CouchDB - 'DB Backup exit Code is <blank>'

[JvSomeren]

Summary

The backup process for a CouchDB instance stops due to an "error" after the compression-step and during the check_exit_code-step.

Steps to reproduce

Setup a Docker instance of db-backup to backup a CouchDB instance. Use simple environment variables as listed under Environment.

Relevant logs and/or screenshots

Note that the exit_code variable is empty (non-existent).

Partial log

2025-01-29.21:23:06 [DEBUG] /etc/services.available/dbbackup-03/run ** [03-couchdb__ALL] Backup 03 routines started time: 2025-01-29 21:23:06 CET
+ bootstrap_filesystem
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ '[' '!' -d /backup/couch ']'
++ stat -c %U /backup/couch
+ '[' dbbackup '!=' dbbackup ']'
++ stat -c %a /backup/couch
+ '[' 700 '!=' 700 ']'
+ '[' -d /backup/archive/ ']'
+ '[' '!' -d /logs ']'
++ stat -c %U /logs
+ '[' dbbackup '!=' dbbackup ']'
++ date +%Y%m%d
+ '[' '!' -d /logs/20250129 ']'
++ stat -c %a /logs
+ '[' 755 '!=' 755 ']'
+ '[' '!' -d /tmp/backups ']'
++ stat -c %U /tmp/backups
+ '[' dbbackup '!=' dbbackup ']'
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ check_availability
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ var_false FALSE
+ '[' false = false ']'
+ case "${dbtype}" in
+ counter=0
+ code_received=0
+ '[' -n admin ']'
+ '[' -n OMITTED ']'
+ _ca_couch_auth='-u admin:OMITTED'
+ '[' 0 '!=' 200 ']'
++ run_as_user curl -XGET -sSL -o /dev/null -L -w '%{http_code}' -u admin:OMITTED couchdb:5984
++ sudo -Eu dbbackup curl -XGET -sSL -o /dev/null -L -w '%{http_code}' -u admin:OMITTED couchdb:5984
+ code_received=200
+ '[' 200 = 200 ']'
+ break
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ backup_couch
+ prepare_dbbackup
+ timer backup start
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ case "${1}" in
+ case "${2}" in
++ run_as_user date +%s
++ sudo -Eu dbbackup date +%s
+ dbbackup_start_time=1738182186
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
++ run_as_user date +%Y%m%d-%H%M%S
++ sudo -Eu dbbackup date +%Y%m%d-%H%M%S
+ now=20250129-212306
++ mktemp -d -p /tmp/backups -t 03_dbbackup.XXXXXX
+ temporary_directory=/tmp/backups/03_dbbackup.xevc0G
+ chown -R dbbackup:dbbackup /tmp/backups/03_dbbackup.xevc0G
+ backup_job_filename_base=couch_all_couchdb
+ backup_job_filename=couch_all_couchdb_20250129-212306.sql
+ backup_job_filename=couch_ALL_couchdb_20250129-212306.txt
+ backup_job_filename_base=couch_ALL_couchdb
+ compression
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ var_false TRUE
+ '[' true = false ']'
+ '[' true = no ']'
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ case "${backup_job_compression,,}" in
+ print_debug '[compression] Selected ZSTD'
+ output_off
+ '[' true = true ']'
+ set +x
2025-01-29.21:23:06 [DEBUG] /etc/services.available/dbbackup-03/run ** [03-couchdb__ALL] [compression] Selected ZSTD
+ compress_cmd=' zstd -q -q --rm -3 -T12 '
+ compression_type=zstd
+ dir_compress_cmd=' zstd -q -q --rm -3 -T12 '
+ extension=.zst
+ backup_job_filename_dir=couch_ALL_couchdb_20250129-212306.txt
+ backup_job_filename=couch_ALL_couchdb_20250129-212306.txt.zst
+ case "${CONTAINER_LOG_LEVEL,,}" in
+ '[' zstd = none ']'
+ compression_string='and compressing with '\''zstd:3'\'' with '\''12'\'' threads'
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ check_exit_code backup couch_ALL_couchdb_20250129-212306.txt.zst
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ case "${1}" in
+ write_log debug 'DB Backup exit Code is '
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ output_off
+ '[' true = true ']'
+ set +x
2025-01-29.21:23:06 [DEBUG] /etc/services.available/dbbackup-03/run ** [03-couchdb__ALL] DB Backup exit Code is 
+ output_on
+ '[' true = true ']'
+ case "$(basename "$0")" in
++ basename ./run
+ case "$PWD" in
+ set -x
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ case "${exit_code}" in
+ write_log error 'DB Backup of '\''couch_ALL_couchdb_20250129-212306.txt.zst'\'' reported errors'
+ var_true ''
+ '[' '' = true ']'
+ '[' '' = yes ']'
+ output_off
+ '[' true = true ']'
+ set +x
2025-01-29.21:23:06 [ERROR] /etc/services.available/dbbackup-03/run ** [03-couchdb__ALL] DB Backup of 'couch_ALL_couchdb_20250129-212306.txt.zst' reported errors
...

Environment

• Image version / tag: 4.1.15
• Host OS: Unraid | Docker

Environment variables

DB03_TYPE=couch
DB03_HOST=couchdb
DB03_PORT=5984
DB03_NAME=ALL
DB03_USER=admin
DB03_PASS=OMITTED
DB03_FILESYSTEM_PATH=/backup/couch
DB03_SPLIT_DB=FALSE

Possible fixes

The variable exit_code is never set and thus results in an error during check_exit_code. Either removing this check or setting the variable based on the output of a command should resolve this.

Besides the issue of exit_code being empty as far as I can tell there is no code actually responsible for backing up the CouchDB instance. I would expect this to happen somewhere in 10-db-backup:532-537. However I could be wrong about this.

[ekovarski]

You aren't wrong, I cobbled this quickly together - it will backup all couchdb databases, exclusion should work as well. Just replace the backup_couch section with this.

Note that if you make a change to docker-compose.yml, eg enable/disable DEBUG=TRUE, you will need to update /assets/functions/10-db-backup again

backup_couch() {
    if [ "${backup_job_db_name,,}" = "all" ] ; then
        write_log debug "Preparing to back up all databases"
        db_names=$(run_as_user curl -X GET -s -u "${backup_job_db_user}:${backup_job_db_pass}" "${backup_job_db_host}:${backup_job_db_port}/_all_dbs"  | tr -d '[]"' | tr ',' '\n' )

        if [ -n "${backup_job_db_name_exclude}" ] ; then
            db_names_exclusions=$(echo "${backup_job_db_name_exclude}" | tr ',' '\n')
            for db_exclude in ${db_names_exclusions} ; do
                write_log debug "Excluding '${db_exclude}' from ALL DB_NAME backups"
                db_names=$(echo "$db_names" | sed "/${db_exclude}/d" )
            done
        fi
    else
        db_names=$(echo "${backup_job_db_name}" | tr ',' '\n')
    fi

    if var_true "${DEBUG_BACKUP_COUCH}" ; then debug off; fi
    write_log debug "Databases Found: $(echo ${db_names} | xargs | tr ' ' ',')"

    for db in ${db_names} ; do
        prepare_dbbackup
        backup_job_filename=couch_${db}_${backup_job_db_host,,}_${now}.txt
        backup_job_filename_base=couch_${db}_${backup_job_db_host,,}
        compression
        pre_dbbackup "${db}"
        write_log notice "Dumping CouchDB database: '${db}' ${compression_string}"
        if var_true "${DEBUG_BACKUP_COUCH}" ; then debug on; fi
        run_as_user ${play_fair} curl -s -X GET -u "${backup_job_db_user}:${backup_job_db_pass}" "${backup_job_db_host}:${backup_job_db_port}/$db/_all_docs?include_docs=true&attachments=true" | ${compress_cmd} | run_as_user tee "${temporary_directory}"/"${backup_job_filename}" > /dev/null
        exit_code=$?
        if var_true "${DEBUG_BACKUP_COUCH}" ; then debug off; fi
        check_exit_code backup "${backup_job_filename}"
        timer backup finish
        file_encryption
        generate_checksum
        move_dbbackup
        check_exit_code move "${backup_job_filename}"
        post_dbbackup "${db}"
        cleanup_old_data
    done
}