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This example guides you through the process of taking an example model, modifying it to run better within Kubeflow, and serving the resulting trained model.
Before we get started there a few requirements.
Follow the Getting Started Guide to deploy Kubeflow
You also need the following command line tools:
To run the client at the end of the example, you must have requirements.txt intalled in your active python environment.
pip install -r requirements.txt
NOTE: These instructions rely on Github, and may cause issues if behind a firewall with many Github users.
Many examples online use models that are unconfigurable, or don't work well in distributed mode. We will modify one of these examples to be better suited for distributed training and model serving.
There is a delta between existing distributed mnist examples and what's needed to run well as a TFJob.
Basically, we must:
- Add options in order to make the model configurable.
- Use
tf.estimator.train_and_evaluate
to enable model exporting and serving. - Define serving signatures for model serving.
The resulting model is model.py.
With our code ready, we will now build/push the docker image.
DOCKER_URL=docker.io/reponame/mytfmodel # Put your docker registry here
docker build . --no-cache -f Dockerfile.model -t ${DOCKER_URL}
docker push ${DOCKER_URL}
With our data and workloads ready, now the cluster must be prepared. We will be deploying the TF Operator, and Argo to help manage our training job.
In the following instructions we will install our required components to a single namespace. For these instructions we will assume the chosen namespace is tfworkflow
:
Let's start by runing the training job on Kubeflow and storing the model in a directory local to the pod e.g. '/tmp'.
This is useful as a smoke test to ensure everything works. Since /tmp
is not a filesystem external to the container, all data
is lost once the job finishes. So to make the model available after the job finishes we will need to use an external filesystem
like GCS or S3 as discussed in the next section.
KSENV=local
cd ks_app
ks env add ${KSENV}
Give the job a name to indicate it is running locally
ks param set --env=${KSENV} train name mnist-train-local
Point the job at your custom training image
ks param set --env=${KSENV} train image $DOCKER_URL
Configure a filepath for the exported model and checkpoints.
ks param set --env=${KSENV} train modelDir ./output
ks param set --env=${KSENV} train exportDir ./output/export
You can now submit the job
ks apply ${KSENV} -c train
And you can check the job
kubectl get tfjobs -o yaml mnist-train-local
And to check the logs
kubectl logs mnist-train-local-chief-0
Storing the model in a directory inside the container isn't useful because the directory is lost as soon as the pod is deleted.
So in the next sections we cover saving the model on a suitable filesystem like GCS or S3.
In this section we describe how to save the model to Google Cloud Storage (GCS).
Storing the model in GCS has the advantages
-
The model is readily available after the job finishes
-
We can run distributed training
- Distributed training requires a storage system accessible to all the machines
Lets start by creating an environment to store parameters particular to writing the model to GCS and running distributed.
KSENV=distributed
cd ks_app
ks env add ${KSENV}
Set an environment variable that points to your GCP project Id
PROJECT=<your project id>
Create a bucket on GCS to store our model. The name must be unique across all GCS buckets
BUCKET=$KSENV-$(date +%s)
gsutil mb gs://$BUCKET/
Give the job a different name (to distinguish it from your job which didn't use GCS)
ks param set --env=${KSENV} train name mnist-train-dist
Next we configure it to run distributed by setting the number of parameter servers and workers to use.
ks param set --env=${KSENV} train numPs 1
ks param set --env=${KSENV} train numWorkers 2
Now we need to configure parameters telling the code to save the model to GCS.
MODEL_PATH=my-model
ks param set --env=${KSENV} train modelDir gs://${BUCKET}/${MODEL_PATH}
ks param set --env=${KSENV} train exportDir gs://${BUCKET}/${MODEL_PATH}/export
In order to write to GCS we need to supply the TFJob with GCP credentials. We do this by telling our training code to use a Google service account.
If you followed the getting started guide for GKE then a number of steps have already been performed for you
-
We created a Google service account named
${DEPLOYMENT}-user
-
You can run the following command to list all service accounts in your project
gcloud --project=${PROJECT} iam service-accounts list
-
-
We stored the private key for this account in a K8s secret named
user-gcp-sa
-
To see the secrets in your cluster
kubectl get secrets -n kubeflow
-
-
We granted this service account permission to read/write GCS buckets in this project
-
To see the IAM policy you can do
gcloud projects get-iam-policy ${PROJECT} --format=yaml
-
The output should look like the following
bindings: ... - members: - serviceAccount:${DEPLOYMENT}-user@${PROJEC}.iam.gserviceaccount.com ... role: roles/storage.admin ... etag: BwV_BqSmSCY= version: 1
-
To use this service account we perform the following steps
-
Mount the secret into the pod
ks param set --env=${KSENV} train secret user-gcp-sa=/var/secrets
-
Note: ensure your envrionment is pointed at the same
kubeflow
namespace as theuser-gcp-sa
secret -
Setting this ksonnet parameter causes a volumeMount and volume to be added to your TFJob
-
To see this you can run
ks show ${KSENV} -c train
-
The output should now include a volumeMount and volume section
apiVersion: kubeflow.org/v1beta1 kind: TFJob metadata: ... spec: tfReplicaSpecs: Chief: ... template: ... spec: containers: - command: ... volumeMounts: - mountPath: /var/secrets name: user-gcp-sa readOnly: true ... volumes: - name: user-gcp-sa secret: secretName: user-gcp-sa ...
-
-
Next we need to set the environment variable
GOOGLE_APPLICATION_CREDENTIALS
so that our code knows where to look for the service account key.ks param set --env=${KSENV} train envVariables GOOGLE_APPLICATION_CREDENTIALS=/var/secrets/user-gcp-sa.json
-
If we look at the spec for our job we can see that the environment variable
GOOGLE_APPLICATION_CREDENTIALS
is set.ks show ${KSENV} -c train
apiVersion: kubeflow.org/v1beta1 kind: TFJob metadata: ... spec: tfReplicaSpecs: Chief: replicas: 1 template: spec: containers: - command: .. env: ... - name: GOOGLE_APPLICATION_CREDENTIALS value: /var/secrets/user-gcp-sa.json ... ... ...
-
You can now submit the job
ks apply ${KSENV} -c train
And you can check the job status
kubectl get tfjobs -o yaml mnist-train-dist
And to check the logs
kubectl logs -f mnist-train-dist-chief-0
To use S3 we need we need to configure TensorFlow to use S3 credentials and variables. These credentials will be provided as kubernetes secrets and the variables will be passed in as environment variables. Modify the below values to suit your environment.
Lets start by creating an environment to store parameters particular to writing the model to S3 and running distributed.
KSENV=distributed
cd ks_app
ks env add ${KSENV}
Give the job a different name (to distinguish it from your job which didn't use S3)
ks param set --env=${KSENV} train name mnist-train-dist
Next we configure it to run distributed by setting the number of parameter servers and workers to use.
ks param set --env=${KSENV} train numPs 1
ks param set --env=${KSENV} train numWorkers 2
Now we need to configure parameters telling the code to save the model to S3.
ks param set --env=${KSENV} train modelDir ${S3_MODEL_PATH_URI}
ks param set --env=${KSENV} train exportDir ${S3_MODEL_EXPORT_URI}
In order to write to S3 we need to supply the TensorFlow code with AWS credentials we also need to set various environment variables configuring access to S3.
-
Define a bunch of environment variables corresponding to your S3 settings; these will be used in subsequent steps
export S3_ENDPOINT=s3.us-west-2.amazonaws.com #replace with your s3 endpoint in a host:port format, e.g. minio:9000 export AWS_ENDPOINT_URL=https://${S3_ENDPOINT} #use http instead of https for default minio installs export AWS_ACCESS_KEY_ID=xxxxx export AWS_SECRET_ACCESS_KEY=xxxxx export AWS_REGION=us-west-2 export BUCKET_NAME=mybucket export S3_USE_HTTPS=1 #set to 0 for default minio installs export S3_VERIFY_SSL=1 #set to 0 for defaul minio installs
-
Create a K8s secret containing your AWS credentials
kubectl create secret generic aws-creds --from-literal=awsAccessKeyID=${AWS_ACCESS_KEY_ID} \ --from-literal=awsSecretAccessKey=${AWS_SECRET_ACCESS_KEY}
-
Pass secrets as environment variables into pod
ks param set --env=${KSENV} train secretKeyRefs AWS_ACCESS_KEY_ID=aws-creds.awsAccessKeyID,AWS_SECRET_ACCESS_KEY=aws-creds.awsSecretAccessKey
-
Setting this ksonnet parameter causes a two new environment variables to be added to your TFJob
-
To see this you can run
ks show ${KSENV} -c train
-
The output should now include two environment variables referencing K8s secret
apiVersion: kubeflow.org/v1beta1 kind: TFJob metadata: ... spec: tfReplicaSpecs: Chief: ... template: ... spec: containers: - command: ... env: - name: AWS_ACCESS_KEY_ID valueFrom: secretKeyRef: key: awsAccessKeyID name: aws-creds - name: AWS_SECRET_ACCESS_KEY valueFrom: secretKeyRef: key: awsSecretAccessKey name: aws-creds ...
-
-
Next we need to set a whole bunch of S3 related environment variables so that TensorFlow knows how to talk to S3
AWSENV="S3_ENDPOINT=${S3_ENDPOINT}" AWSENV="${AWSENV},AWS_ENDPOINT_URL=${AWS_ENDPOINT_URL}" AWSENV="${AWSENV},AWS_REGION=${AWS_REGION}" AWSENV="${AWSENV},BUCKET_NAME=${BUCKET_NAME}" AWSENV="${AWSENV},S3_USE_HTTPS=${S3_USE_HTTPS}" AWSENV="${AWSENV},S3_VERIFY_SSL=${S3_VERIFY_SSL}" ks param set --env=${KSENV} train envVariables ${AWSENV}
-
If we look at the spec for our job we can see that the environment variables related to S3 are set.
ks show ${KSENV} -c train apiVersion: kubeflow.org/v1beta1 kind: TFJob metadata: ... spec: tfReplicaSpecs: Chief: replicas: 1 template: spec: containers: - command: .. env: ... - name: AWS_REGION value: us-west-2 - name: BUCKET_NAME value: somebucket ... ... ...
-
You can now submit the job
ks apply ${KSENV} -c train
And you can check the job
kubectl get tfjobs -o yaml mnist-train-dist
And to check the logs
kubectl logs -f mnist-train-dist-chief-0
There are various ways to monitor workflow/training job. In addition to using kubectl
to query for the status of pods
, some basic dashboards are also available.
Configure TensorBoard to point to your model location
ks param set tensorboard --env=${KSENV} logDir ${LOGDIR}
Assuming you followed the directions above if you used GCS you can use the following value
LOGDIR=gs://${BUCKET}/${MODEL_PATH}
You need to point TensorBoard to GCP credentials to access GCS bucket with model.
-
Mount the secret into the pod
ks param set --env=${KSENV} tensorboatd secret user-gcp-sa=/var/secrets
-
Setting this ksonnet parameter causes a volumeMount and volume to be added to TensorBoard deployment
-
To see this you can run
ks show ${KSENV} -c tensorboard
-
The output should now include a volumeMount and volume section
-
-
Next we need to set the environment variable
GOOGLE_APPLICATION_CREDENTIALS
so that our code knows where to look for the service account key.ks param set --env=${KSENV} tensorboard envVariables GOOGLE_APPLICATION_CREDENTIALS=/var/secrets/user-gcp-sa.json
-
If we look at the spec for TensorBoard deployment we can see that the environment variable
GOOGLE_APPLICATION_CREDENTIALS
is set.ks show ${KSENV} -c tensorboard
... env: ... - name: GOOGLE_APPLICATION_CREDENTIALS value: /var/secrets/user-gcp-sa.json
-
Configure TensorBoard to point to your model location
ks param set tensorboard --env=${KSENV} logDir ${LOGDIR}
Assuming you followed the directions above if you used S3 you can use the following value
LOGDIR=s3://${BUCKET}/${MODEL_PATH}
You need to point TensorBoard to AWS credentials to access S3 bucket with model.
-
Pass secrets as environment variables into pod
ks param set --env=${KSENV} tensorboard secretKeyRefs AWS_ACCESS_KEY_ID=aws-creds.awsAccessKeyID,AWS_SECRET_ACCESS_KEY=aws-creds.awsSecretAccessKey
-
Setting this ksonnet parameter causes a two new environment variables to be added to TensorBoard deployment
-
To see this you can run
ks show ${KSENV} -c tensorboard
-
The output should now include two environment variables referencing K8s secret
... spec: containers: - command: ... env: ... - name: AWS_ACCESS_KEY_ID valueFrom: secretKeyRef: key: awsAccessKeyID name: aws-creds - name: AWS_SECRET_ACCESS_KEY valueFrom: secretKeyRef: key: awsSecretAccessKey name: aws-creds ...
-
-
Next we need to set a whole bunch of S3 related environment variables so that TensorBoard knows how to talk to S3
AWSENV="S3_ENDPOINT=${S3_ENDPOINT}" AWSENV="${AWSENV},AWS_ENDPOINT_URL=${AWS_ENDPOINT_URL}" AWSENV="${AWSENV},AWS_REGION=${AWS_REGION}" AWSENV="${AWSENV},BUCKET_NAME=${BUCKET_NAME}" AWSENV="${AWSENV},S3_USE_HTTPS=${S3_USE_HTTPS}" AWSENV="${AWSENV},S3_VERIFY_SSL=${S3_VERIFY_SSL}" ks param set --env=${KSENV} tensorboard envVariables ${AWSENV}
-
If we look at the spec for TensorBoard deployment we can see that the environment variables related to S3 are set.
ks show ${KSENV} -c tensorboard
... spec: containers: - command: .. env: ... - name: AWS_REGION value: us-west-2 - name: BUCKET_NAME value: somebucket ...
-
Now you can deploy TensorBoard
ks apply ${KSENV} -c tensorboard
To access TensorBoard using port-forwarding
kubectl -n jlewi port-forward service/tensorboard-tb 8090:80
TensorBoard can now be accessed at http://127.0.0.1:8090.
The model code will export the model in saved model format which is suitable for serving with TensorFlow serving.
To serve the model follow the instructions below. The instructins vary slightly based on where you are storing your model (e.g. GCS, S3, PVC). Depending on the storage system we provide different ksonnet components as a convenience for setting relevant environment variables.
Here we show to serve the model when it is stored on GCS. This assumes that when you trained the model you set exportDir
to a GCS
URI; if not you can always copy it to GCS using gsutil
.
Check that a model was exported
EXPORT_DIR=gs://${BUCKET}/${MODEL_PATH}/export
gsutil ls -r ${EXPORT_DIR}
The output should look something like
${EXPORT_DIR}/1547100373/saved_model.pb
${EXPORT_DIR}/1547100373/variables/:
${EXPORT_DIR}/1547100373/variables/
${EXPORT_DIR}/1547100373/variables/variables.data-00000-of-00001
${EXPORT_DIR}/1547100373/variables/variables.index
The number 1547100373
is a version number auto-generated by TensorFlow; it will vary on each run but should be monotonically increasing if you save a model to the same location as a previous location.
Set your model path
ks param set --env=${KSENV} mnist-deploy-gcp modelBasePath ${EXPORT_DIR}
Deploy it
ks apply ${KSENV} -c mnist-deploy-gcp
You can check the deployment by running
kubectl describe deployments mnist-deploy-gcp
Finally, run a service to make the deployment accessible to other pods in the cluster
ks apply ${KSENV} -c mnist-service
The service should make the mnist-deploy-gcp
deployment accessible over port 9000
kubectl describe service mnist-service
TODO: Add instructions
TODO: Add instructions
The example comes with a simple web front end that can be used with your model.
To deploy the web front end
ks apply ${KSENV} -c web-ui
To connect to the web app via port-forwarding
POD_NAME=$(kubectl get pods --selector=app=web-ui --template '{{range .items}}{{.metadata.name}}{{"\n"}}{{end}}')
kubectl port-forward ${POD_NAME} 8080:5000
You should now be able to open up the web app at http://localhost:8080.
If you are using GCP and have set up IAP then you can access the web UI at
https://${DEPLOYMENT}.endpoints.${PROJECT}.cloud.goog/${NAMESPACE}/mnist/
This is an example of what your machine learning can look like. Feel free to play with the tunables and see if you can increase your model's accuracy (increasing model-train-steps
can go a long way).