Feature #133 - Add a FollowOutput method to attach log consumers to

README.md

@@ -116,3 +116,45 @@ req := ContainerRequest{
 	Cmd: []string{"echo", "command override!"},
 }
 ```
+
+## Following Container Logs
+
+If you wish to follow container logs, you can set up `LogConsumer`s.  The log following functionality follows
+a producer-consumer model.  You will need to explicitly start and stop the producer.  As logs are written to either
+`stdout`, or `stderr` (`stdin` is not supported) they will be forwarded (produced) to any associated `LogConsumer`s.  You can associate `LogConsumer`s
+with the `.FollowOutput` function.
+
+**Please note** if you start the producer you should always stop it explicitly.
+
+for example, this consumer will just add logs to a slice
+
+```go
+type TestLogConsumer struct {
+	Msgs []string
+}
+
+func (g *TestLogConsumer) Accept(l Log) {
+	g.Msgs = append(g.Msgs, string(l.Content))
+}
+```
+
+this can be used like so:
+```go
+g := TestLogConsumer{
+	Msgs: []string{},
+}
+
+err := c.StartLogProducer(ctx)
+if err != nil {
+	// do something with err
+}
+
+c.FollowOutput(&g)
+
+// some stuff happens...
+
+err = c.StopLogProducer()
+if err != nil {
+	// do something with err
+}
+```

container.go

@@ -38,9 +38,12 @@ type Container interface {
 	Start(context.Context) error                                    // start the container
 	Terminate(context.Context) error                                // terminate the container
 	Logs(context.Context) (io.ReadCloser, error)                    // Get logs of the container
-	Name(context.Context) (string, error)                           // get container name
-	Networks(context.Context) ([]string, error)                     // get container networks
-	NetworkAliases(context.Context) (map[string][]string, error)    // get container network aliases for a network
+	FollowOutput(LogConsumer)
+	StartLogProducer(context.Context) error
+	StopLogProducer() error
+	Name(context.Context) (string, error)                        // get container name
+	Networks(context.Context) ([]string, error)                  // get container networks
+	NetworkAliases(context.Context) (map[string][]string, error) // get container network aliases for a network
 	Exec(ctx context.Context, cmd []string) (int, error)
 }
 

docker.go

@@ -3,6 +3,7 @@ package testcontainers
 import (
 	"bytes"
 	"context"
+	"encoding/binary"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -43,6 +44,8 @@ type DockerContainer struct {
 	sessionID         uuid.UUID
 	terminationSignal chan bool
 	skipReaper        bool
+	consumers         []LogConsumer
+	stopProducer      chan bool
 }
 
 func (c *DockerContainer) GetContainerID() string {
@@ -192,6 +195,18 @@ func (c *DockerContainer) Logs(ctx context.Context) (io.ReadCloser, error) {
 	return c.provider.client.ContainerLogs(ctx, c.ID, options)
 }
 
+// FollowOutput adds a LogConsumer to be sent logs from the container's
+// STDOUT and STDERR
+func (c *DockerContainer) FollowOutput(consumer LogConsumer) {
+	if c.consumers == nil {
+		c.consumers = []LogConsumer{
+			consumer,
+		}
+	} else {
+		c.consumers = append(c.consumers, consumer)
+	}
+}
+
 // Name gets the name of the container.
 func (c *DockerContainer) Name(ctx context.Context) (string, error) {
 	inspect, err := c.inspectContainer(ctx)
@@ -272,6 +287,84 @@ func (c *DockerContainer) Exec(ctx context.Context, cmd []string) (int, error) {
 	return exitCode, nil
 }
 
+// StartLogProducer will start a concurrent process that will continuously read logs
+// from the container and will send them to each added LogConsumer
+func (c *DockerContainer) StartLogProducer(ctx context.Context) error {
+	go func() {
+		options := types.ContainerLogsOptions{
+			ShowStdout: true,
+			ShowStderr: true,
+			Follow:     true,
+		}
+
+		ctx, cancel := context.WithTimeout(ctx, time.Second*5)
+		defer cancel()
+
+		r, err := c.provider.client.ContainerLogs(ctx, c.GetContainerID(), options)
+		if err != nil {
+			// if we can't get the logs, panic, we can't return an error to anything
+			// from within this goroutine
+			panic(err)
+		}
+
+		for {
+			select {
+			case <-c.stopProducer:
+				err := r.Close()
+				if err != nil {
+					// we can't close the read closer, this should never happen
+					panic(err)
+				}
+				return
+			default:
+				h := make([]byte, 8)
+				_, err := r.Read(h)
+				if err != nil {
+					// this explicitly ignores errors
+					// because we want to keep procesing even if one of our reads fails
+					continue
+				}
+
+				count := binary.BigEndian.Uint32(h[4:])
+				if count == 0 {
+					continue
+				}
+				logType := h[0]
+				if logType > 2 {
+					panic(fmt.Sprintf("received inavlid log type: %d", logType))
+				}
+
+				// a map of the log type --> int representation in the header, notice the first is blank, this is stdin, but the go docker client doesn't allow following that in logs
+				logTypes := []string{"", StdoutLog, StderrLog}
+
+				b := make([]byte, count)
+				_, err = r.Read(b)
+				if err != nil {
+					// TODO: add-logger: use logger to log out this error
+					fmt.Fprintf(os.Stderr, "error occurred reading log with known length %s", err.Error())
+					continue
+				}
+				for _, c := range c.consumers {
+					c.Accept(Log{
+						LogType: logTypes[logType],
+						Content: b,
+					})
+				}
+			}
+
+		}
+	}()
+
+	return nil
+}
+
+// StopLogProducer will stop the concurrent process that is reading logs
+// and sending them to each added LogConsumer
+func (c *DockerContainer) StopLogProducer() error {
+	c.stopProducer <- true
+	return nil
+}
+
 // DockerNetwork represents a network started using Docker
 type DockerNetwork struct {
 	ID                string // Network ID from Docker
@@ -486,6 +579,7 @@ func (p *DockerProvider) CreateContainer(ctx context.Context, req ContainerReque
 		provider:          p,
 		terminationSignal: termSignal,
 		skipReaper:        req.SkipReaper,
+		stopProducer:      make(chan bool),
 	}
 
 	return c, nil

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/docker/docker v0.7.3-0.20190506211059-b20a14b54661
 	github.com/docker/go-connections v0.4.0
 	github.com/docker/go-units v0.3.3 // indirect
+	github.com/gin-gonic/gin v1.5.0
 	github.com/go-redis/redis v6.15.7+incompatible
 	github.com/go-sql-driver/mysql v1.5.0
 	github.com/gogo/protobuf v1.2.0 // indirect
@@ -27,11 +28,10 @@ require (
 	github.com/pkg/errors v0.9.1
 	github.com/satori/go.uuid v1.2.0
 	github.com/sirupsen/logrus v1.2.0 // indirect
-	golang.org/x/sys v0.0.0-20181228144115-9a3f9b0469bb // indirect
 	golang.org/x/time v0.0.0-20181108054448-85acf8d2951c // indirect
 	google.golang.org/grpc v1.17.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
-	gotest.tools v0.0.0-20181223230014-1083505acf35 // indirect
+	gotest.tools v0.0.0-20181223230014-1083505acf35
 )
 
 go 1.13

go.sum

@@ -10,6 +10,7 @@ github.com/cenkalti/backoff v2.2.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QH
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/containerd/continuity v0.0.0-20190426062206-aaeac12a7ffc h1:TP+534wVlf61smEIq1nwLLAjQVEK2EADoW3CX9AuT+8=
 github.com/containerd/continuity v0.0.0-20190426062206-aaeac12a7ffc/go.mod h1:GL3xCUCBDV3CZiTSEKksMWbLE66hEyuu9qyDOOqM47Y=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/docker/distribution v2.7.1-0.20190205005809-0d3efadf0154+incompatible h1:dvc1KSkIYTVjZgHf/CTC2diTYC8PzhaA5sFISRfNVrE=
@@ -22,6 +23,14 @@ github.com/docker/go-units v0.3.3 h1:Xk8S3Xj5sLGlG5g67hJmYMmUgXv5N4PhkjJHHqrwnTk
 github.com/docker/go-units v0.3.3/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
 github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
+github.com/gin-contrib/sse v0.1.0 h1:Y/yl/+YNO8GZSjAhjMsSuLt29uWRFHdHYUb5lYOV9qE=
+github.com/gin-contrib/sse v0.1.0/go.mod h1:RHrZQHXnP2xjPF+u1gW/2HnVO7nvIa9PG3Gm+fLHvGI=
+github.com/gin-gonic/gin v1.5.0 h1:fi+bqFAx/oLK54somfCtEZs9HeH1LHVoEPUgARpTqyc=
+github.com/gin-gonic/gin v1.5.0/go.mod h1:Nd6IXA8m5kNZdNEHMBd93KT+mdY3+bewLgRvmCsR2Do=
+github.com/go-playground/locales v0.12.1 h1:2FITxuFt/xuCNP1Acdhv62OzaCiviiE4kotfhkmOqEc=
+github.com/go-playground/locales v0.12.1/go.mod h1:IUMDtCfWo/w/mtMfIE/IG2K+Ey3ygWanZIBtBW0W2TM=
+github.com/go-playground/universal-translator v0.16.0 h1:X++omBR/4cE2MNg91AoC3rmGrCjJ8eAeUP/K/EKx4DM=
+github.com/go-playground/universal-translator v0.16.0/go.mod h1:1AnU7NaIRDWWzGEKwgtJRd2xk99HeFyHw3yid4rvQIY=
 github.com/go-redis/redis v6.15.6+incompatible h1:H9evprGPLI8+ci7fxQx6WNZHJSb7be8FqJQRhdQZ5Sg=
 github.com/go-redis/redis v6.15.6+incompatible/go.mod h1:NAIEuMOZ/fxfXJIrKDQDz8wamY7mA7PouImQ2Jvg6kA=
 github.com/go-redis/redis v6.15.7+incompatible h1:3skhDh95XQMpnqeqNftPkQD9jL9e5e36z/1SUm6dy1U=
@@ -36,14 +45,18 @@ github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfU
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.2 h1:6nsPYzhq5kReh6QImI3k5qWzO4PEbvbIW2cwSfR/6xs=
+github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/google/go-cmp v0.2.0 h1:+dTQ8DZQJz0Mb/HjFlkptS1FeQ4cWSnN941F8aEG4SQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
+github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/gorilla/context v1.1.1 h1:AWwleXJkX/nhcU9bZSnZoi3h/qGYqQAGhq6zZe/aQW8=
 github.com/gorilla/context v1.1.1/go.mod h1:kBGZzfjB9CEq2AlWe17Uuf7NDRt0dE0s8S51q0aT7Yg=
 github.com/gorilla/mux v1.6.2 h1:Pgr17XVTNXAk3q/r4CpKzC5xBM/qW1uVLV+IhRZpIIk=
 github.com/gorilla/mux v1.6.2/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
 github.com/hpcloud/tail v1.0.0 h1:nfCOvKYfkgYP8hkirhJocXT2+zOD8yUNjXaWfTlyFKI=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
+github.com/json-iterator/go v1.1.7/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
@@ -52,6 +65,12 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/leodido/go-urn v1.1.0 h1:Sm1gr51B1kKyfD2BlRcLSiEkffoG96g6TPv6eRoEiB8=
+github.com/leodido/go-urn v1.1.0/go.mod h1:+cyI34gQWZcE1eQU7NVgKkkzdXDQHr1dBMtdAPozLkw=
+github.com/mattn/go-isatty v0.0.9 h1:d5US/mDsogSGW37IV293h//ZFaeajb69h+EHFsv2xGg=
+github.com/mattn/go-isatty v0.0.9/go.mod h1:YNRxwqDuOph6SZLI9vUUz6OYw3QyUt7WiY2yME+cCiQ=
+github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
+github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/morikuni/aec v0.0.0-20170113033406-39771216ff4c h1:nXxl5PrvVm2L/wCy8dQu6DMTwH4oIuGN8GJDAlqDdVE=
 github.com/morikuni/aec v0.0.0-20170113033406-39771216ff4c/go.mod h1:BbKIizmSmc5MMPqRYbxO4ZU0S0+P200+tUnFx7PXmsc=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
@@ -80,9 +99,16 @@ github.com/satori/go.uuid v1.2.0/go.mod h1:dA0hQrYB0VpLJoorglMZABFdXlWrHn1NEOzdh
 github.com/sirupsen/logrus v1.2.0 h1:juTguoYk5qI21pwyTXY3B3Y5cOTH3ZUyZCg1v/mihuo=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
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+github.com/ugorji/go v1.1.7 h1:/68gy2h+1mWMrwZFeD1kQialdSzAb432dtpeJ42ovdo=
+github.com/ugorji/go v1.1.7/go.mod h1:kZn38zHttfInRq0xu/PH0az30d+z6vm202qpg1oXVMw=
+github.com/ugorji/go/codec v1.1.7 h1:2SvQaVZ1ouYrrKKwoSk2pzd4A9evlKJb9oTL+OaLUSs=
+github.com/ugorji/go/codec v1.1.7/go.mod h1:Ax+UKWsSmolVDwsd+7N3ZtXu+yMGCf907BLYF3GoBXY=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793 h1:u+LnwYTOOW7Ukr/fppxEb1Nwz0AtPflrblfvUudpo+I=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
@@ -98,6 +124,8 @@ golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181228144115-9a3f9b0469bb h1:pf3XwC90UUdNPYWZdFjhGBE7DUFuK3Ct1zWmZ65QN30=
 golang.org/x/sys v0.0.0-20181228144115-9a3f9b0469bb/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a h1:aYOabOQFp6Vj6W1F80affTUvO9UxmJRx8K0gsfABByQ=
+golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/time v0.0.0-20181108054448-85acf8d2951c h1:fqgJT0MGcGpPgpWU7VRdRjuArfcOvC4AoJmILihzhDg=
@@ -115,10 +143,15 @@ gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/fsnotify.v1 v1.4.7 h1:xOHLXZwVvI9hhs+cLKq5+I5onOuwQLhQwiu63xxlHs4=
 gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
+gopkg.in/go-playground/assert.v1 v1.2.1/go.mod h1:9RXL0bg/zibRAgZUYszZSwO/z8Y/a8bDuhia5mkpMnE=
+gopkg.in/go-playground/validator.v9 v9.29.1 h1:SvGtYmN60a5CVKTOzMSyfzWDeZRxRuGvRQyEAKbw1xc=
+gopkg.in/go-playground/validator.v9 v9.29.1/go.mod h1:+c9/zcJMFNgbLvly1L1V+PpxWdVbfP1avr/N00E2vyQ=
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 h1:uRGJdciOHaEIrze2W8Q3AKkepLTh2hOroT7a+7czfdQ=
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 honnef.co/go/tools v0.0.0-20180728063816-88497007e858/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=

logconsumer.go

@@ -0,0 +1,22 @@
+package testcontainers
+
+// StdoutLog is the log type for STDOUT
+const StdoutLog = "STDOUT"
+
+// StderrLog is the log type for STDERR
+const StderrLog = "STDERR"
+
+// Log represents a message that was created by a process,
+// LogType is either "STDOUT" or "STDERR",
+// Content is the byte contents of the message itself
+type Log struct {
+	LogType string
+	Content []byte
+}
+
+// LogConsumer represents any object that can
+// handle a Log, it is up to the LogConsumer instance
+// what to do with the log
+type LogConsumer interface {
+	Accept(Log)
+}