Simplest gRPC API with working generated client libraries & samples – # codelab

. Simplest gRPC API with working generated client libraries & samples .md

🦑 G.A.P.I.C 🖥 codelab 🎓

.
├── artman_dogs.yaml
├── dogs.proto
├── dogs_gapic.yaml
├── dogs_server.js
├── dogs_service.yaml
└── generate-and-run.sh

---

{{ potential source material for a simple gRPC/GAPIC codelab }}

artman_dogs.yaml

common:
  api_name: dogs
  api_version: v1
  organization_name: codelabs
  service_yaml: dogs_service.yaml
  gapic_yaml: dogs_gapic.yaml
  src_proto_paths:
  - dogs.proto
  proto_deps:
  - name: google-common-protos
artifacts:
- name: python_gapic
  type: GAPIC
  language: PYTHON
- name: php_gapic
  type: GAPIC
  language: PHP

dogs.proto

syntax = "proto3";

package codelabs.dogs.v1;

service DogsService {
  rpc ListDogs(Empty) returns (DogList) {}
  rpc AddDog(Dog)     returns (Empty)   {}
  rpc RemoveDog(Dog)  returns (Empty)   {}
}

message Empty {}
message Dog { string name = 1; }
message DogList { repeated Dog dogs = 1; }

dogs_gapic.yaml

type: com.google.api.codegen.ConfigProto
config_schema_version: 1.0.0
language_settings:
  python:
    package_name: codelabs.dogs_v1.gapic
  php:
    package_name: Codelabs\Dogs\V1
interfaces:
- name: codelabs.dogs.v1.DogsService
  methods:
  - name: ListDogs
    samples:
      standalone:
      - calling_forms: ".*"
        value_sets: list_dogs
        region_tag: list_dogs
    sample_value_sets:
    - id: list_dogs
      description: "List Dogs"
      on_success:
      - loop:
          variable: dog
          collection: $resp.dogs
          body:
            - print:
              - "Dog name: %s"
              - dog.name
  - name: AddDog
    samples:
      standalone:
      - calling_forms: ".*"
        value_sets: add_dog
        region_tag: add_dog
    sample_value_sets:
    - id: add_dog
      description: "Add Dog"
      parameters:
        defaults:
        - name="Your dog’s name, e.g. Rover"
        attributes:
        - parameter: name
          sample_argument_name: name
      on_success:
      - print:
        - "Dog added"
  - name: RemoveDog
    samples:
      standalone:
      - calling_forms: ".*"
        value_sets: remove_dog
        region_tag: remove_dog
    sample_value_sets:
    - id: remove_dog
      description: "Remove Dog"
      parameters:
        defaults:
        - name="Your dog’s name, e.g. Rover"
        attributes:
        - parameter: name
          sample_argument_name: name
      on_success:
      - print:
        - "Dog removed"

dogs_server.js

// To run: npm install grpc && node dogs_server.js

const grpc    = require('grpc')
const proto   = grpc.load('dogs.proto')
const service = proto.codelabs.dogs.v1.DogsService.service
const server  = new grpc.Server()
const dogs    = [{ name: "Rover" }, { name: "Spot" }]

server.addService(service, {

  listDogs: function(call, callback) {
    callback(null, dogs)
  },

  addDog: function(call, callback) {
    const dog = call.request
    dogs.push(dog)
    callback(null, {})
  },

  removeDog: function(call, callback) {
    const dog = call.request
    const dogIndex = dogs.findIndex(d => d.name == dog.name)
    if (dogIndex > -1) {
      dogs.splice(dogIndex, 1)
      callback(null, {})
    } else {
      callback({ code: grpc.status.NOT_FOUND, details: 'Not found' })
    }
  }
})

console.log('gRPC listening on localhost:2222')
server.bind('localhost:2222', grpc.ServerCredentials.createInsecure())
server.start()

dogs_service.yaml

type: google.api.Service
config_version: 3
name: localhost:2222
apis:
- name: codelabs.dogs.v1.DogsService

generate-and-run.sh

#! /bin/bash

language=python
artman_yaml=artman_dogs.yaml

echo "–> –> –> Deleting previous artman-genfiles artifacts"
rm_genfiles_output="`rm -rfv ./artman-genfiles`"
echo "–> –> –> Deleted `echo -e "$rm_genfiles_output" | wc -l` files/dirs"

root="`pwd`"

# Required dependencies (or it blows up)
googleapis_dir="$(samplegen --info | grep "googleapis =" | awk '{print $3}')"
mkdir -pv ./google/{api,rpc,type,longrunning,iam/v1}
for filepath in google/api/{http,annotations}.proto; do
  cp -v "$googleapis_dir/$filepath" "./$filepath"
done

echo "–> –> –> Generating Python Library"
gapicgenerator_dir="$(samplegen --info | grep "gapic_generator =" | awk '{print $3}')"
output=`docker run --rm -e RUNNING_IN_ARTMAN_DOCKER=True -v "$(pwd):/googleapis"    \
-v "$gapicgenerator_dir:/toolkit" -w /googleapis googleapis/artman /bin/bash -c     \
"artman --local --config $artman_yaml generate ${language}_gapic" 2>&1`
docker_exit_code=$?
echo -e $output

if [ $docker_exit_code -ne 0 ]; then
  if [[ "$output" =~ "Path gapic not found in" ]]; then
    echo "–> –> –> Generation may have failed ($docker_exit_code)"
    echo "–> –> –> 'dogs' related directories created:"
    find $root/artman-genfiles -type d -name "*dog*"
  else
    echo "–> –> –> Generating $language failed ($docker_exit_code)"
    exit $docker_exit_code
  fi
fi

python_library_root="artman-genfiles/python/dogs-v1"
python_samples_path="samples/codelabs/dogs_v1/gapic/list_dogs"

cd "$root/$python_library_root"

echo "–> –> –> FIX standardize import namespaces"
grep -rl "from codelabs.dogs\.v1" codelabs | xargs -n1 sed -i.bak -e "s/from codelabs.dogs.v1/from codelabs.dogs_v1/"
find codelabs/ -name "*.py.bak" -exec rm {} \;

echo "–> –> –> Copy pb2 proto files into package"
mv ../grpc-codelabs-dogs-v1/codelabs/dogs_v1/proto codelabs/dogs_v1/
touch codelabs/dogs_v1/proto/__init__.py

echo "–> –> –> FIX pb2 proto imports"
grep -rl "from codelabs.dogs_v1 import dogs_pb2" . | xargs -n1 sed -i.bak -e "s/dogs_v1 import dogs_pb2/dogs_v1.proto import dogs_pb2/"
find codelabs/ -name "*.py.bak" -exec rm {} \;

echo "–> –> –> FIX samples to use localhost server (without auth)"
for sample in `find samples/codelabs/dogs_v1/gapic -name "*.py"`; do
  sed -i.bak -e $'s/import sys/import sys\\\nfrom grpc import insecure_channel/' "$sample"
  find samples/ -name "*.py.bak" -exec rm {} \;
  sed -i.bak -e 's/\.DogsServiceClient()/.DogsServiceClient(channel=insecure_channel("localhost:2222"))/' "$sample"
  find samples/ -name "*.py.bak" -exec rm {} \;
done

echo "–> –> –> FIX setup.py"
for replacement in "s/^.*namespace.*$//"                             \
                   "s/if 'google.cloud'.*$//"                        \
                   "s/startswith('google')/startswith('codelabs')/"
do
  sed -i.bak -e "$replacement" setup.py
done

echo "–> –> –> Install Generated Library"
virtualenv --python python3 env
source env/bin/activate
pip install .

echo "–> –> –> Running Python Samples"
echo "–> –> –> Sample: List Dogs"
python samples/codelabs/dogs_v1/gapic/list_dogs/list_dogs_request_list_dogs.py
echo "–> –> –> Sample: Add Dog"
python samples/codelabs/dogs_v1/gapic/add_dog/add_dog_request_add_dog.py --name "Rex"
echo "–> –> –> Sample: List Dogs"
python samples/codelabs/dogs_v1/gapic/list_dogs/list_dogs_request_list_dogs.py
echo "–> –> –> Sample: Remove Dogs"
python samples/codelabs/dogs_v1/gapic/remove_dog/remove_dog_request_remove_dog.py --name "Rex"
echo "–> –> –> Sample: List Dogs"
python samples/codelabs/dogs_v1/gapic/list_dogs/list_dogs_request_list_dogs.py