Testcontainers-java: Wait.forLogMessage times out constantly for Neo4j docker image

[michael-simons]

Hi,

I cannot get the Wait.forLogMessage to work with a custom container based on the official Neo4j image:

This repeatedly times out:

 new GenericContainer("neo4j:3.4.7") // TODO Derive from Maven properties
            .withExposedPorts(7687)
            .withEnv("NEO4J_AUTH", "none")
            .withLogConsumer(new Slf4jLogConsumer(LoggerFactory.getLogger(Neo4jClientVerificationTest.class)))
            .waitingFor(forLogMessage(".*Bolt enabled on 0\\.0\\.0\\.0:7687\\.", 1));

I'm on Java 11, full example is here

I thought I was stupid and didn't get the regex right, but every other, i.e. .*config.* fails, too

[bsideup]

Hi @michael-simons,

Does it work if you add .*\n at the end?
Something like forLogMessage(".*Bolt enabled on 0\\.0\\.0\\.0:7687\\..*\n", 1)

[michael-simons]

Lovely. That works. I'm happy that it was my fault.

I was expecting the matcher is running in single line mode (pretty much like the docker maven plugin.

[bsideup]

@michael-simons honestly - I expect the same every time 😂 We should probably consider that /cc @rnorth @kiview

[kiview]

Yes, I can totally understand this confusion. I always set the global flag on the regex so wildcard matches line break.

[rnorth]

Yeah, let’s change this, as it’s a bit of a nasty surprise. (I too have been caught out by it once!)

The question is how to change it; altering the current behaviour seems unpleasant. A small change to the method signature would be a breaking change, but would be quickly found and fixed. Let’s discuss options.

[kiview]

I would think the easiest change would be adding the DOTALL flag (see https://docs.oracle.com/javase/8/docs/api/java/util/regex/Pattern.html#DOTALL) as a default and it would possibly not really break anything.

[michael-simons]

Yep, regexes ending in \n would still match.