Compile samples instead of hard code them in API server

backend/Dockerfile

@@ -14,6 +14,15 @@ COPY . .
 RUN apk add --update gcc musl-dev
 RUN go build -o /bin/apiserver backend/src/apiserver/*.go
 
+FROM python:3.5.0-slim as compiler
+
+# This is hard coded to 0.0.26. Once kfp DSK release process is automated,
+# we can dynamically refer to the version from same commit SHA.
+RUN pip install https://storage.googleapis.com/ml-pipeline/release/0.0.26/kfp-0.0.26.tar.gz --upgrade
+WORKDIR /samples
+COPY ./samples .
+RUN  find . -maxdepth 2 -name "*.py" -exec dsl-compile --py {} --output {}.tar.gz \;
+
 FROM alpine
 
 ARG COMMIT_SHA=unknown
@@ -24,7 +33,8 @@ WORKDIR /bin
 COPY --from=builder /bin/apiserver /bin/apiserver
 COPY --from=builder /go/src/github.com/kubeflow/pipelines/third_party/license.txt /bin/license.txt
 COPY backend/src/apiserver/config/ /config
-COPY backend/src/apiserver/samples/ /samples
+
+COPY --from=compiler /samples/ /samples/
 
 # Adding CA certificate so API server can download pipeline through URL
 RUN apk add ca-certificates
@@ -33,4 +43,4 @@ RUN apk add ca-certificates
 EXPOSE 8888
 
 # Start the apiserver
-CMD apiserver --config=/config --sampleconfig=/samples/sample_config.json
+CMD apiserver --config=/config --sampleconfig=/config/sample_config.json

backend/src/apiserver/config/sample_config.json

@@ -0,0 +1,37 @@
+[
+  {
+    "name":"[Sample] ML - XGBoost - Training with Confusion Matrix",
+    "description":"A trainer that does end-to-end distributed training for XGBoost models. For source code, refer to https://github.com/kubeflow/pipelines/tree/master/samples/xgboost-spark",
+    "file":"/samples/xgboost-spark/xgboost-training-cm.py.tar.gz"
+  },
+  {
+    "name":"[Sample] ML - TFX - Taxi Tip Prediction Model Trainer",
+    "description":"Example pipeline that does classification with model analysis based on a public tax cab BigQuery dataset. For source code, refer to https://github.com/kubeflow/pipelines/tree/master/samples/tfx",
+    "file":"/samples/tfx/taxi-cab-classification-pipeline.py.tar.gz"
+  },
+  {
+    "name":"[Sample] Basic - Sequential",
+    "description":"A pipeline with two sequential steps. For source code, refer to https://github.com/kubeflow/pipelines/blob/master/samples/basic/sequential.py",
+    "file":"/samples/basic/sequential.py.tar.gz"
+  },
+  {
+    "name":"[Sample] Basic - Parallel Join",
+    "description":"A pipeline that downloads two messages in parallel and print the concatenated result. For source code, refer to https://github.com/kubeflow/pipelines/blob/master/samples/basic/parallel_join.py",
+    "file":"/samples/basic/parallel_join.py.tar.gz"
+  },
+  {
+    "name":"[Sample] Basic - Immediate Value",
+    "description":"A pipeline with parameter values hard coded. For source code, refer to https://github.com/kubeflow/pipelines/blob/master/samples/basic/immediate_value.py",
+    "file":"/samples/basic/immediate_value.py.tar.gz"
+  },
+  {
+    "name":"[Sample] Basic - Exit Handler",
+    "description":"A pipeline that downloads a message and print it out. Exit Handler will run at the end. For source code, refer to https://github.com/kubeflow/pipelines/blob/master/samples/basic/exit_handler.py",
+    "file":"/samples/basic/exit_handler.py.tar.gz"
+  },
+  {
+    "name":"[Sample] Basic - Condition",
+    "description":"A pipeline shows how to use dsl.Condition. For source code, refer to https://github.com/kubeflow/pipelines/blob/master/samples/basic/condition.py",
+    "file":"/samples/basic/condition.py.tar.gz"
+  }
+]

backend/src/apiserver/main.go

@@ -22,6 +22,7 @@ import (
 	"io/ioutil"
 	"net"
 	"net/http"
+	"time"
 
 	"github.com/golang/glog"
 	api "github.com/kubeflow/pipelines/backend/api/go_client"
@@ -30,6 +31,9 @@ import (
 	"github.com/grpc-ecosystem/grpc-gateway/runtime"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/reflection"
+	"os"
+	"github.com/pkg/errors"
+	"fmt"
 )
 
 var (
@@ -48,7 +52,10 @@ func main() {
 	initConfig()
 	clientManager := newClientManager()
 	resourceManager := resource.NewResourceManager(&clientManager)
-	loadSamples(resourceManager)
+	err:= loadSamples(resourceManager)
+	if err!=nil{
+		glog.Fatalf("Failed to load samples. Err: %v", err.Error())
+	}
 	go startRpcServer(resourceManager)
 	startHttpProxy(resourceManager)
 
@@ -119,29 +126,41 @@ func registerHttpHandlerFromEndpoint(handler RegisterHttpHandlerFromEndpoint, se
 }
 
 // Preload a bunch of pipeline samples
-func loadSamples(resourceManager *resource.ResourceManager) {
+func loadSamples(resourceManager *resource.ResourceManager) error {
 	configBytes, err := ioutil.ReadFile(*sampleConfigPath)
 	if err != nil {
-		glog.Warningf("Failed to read sample configurations. Err: %v", err.Error())
-		return
+		return errors.New(fmt.Sprintf("Failed to read sample configurations file. Err: %v", err.Error()))
 	}
 	type config struct {
 		Name        string
 		Description string
 		File        string
 	}
 	var configs []config
-	if json.Unmarshal(configBytes, &configs) != nil {
-		glog.Warningf("Failed to read sample configurations. Err: %v", err.Error())
-		return
+	if err:= json.Unmarshal(configBytes, &configs);err != nil {
+		return errors.New(fmt.Sprintf("Failed to read sample configurations. Err: %v", err.Error()))
 	}
 	for _, config := range configs {
-		sampleBytes, err := ioutil.ReadFile(config.File)
+		reader, err:= os.Open(config.File)
 		if err != nil {
-			glog.Warningf("Failed to load sample %s. Error: %v", config.Name, err.Error())
+			return errors.New(fmt.Sprintf("Failed to load sample %s. Error: %v", config.Name, err.Error()))
+		}
+		pipelineFile, err := server.ReadPipelineFile(config.File, reader, server.MaxFileLength)
+		if err!=nil{
+			return errors.New(fmt.Sprintf("Failed to decompress the file %s. Error: %v", config.Name, err.Error()))
+		}
+		_, err = resourceManager.CreatePipeline(config.Name, config.Description, pipelineFile)
+		if err!=nil{
+			// Log the error but not fail. The API Server pod can restart and it could potentially cause name collision.
+			// In the future, we might consider loading samples during deployment, instead of when API server starts.
+			glog.Warningf(fmt.Sprintf("Failed to create pipeline for %s. Error: %v", config.Name, err.Error()))
 			continue
 		}
-		resourceManager.CreatePipeline(config.Name, config.Description, sampleBytes)
+
+		// Since the default sorting is by create time,
+		// Sleep one second makes sure the samples are showing up in the same order as they are added.
+		time.Sleep(1*time.Second)
 	}
 	glog.Info("All samples are loaded.")
+	return nil
 }