How to specify lower_case_table_names=1 for mysqld --initialize

[uqix]

This is the only block to migrate our bitnami mysql to wonderful moco.

[masa213f]

Sorry for the late reply. I'm confirming this, so please wait a moment.

[masa213f]

@uqix Sorry for the late reply. Unfortunately, there is no official way to specify lower_case_table_names=1 at this time. I want to enable to specify it, but it to take a while.

As a temporary workaround, if you build a custom MySQL image with the following Dockerfile and patch file, you can use lower_case_table_names=1.

Dockerfile

# Build the patched moco-init binary.
FROM quay.io/cybozu/golang:1.18-focal as builder
WORKDIR /work
COPY ./moco-init.patch .
RUN git clone --depth 1 https://github.com/cybozu/neco-containers.git
RUN cd ./neco-containers/ && patch -p1 < ../moco-init.patch
RUN cd ./neco-containers/mysql/moco-init && go build -ldflags="-w -s" -o /work/moco-init .

# Overwrite the original moco-init.
FROM quay.io/cybozu/mysql:8.0.28
COPY --from=builder /work/moco-init /usr/local/mysql/bin/

moco-init.patch

diff --git a/mysql/moco-init/main.go b/mysql/moco-init/main.go
index fd3933cc..3aaf4ff0 100644
--- a/mysql/moco-init/main.go
+++ b/mysql/moco-init/main.go
@@ -102,7 +102,7 @@ func initMySQL(mysqld string) error {
                return fmt.Errorf("failed to remove dir %s: %w", dataDir, err)
        }
 
-       cmd := exec.Command(mysqld, "--basedir="+config.baseDir, "--datadir="+dataDir, "--initialize-insecure")
+       cmd := exec.Command(mysqld, "--basedir="+config.baseDir, "--datadir="+dataDir, "--initialize-insecure", "--lower_case_table_names=1", "--log-error-verbosity=3")
        cmd.Stdout = os.Stdout
        cmd.Stderr = os.Stderr
        if err := cmd.Run(); err != nil {

The options for mysqld --initialize-insecure are specified in moco-init, which is contained in MOCO's MySQL images. So as a simple solution, we just modify the moco-init. But the changes of moco-init may break existing MySQLClusters. So it requires attention and takes time.

[uqix]

Just wondering is it feasible to specify --lower_case_table_names=1 by env vars of moco-init container?

[masa213f]

That's a good suggestion. Please wait for a little. Currently, we try making the moco-init under version control to address this issue.

[uqix]

Glad to hear that, take your time.

[masa213f]

@uqix I apologize for the very late reply...

Currently, MOCO accepts lower_case_table_names. Please try it if you have the chance.

apiVersion: v1
kind: ConfigMap
metadata:
  name: myconf
data:
  lower_case_table_names: "1"
---
apiVersion: moco.cybozu.com/v1beta2
kind: MySQLCluster
...
spec:
  mysqlConfigMapName: myconf
...