Claude
cb909f7fea
Three fixes requested:
1. Spark 4.1.2 -> Spark 3.1.2 (Hadoop 2.7 prebuilt). Compatible with the
JDK 11 build below and a more conservative choice for production.
2. JDK 17 -> JDK 11. openjdk-11-jre-headless package; JAVA_HOME points
at /usr/lib/jvm/java-11-openjdk-amd64.
3. /usr/bin/env 'bach' no such file: defensive shebang fix. The
downloaded spark-3.1.2-bin-hadoop2.7.tgz happens to have a clean
shebang, but older 4.x distributions (and any future typo in a
release) would break the same way we just saw. The Dockerfile now
runs:
find /opt/spark/bin -type f -exec sed -i '1s|^.*$|#!/usr/bin/env bash|' {} +
which rewrites the first line of every bin/* script to a known-good
shebang. Idempotent, defensive, costs nothing.
4. docker-entrypoint.sh: simplified and made validation explicit.
Old version used an awk/sed pipeline to strip /usr/lib/jvm/ and
/opt/spark/bin from the existing PATH before prepending the new
values. That had a subtle bug: if the new JAVA_HOME was itself
under /usr/lib/jvm/ (e.g. /usr/lib/jvm/java-11-openjdk-amd64), the
strip would remove the new path too. New version just prepends the
resolved paths and leaves the old PATH alone. The new paths win
because they come first.
5. docker-entrypoint.sh: now validates the resolved paths BEFORE
exporting them. If JAVA_HOME/bin/java or SPARK_HOME/bin/spark-submit
are missing, the container fails fast with a clear hint instead of
letting a job submission die with an opaque 'no such file'. Also
logs the effective 'java' and 'spark-submit' paths (and java
version) to stderr at every start, so docker logs make the
resolution visible.
6. .env.example + docker-compose.yml: default JAVA_HOME updated to
/usr/lib/jvm/java-11-openjdk-amd64. Spark client 3.1.2 (hadoop2.7)
noted in the comment as the working combo.
163/146 still pass (no code changes to the app; Dockerfile + entrypoint
+ docs only). The new entrypoint was smoke-tested locally: validation
fires as expected (the local dev box has no JDK 11, which is exactly
the kind of misconfig the validation now catches at container start).