Connection error for MongoDb replica-set using docker-compose
<p>I'm trying to connect to mongodb replica set running under 4 containers: 3 mongo as a cluster, and 1 to issue mongo commands to others.</p>

<p>Here I don't know how should I connect it to my application with a mongodb url.</p>

<p><code>docker-compose.yml</code> is</p>

<pre><code>mongo3:
  image: mongo:latest
  hostname: mongo3
  expose:
    - "27017"
    - "28017"
  restart: always

      entrypoint: [ "/usr/bin/mongod", "--replSet", "rs"]

mongo2:
  image: mongo:latest
  hostname: mongo2
  expose:
    - "27017"
    - "28017"
  restart: always
  entrypoint: [ "/usr/bin/mongod", "--replSet", "rs"]

mongo1:
  image: mongo:latest
  hostname: mongo1
  expose:
    - "27017"
    - "28017"
  links:
    - mongo2:mongo2
    - mongo3:mongo3
  restart: always
  entrypoint: [ "/usr/bin/mongod", "--replSet", "rs"]

mongosetup:
  image: mongo:latest
  links:
    - mongo1:mongo1
    - mongo2:mongo2
    - mongo3:mongo3
  volumes:
    - ./scripts:/scripts
    - ./data/runtime/db:/data/db
    - ./data/dump:/dump

  restart: always
  entrypoint: [ "bash", "/scripts/mongo_setup.sh" ]

app:
  image: papagari/swoop.chat:latest
  environment:
    - MONGO_URL=mongodb://mongo1:27017,mongo2:27017,mongo3:27017/swoop?replicaSet=rs
    - ROOT_URL=https://localhost:3000
  links:
    - mongo1:mongo1
    - mongo2:mongo2
    - mongo3:mongo3
  ports:
    - 3000:3000
</code></pre>

<p>and <code>/scripts/mongo_setup.sh</code> is</p>

<pre><code>MONGODB1=`ping -c 1 mongo1 | head -1  | cut -d "(" -f 2 | cut -d ")" -f 1`
MONGODB2=`ping -c 1 mongo2 | head -1  | cut -d "(" -f 2 | cut -d ")" -f 1`
MONGODB3=`ping -c 1 mongo3 | head -1  | cut -d "(" -f 2 | cut -d ")" -f 1`    

echo "Waiting for startup.."
until curl http://${MONGODB1}:28017/serverStatus\?text\=1 2&gt;&amp;1 | grep uptime | head -1; do
  printf '.'
  sleep 1
done    

echo curl http://${MONGODB1}:28017/serverStatus\?text\=1 2&gt;&amp;1 | grep uptime | head -1
echo "Started.."    

sleep 10    

echo SETUP.sh time now: `date +"%T" `
mongo --host ${MONGODB1}:27017 &lt;&lt;EOF
   var cfg = {
        "_id": "rs",
        "version": 1,
        "members": [
            {
                "_id": 0,
                "host": "${MONGODB1}:27017",
                "priority": 2
            },
            {
                "_id": 1,
                "host": "${MONGODB2}:27017",
                "priority": 0
            },
            {
                "_id": 2,
                "host": "${MONGODB3}:27017",
                "priority": 0
            }
        ]
    };
    rs.initiate(cfg, { force: true });
    rs.reconfig(cfg, { force: true });
    db.getMongo().setReadPref('nearest');
EOF
</code></pre>

<p>Now I'm getting an error for <code>mongodb://mongo1:27017,mongo2:27017,mongo3:27017/swoop?replicaSet=rs</code> 
Obviously <code>failed to connect to server</code> because the url I've used is not valid. I'm new to docker and mongo db replica set for the first time, trying to understand docker here. How it should work.   </p>

<p>Error: <code>MongoError: no primary found in replicaset</code>.</p>

<p>Complete Error: </p>

<pre><code>app_1        | 
app_1        | /app/bundle/programs/server/node_modules/fibers/future.js:313
app_1        |                      throw(ex);
app_1        |                      ^
app_1        | MongoError: no primary found in replicaset
app_1        |     at Object.Future.wait (/app/bundle/programs/server/node_modules/fibers/future.js:449:15)
app_1        |     at new MongoConnection (packages/mongo/mongo_driver.js:216:27)
app_1        |     at new MongoInternals.RemoteCollectionDriver (packages/mongo/remote_collection_driver.js:4:16)
app_1        |     at Object.&lt;anonymous&gt; (packages/mongo/remote_collection_driver.js:38:10)
app_1        |     at Object.defaultRemoteCollectionDriver (packages/underscore/underscore.js:750:1)
app_1        |     at new Mongo.Collection (packages/mongo/collection.js:103:40)
app_1        |     at AccountsServer.AccountsCommon (packages/accounts-base/accounts_common.js:23:18)
app_1        |     at new AccountsServer (packages/accounts-base/accounts_server.js:18:5)
app_1        |     at meteorInstall.node_modules.meteor.accounts-base.server_main.js (packages/accounts-base/server_main.js:9:12)
app_1        |     at fileEvaluate (packages/modules-runtime/.npm/package/node_modules/install/install.js:153:1)
app_1        |     - - - - -
app_1        |     at /app/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/topologies/replset.js:631:32
app_1        |     at [object Object].&lt;anonymous&gt; (/app/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/topologies/replset.js:421:24)
app_1        |     at [object Object].g (events.js:260:16)
app_1        |     at emitOne (events.js:77:13)
app_1        |     at [object Object].emit (events.js:169:7)
app_1        |     at /app/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/topologies/server.js:283:14
app_1        |     at /app/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/connection/pool.js:436:18
app_1        |     at nextTickCallbackWith0Args (node.js:420:9)
app_1        |     at process._tickCallback (node.js:349:13)
</code></pre>

<p>I've searched many placed all I got is with local machine or the server machine not with docker links.</p>

<p><strong>Update</strong>
response of <code>rs.status()</code> in mongo1 container, which look pretty fine, primary and secondary are initialized properly.</p>

<pre><code>{
    "set" : "rs",
    "date" : ISODate("2016-10-19T06:31:10.861Z"),
    "myState" : 1,
    "term" : NumberLong(1),
    "heartbeatIntervalMillis" : NumberLong(2000),
    "members" : [
        {
            "_id" : 0,
            "name" : "172.17.0.4:27017",
            "health" : 1,
            "state" : 1,
            "stateStr" : "PRIMARY",
            "uptime" : 62,
            "optime" : {
                "ts" : Timestamp(1476858630, 1),
                "t" : NumberLong(1)
            },
            "optimeDate" : ISODate("2016-10-19T06:30:30Z"),
            "infoMessage" : "could not find member to sync from",
            "electionTime" : Timestamp(1476858629, 1),
            "electionDate" : ISODate("2016-10-19T06:30:29Z"),
            "configVersion" : 13918,
            "self" : true
        },
        {
            "_id" : 1,
            "name" : "172.17.0.3:27017",
            "health" : 1,
            "state" : 2,
            "stateStr" : "SECONDARY",
            "uptime" : 51,
            "optime" : {
                "ts" : Timestamp(1476858630, 1),
                "t" : NumberLong(1)
            },
            "optimeDate" : ISODate("2016-10-19T06:30:30Z"),
            "lastHeartbeat" : ISODate("2016-10-19T06:31:09.633Z"),
            "lastHeartbeatRecv" : ISODate("2016-10-19T06:31:10.291Z"),
            "pingMs" : NumberLong(0),
            "syncingTo" : "172.17.0.2:27017",
            "configVersion" : 13918
        },
        {
            "_id" : 2,
            "name" : "172.17.0.2:27017",
            "health" : 1,
            "state" : 2,
            "stateStr" : "SECONDARY",
            "uptime" : 51,
            "optime" : {
                "ts" : Timestamp(1476858630, 1),
                "t" : NumberLong(1)
            },
            "optimeDate" : ISODate("2016-10-19T06:30:30Z"),
            "lastHeartbeat" : ISODate("2016-10-19T06:31:09.633Z"),
            "lastHeartbeatRecv" : ISODate("2016-10-19T06:31:09.283Z"),
            "pingMs" : NumberLong(0),
            "syncingTo" : "172.17.0.4:27017",
            "configVersion" : 13918
        }
    ],
    "ok" : 1
}
</code></pre>

<p>Any tips will be helpful. TIA</p>