feat: add --ignore-tables flag and fix broken DB_DUMP_EXCLUDE

[michabbb]

Summary

New feature: --ignore-tables

• Wires up the existing but unused IgnoreTables support in pkg/database/mysql/dump.go to the CLI and environment variables
• Adds --ignore-tables CLI flag (auto-binds to DB_DUMP_IGNORE_TABLES env var via viper)
• Threads IgnoreTables []string through all intermediate layers (DumpOpts → DumpOptions → database.DumpOpts → mysql.Data)
• Fixes isIgnoredTable() to support qualified database.table format (e.g. mydb.mytable) in addition to bare table names

Bug fix: DB_DUMP_EXCLUDE / --exclude was completely broken

• The Exclude field in DumpOptions was populated from CLI/env vars but never read in the Dump() function (pkg/core/dump.go)
• All databases were dumped regardless of the exclude list — the field was dead code
• Extracted filterExcludedDatabases() function and applied it after schema discovery
• Fixed documentation typo (space-separated → comma-separated format)

Motivation

--ignore-tables: The old shell-based image supported MYSQLDUMP_OPTS="--ignore-table=db.table", but this was lost in the Go rewrite (v1.0+). The underlying mysql.Data.IgnoreTables field and isIgnoredTable() method already existed but were never connected to any user-facing configuration. This was reported in #309.

DB_DUMP_EXCLUDE: The exclude feature was documented and accepted via CLI/env vars, but the filtering logic was never implemented in pkg/core/dump.go. The opts.Exclude field was set but never read, causing disk-full incidents in production.

Usage

Exclude databases

# CLI flag
dump --exclude=tempdb,archivedb

# Environment variable
DB_DUMP_EXCLUDE=tempdb,archivedb

Ignore tables

# CLI flag
dump --ignore-tables=mydb.mytable,otherdb.bigtable

# or multiple flags
dump --ignore-tables=mydb.mytable --ignore-tables=otherdb.bigtable

# Environment variable (e.g. docker-compose)
DB_DUMP_IGNORE_TABLES=mydb.mytable,otherdb.bigtable

Both qualified (database.table) and unqualified (table) formats are supported:

• backuppc.hosts — ignores hosts only in the backuppc database
• hosts — ignores hosts in all databases

Test plan

• Added 3 test cases to cmd/dump_test.go for --exclude: single, comma-separated, multiple flags
• Added 7 test cases in pkg/core/dump_test.go for filterExcludedDatabases()
• Added 3 test cases to cmd/dump_test.go for --ignore-tables
• Added 10 test cases in pkg/database/mysql/dump_test.go for isIgnoredTable()
• All existing tests pass
• Verified with real MySQL: DB_DUMP_EXCLUDE now correctly excludes databases from the dump

Closes #309

[Copilot]

Pull request overview

This PR exposes MySQL dump table-ignoring functionality via CLI/env configuration and ensures the MySQL dumper correctly matches both qualified and unqualified ignore-table inputs.

Changes:

• Add --ignore-tables CLI flag (Viper-backed env var support) and thread IgnoreTables []string through core/database option layers down into the MySQL dumper.
• Extend mysql.Data.isIgnoredTable() to support qualified database.table entries alongside bare table names.
• Add unit tests for CLI parsing/binding and isIgnoredTable() matching behavior.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
cmd/dump.go	Adds --ignore-tables flag and passes parsed ignore list into core.DumpOptions.
cmd/dump_test.go	Adds test cases for single, comma-separated, and repeated --ignore-tables usage.
pkg/core/dumpoptions.go	Adds IgnoreTables to core.DumpOptions.
pkg/core/dump.go	Threads IgnoreTables into database.DumpOpts.
pkg/database/dump.go	Adds IgnoreTables to database.DumpOpts and passes it into mysql.Data.
pkg/database/mysql/dump.go	Updates ignore matching to handle qualified schema.table entries.
pkg/database/mysql/dump_test.go	Adds tests covering qualified/unqualified ignore-table matching.

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[Copilot]

The --ignore-tables help text/documentation implies only database.table values are supported, but isIgnoredTable() also supports unqualified table names (applies to all schemas). Please update the flag comment/description to mention both formats so CLI --help matches actual behavior.

Suggested change

	// ignore-tables: tables to exclude from the dump (format: database.table)
	flags.StringSlice("ignore-tables", []string{}, "Tables to exclude from the dump. Format: database.table (e.g. mydb.mytable). Can be specified multiple times or as a comma-separated list.")
	// ignore-tables: tables to exclude from the dump (formats: database.table or table)
	flags.StringSlice("ignore-tables", []string{}, "Tables to exclude from the dump. Formats: database.table (e.g. mydb.mytable) or table (applies to all databases/schemas). Can be specified multiple times or as a comma-separated list.")

[deitch]

Solid PR, thank you.

[deitch]

The commits need to be signed, see this error. Kindly sign them and repush; as soon as that is done and CI is green, we can merge it in.

[michabbb]

@deitch is also fixed the missing code for DB_DUMP_EXCLUDE 😏

[deitch]

Thanks. It still needs signed commits (see previous comment). And it is out of date, needs a rebase.