notes.yml

# Step 1
# CircleCI uses a YAML file to identify how you want your testing environment setup and what tests you want to run. On CircleCI 2.0, this file must be called config.yml and must be in a hidden folder called .circleci (on Mac, Linux, and Windows systems, files and folders whose names start with a period are treated as system files that are hidden from users by default).

version: 2
jobs:
  build:
    docker:
      - image: circleci/node:4.8.2
    steps:
      - checkout
      - run: echo "A first hello"


# Step 2
# Using Workflows

version: 2
jobs:
  build:
    docker:
      - image: circleci/node:4.8.2
    steps:
      - checkout
      - run: echo "A first hello"
  build:
    docker:
      - image: circleci/node:4.8.2
    steps:
      - checkout
      - run: echo "A first hello"

# Step 2a

version: 2
jobs:
  one:
    docker:
      - image: circleci/node:4.8.2
    steps:
      - checkout
      - run: echo "A first hello"
      - run: sleep 25
  two:
    docker:
      - image: circleci/node:4.8.2
    steps:
      - checkout
      - run: echo "A more familiar hi"
      - run: sleep 15
workflows:
  version: 2
  one_and_two:
    jobs:
      - one
      - two      


# Step 3
# Adding some changes to use Workspaces
# Each Workflow has an associated Workspace which can be used to transfer files to downstream jobs as the workflow progresses. You can use workspaces to pass along data that is unique to this run and which is needed for downstream jobs.

version: 2
jobs:
  one:
    docker:
      - image: circleci/node:4.8.2
    steps:
      - checkout
      - run: echo "A first hello"
      - run: mkdir -p my_workspace
      - run: echo "Trying out workspaces" > my_workspace/echo-output
      - persist_to_workspace:
          # Must be an absolute path, or relative path from working_directory
          root: my_workspace
          # Must be relative path from root
          paths:
            - echo-output      
  two:
    docker:
      - image: circleci/node:4.8.2
    steps:
      - checkout
      - run: echo "A more familiar hi"  
      - attach_workspace:
          # Must be absolute path or relative path from working_directory
          at: my_workspace

      - run: |
          if [[ $(cat my_workspace/echo-output) == "Trying out workspaces" ]]; then
            echo "It worked!";
          else
            echo "Nope!"; exit 1
          fi
workflows:
  version: 2
  one_and_two:
    jobs:
      - one
      - two:
          requires:
            - one

# Step 4
# Caching
# npm init; npm i react
version: 2
jobs:
  one:
    docker:
      - image: circleci/node:4.8.2
    steps:
      - checkout
      - restore_cache:
          key: npm-cache-{{ .Branch }}-{{ checksum "package.json" }}
      - run: npm i
      - save_cache:
          key: npm-cache-{{ .Branch }}-{{ checksum "package.json" }}
          paths:
            - node_modules

# Step 5
# Multiple containers - Database

version: 2
jobs:
  one:
    docker:
      - image: circleci/node:4.8.2
        environment:
          TEST_DATABASE_URL: postgresql://root@localhost/circle_test
      - image: circleci/postgres:9.6.5-alpine-ram
    steps:
      - checkout
      - run: sudo apt install postgresql-client-9.6
      - run: whoami
      - run: |
          psql \
          -d $TEST_DATABASE_URL \
          -c "CREATE TABLE test (name char(25));"
      - run: |
          psql \
          -d $TEST_DATABASE_URL \
          -c "INSERT INTO test (name char(25));"
      - run: |
          psql \
          -d $TEST_DATABASE_URL \
          -c "SELECT * from test"