64-60-0
    $ gomote push user-username-openbsd-amd64-60-0
    $ gomote run user-username-openbsd-amd64-60-0 go/src/make.bash
    $ gomote run user-username-openbsd-amd64-60-0 go/bin/go test -v -short os

To list the subcommands, run "gomote" without arguments:

    Commands:

      create     create a buildlet; with no args, list types of buildlets
      destroy    destroy a buildlet
      gettar     extract a tar.gz from a buildlet
      list       list active buildlets
      ls         list the contents of a directory on a buildlet
      ping       test whether a buildlet is alive and reachable
      push       sync your GOROOT directory to the buildlet
      put        put files on a buildlet
      put14      put Go 1.4 in place
      puttar     extract a tar.gz to a buildlet
      rm         delete files or directories
      run        run a command on a buildlet
      ssh        ssh to a buildlet

To list all the builder types available, run "create" with no arguments:

    $ gomote create
    (list tons of buildlet types)

The "gomote run" command has many of its own flags:

    $ gomote run -h
    run usage: gomote run [run-opts] <instance> <cmd> [args...]
      -builderenv string
            Optional alternate builder to act like. Must share the same
            underlying buildlet host type, or it's an error. For
            instance, linux-amd64-race or linux-386-387 are compatible
            with linux-amd64, but openbsd-amd64 and openbsd-386 are
            different hosts.
      -debug
            write debug info about the command's execution before it begins
      -dir string
            Directory to run from. Defaults to the directory of the
            command, or the work directory if -system is true.
      -e value
            Environment variable KEY=value. The -e flag may be repeated
            multiple times to add multiple things to the environment.
      -path string
            Comma-separated list of ExecOpts.Path elements. The special
            string 'EMPTY' means to run without any $PATH. The empty
            string (default) does not modify the $PATH. Otherwise, the
            following expansions apply: the string '$PATH' expands to
            the current PATH element(s), the substring '$WORKDIR'
            expands to the buildlet's temp workdir.
      -system
            run inside the system, and not inside the workdir; this is implicit if cmd starts with '/'


Debugging buildlets directly

Using "gomote create" contacts the build coordinator (farmer.golang.org) and
requests that it create the buildlet on your behalf. All subsequent commands
(such as "gomote run" or "gomote ls") then proxy your request via the
coordinator. To access a buildlet directly (for example, when working on the
buildlet code), you can skip the "gomote create" step and use the special
builder name "<build-config-name>@ip[:port>", such as
"windows-amd64-2008@10.1.5.3".
```

## Tricks

### Windows

```
$ gomote run -path '$PATH,$WORKDIR/go/bin' -e 'GOROOT=c:\workdir\go' $MOTE go/src/make.bat
$ gomote run -path '$PATH,$WORKDIR/go/bin' -e 'GOROOT=c:\workdir\go' $MOTE go/bin/go.exe test cmd/go -short
```

### Subrepos on Windows

```
$ tar --exclude .git -C ~/go/src/ -zc golang.org/x/tools | gomote puttar -dir=gopath/src $MOTE
$ gomote run -e 'GOPATH=c:/workdir/gopath' $MOTE go/bin/go test -run=TestFixImportsVendorPackage golang.org/x/tools/imports
```

If ssh'd into the machine, these envvars may be handy:

```
$ set GOPATH=c:\workdir\gopath
$ set PATH=%PATH%;c:\workdir\gopath\bin;c:\workdir\go\bin
$ set CGO_ENABLED=0
```

### Subrepos on Unix

Testing golang.org/x/sys/unix on $MOTE

```
$ tar -C $GOPATH/src/ -zc golang.org/x/sys/unix | gomote puttar -dir=gopath/src $MOTE
$ gomote run -e 'GOPATH=/tmp/workdir/gopath' -dir 'gopath/src/golang.org/x/sys/unix' $MOTE go/bin/go test -v golang.org/x/sys/unix
```

(The GOPATH part is for GOPATH compatibility mode; the `-dir` is for modules mode, which looks in the working directory and up for `go.mod`)

### Android

```
export MOTE=`gomote create android-arm64-wikofever`
gomote push $MOTE
gomote run $MOTE go/src/make.bash
```
PATH must contain the exec wrapper, go_android_*_exec, built by make.bash.

```
gomote run -path '$PATH,$WORKDIR/go/bin' $MOTE go/bin/go test math/big
```

## About Buildlets

http://farmer.golang.org/builders lists information about how each buildlet is deployed and configured.
The information is from golang.org/x/build/dashboard and golang.org/x/build/env.


## Access token

To get an access token, you will need to ask one of the editors of the `golang-org` Google Cloud project (TODO: how do I found out who those people are?) to provide you with the hash reported by the page at `https://build-dot-golang-org.appspot.com/key?builder=user-$USER`, where `USER` is your username.  Write the resulting token to the gomote config file, as in this hypothetical example: 

```
$ echo d41d8cd98f00b204e9800998ecf8427e > $HOME/.config/gomote/user-$USER.token
```