This project is an example of using Consul, Vault, and Vault UI in a high availability (HA) configuration. Conveniently packaged as Docker services for provisioning via Docker Compose.
Features:
- dnsmasq makes Consul DNS available to all containers. A secondary dnsmasq server is provided which grants HA to the DNS available to all containers. This allows consul-template to update DNS with zero DNS downtime. consul-template will create a lock to ensure it is not possible for both primary and secondary DNS servers to be down during DNS configuration updates as part of service discovery.
- consul-template updates dnsmasq configuration and restarts dnsmasq when the configuration has changed (e.g. consul cluster size is increased on the fly). This makes consul DNS lookups HA.
- Vault is registered via service discovery which is exposed via Consul DNS.
- Persists data across restarts as long as the cluster is gracefully shut down.
See [
Starting and stoppingsection][#starting-and-stopping]. - Local docker infrastructure is able to anonymously authenticate with Vault via approle method and its CIDR address.
- Linux and Mac OS with docker supported.
Supplemental reading material:
- Hitchhiker's guide to administering Vault
- Vault Auth By CIDR enables anonymous login to Vault from docker infrastructure.
Remove
--scale vault=3if you want to start one instance of Vault.docker compose up -dwould bring only Consul up in HA configuration.
./scripts/consul-agent.sh --bootstrap
docker compose up --scale vault=3 -d
Configure your browser to use the SOCKS5 proxy listening on localhost:1080.
With your browser configured to use the proxy visit
http://consul.service.consul:8500/ and wait for the cluster to be ready.
After the vault service has all nodes available, it is time to initialize vault.
If you wish to secure secret.txt with GPG, then set the recipient_list
environment variable. For example, the following.
export recipient_list="<gpg fingerprint to your secret gpg key>"
If you do not use GPG or do not want to, then skip setting recipient_list.
Initialize vault witht he following command.
./scripts/initialize-vault.sh
The credentials for vault are located in the file secret.txt which is created
when Vault is initialized. Alternately, secret.txt.gpg if using GPG
encryption.
Configure your web browser to use the SOCKS5 proxy listening on
localhost:1080.
In Firefox, do the following:
- Edit connections settings
- Set Manual proxy configuration
- Set SOCKS host to
localhost, set Port to1080, and checkSOCKS v5boolean.
Alternately install FoxyProxy extension which is an extension for quickly switching proxies on or off.
For other browsers, web search how to configure proxy settings or see what extensions are available for managing proxy settings.
Visit http://portal.service.consul/. It provides links to other web UIs and if you configure additional portal services, then they will also show up automatically.
Alternately, you can visit consul and vault directly at:
To log into Vault UI you must generate for yourself an admin token.
./scripts/get-admin-token.sh
The root user token for Vault is stored in secret.txt at the root of this
repository after you initialize Vault.
For playing around with service discovery I have created other docker compose files which will automatically register with this consul cluster. Here's a list of what I have created so far.
With HA enabled, container instances of consul and vault can be terminated with minor disruptions.
Consul can be scaled up on the fly. consul-template will automatically update
dnsmasq to include new services. dnsmasq will experience zero downtime.
docker compose up --scale vault=3 --scale consul-worker=6 -d
To play with failover for killing consul instances, it is recommended to review fault tolerance for consul HA deployments.
Because high availability clusters have to gossip across nodes you can't execute
a simple docker compose down without corrupting the clusters. Instead, you
have to gracefully shut down all clusters that depend on consul and then
gracefully shutdown consul itself. For this, I have provided a script.
Stop consul and vault cluster safely.
./scripts/graceful-shutdown.sh
Start the consul and vault clusters.
docker compose up -d
Currently, output from the dnsmasq and dnsmasq-secondary servers are
minimal. Verbosity of output can be increased for troubleshooting. Edit
docker compose.yml and add --log-queries to the dnsmasq command.
DNS client troubleshooting using Docker.
docker compose run dns-troubleshoot
Using the dig command inside of the container.
# rely on the internal container DNS
dig consul.service.consul
# specify the dnsmasq hostname as the DNS server
dig @dnsmasq vault.service.consul
# reference vault DNS by tags
dig active.vault.service.consul
dig standby.vault.service.consul
View vault logs.
docker compose logs vault
User docker exec to log into container names. It allows you to poke around
the runtime of the container.
Run a SOCKS5 proxy for use with your browser.
docker run --network docker-compose-ha-consul-vault-ui_internal --dns 172.16.238.2 --init -p 127.0.0.1:1080:1080 --rm serjs/go-socks5-proxy
Configure your browser to use SOCKS proxy at 127.0.0.1:1080.
It's possible a cluster was shutdown uncleanly and put into an irrecoverable
state with no leader. If you have ever cleanly shut down consul, then it's
possible you have a backup in the backups/ directory.
If you're in this leaderless state, then wipe out your old cluster data with the following command (this will permanently delete all old data).
docker compose down -v
Start a new cluster.
docker compose up -d
The latest backup can be restored via the following script.
./scripts/restore-consul.sh
If you have a specific backup you wish to restore, then you can call it as an argument.
./scripts/restore-consul.sh backups/backup.snap
