Cannot connect to scala collector running inside Docker


I am running Scala collector inside docker in AWS instance. The collector inside the docker is running on port 2000 and I am trying to access it on port 80 outside the container. The docker is running fine but when I try to access it from outside using :

curl http://localhost:80/health

Then I am getting this instead of OK :
curl: (52) Empty reply from server

Docker commands I am using to run the container is as follows:

$ docker run -v ${PWD}/config:/snowplow/config  -p 80:2000  -e 'SP_JAVA_OPTS=-Xms512m -Xmx512m'  --config /snowplow/config/config.hocon

Scala config I am using is as follows:

                   # Copyright (c) 2013-2020 Snowplow Analytics Ltd. All rights reserved.
# This program is licensed to you under the Apache License Version 2.0, and
# you may not use this file except in compliance with the Apache License
# Version 2.0.  You may obtain a copy of the Apache License Version 2.0 at
# Unless required by applicable law or agreed to in writing, software
# distributed under the Apache License Version 2.0 is distributed on an "AS
# implied.  See the Apache License Version 2.0 for the specific language
# governing permissions and limitations there under.

# This file (config.hocon.sample) contains a template with
# configuration options for the Scala Stream Collector.
# To use, copy this to 'application.conf' and modify the configuration options.

# 'collector' contains configuration options for the main Scala collector.
collector {
  # The collector runs as a web service specified on the following interface and port.
  interface = ""
  port = 2000

  # optional SSL/TLS configuration
  ssl {
enable = false
# whether to redirect HTTP to HTTPS
redirect = false
port = 9543

  # The collector responds with a cookie to requests with a path that matches the 'vendor/version' protocol.
  # The expected values are:
  # - com.snowplowanalytics.snowplow/tp2 for Tracker Protocol 2
  # - r/tp2 for redirects
  # - com.snowplowanalytics.iglu/v1 for the Iglu Webhook
  # Any path that matches the 'vendor/version' protocol will result in a cookie response, for use by custom webhooks
  # downstream of the collector.
  # But you can also map any valid (i.e. two-segment) path to one of the three defaults.
  # Your custom path must be the key and the value must be one of the corresponding default paths. Both must be full
  # valid paths starting with a leading slash.
  # Pass in an empty map to avoid mapping.
  paths {
 "/com.acme/track" = "/com.snowplowanalytics.snowplow/tp2"
 "/com.acme/redirect" = "/r/tp2"
 "/com.acme/iglu" = "/com.snowplowanalytics.iglu/v1"

  # Configure the P3P policy header.
  p3p {
policyRef = "/w3c/p3p.xml"

  # Cross domain policy configuration.
  # If "enabled" is set to "false", the collector will respond with a 404 to the /crossdomain.xml
  # route.
  crossDomain {
enabled = false
# Domains that are granted access, * will match and
domains = [ "*" ]
# Whether to only grant access to HTTPS or both HTTPS and HTTP sources
secure = true

  # The collector returns a cookie to clients for user identification
  # with the following domain and expiration.
  cookie {
enabled = true
expiration ="365 days"
# Network cookie name
name = "collector_Cookie_Name"

# The domain is optional and will make the cookie accessible to other
# applications on the domain. Comment out these lines to tie cookies to
# the collector's full domain.
# The domain is determined by matching the domains from the Origin header of the request
# to the list below. The first match is used. If no matches are found, the fallback domain will be used,
# if configured.
# If you specify a main domain, all subdomains on it will be matched.
# If you specify a subdomain, only that subdomain will be matched.
# Examples:
# will match, and
# will match but not or
#domains = [
#"" # e.g. "" -> any origin domain ending with this will be matched and will be returned
#   domains += ${?COLLECTOR_COOKIE_DOMAIN_1}
#   domains += ${?COLLECTOR_COOKIE_DOMAIN_2}
# ... more domains
# If specified, the fallback domain will be used if none of the Origin header hosts matches the list of
# cookie domains configured above. (For example, if there is no Origin header.)
fallbackDomain = ""
secure = false
httpOnly = false
# The sameSite is optional. You can choose to not specify the attribute, or you can use `Strict`,
# `Lax` or `None` to limit the cookie sent context.
#   Strict: the cookie will only be sent along with "same-site" requests.
#   Lax: the cookie will be sent with same-site requests, and with cross-site top-level navigation.
#   None: the cookie will be sent with same-site and cross-site requests.
sameSite = "None"

  # If you have a do not track cookie in place, the Scala Stream Collector can respect it by
  # completely bypassing the processing of an incoming request carrying this cookie, the collector
  # will simply reply by a 200 saying "do not track".
  # The cookie name and value must match the configuration below, where the names of the cookies must
  # match entirely and the value could be a regular expression.
  doNotTrackCookie {
enabled = false
name = "Test"
value = "Test"

  # When enabled and the cookie specified above is missing, performs a redirect to itself to check
  # if third-party cookies are blocked using the specified name. If they are indeed blocked,
  # fallbackNetworkId is used instead of generating a new random one.
  cookieBounce {
enabled = false
# The name of the request parameter which will be used on redirects checking that third-party
# cookies work.
name = "n3pc"
# Network user id to fallback to when third-party cookies are blocked.
fallbackNetworkUserId = "00000000-0000-4000-A000-000000000000"

# Optionally, specify the name of the header containing the originating protocol for use in the
# bounce redirect location. Use this if behind a load balancer that performs SSL termination.
# The value of this header must be http or https. Example, if behind an AWS Classic ELB.
forwardedProtocolHeader = "X-Forwarded-Proto"

  # When enabled, redirect prefix `r/` will be enabled and its query parameters resolved.
  # Otherwise the request prefixed with `r/` will be dropped with `404 Not Found`
  # Custom redirects configured in `paths` can still be used.
  enableDefaultRedirect = false

  # When enabled, the redirect url passed via the `u` query parameter is scanned for a placeholder
  # token. All instances of that token are replaced withe the network ID. If the placeholder isn't
  # specified, the default value is `${SP_NUID}`.
  redirectMacro {
enabled = false
# Optional custom placeholder token (defaults to the literal `${SP_NUID}`)
placeholder = "[TOKEN]"

  # Customize response handling for requests for the root path ("/").
  # Useful if you need to redirect to web content or privacy policies regarding the use of this collector.
  rootResponse {
enabled = false
statusCode = 302
# Optional, defaults to empty map
headers = {
  Location = "",
  X-Custom = "something"
# Optional, defaults to empty string
body = "302, redirecting"

  # Configuration related to CORS preflight requests
  cors {
# The Access-Control-Max-Age response header indicates how long the results of a preflight
# request can be cached. -1 seconds disables the cache. Chromium max is 10m, Firefox is 24h.
accessControlMaxAge = 5 seconds

  # Configuration of prometheus http metrics
  prometheusMetrics {
# If metrics are enabled then all requests will be logged as prometheus metrics
# and '/metrics' endpoint will return the report about the requests
enabled = false
# Custom buckets for http_request_duration_seconds_bucket duration metric
#durationBucketsInSeconds = [0.1, 3, 10]

  streams {
# Events which have successfully been collected will be stored in the good stream/topic
# good = "my-first-python-topic"
good = ""

# Events that are too big (w.r.t Kinesis 1MB limit) will be stored in the bad stream/topic
#bad = "bad-topic"
bad = ""

# Whether to use the incoming event's ip as the partition key for the good stream/topic
# Note: Nsq does not make use of partition key.
useIpAddressAsPartitionKey = false

# Enable the chosen sink by uncommenting the appropriate configuration
sink {
  # Choose between kinesis, google-pub-sub, kafka, nsq, or stdout.
  # To use stdout, comment or remove everything in the "collector.streams.sink" section except
  # "enabled" which should be set to "stdout".
  enabled = kafka

  # Region where the streams are located
  # region = {{kinesisRegion}}

  ## Optional endpoint url configuration to override aws kinesis endpoints,
  ## this can be used to specify local endpoints when using localstack
  # customEndpoint = {{kinesisEndpoint}}

  # Thread pool size for Kinesis API requests
  threadPoolSize = 10

  # Optional SQS buffer for good and bad events (respectively).
  # When messages can't be sent to Kinesiss, they will be sent to SQS.
  # If not configured, sending to Kinesis will be retried.
  #sqsGoodBuffer = {{sqsGoodBuffer}}

  #sqsBadBuffer = {{sqsBadBuffer}}

  # The following are used to authenticate for the Amazon Kinesis sink.
  # If both are set to 'default', the default provider chain is used
  # (see
  # If both are set to 'iam', use AWS IAM Roles to provision credentials.
  # If both are set to 'env', use environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY
  #aws {
  #  accessKey = iam
  #  secretKey = iam

  # Minimum and maximum backoff periods, in milliseconds
  #backoffPolicy {
  #  minBackoff = {{minBackoffMillis}}
  #  maxBackoff = {{maxBackoffMillis}}

  # Or Google Pubsub
  #googleProjectId = ID
  ## Minimum, maximum and total backoff periods, in milliseconds
  ## and multiplier between two backoff
  #backoffPolicy {
  #  minBackoff = {{minBackoffMillis}}
  #  maxBackoff = {{maxBackoffMillis}}
  #  totalBackoff = {{totalBackoffMillis}} # must be >= 10000
  #  multiplier = {{backoffMultiplier}}

  # Or Kafka
  brokers = "PLAINTEXT://localhost:9092"
  ## Number of retries to perform before giving up on sending a record
  retries = 0
  # The kafka producer has a variety of possible configuration options defined at
  # Some values are set to other values from this config by default:
  # "bootstrap.servers" = brokers
  # "buffer.memory"     = buffer.byteLimit
  # ""         = buffer.timeLimit
  producerConf {
acks = all
  #  "key.serializer"     = "org.apache.kafka.common.serialization.StringSerializer"
  #  "value.serializer"   = "org.apache.kafka.common.serialization.StringSerializer"

  # Or NSQ
  ## Host name for nsqd
  #host = "{{nsqHost}}"
  ## TCP port for nsqd, 4150 by default
  #port = {{nsqdPort}}

# Incoming events are stored in a buffer before being sent to Kinesis/Kafka.
# Note: Buffering is not supported by NSQ.
# The buffer is emptied whenever:
# - the number of stored records reaches record-limit or
# - the combined size of the stored records reaches byte-limit or
# - the time in milliseconds since the buffer was last emptied reaches time-limit
buffer {
  byteLimit = 100000
  recordLimit = 1000 # Not supported by Kafka; will be ignored
  timeLimit = 60


# Akka has a variety of possible configuration options defined at
akka {
  loglevel = DEBUG # 'OFF' for no logging, 'DEBUG' for all logging.
  loggers = ["akka.event.slf4j.Slf4jLogger"]

  # akka-http is the server the Stream collector uses and has configurable options defined at
  http.server {
# To obtain the hostname in the collector, the 'remote-address' header
# should be set. By default, this is disabled, and enabling it
# adds the 'Remote-Address' header to every request automatically.
remote-address-header = on

raw-request-uri-header = on

# Define the maximum request length (the default is 2048)
parsing {
  max-uri-length = 32768
  uri-parsing-mode = relaxed

  # By default setting `collector.ssl` relies on JSSE (Java Secure Socket
  # Extension) to enable secure communication.
  # To override the default settings set the following section as per
  # ssl-config {
  #   debug = {
  #     ssl = true
  #   }
  #   keyManager = {
  #     stores = [
  #       {type = "PKCS12", classpath = false, path = "/etc/ssl/mycert.p12", password = "mypassword" }
  #     ]
  #   }
  #   loose {
  #     disableHostnameVerification = false
  #   }
  # }

Please help me understand what I could be doing wrong.

I need your help to set up collector from scratch? can you please help

Hi @pramod.niralakeri if you need examples of setting up the Collector we have Terraform modules which have a full working example (on both AWS & GCP).

Hi Snowplow team and @josh - is there any reason all the Snowplow docs online have the enricher and collector using ec2 instances. Could I easily use container instances for these components? Our team is also considering moving the lambda pieces into a container too.

Can you forsee any issues with either approach? Or do you know of others who have successfully done this?

Hello @Nathan_Hampshire - there are pre-build docker images from Snowplow you can use to have your pipeline containerized. Here. That said - I have been using these images in production since last 6 months - and faced no issues.

I hope this helps.


Thanks Dhruvi but I’m already aware of the existence of the docket images. Im more interested in seeing an example of those images being deployed.

Typically helm charts handle this but for some reason all SP documentation points to using an EC2 instance to run a container via terraform. This isn’t really best practice and so I’m wondering why SP aren’t advocating/showing an appropriate deployment pattern for their container images.

Hi @Nathan_Hampshire we won’t for a tech stack where we could deploy everything for you in the quick-start. It was well beyond the scope of the quick-start to also bundle in an entire Kubernetes cluster along with everything else needed - so we went for cheap and low-tech assuming that there would be no pre-existing infrastructure to hook into.

All the deployments are EC2 but if you take a peek at the user-data you will note that they just launch a Docker container - so all the instructions on how to launch the application are in there and would just need to be translated to a Kubernetes deployment.

We don’t have any immediate plans to include application specific Helm charts as part of the quick-start though we do have some base building blocks you can leverage over here (GitHub - snowplow-devops/helm-charts: Helm Charts for Snowplow services and utilities.). You can use for example the service-deployment and pass in the variables you would need for any of the applications we run.