teleport

Gravitational Teleport as MacOS Library

Introduction

Teleport is a modern SSH service built by Gravitational for remotely accessing clusters of Linux servers via SSH. Teleport has many excellent features: the most unmentioned one of it all is to be built as a MacOS library (or any other platform for that matter).

PocketCluster is a MacOS cluster manager application which lets its users "Click and Build" a SBC (Single Board Computer) cluster. The application needed a cluster-wise internal service that could bond a MacOS master and several SBC slaves in a secure and reliable way; Teleport fitted in the role.

Building Teleport as Library

Teleport source code consists of the actual Teleport service and client binary written in Golang. They are built into static library, and their symbols are exposed in C space.

#!/bin/bash

# Exit if any command fails
set -e

# Figure out where things are coming from and going to
export GOROOT="/opt/go-1.7.6"
export GOREPO=${GOREPO:-"${HOME}/Workspace/POCKETPKG"}
export GOWORKPLACE=${GOWORKPLACE:-"${HOME}/Workspace/GOPLACE"}
export GOPATH="${GOREPO}:${GOWORKPLACE}"
export GO=${GOROOT}/bin/go
export GG_BUILD="${PWD}/../../.build"
export ARCHIVE="${GG_BUILD}/pc-core.a"
#PATH=${PATH:-"$GEM_HOME/ruby/2.0.0/bin:$HOME/.util:$GOROOT/bin:$GOREPO/bin:$GOWORKPLACE/bin:$HOME/.util:$NATIVE_PATH"}
export PATH="$GOROOT/bin:$GOREPO/bin:$GOWORKPLACE/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin"
export VERBOSE=${VERBOSE:-0}

# Clean old directory
if [ -d ${GG_BUILD} ]; then
    rm -rf ${GG_BUILD} && mkdir -p ${GG_BUILD}
fi

echo "--- --- --- --- --- --- --- --- --- --- --- --- GO ENVIRONMENTS --- --- --- --- --- --- --- --- --- --- --- ---"
echo $(GO version)
GO env
echo "--- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---"

echo "Make the temp folders for go objects"
mkdir -p ${GG_BUILD}

echo "Generate _cgo_export.h and copy into source folder"
${GO} tool cgo -objdir ${GG_BUILD} native_*.go main.go

echo "Compile and produce object files"
# [Default mode] First trial
#CGO_ENABLED=1 CC=clang ${GO} build -ldflags '-tmpdir '${GG_BUILD}' -linkmode external' ./...

# [Default mode] External clang linker
#CGO_ENABLED=1 CC=clang ${GO} build -v -x -ldflags '-v -tmpdir '${GG_BUILD}' -linkmode external -extld clang' ./...

# [Archive mode]
#CGO_ENABLED=1 CC=clang ${GO} build -v -x -buildmode=c-archive -ldflags '-v -tmpdir '${GG_BUILD}' -linkmode external' ./...

# [Shared mode] go.dwarf file
#CGO_ENABLED=1 CC=clang ${GO} build -v -x -buildmode=c-shared -ldflags '-v -tmpdir '${GG_BUILD}' -linkmode external' ./...

# [Archive mode] prevents go.dwarf generated (-w), strip symbol (-s)
#CGO_ENABLED=1 CC=clang ${GO} build -v -x -buildmode=c-archive -ldflags '-v -w -s -tmpdir '${GG_BUILD}' -linkmode external' ./...

# [Default mode] default mode (we need main() function), disable go.dwarf generation (-w), strip symbol (-s)
if [[ ${VERBOSE} -eq 1 ]]; then
    CGO_ENABLED=1 CC=clang ${GO} build -v -x -ldflags '-v -s -w -tmpdir '${GG_BUILD}' -linkmode external' ./...
else
    # (2017/11/15) -v=2 link flag is added to unused method removal
    # https://go-review.googlesource.com/c/go/+/20483
    CGO_ENABLED=1 CC=clang ${GO} build -ldflags '-s -w -v=2 -tmpdir '${GG_BUILD}' -linkmode external' ./...
fi

echo "Combine the object files into a static library"
ar rcs ${ARCHIVE} ${GG_BUILD}/*.o
mv ${GG_BUILD}/_cgo_export.h ${GG_BUILD}/pc-core.h
rm static*
echo "${ARCHIVE} generated!"

Status

This project is not maintained.