go-agent

#!/bin/bash

# Use this script to start up your GoCD agent process. The script assumes that —
# - no agent is installed via deb/rpm
# - curl is available on $PATH
# - user `go` exists

die () {
    echo
    echo "$*"
    echo
    exit 1
}

download_file () {
  local remote_path="$1"
  local local_path="$2"
  local url="${GO_EA_SERVER_URL}${remote_path}"

  echo "Downloading remote file ${url} into ${local_path}."
  curl --fail --silent --insecure "${url}" -o "${local_path}" || die "Could not fetch ${url}."
}

get_checksums () {
  local url="${GO_EA_SERVER_URL}/admin/latest-agent.status"
  curl --fail --silent --insecure "${url}" -D - || die "Could not fetch ${url}"
}

get_checksum () {
  local checksums="${1}"
  local header="${2}"
  echo "${checksums}" | tr -d '\r' | grep "${header}" | sed -e "s/${header}: //g"
}

if [[ "$(whoami)" != 'go' ]]; then
  echo "Must run this script as the `go` user"
  exit -1
fi

mkdir -p /go/config || die "Could not create /go/config"
cd /go || die "Could not chdir to /go"

# write out autoregister.properties
(
cat <<EOF
agent.auto.register.key=${GO_EA_AUTO_REGISTER_KEY}
agent.auto.register.environments=${GO_EA_AUTO_REGISTER_ENVIRONMENT}
agent.auto.register.elasticAgent.agentId=${GO_EA_AUTO_REGISTER_ELASTIC_AGENT_ID}
agent.auto.register.elasticAgent.pluginId=${GO_EA_AUTO_REGISTER_ELASTIC_PLUGIN_ID}
EOF
) > ./config/autoregister.properties

while true; do
  download_file '/admin/agent' 'agent.jar'
  download_file '/admin/agent-plugins.zip' 'agent-plugins.zip'
  download_file '/admin/tfs-impl.jar' 'tfs-impl.jar'

  checksums=$(get_checksums)
  agent_md5=$(get_checksum "${checksums}" 'Agent-Content-MD5')
  tfs_md5=$(get_checksum "${checksums}" 'TFS-SDK-Content-MD5')
  plugins_md5=$(get_checksum "${checksums}" 'Agent-Plugins-Content-MD5')
  agent_launcher_md5=$(get_checksum "${checksums}" 'Agent-Launcher-Content-MD5')

  echo "Launching the GoCD Agent, and waiting for it to exit..."
  RUN_CMD=(java -Dcruise.console.publish.interval=10 \
            -Xms128m \
            -Xmx256m \
            -Djava.security.egd=file:/dev/./urandom \
            -Dagent.plugins.md5="${plugins_md5}" \
            -Dagent.binary.md5="${agent_md5}" \
            -Dagent.launcher.md5="${agent_launcher_md5}" \
            -Dagent.tfs.md5="${tfs_md5}" \
            -jar \
            agent.jar \
            -serverUrl \
            "${GO_EA_SERVER_URL}")
  "${RUN_CMD[@]}"
  echo "The GoCD Agent exited with code $?. Waiting 10 seconds before re-launching"
  sleep 10
done