agent/local: store proxy on local state, wip, not working yet

agent/local/proxy.go

@@ -0,0 +1,26 @@
+package local
+
+import (
+	"fmt"
+	"os/exec"
+
+	"github.com/hashicorp/consul/agent/proxy"
+	"github.com/hashicorp/consul/agent/structs"
+)
+
+// newProxyProcess returns the proxy.Proxy for the given ManagedProxy
+// state entry. proxy.Proxy is the actual managed process. The returned value
+// is the initialized struct but isn't explicitly started.
+func (s *State) newProxyProcess(p *structs.ConnectManagedProxy, pToken string) (proxy.Proxy, error) {
+	switch p.ExecMode {
+	case structs.ProxyExecModeDaemon:
+		return &proxy.Daemon{
+			Command:    exec.Command(p.Command),
+			ProxyToken: pToken,
+			Logger:     s.logger,
+		}, nil
+
+	default:
+		return nil, fmt.Errorf("unsupported managed proxy type: %q", p.ExecMode)
+	}
+}

agent/local/state.go

@@ -14,6 +14,7 @@ import (
 	"github.com/hashicorp/go-uuid"
 
 	"github.com/hashicorp/consul/acl"
+	"github.com/hashicorp/consul/agent/proxy"
 	"github.com/hashicorp/consul/agent/structs"
 	"github.com/hashicorp/consul/agent/token"
 	"github.com/hashicorp/consul/api"
@@ -126,6 +127,9 @@ type ManagedProxy struct {
 	// use service-scoped ACL tokens distributed externally.
 	ProxyToken string
 
+	// ManagedProxy is the managed proxy itself that is running.
+	ManagedProxy proxy.Proxy
+
 	// WatchCh is a close-only chan that is closed when the proxy is removed or
 	// updated.
 	WatchCh chan struct{}
@@ -603,6 +607,14 @@ func (l *State) AddProxy(proxy *structs.ConnectManagedProxy, token string) (*str
 		return nil, err
 	}
 
+	// Initialize the managed proxy process. This doesn't start anything,
+	// it only sets up the structures we'll use. To start the proxy, the
+	// caller should call Proxy and use the returned ManagedProxy instance.
+	proxyProcess, err := l.newProxyProcess(proxy, pToken)
+	if err != nil {
+		return nil, err
+	}
+
 	// Lock now. We can't lock earlier as l.Service would deadlock and shouldn't
 	// anyway to minimise the critical section.
 	l.Lock()
@@ -650,9 +662,10 @@ func (l *State) AddProxy(proxy *structs.ConnectManagedProxy, token string) (*str
 		close(old.WatchCh)
 	}
 	l.managedProxies[svc.ID] = &ManagedProxy{
-		Proxy:      proxy,
-		ProxyToken: pToken,
-		WatchCh:    make(chan struct{}),
+		Proxy:        proxy,
+		ProxyToken:   pToken,
+		ManagedProxy: proxyProcess,
+		WatchCh:      make(chan struct{}),
 	}
 
 	// No need to trigger sync as proxy state is local only.

agent/proxy/daemon_test.go

@@ -11,6 +11,10 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func TestDaemon_impl(t *testing.T) {
+	var _ Proxy = new(Daemon)
+}
+
 func TestDaemonStartStop(t *testing.T) {
 	require := require.New(t)
 	td, closer := testTempDir(t)

agent/proxy/proxy.go

@@ -10,3 +10,19 @@ package proxy
 // EnvProxyToken is the name of the environment variable that is passed
 // to managed proxies containing the proxy token.
 const EnvProxyToken = "CONNECT_PROXY_TOKEN"
+
+// Proxy is the interface implemented by all types of managed proxies.
+//
+// Calls to all the functions on this interface must be concurrency safe.
+// Please read the documentation carefully on top of each function for expected
+// behavior.
+type Proxy interface {
+	// Start starts the proxy. If an error is returned then the managed
+	// proxy registration is rejected. Therefore, this should only fail if
+	// the configuration of the proxy itself is irrecoverable, and should
+	// retry starting for other failures.
+	Start() error
+
+	// Stop stops the proxy.
+	Stop() error
+}