Merge pull request #22 from sameersbn/support-replicaset-config

adds support for configuring a replicaSet

bitnami/mongodb/README.md

@@ -119,6 +119,76 @@ myapp:
 
 Inside `myapp`, use `mongodb` as the hostname for the MongoDB server.
 
+## Setting up a replicaSet
+
+A [replica set](https://docs.mongodb.com/manual/replication/) can easily be setup with the Bitnami MongoDB Docker Image using the following environment variables:
+
+ - `MONGODB_REPLICASET_MODE`: MongoDB replica set mode. Possible values `primary`,`secondary` or `arbiter`. No defaults.
+ - `MONGODB_REPLICASET_NAME`: MongoDB replica set name. Defaults to `replicaset`.
+ - `MONGODB_PRIMARY_HOST`: MongoDB primary host. No defaults.
+ - `MONGODB_PRIMARY_PORT`: MongoDB primary port. Defaults to `27017`
+ - `MONGODB_PRIMARY_USER`: MongoDB primary user. Defaults to `root`.
+ - `MONGODB_PRIMARY_PASSWORD`: MongoDB primary user password. No defaults.
+
+In a replica set you can have one primary and zero or more secondary nodes.
+
+### Step 1: Create the primary node
+
+The first step is to start the MongoDB primary node.
+
+```bash
+docker run --name mongodb-primary \
+  -e MONGODB_REPLICASET_MODE=primary \
+  bitnami/mongodb:latest
+```
+
+In the above command the container is configured as the `primary` node using the `MONGODB_REPLICASET_MODE` parameter.
+
+### Step 2: Create the secondary node
+
+Next we start a MongoDB secondary node.
+
+```bash
+docker run --name mongodb-secondary \
+  --link mongodb-primary:primary \
+  -e MONGODB_REPLICASET_MODE=secondary \
+  -e MONGODB_PRIMARY_HOST=primary \
+  -e MONGODB_PRIMARY_PORT=27017 \
+  bitnami/mongodb:latest
+```
+
+In the above command the container is configured as a `secondary` using the `MONGODB_REPLICASET_MODE` parameter. The `MONGODB_PRIMARY_HOST` and `MONGODB_PRIMARY_PORT` parameters are used connect to the MongoDB primary.
+
+You now have a two node MongoDB replica set which can be scaled by adding/removing secondary nodes.
+
+With Docker Compose the replica set can be setup using:
+
+```yaml
+primary:
+  image: bitnami/mongodb:latest
+  environment:
+    - MONGODB_REPLICASET_MODE=primary
+
+secondary:
+  image: bitnami/mongodb:latest
+  links:
+    - primary:primary
+  environment:
+    - MONGODB_REPLICASET_MODE=secondary
+    - MONGODB_PRIMARY_HOST=primary
+    - MONGODB_PRIMARY_PORT=6379
+```
+
+Scale the number of secondary nodes using:
+
+```bash
+docker-compose scale primary=1 secondary=3
+```
+
+The above command scales up the number of secondary nodes to `3`. You can scale down in the same way.
+
+> **Note**: You should not scale up/down the number of primary nodes. Always have only one primary node running.
+
 # Configuration
 
 ## Setting the root password on first run

bitnami/mongodb/rootfs/app-entrypoint.sh

@@ -8,7 +8,13 @@ if [[ "$1" == "harpoon" && "$2" == "start" ]]; then
       ${MONGODB_ROOT_PASSWORD:+--rootPassword $MONGODB_ROOT_PASSWORD} \
       ${MONGODB_USER:+--username $MONGODB_USER} \
       ${MONGODB_PASSWORD:+--password $MONGODB_PASSWORD} \
-      ${MONGODB_DATABASE:+--database $MONGODB_DATABASE}
+      ${MONGODB_DATABASE:+--database $MONGODB_DATABASE} \
+      ${MONGODB_REPLICASET_MODE:+--replicaSetMode $MONGODB_REPLICASET_MODE} \
+      ${MONGODB_REPLICASET_NAME:+--replicaSetName $MONGODB_REPLICASET_NAME} \
+      ${MONGODB_PRIMARY_HOST:+--primaryHost $MONGODB_PRIMARY_HOST} \
+      ${MONGODB_PRIMARY_PORT:+--primaryPort $MONGODB_PRIMARY_PORT} \
+      ${MONGODB_PRIMARY_USER:+--primaryUser $MONGODB_PRIMARY_USER} \
+      ${MONGODB_PRIMARY_PASSWORD:+--primaryPassword $MONGODB_PRIMARY_PASSWORD}
   fi
   chown $BITNAMI_APP_USER: /bitnami/$BITNAMI_APP_NAME || true
 fi

bitnami/mongodb/test.sh

@@ -8,7 +8,7 @@ MONGODB_PASSWORD=test_password
 APP_NAME=mongodb
 VOL_PREFIX=/bitnami/$APP_NAME
 VOLUMES=$VOL_PREFIX
-SLEEP_TIME=30
+SLEEP_TIME=60
 load tests/docker_helper
 
 # Link to container and execute mongo client
@@ -21,6 +21,7 @@ mongo_client() {
 # Cleans up all running/stopped containers and host mounted volumes
 cleanup_environment() {
   container_remove_full default
+  container_remove_full secondary
 }
 
 # Teardown called at the end of each test
@@ -168,3 +169,123 @@ cleanup_environment
   run mongo_client default -u $MONGODB_USER -p $MONGODB_PASSWORD $MONGODB_DATABASE --eval "printjson(db.getCollectionNames())"
   [[ "$output" =~ '"users"' ]]
 }
+
+@test "Can't create replicaSet with authentication" {
+  run container_create default \
+    -e MONGODB_REPLICASET_MODE=primary \
+    -e MONGODB_PASSWORD=$MONGODB_PASSWORD
+  [[ "$output" =~ "Not possible to configure replica set scenario using authentication" ]]
+}
+
+@test "Can't create secondary replicaSet node without specifying MONGODB_PRIMARY_HOST" {
+  run container_create secondary \
+    -e MONGODB_REPLICASET_MODE=secondary
+  [[ "$output" =~ "provide the --primaryHost property" ]]
+}
+
+@test "Can create replicaSet without authentication" {
+  container_create default -d \
+    -e MONGODB_REPLICASET_MODE=primary
+
+  container_create secondary -d \
+    $(container_link default $CONTAINER_NAME) \
+    -e MONGODB_REPLICASET_MODE=secondary \
+    -e MONGODB_PRIMARY_HOST=$CONTAINER_NAME
+
+  run mongo_client default $MONGODB_DATABASE --eval "printjson(db.createCollection('users'))"
+  [[ "$output" =~ '"ok" : 1' ]]
+
+  sleep 3
+  run mongo_client secondary $MONGODB_DATABASE --eval "rs.slaveOk(); printjson(db.getCollectionNames())"
+  [[ "$output" =~ '"users"' ]]
+}
+
+@test "Secondary node in replicaSet synchronizes with the primary (delayed start)" {
+  container_create default -d \
+    -e MONGODB_REPLICASET_MODE=primary
+
+  run mongo_client default $MONGODB_DATABASE --eval "printjson(db.createCollection('users'))"
+  [[ "$output" =~ '"ok" : 1' ]]
+
+  container_create secondary -d \
+    $(container_link default $CONTAINER_NAME) \
+    -e MONGODB_REPLICASET_MODE=secondary \
+    -e MONGODB_PRIMARY_HOST=$CONTAINER_NAME
+
+  run mongo_client secondary $MONGODB_DATABASE --eval "rs.slaveOk(); printjson(db.getCollectionNames())"
+  [[ "$output" =~ '"users"' ]]
+}
+
+@test "replicaSet setup and state is preserved after restart" {
+  container_create default -d \
+    -e MONGODB_REPLICASET_MODE=primary
+
+  run mongo_client default $MONGODB_DATABASE --eval "printjson(db.createCollection('users'))"
+  [[ "$output" =~ '"ok" : 1' ]]
+
+  container_create secondary -d \
+    $(container_link default $CONTAINER_NAME) \
+    -e MONGODB_REPLICASET_MODE=secondary \
+    -e MONGODB_PRIMARY_HOST=$CONTAINER_NAME
+
+  container_restart secondary
+  container_restart default
+
+  run mongo_client default $MONGODB_DATABASE --eval "printjson(db.createCollection('networks'))"
+  [[ "$output" =~ '"ok" : 1' ]]
+
+  sleep 3
+  run mongo_client secondary $MONGODB_DATABASE --eval "rs.slaveOk(); printjson(db.getCollectionNames())"
+  [[ "$output" =~ '"users"' ]]
+  [[ "$output" =~ '"networks"' ]]
+}
+
+@test "replicaSet setup and state is preserved after deletion" {
+  container_create_with_host_volumes default -d \
+    -e MONGODB_REPLICASET_MODE=primary
+
+  run mongo_client default $MONGODB_DATABASE --eval "printjson(db.createCollection('users'))"
+  [[ "$output" =~ '"ok" : 1' ]]
+
+  container_create_with_host_volumes secondary -d \
+    $(container_link default $CONTAINER_NAME) \
+    -e MONGODB_REPLICASET_MODE=secondary \
+    -e MONGODB_PRIMARY_HOST=$CONTAINER_NAME
+
+  container_remove secondary
+  container_remove default
+
+  container_create_with_host_volumes default -d
+  container_create_with_host_volumes secondary -d $(container_link default $CONTAINER_NAME)
+
+  run mongo_client default $MONGODB_DATABASE --eval "printjson(db.createCollection('networks'))"
+  [[ "$output" =~ '"ok" : 1' ]]
+
+  sleep 3
+  run mongo_client secondary $MONGODB_DATABASE --eval "rs.slaveOk(); printjson(db.getCollectionNames())"
+  [[ "$output" =~ '"users"' ]]
+  [[ "$output" =~ '"networks"' ]]
+}
+
+@test "Slave recovers if master is temporarily offine" {
+  container_create_with_host_volumes default -d \
+    -e MONGODB_REPLICASET_MODE=primary
+
+  run mongo_client default $MONGODB_DATABASE --eval "printjson(db.createCollection('users'))"
+  [[ "$output" =~ '"ok" : 1' ]]
+
+  container_create_with_host_volumes secondary -d \
+    $(container_link default $CONTAINER_NAME) \
+    -e MONGODB_REPLICASET_MODE=secondary \
+    -e MONGODB_PRIMARY_HOST=$CONTAINER_NAME
+
+  container_restart default
+
+  run mongo_client default $MONGODB_DATABASE --eval "printjson(db.createCollection('networks'))"
+  [[ "$output" =~ '"ok" : 1' ]]
+
+  sleep 3
+  run mongo_client secondary $MONGODB_DATABASE --eval "rs.slaveOk(); printjson(db.getCollectionNames())"
+  [[ "$output" =~ '"users"' ]]
+  [[ "$output" =~ '"networks"' ]]
+}