Using the exec command with the docker API, and capturing output

simple-exec-with-docker-remote-api.sh

#! /usr/bin/env bash

# Create the container with a long running process.  If PID1 exists before
# we send the exec commands, they will fail because the container is not running
#
CONTAINER_NAME="TEST-`uuidgen`"
curl --silent --unix-socket /var/run/docker.sock "http:/containers/create?name=${CONTAINER_NAME}" -XPOST \
  -H "Content-Type: application/json" \
  -d '{
    "Image": "ruby:latest",
    "Cmd": [ "sleep", "10" ]
  }' | jq '.'

# Start the container
#
curl --silent --unix-socket /var/run/docker.sock "http:/containers/${CONTAINER_NAME}/start" -XPOST \
  -H "Content-Type: application/json" \
  --output /dev/null \
  --write-out "%{http_code}"
echo ""

# Create the exec
#
EXEC_CREATE=`curl --silent --unix-socket /var/run/docker.sock "http:/containers/${CONTAINER_NAME}/exec" -XPOST \
  -H "Content-Type: application/json" \
  -d '{
    "AttachStdout": true,
    "Tty": true,
    "Cmd": [ "ruby", "-e", "5.times { puts :hi; sleep 1 }"]
  }'
`
echo $EXEC_CREATE | jq '.'

# Run the exec
#
EXEC_ID=$(echo $EXEC_CREATE | jq -r '.Id')
curl --silent --unix-socket /var/run/docker.sock "http:/exec/${EXEC_ID}/start" -XPOST \
  -H "Content-Type: application/json" \
  -d '{
    "Detach": false,
    "Tty": true
  }'

# Or use the logging API to attach to the container, and delete the JSON
# from `start`
#
# curl --silent --unix-socket /var/run/docker.sock "http:/containers/${CONTAINER_NAME}/attach?stream=1&stdout=1&stderr=1" -XPOST