Support `mongodb+srv` protocol for connecting to MongoDB Atlas

[lbroudoux]

Reason/Context

MongoDB Atlas imposes a connection to its service using a mongodb+srv:// prefixed URL. However, as of today, we impose a hard-coded value of mongodb:// in the SPRING_DATA_MONGODB_URI deployment environment variable.

This results in a badly shaped URL when using the URI provided by Atlas. Putting the hostname + 443 port only doesn't work either, as the driver detects it's a cluster and expects to retrieve additional shard names using SRV records.

Description

We need a way to connect to a Mongo SRV compatible cluster from the Helm chart installation.

Implementation ideas

Turning mongodb:// prefix into mongodb+srv:// doesn't work with our default provided database. First error is that a port must not be provided in srv mode, and if we remove the port, we get this one:

com.mongodb.MongoConfigurationException: Failed looking up SRV record for '_mongodb._tcp.microcks-mongodb'.
 at com.mongodb.internal.dns.DefaultDnsResolver.resolveHostFromSrvRecords(DefaultDnsResolver.java:108)
 at com.mongodb.internal.connection.DefaultDnsSrvRecordMonitor$DnsSrvRecordMonitorRunnable.run(DefaultDnsSrvRecordMonitor.java:80)
 at java.base/java.lang.Thread.run(Thread.java:1583)
Caused by: com.mongodb.spi.dns.DnsWithResponseCodeException: DNS name not found [response code 3]
 at com.mongodb.internal.dns.JndiDnsClient.getResourceRecordData(JndiDnsClient.java:55)
 at com.mongodb.internal.dns.DefaultDnsResolver.resolveHostFromSrvRecords(DefaultDnsResolver.java:84)
 ... 2 common frames omitted
Caused by: javax.naming.NameNotFoundException: DNS name not found [response code 3]
 at jdk.naming.dns/com.sun.jndi.dns.DnsClient.checkResponseCode(DnsClient.java:785)
 at jdk.naming.dns/com.sun.jndi.dns.DnsClient.isMatchResponse(DnsClient.java:703)

Looks like we need to completely review how we build the SPRING_DATA_MONGODB_URI

[lbroudoux]

Now done and available in the nightly container image.