whistory

Note: Make sure you’ve set up the test environment so you can follow along in the tutorial.

Use the whistory command to view a history of all executed commands that have interacted with the Wash server.

bash-3.2$ wash
Welcome to Wash!
  Wash includes several built-in commands: wexec, find, list, meta, tail.
  See commands run with wash via 'whistory', and logs with 'whistory <id>'.
Try 'help'
wash . ❯ ls
aws/
docker/
gcp/
kubernetes/
wash . ❯ ls docker/volumes/wash_tutorial_redis
appendonly.aof
wash . ❯ cat docker/volumes/wash_tutorial_redis/appendonly.aof
wash . ❯ whistory
1  2019-10-05 14:51  ls -G .
2  2019-10-05 14:51  ls -G
3  2019-10-05 14:51  wash
4  2019-10-05 14:51  ls -G docker/volumes/wash_tutorial_redis
5  2019-10-05 14:51  cat docker/volumes/wash_tutorial_redis/appendonly.aof
6  2019-10-05 14:52  wash whistory
wash . ❯ exit
Goodbye!

We see that whistory recorded all of our activity1. This activity is specific to our session and will not appear in any other sessions. We can test this by starting a new session and running the command again:

bash-3.2$ wash
Welcome to Wash!
  Wash includes several built-in commands: wexec, find, list, meta, tail.
  See commands run with wash via 'whistory', and logs with 'whistory <id>'.
Try 'help'
wash . ❯ whistory
1  2019-09-25 21:19  ls -G .
2  2019-09-25 21:19  wash whistory
wash . ❯ exit
Goodbye!

Notice from the output that this session’s history is different from the previous session.

You can pass in the command’s history ID to view a detailed log of its activity.


wash . ❯ whistory
1  2019-09-25 21:24  ls -G .
2  2019-09-25 21:24  ls -G docker/containers
3  2019-09-25 21:24  wash whistory
wash . ❯ whistory 2
Sep 25 21:24:54.902 FUSE: List /docker/containers
Sep 25 21:24:54.919 Listing 20 containers in &{{containers {{0 0 <nil>} {0 0 <nil>} {0 0 <nil>} {0 0 <nil>} 0 false 0 false map[]} 35 /docker/containers [15000000000 15000000000 15000000000] map[] false} 0xc0002cc880}
Sep 25 21:24:54.921 FUSE: Listed in /docker/containers: [{Inode:0 Type:dir Name:k8s_compose_compose-6c67d745f6-q54n8_docker_57a0f7e9-c41c-11e9-9d31-025000000001_5} {Inode:0 Type:dir Name:k8s_POD_coredns-fb8b8dccf-2mdnw_kube-system_bfbca97d-c3e6-11e9-9d31-025000000001_5} {Inode:0 Type:dir Name:k8s_POD_redis_default_4d21ee44-c5c7-11e9-9d31-025000000001_5} {Inode:0 Type:dir Name:k8s_POD_kube-proxy-v4fc5_kube-system_bfc80631-c3e6-11e9-9d31-025000000001_5} {Inode:0 Type:dir Name:k8s_POD_kube-controller-manager-docker-desktop_kube-system_9c58c6d32bd3a2d42b8b10905b8e8f54_5} {Inode:0 Type:dir Name:k8s_POD_kube-apiserver-docker-desktop_kube-system_7c4f3d43558e9fadf2d2b323b2e78235_5} {Inode:0 Type:dir Name:k8s_coredns_coredns-fb8b8dccf-2mdnw_kube-system_bfbca97d-c3e6-11e9-9d31-025000000001_9} {Inode:0 Type:dir Name:k8s_redis_redis_default_4d21ee44-c5c7-11e9-9d31-025000000001_5} {Inode:0 Type:dir Name:k8s_etcd_etcd-docker-desktop_kube-system_3773efb8e009876ddfa2c10173dba95e_5} {Inode:0 Type:dir Name:k8s_kube-apiserver_kube-apiserver-docker-desktop_kube-system_7c4f3d43558e9fadf2d2b323b2e78235_5} {Inode:0 Type:dir Name:k8s_POD_etcd-docker-desktop_kube-system_3773efb8e009876ddfa2c10173dba95e_5} {Inode:0 Type:dir Name:k8s_kube-scheduler_kube-scheduler-docker-desktop_kube-system_124f5bab49bf26c80b1c1be19641c3e8_6} {Inode:0 Type:dir Name:k8s_coredns_coredns-fb8b8dccf-nsrj4_kube-system_bfbdb38c-c3e6-11e9-9d31-025000000001_9} {Inode:0 Type:dir Name:k8s_compose_compose-api-57ff65b8c7-gpk27_docker_579e832e-c41c-11e9-9d31-025000000001_8} {Inode:0 Type:dir Name:k8s_POD_compose-6c67d745f6-q54n8_docker_57a0f7e9-c41c-11e9-9d31-025000000001_6} {Inode:0 Type:dir Name:k8s_POD_compose-api-57ff65b8c7-gpk27_docker_579e832e-c41c-11e9-9d31-025000000001_5} {Inode:0 Type:dir Name:k8s_kube-proxy_kube-proxy-v4fc5_kube-system_bfc80631-c3e6-11e9-9d31-025000000001_5} {Inode:0 Type:dir Name:k8s_POD_coredns-fb8b8dccf-nsrj4_kube-system_bfbdb38c-c3e6-11e9-9d31-025000000001_5} {Inode:0 Type:dir Name:k8s_kube-controller-manager_kube-controller-manager-docker-desktop_kube-system_9c58c6d32bd3a2d42b8b10905b8e8f54_5} {Inode:0 Type:dir Name:k8s_POD_kube-scheduler-docker-desktop_kube-system_124f5bab49bf26c80b1c1be19641c3e8_5}]

This session’s history consists of three entries. The second entry, with an ID of 2, is the command ls -G docker/containers. From the whistory output, we can see that its activity consisted of making a List /docker/containers request to Wash’s underlying FUSE library. Notice that the activity also recorded the List endpoint’s raw response.

whistory is primarily useful for debugging Wash-related failures. A typical pattern is to execute the failed command, then view its activity log to see if you can isolate the failure.

Exercises

  1. Execute each of the following commands and then use whistory to report all the requests that were made to the server. You should only report requests of the form FUSE: <Request> <Entry> or API: <Request> <Entry>. Ignore any analytics requests.

    Note: Do not worry if you’ve disabled analytics. Wash swallows all analytics requests and no data is actually sent to Google Analytics. For more information, see our analytics docs.

    1. wexec docker/containers/wash_tutorial_redis_1 uname

      AnswerAPI: Exec docker/containers/wash_tutorial_redis_1

    2. meta docker/containers/wash_tutorial_redis_1

      AnswerAPI: Metadata docker/containers/wash_tutorial_redis_1

    3. cat docker/volumes/wash_tutorial_redis/appendonly.aof

      AnswerFUSE: Open docker/volumes/wash_tutorial_redis/appendonly.aof

    4. find docker -kind '*container'

      Answer API: List docker
      API: List docker/containers

Next steps

That’s the end of the Debugging series! Click here to go back to the tutorials page.

  1. Ignore the ls -G . and wash for now. Those will be fixed in 521. ↩