From 89a00f030e013af859d0dd6e260119715702d538 Mon Sep 17 00:00:00 2001
From: Samuel Ortiz <sameo@linux.intel.com>
Date: Mon, 9 Oct 2017 22:13:39 +0200
Subject: [PATCH] oci: Support containers with identical ID prefixes

Starting 2 containers with the same ID prefixes is a valid use case.
Although the Docker CLI supports shortened container IDs, italways
call the runtime with the full and complete ID.

Fixes #699

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
---
 oci.go      | 29 ++++-------------------------
 oci_test.go | 44 +++++++++++++++++++-------------------------
 2 files changed, 23 insertions(+), 50 deletions(-)

diff --git a/oci.go b/oci.go
index 988d41de..4380c190 100644
--- a/oci.go
+++ b/oci.go
@@ -20,7 +20,6 @@ import (
 	"net"
 	"os"
 	"path/filepath"
-	"strings"
 	"syscall"
 
 	vc "github.com/containers/virtcontainers"
@@ -43,21 +42,13 @@ const (
 	cgroupFsType = 0x27e0eb
 )
 
-var (
-	errNeedLinuxResource     = errors.New("Linux resource cannot be empty")
-	errPrefixContIDNotUnique = errors.New("Partial container ID not unique")
-)
+var errNeedLinuxResource = errors.New("Linux resource cannot be empty")
 
 var cgroupsDirPath = "/sys/fs/cgroup"
 
 // getContainerInfo returns the container status and its pod ID.
 // It internally expands the container ID from the prefix provided.
-// An error is returned if >1 containers are found with the specified
-// prefix.
 func getContainerInfo(containerID string) (vc.ContainerStatus, string, error) {
-	var cStatus vc.ContainerStatus
-	var podID string
-
 	// container ID MUST be provided.
 	if containerID == "" {
 		return vc.ContainerStatus{}, "", fmt.Errorf("Missing container ID")
@@ -68,29 +59,17 @@ func getContainerInfo(containerID string) (vc.ContainerStatus, string, error) {
 		return vc.ContainerStatus{}, "", err
 	}
 
-	matchFound := false
 	for _, podStatus := range podStatusList {
 		for _, containerStatus := range podStatus.ContainersStatus {
 			if containerStatus.ID == containerID {
 				return containerStatus, podStatus.ID, nil
 			}
-
-			if strings.HasPrefix(containerStatus.ID, containerID) {
-				if matchFound {
-					return vc.ContainerStatus{}, "", errPrefixContIDNotUnique
-				}
-
-				matchFound = true
-				cStatus = containerStatus
-				podID = podStatus.ID
-			}
 		}
 	}
 
-	if matchFound {
-		return cStatus, podID, nil
-	}
-
+	// Not finding a container should not trigger an error as
+	// getContainerInfo is used for checking the existence and
+	// the absence of a container ID.
 	return vc.ContainerStatus{}, "", nil
 }
 
diff --git a/oci_test.go b/oci_test.go
index b405b498..8762f130 100644
--- a/oci_test.go
+++ b/oci_test.go
@@ -79,34 +79,27 @@ func TestGetContainerInfoContainerIDEmptyFailure(t *testing.T) {
 	assert.Empty(status.ID, "Expected blank fullID, but got %v", status.ID)
 }
 
-func TestGetContainerInfoDuplicateContainerID(t *testing.T) {
+func TestGetContainerInfo(t *testing.T) {
 	assert := assert.New(t)
 
 	pod := &vcMock.Pod{
 		MockID: testPodID,
 	}
 
-	containerID := testContainerID + testContainerID
+	containerID := testContainerID
+
+	containerStatus := vc.ContainerStatus{
+		ID: containerID,
+		Annotations: map[string]string{
+			oci.ContainerTypeKey: string(vc.PodSandbox),
+		},
+	}
 
 	testingImpl.ListPodFunc = func() ([]vc.PodStatus, error) {
 		return []vc.PodStatus{
 			{
-				ID: pod.ID(),
-				ContainersStatus: []vc.ContainerStatus{
-					// 2 containers with same ID
-					{
-						ID: containerID,
-						Annotations: map[string]string{
-							oci.ContainerTypeKey: string(vc.PodSandbox),
-						},
-					},
-					{
-						ID: containerID,
-						Annotations: map[string]string{
-							oci.ContainerTypeKey: string(vc.PodSandbox),
-						},
-					},
-				},
+				ID:               pod.ID(),
+				ContainersStatus: []vc.ContainerStatus{containerStatus},
 			},
 		}, nil
 	}
@@ -115,12 +108,13 @@ func TestGetContainerInfoDuplicateContainerID(t *testing.T) {
 		testingImpl.ListPodFunc = nil
 	}()
 
-	_, _, err := getContainerInfo(testContainerID)
-	assert.Error(err)
-	assert.Equal(err, errPrefixContIDNotUnique)
+	status, podID, err := getContainerInfo(testContainerID)
+	assert.NoError(err)
+	assert.Equal(podID, pod.ID())
+	assert.Equal(status, containerStatus)
 }
 
-func TestGetContainerInfo(t *testing.T) {
+func TestGetContainerInfoMismatch(t *testing.T) {
 	assert := assert.New(t)
 
 	pod := &vcMock.Pod{
@@ -149,11 +143,11 @@ func TestGetContainerInfo(t *testing.T) {
 		testingImpl.ListPodFunc = nil
 	}()
 
-	status, podID, err := getContainerInfo(testContainerID)
+	_, podID, err := getContainerInfo(testContainerID)
 	assert.NoError(err)
-	assert.Equal(podID, pod.ID())
-	assert.Equal(status, containerStatus)
+	assert.Equal(podID, "")
 }
+
 func TestValidCreateParamsContainerIDEmptyFailure(t *testing.T) {
 	assert := assert.New(t)
 	_, err := validCreateParams("", "")