Loki: s3_secret_access_key does not allow slashes

[PabloCastellano]

Describe the bug
Loki fails to start when an s3 bucket is configured as storage and the secret key contains a slash. I have generated a different access key pair whose secret key doesn't contain a slash character and it works fine.

To Reproduce
Steps to reproduce the behavior:

1. Configure s3 storage with a secret key that contains a slash. E.g.

storage_config:
  boltdb:
    directory: /tmp/loki/index
  filesystem:
    directory: /tmp/loki/chunks
  aws:
    s3: s3://ASDFGHJIQWETTYUI:Jkasduahdkjh213kj1h31+lkjaflkjzvKASDOasofhjafaKFAF/GoQd@region/bucket_name

1. Start Loki (master-765b34d)

Expected behavior
Loki should correctly parse the secret key and don't interpret it as a port

Environment:

• Infrastructure: Docker running in a VM
• Deployment tool: Docker-compose

Screenshots, Promtail config, or terminal output

failed parsing config: /etc/loki/local-config.yaml: parse s3://ASDFGHJIQWETTYUI:Jkasduahdkjh213kj1h31+lkjaflkjzvKASDOasofhjafaKFAF/GoQd@region/bucket_name invalid port ":Jkasduahdkjh213kj1h31+lkjaflkjzvKASDOasofhjafaKFAF" after 
host

[adityacs]

@PabloCastellano you should encode the URL. Try Like below
s3://ASDFGHJIQWETTYUI:Jkasduahdkjh213kj1h31+lkjaflkjzvKASDOasofhjafaKFAF%2FGoQd@region/bucket_name

/ is replaced with %2F

FYR: Check the comment here https://github.com/weaveworks/common/blob/master/aws/config.go#L16

[owen-d]

Nice digging @adityacs. I do think we should have nicer error handling for this (or transparently handle this case)

[PabloCastellano]

I can confirm that URL encoding the character works. In my opinion there should be better error handling or at least the documentation should warn you. I can provide a PR for documentation if you think this is useful

[owen-d]

Definitely! Feel free to stop by #loki-dev on grafana.slack.com if you have any questions.

[stale[bot]]

This issue has been automatically marked as stale because it has not had any activity in the past 30 days. It will be closed in 7 days if no further activity occurs. Thank you for your contributions.

[slim-bean]

@PabloCastellano are you still available to add some documentation around this, that would be very helpful!