Docker: allow automatic cluster registration

A minimal example of how to use this change in docker-compose:
```
  register-cluster:
    image: cassandra-reaper:latest
    networks:
      - tlp_dashboards_net
    command: ["register-clusters", "cassandra:7199", "reaper", "8080"]
    depends_on:
      - cassandra
      - cassandra2
      - reaper
      - stress
```

src/docs/content/docs/configuration/docker_vars.md

@@ -29,6 +29,7 @@ The Docker environment variables listed in this section map directly to Reaper s
 <code class="codeLarge">REAPER_INCREMENTAL_REPAIR</code> | [incrementalRepair]({{< relref "reaper_specific.md#incrementalrepair" >}}) | false
 <code class="codeLarge">REAPER_JMX_AUTH_PASSWORD</code> | [password]({{< relref "reaper_specific.md#password" >}}) |
 <code class="codeLarge">REAPER_JMX_AUTH_USERNAME</code> | [username]({{< relref "reaper_specific.md#username" >}}) |
+<code class="codeLarge">REAPER_JMX_CREDENTIALS</code> | [jmxCredentials]({{< relref "reaper_specific.md#jmxcredentials" >}}) |
 <code class="codeLarge">REAPER_JMX_CONNECTION_TIMEOUT_IN_SECONDS</code> | [jmxConnectionTimeoutInSeconds]({{< relref "reaper_specific.md#jmxconnectiontimeoutinseconds" >}}) | 20
 <code class="codeLarge">REAPER_JMX_PORTS</code> | [jmxPorts]({{< relref "reaper_specific.md#jmxports" >}}) | {}
 <code class="codeLarge">REAPER_LOGGING_APPENDERS_CONSOLE_LOG_FORMAT</code> | [logFormat]({{< relref "reaper_specific.md#logformat" >}}) | "%-6level [%d] [%t] %logger{5} - %msg %n"

src/docs/content/docs/download/docker.md

@@ -95,6 +95,31 @@ The Docker Compose services available allow for orchestration of an environment
 
 In addition to the environment using Reaper's default settings, Docker Compose services are provided that allow orchestration of an environment in which the connections between Reaper and Cassandra are SSL encrypted. The services which create this environment contain a `-ssl` suffix in their name.
 
+It is also possible to automate registering the Cassandra cluster with Reaper and making Reaper start repairing non-system keyspaces automatically. To register a cluster, run the Reaper image with the `register-cluster` command:
+
+```yaml
+  register-clusters:
+    image: cassandra-reaper:latest
+    links:
+      - cassandra
+      - reaper-in-memory
+    command: ["register-clusters", "cassandra:7199", "reaper-in-memory", "8080"]
+``` 
+
+The `register-clusters` arguments are:
+
+- `cassandra:7199` - host and (JMX) port of a node in the cluster we want to register.
+- `reaper-in-memory` - hostname of the Reaper instance.
+- `8080` - the port on which Reaper listens on.
+
+To make Reaper automatically start repairs, make sure the following environment variables are set:
+
+```bash
+REAPER_AUTO_SCHEDULING_ENABLED="True"
+REAPER_AUTO_SCHEDULING_TIME_BEFORE_FIRST_SCHEDULE="PT1M"
+REAPER_AUTO_SCHEDULING_PERIOD_BETWEEN_POLLS="PT1M"
+```
+
 All available Docker Compose services can be found in the [docker-compose.yml](https://github.com/thelastpickle/cassandra-reaper/blob/master/src/packaging/docker-compose.yml) file.
 
 

src/packaging/docker-compose.yml

@@ -167,3 +167,10 @@ services:
       - ./docker-services/reaper-in-memory/reaper-in-memory.env
     links:
       - cassandra
+
+  register-clusters:
+    image: cassandra-reaper:latest
+    links:
+      - cassandra
+      - reaper-in-memory
+    command: ["register-clusters", "cassandra:7199", "reaper-in-memory", "8080"]

src/packaging/docker-services/reaper-in-memory/reaper-in-memory.env

@@ -15,3 +15,8 @@
 # limitations under the License.
 
 REAPER_STORAGE_TYPE=memory
+
+REAPER_AUTO_SCHEDULING_ENABLED="True"
+REAPER_AUTO_SCHEDULING_INITIAL_DELAY_PERIOD="PT15S"
+REAPER_AUTO_SCHEDULING_TIME_BEFORE_FIRST_SCHEDULE="PT1M"
+REAPER_AUTO_SCHEDULING_PERIOD_BETWEEN_POLLS="PT1M"

src/server/src/main/docker/Dockerfile

@@ -37,6 +37,7 @@ ENV REAPER_SEGMENT_COUNT=200 \
     REAPER_AUTO_SCHEDULING_PERIOD_BETWEEN_POLLS=PT10M \
     REAPER_AUTO_SCHEDULING_TIME_BEFORE_FIRST_SCHEDULE=PT5M \
     REAPER_AUTO_SCHEDULING_SCHEDULE_SPREAD_PERIOD=PT6H \
+    REAPER_AUTO_SCHEDULING_EXCLUDED_CLUSTERS="[]" \
     REAPER_AUTO_SCHEDULING_EXCLUDED_KEYSPACES="[]" \
     REAPER_JMX_PORTS="{}" \
     REAPER_JMX_AUTH_USERNAME="" \
@@ -76,9 +77,9 @@ ENV REAPER_SEGMENT_COUNT=200 \
 
 # used to run spreaper cli
 RUN apk add --update \
-    python \
-    py-pip \
-  && pip install requests \
+    python3 \
+    py3-pip \
+  && pip3 install requests \
   && rm -rf /var/cache/apk/*
 
 

src/server/src/main/docker/entrypoint.sh

@@ -14,8 +14,24 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+function wait_for {
+  HOST=$1
+  PORT=$2
+
+  echo "Checking if ${HOST}:${PORT} is up ..."
+  nc -zv ${HOST} ${PORT} > /dev/null 2>&1
+  port_open=$?
+  while [ "${port_open}" != 0 ]
+  do
+      echo "${HOST} is not yet up, will retry in 20s"
+      sleep 20
+      nc -zv ${HOST} ${PORT} > /dev/null 2>&1
+      port_open=$?
+  done
+  echo "${HOST}:${PORT} is up!"
+}
+
 if [ "$1" = 'cassandra-reaper' ]; then
-    set -x
 
     # get around `/usr/local/bin/configure-persistence.sh: line 65: can't create /etc/cassandra-reaper.yml: Interrupted system call` unknown error
     touch /etc/cassandra-reaper.yml
@@ -30,4 +46,42 @@ if [ "$1" = 'cassandra-reaper' ]; then
             /etc/cassandra-reaper.yml
 fi
 
+if [ "$1" = 'register-clusters' ]; then
+
+  if [ -z "$2" ]; then
+    echo "The register-clusters command needs its 1st argument to be a 'host:port,...' string pointing to C* nodes to repair"
+    exit 1
+  fi
+  REAPER_AUTO_SCHEDULING_SEEDS=$2
+
+  if [ -z "$3" ]; then
+    echo "The register-clusters command needs additional argument indicating the Reaper host"
+    exit 1
+  fi
+  REAPER_HOST=$3
+
+  if [ -z "$4" ]; then
+    echo "The register-clusters command takes additional argument indicating the Reaper port. Defaulting to 8080"
+    REAPER_PORT=8080
+  else
+    REAPER_PORT=$4
+  fi
+
+  mkdir -p ~/.reaper
+  echo "admin" > ~/.reaper/credentials
+
+  wait_for ${REAPER_HOST} ${REAPER_PORT}
+
+  for SEED in $(echo "${REAPER_AUTO_SCHEDULING_SEEDS}" | sed "s/,/ /g"); do
+    SEED_HOST=$(echo ${SEED} | cut -d':' -f1)
+    SEED_PORT=$(echo ${SEED} | cut -d':' -f2)
+    wait_for ${SEED_HOST} ${SEED_PORT}
+    /usr/local/bin/spreaper login --reaper-host "${REAPER_HOST}" --reaper-port "${REAPER_PORT}" admin
+    /usr/local/bin/spreaper add-cluster --reaper-host "${REAPER_HOST}" --reaper-port "${REAPER_PORT}" "${SEED_HOST}" "${SEED_PORT}"
+  done
+
+  exit 0
+
+fi
+
 exec "$@"