fix: pass docker context key when reusing a container (#550)

* fix: pass docker context key when reusing a container

* feat: add sessionID HTTP Header to the Docker client setup (#570)

* chore: create network's session ID for reaper, only

* chore: include reaper-specific labels to the reaper container

* feat: initialise sessionID just once

* chore: do not expose the sessionID function

* fix: update reaper tests

* chore: add unit tests for extracting the docker host for reaper

* chore: add tests for the docker host when it's passed as part of the context

docker.go

@@ -1164,7 +1164,7 @@ func (p *DockerProvider) ReuseOrCreateContainer(ctx context.Context, req Contain
 	sessionID := sessionID()
 	var termSignal chan bool
 	if !req.SkipReaper {
-		r, err := NewReaper(ctx, sessionID.String(), p, req.ReaperImage)
+		r, err := NewReaper(context.WithValue(ctx, dockerHostContextKey, p.host), sessionID.String(), p, req.ReaperImage)
 		if err != nil {
 			return nil, fmt.Errorf("%w: creating reaper failed", err)
 		}

reaper_test.go

@@ -58,6 +58,7 @@ func Test_NewReaper(t *testing.T) {
 		name   string
 		req    ContainerRequest
 		config TestContainersConfig
+		ctx    context.Context
 	}
 
 	tests := []cases{
@@ -76,6 +77,15 @@ func Test_NewReaper(t *testing.T) {
 				RyukPrivileged: true,
 			},
 		},
+		{
+			name: "docker-host in context",
+			req: createContainerRequest(func(req ContainerRequest) ContainerRequest {
+				req.Mounts = Mounts(BindMount("/value/in/context.sock", "/var/run/docker.sock"))
+				return req
+			}),
+			config: TestContainersConfig{},
+			ctx:    context.WithValue(context.TODO(), dockerHostContextKey, "unix:///value/in/context.sock"),
+		},
 	}
 
 	for _, test := range tests {
@@ -86,11 +96,54 @@ func Test_NewReaper(t *testing.T) {
 				config: test.config,
 			}
 
-			_, err := NewReaper(context.TODO(), "sessionId", provider, "reaperImage")
+			if test.ctx == nil {
+				test.ctx = context.TODO()
+			}
+
+			_, err := NewReaper(test.ctx, "sessionId", provider, "reaperImage")
 			// we should have errored out see mockReaperProvider.RunContainer
 			assert.EqualError(t, err, "expected")
 
 			assert.Equal(t, test.req, provider.req, "expected ContainerRequest doesn't match the submitted request")
 		})
 	}
 }
+
+func Test_ExtractDockerHost(t *testing.T) {
+	t.Run("Docker Host as environment variable", func(t *testing.T) {
+		t.Setenv("TESTCONTAINERS_DOCKER_SOCKET_OVERRIDE", "/path/to/docker.sock")
+		host := extractDockerHost(context.Background())
+
+		assert.Equal(t, "/path/to/docker.sock", host)
+	})
+
+	t.Run("Default Docker Host", func(t *testing.T) {
+		host := extractDockerHost(context.Background())
+
+		assert.Equal(t, "/var/run/docker.sock", host)
+	})
+
+	t.Run("Malformed Docker Host is passed in context", func(t *testing.T) {
+		ctx := context.Background()
+
+		host := extractDockerHost(context.WithValue(ctx, dockerHostContextKey, "path-to-docker-sock"))
+
+		assert.Equal(t, "/var/run/docker.sock", host)
+	})
+
+	t.Run("Malformed Schema Docker Host is passed in context", func(t *testing.T) {
+		ctx := context.Background()
+
+		host := extractDockerHost(context.WithValue(ctx, dockerHostContextKey, "http://path to docker sock"))
+
+		assert.Equal(t, "/var/run/docker.sock", host)
+	})
+
+	t.Run("Unix Docker Host is passed in context", func(t *testing.T) {
+		ctx := context.Background()
+
+		host := extractDockerHost(context.WithValue(ctx, dockerHostContextKey, "unix:///this/is/a/sample.sock"))
+
+		assert.Equal(t, "/this/is/a/sample.sock", host)
+	})
+}