My goal is to loop over a list of keys and generate a DUMP for each key
I am using redis-cli installed via npm which is why I call it as rdcli
# For reading comprehension:
export RED="rdcli -h $redis_endpoint -p $redis_port -a $redis_pass"
# This returns a list of my redis keys
$RED KEYS "*"
# The returned lines are numbered so I strip them off like so
$RED KEYS "*" | cut -d' ' -f2-
# This generates a file of serialized data which I can later pass to my new redis instance
$RED DUMP $key >> redis.dmp
This works fine when $key is a single key. However, if I attempt to loop over the list of redis keys
for key in $($RED KEYS "*" | cut -d' ' -f2-); do
$RED DUMP $key;
done
or
$RED KEYS "*" | cut -d' ' -f2- | xargs -I key $RED DUMP key
or
# runfile.file contains fully expanded, hardcoded commands
# Ex:
# rdcli -h xxx -p yyy -a zzz DUMP :1:aaa
# rdcli -h xxx -p yyy -a zzz DUMP :1:bbb
# rdcli -h xxx -p yyy -a zzz DUMP :1:ccc
chmod +x runfile.file
./runfile.file
# this may be a separate issue but the symptoms are the same
Output:
(nil)
(nil)
(nil)
(nil)
...
My only hint is that enabling debug mode with set -x reveals that
$RED DUMP $key
# where $key is set during runtime
is being evaluated as
rdcli -h xxx -p yyy -a zzz DUMP ':1:aaa'
# and subsequently spitting out (nil)
If I copy and paste rdcli -h xxx -p yyy -a zzz DUMP ':1:aaa' back into the shell it correctly returns serialized code but I am unable to do this programatically.
Additional info:
- I have thousands of keys so I cannot do this by hand
- I am pulling the keys from a heroku redis instance and have no way to download a backup or save
- I am migrating to an Elasticache redis which prevents me from setting it up as a follower of the heroku instance as these commands are restricted
- The two redis servers cannot communicate directly which is why I am using the DUMP and restore method
