Implement Docker wait conditions

Signed-off-by: Matej Vasek <mvasek@redhat.com>

1 files changed, 197 insertions, 34 deletions

diff --git a/pkg/api/handlers/utils/containers.go b/pkg/api/handlers/utils/containers.go
index 7443f9b46..518309a03 100644
--- a/pkg/api/handlers/utils/containers.go
+++ b/pkg/api/handlers/utils/containers.go
@@ -1,67 +1,230 @@
 package utils
 
 import (
+	"context"
+	"fmt"
 	"net/http"
+	"strconv"
 	"time"
 
-	"github.com/containers/podman/v2/libpod"
-	"github.com/containers/podman/v2/libpod/define"
 	"github.com/containers/podman/v2/pkg/domain/entities"
 	"github.com/containers/podman/v2/pkg/domain/infra/abi"
+
+	"github.com/containers/podman/v2/pkg/api/handlers"
+	"github.com/sirupsen/logrus"
+
+	"github.com/containers/podman/v2/libpod/define"
+
+	"github.com/containers/podman/v2/libpod"
 	"github.com/gorilla/schema"
 	"github.com/pkg/errors"
 )
 
-func WaitContainer(w http.ResponseWriter, r *http.Request) (int32, error) {
+type waitQueryDocker struct {
+	Condition string `schema:"condition"`
+}
+
+type waitQueryLibpod struct {
+	Interval  string                   `schema:"interval"`
+	Condition []define.ContainerStatus `schema:"condition"`
+}
+
+func WaitContainerDocker(w http.ResponseWriter, r *http.Request) {
+	var err error
+	ctx := r.Context()
+
+	query := waitQueryDocker{}
+
+	decoder := ctx.Value("decoder").(*schema.Decoder)
+	if err = decoder.Decode(&query, r.URL.Query()); err != nil {
+		Error(w, "Something went wrong.", http.StatusBadRequest, errors.Wrapf(err, "failed to parse parameters for %s", r.URL.String()))
+		return
+	}
+
+	interval := time.Nanosecond
+
+	condition := "not-running"
+	if _, found := r.URL.Query()["condition"]; found {
+		condition = query.Condition
+		if !isValidDockerCondition(query.Condition) {
+			BadRequest(w, "condition", condition, errors.New("not a valid docker condition"))
+			return
+		}
+	}
+
+	name := GetName(r)
+
+	exists, err := containerExists(ctx, name)
+
+	if err != nil {
+		InternalServerError(w, err)
+		return
+	}
+	if !exists {
+		ContainerNotFound(w, name, define.ErrNoSuchCtr)
+		return
+	}
+
+	// In docker compatibility mode we have to send headers in advance,
+	// otherwise docker client would freeze.
+	w.Header().Add("Content-Type", "application/json")
+	w.WriteHeader(200)
+	if flusher, ok := w.(http.Flusher); ok {
+		flusher.Flush()
+	}
+
+	exitCode, err := waitDockerCondition(ctx, name, interval, condition)
+	msg := ""
+	if err != nil {
+		logrus.Errorf("error while waiting on condtion: %q", err)
+		msg = err.Error()
+	}
+	responseData := handlers.ContainerWaitOKBody{
+		StatusCode: int(exitCode),
+		Error: struct {
+			Message string
+		}{
+			Message: msg,
+		},
+	}
+	enc := json.NewEncoder(w)
+	enc.SetEscapeHTML(true)
+	err = enc.Encode(&responseData)
+	if err != nil {
+		logrus.Errorf("unable to write json: %q", err)
+	}
+}
+
+func WaitContainerLibpod(w http.ResponseWriter, r *http.Request) {
 	var (
-		err      error
-		interval time.Duration
+		err        error
+		interval   = time.Millisecond * 250
+		conditions = []define.ContainerStatus{define.ContainerStateStopped, define.ContainerStateExited}
 	)
-	runtime := r.Context().Value("runtime").(*libpod.Runtime)
-	// Now use the ABI implementation to prevent us from having duplicate
-	// code.
-	containerEngine := abi.ContainerEngine{Libpod: runtime}
 	decoder := r.Context().Value("decoder").(*schema.Decoder)
-	query := struct {
-		Interval  string                   `schema:"interval"`
-		Condition []define.ContainerStatus `schema:"condition"`
-	}{
-		// Override golang default values for types
-	}
+	query := waitQueryLibpod{}
 	if err := decoder.Decode(&query, r.URL.Query()); err != nil {
 		Error(w, "Something went wrong.", http.StatusBadRequest, errors.Wrapf(err, "failed to parse parameters for %s", r.URL.String()))
-		return 0, err
-	}
-	options := entities.WaitOptions{
-		Condition: []define.ContainerStatus{define.ContainerStateStopped},
 	}
-	name := GetName(r)
+
 	if _, found := r.URL.Query()["interval"]; found {
 		interval, err = time.ParseDuration(query.Interval)
 		if err != nil {
 			InternalServerError(w, err)
-			return 0, err
+			return
 		}
-	} else {
-		interval, err = time.ParseDuration("250ms")
-		if err != nil {
+	}
+
+	if _, found := r.URL.Query()["condition"]; found {
+		if len(query.Condition) > 0 {
+			conditions = query.Condition
+		}
+	}
+
+	name := GetName(r)
+
+	waitFn := createContainerWaitFn(r.Context(), name, interval)
+
+	exitCode, err := waitFn(conditions...)
+	if err != nil {
+		if errors.Cause(err) == define.ErrNoSuchCtr {
+			ContainerNotFound(w, name, err)
+			return
+		} else {
 			InternalServerError(w, err)
-			return 0, err
+			return
 		}
 	}
-	options.Interval = interval
+	WriteResponse(w, http.StatusOK, strconv.Itoa(int(exitCode)))
+}
 
-	if _, found := r.URL.Query()["condition"]; found {
-		options.Condition = query.Condition
+type containerWaitFn func(conditions ...define.ContainerStatus) (int32, error)
+
+func createContainerWaitFn(ctx context.Context, containerName string, interval time.Duration) containerWaitFn {
+
+	runtime := ctx.Value("runtime").(*libpod.Runtime)
+	var containerEngine entities.ContainerEngine = &abi.ContainerEngine{Libpod: runtime}
+
+	return func(conditions ...define.ContainerStatus) (int32, error) {
+		opts := entities.WaitOptions{
+			Condition: conditions,
+			Interval:  interval,
+		}
+		ctrWaitReport, err := containerEngine.ContainerWait(ctx, []string{containerName}, opts)
+		if err != nil {
+			return -1, err
+		}
+		if len(ctrWaitReport) != 1 {
+			return -1, fmt.Errorf("the ContainerWait() function returned unexpected count of reports: %d", len(ctrWaitReport))
+		}
+		return ctrWaitReport[0].ExitCode, ctrWaitReport[0].Error
 	}
+}
 
-	report, err := containerEngine.ContainerWait(r.Context(), []string{name}, options)
+func isValidDockerCondition(cond string) bool {
+	switch cond {
+	case "next-exit", "removed", "not-running", "":
+		return true
+	}
+	return false
+}
+
+func waitDockerCondition(ctx context.Context, containerName string, interval time.Duration, dockerCondition string) (int32, error) {
+
+	containerWait := createContainerWaitFn(ctx, containerName, interval)
+
+	var err error
+	var code int32
+	switch dockerCondition {
+	case "next-exit":
+		code, err = waitNextExit(containerWait)
+	case "removed":
+		code, err = waitRemoved(containerWait)
+	case "not-running", "":
+		code, err = waitNotRunning(containerWait)
+	default:
+		panic("not a valid docker condition")
+	}
+	return code, err
+}
+
+var notRunningStates = []define.ContainerStatus{
+	define.ContainerStateCreated,
+	define.ContainerStateRemoving,
+	define.ContainerStateStopped,
+	define.ContainerStateExited,
+	define.ContainerStateConfigured,
+}
+
+func waitRemoved(ctrWait containerWaitFn) (int32, error) {
+	code, err := ctrWait(define.ContainerStateUnknown)
+	if err != nil && errors.Cause(err) == define.ErrNoSuchCtr {
+		return code, nil
+	} else {
+		return code, err
+	}
+}
+
+func waitNextExit(ctrWait containerWaitFn) (int32, error) {
+	_, err := ctrWait(define.ContainerStateRunning)
 	if err != nil {
-		return 0, err
+		return -1, err
 	}
-	if len(report) == 0 {
-		InternalServerError(w, errors.New("No reports returned"))
-		return 0, err
+	return ctrWait(notRunningStates...)
+}
+
+func waitNotRunning(ctrWait containerWaitFn) (int32, error) {
+	return ctrWait(notRunningStates...)
+}
+
+func containerExists(ctx context.Context, name string) (bool, error) {
+	runtime := ctx.Value("runtime").(*libpod.Runtime)
+	var containerEngine entities.ContainerEngine = &abi.ContainerEngine{Libpod: runtime}
+
+	var ctrExistsOpts entities.ContainerExistsOptions
+	ctrExistRep, err := containerEngine.ContainerExists(ctx, name, ctrExistsOpts)
+	if err != nil {
+		return false, err
 	}
-	return report[0].ExitCode, report[0].Error
+	return ctrExistRep.Value, nil
 }