Unattended install updates (#433)

* Remove unnecessary '--sync' from 'plan execute' which was
ill-concieved.
* Move operation execute responsibility from Server to Executor. Factor
out event dispatching into a separate type and implement for both
use-cases - installer and install agent.
* Ensure proper execution of install steps on the agent.
* Add dispatcher tests. Fix a bug in buffered dispatcher with duplicate events
* Close dispatcher in executeConcurrentStep for all exit points

build.assets/Dockerfile

@@ -42,7 +42,7 @@ RUN (mkdir -p /opt/protoc && \
 RUN cd ${GOPATH}/src/github.com/gogo/protobuf && git reset --hard ${GOGO_PROTO_TAG} && make install
 RUN cd ${GOPATH}/src/github.com/grpc-ecosystem/grpc-gateway && git reset --hard ${GRPC_GATEWAY_TAG} && go install ./protoc-gen-grpc-gateway
 
-ENV PROTO_INCLUDE "/usr/local/include":"${GOPATH}/src":"${GOPATH}/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis":"${GOPATH}/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis":"${GOGOPROTO_ROOT}/protobuf"
+ENV PROTO_INCLUDE "/usr/local/include":"${GOPATH}/src":"${GOPATH}/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis":"${GOPATH}/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis":"${GOGOPROTO_ROOT}/protobuf":"${GOGOPROTO_ROOT}/gogoproto"
 
 # install DEP tool
 RUN wget --quiet -O /usr/bin/dep https://github.com/golang/dep/releases/download/v0.4.1/dep-linux-amd64 && chmod +x /usr/bin/dep

lib/expand/bootstrap.go

@@ -26,8 +26,8 @@ import (
 	"github.com/gravitational/trace"
 )
 
-// bootstrap initializes the local peer data
-func (p *Peer) bootstrap() error {
+// init initializes the peer after a successful connect
+func (p *Peer) init(ctx operationContext) error {
 	if err := p.clearLogins(); err != nil {
 		return trace.Wrap(err)
 	}
@@ -37,6 +37,12 @@ func (p *Peer) bootstrap() error {
 	if err := p.configureStateDirectory(); err != nil {
 		return trace.Wrap(err)
 	}
+	if err := p.ensureServiceUserAndBinary(ctx); err != nil {
+		return trace.Wrap(err)
+	}
+	if err := p.startAgent(ctx); err != nil {
+		return trace.Wrap(err)
+	}
 	return nil
 }