https://github.com/kkrull/docker-sandbox
A place to develop new ideas in Docker
https://github.com/kkrull/docker-sandbox
Last synced: 3 months ago
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A place to develop new ideas in Docker
- Host: GitHub
- URL: https://github.com/kkrull/docker-sandbox
- Owner: kkrull
- Created: 2016-04-14T00:46:49.000Z (about 9 years ago)
- Default Branch: master
- Last Pushed: 2024-05-23T17:48:28.000Z (about 1 year ago)
- Last Synced: 2025-01-14T09:56:11.994Z (5 months ago)
- Language: Dockerfile
- Size: 5.86 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
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README
# Dockerfiles
A collection of `Dockerfile`s that I'm using to learn how to use Docker.
## Docker
### Notes
`docker logs` shows the output that is written to stdout by the container's foreground process. It's not really looking
at log files per se.
`docker inspect` shows lots of useful information about the container and how it is mapped onto the host filesystem.
### References
- [Docker Quickstart](https://docs.docker.com/engine/quickstart/)
- [Docker's Learn by Example](https://docs.docker.com/engine/userguide/containers/dockerizing/)
- The section on [Docker Networking](https://docs.docker.com/engine/userguide/containers/networkingcontainers/) looks
like it will be helpful.
## Containers
### consul-server
Use `bin/agent-dev` to run a container with the consul agent in dev mode. `docker logs consul_server` then shows:
```
vagrant@docker-test:~/src/dockerfiles/consul-server$ docker logs consul_server
==> Starting Consul agent...
==> Starting Consul agent RPC...
==> Consul agent running!
Node name: '3cf41a905164'
Datacenter: 'dc1'
Server: true (bootstrap: false)
Client Addr: 127.0.0.1 (HTTP: 8500, HTTPS: -1, DNS: 8600, RPC: 8400)
Cluster Addr: 172.17.0.2 (LAN: 8301, WAN: 8302)
Gossip encrypt: false, RPC-TLS: false, TLS-Incoming: false
Atlas:
...
2016/04/14 04:04:13 [INFO] serf: EventMemberJoin: 3cf41a905164 172.17.0.2
2016/04/14 04:04:13 [INFO] serf: EventMemberJoin: 3cf41a905164.dc1 172.17.0.2
2016/04/14 04:04:13 [INFO] raft: Node at 172.17.0.2:8300 [Follower] entering Follower state
2016/04/14 04:04:13 [INFO] consul: adding LAN server 3cf41a905164 (Addr: 172.17.0.2:8300) (DC: dc1)
2016/04/14 04:04:13 [INFO] consul: adding WAN server 3cf41a905164.dc1 (Addr: 172.17.0.2:8300) (DC: dc1)
2016/04/14 04:04:13 [DEBUG] Automatically reaping child processes
2016/04/14 04:04:13 [ERR] agent: failed to sync remote state: No cluster leader
2016/04/14 04:04:14 [WARN] raft: Heartbeat timeout reached, starting election
2016/04/14 04:04:14 [INFO] raft: Node at 172.17.0.2:8300 [Candidate] entering Candidate state
2016/04/14 04:04:14 [DEBUG] raft: Votes needed: 1
2016/04/14 04:04:14 [DEBUG] raft: Vote granted. Tally: 1
2016/04/14 04:04:14 [INFO] raft: Election won. Tally: 1
2016/04/14 04:04:14 [INFO] raft: Node at 172.17.0.2:8300 [Leader] entering Leader state
2016/04/14 04:04:14 [INFO] consul: cluster leadership acquired
2016/04/14 04:04:14 [INFO] consul: New leader elected: 3cf41a905164
2016/04/14 04:04:14 [INFO] raft: Disabling EnableSingleNode (bootstrap)
2016/04/14 04:04:14 [DEBUG] raft: Node 172.17.0.2:8300 updated peer set (2): [172.17.0.2:8300]
2016/04/14 04:04:14 [DEBUG] consul: reset tombstone GC to index 2
2016/04/14 04:04:14 [INFO] consul: member '3cf41a905164' joined, marking health alive
2016/04/14 04:04:15 [INFO] agent: Synced service 'consul'
```
and this command now works
vagrant$ docker exec -it consul_server /bin/bash
consul_server# curl http://localhost:8500/v1/catalog/nodes
Consul uses a bunch of ports:
- 8500: REST API
- 8600: DNS server
- All the other ones listed in the `Dockerfile`
Note that the consul REST server only seems to accept connections on `localhost`:
vagrant$ docker run -d -P --name consul consul_server
vagrant$ docker exec -it consul /bin/bash
# curl localhost:8500
Consul Agent
# curl 172.17.0.3:8500
curl: (7) Failed to connect to 172.17.0.3 port 8500: Connection refused
Some more links that are helpful in learning consul:
- [Key Value](https://www.consul.io/intro/getting-started/kv.html) store.
- A quick blog post [Consul introduction](http://blog.scottlowe.org/2015/02/06/quick-intro-to-consul/) that breaks it
all down while avoiding marketing hype.