Version 3.3.12 home Download and build Libraries and tools Branch management Demo Discovery service protocol Frequently Asked Questions (FAQ) Logging conventions Metrics Production users Reporting bugs Tuning etcd release guide Benchmarks Benchmarking etcd v2.1.0 Benchmarking etcd v2.2.0 Benchmarking etcd v2.2.0-rc Benchmarking etcd v2.2.0-rc-memory Benchmarking etcd v3 Storage Memory Usage Benchmark Watch Memory Usage Benchmark Developer guide Experimental APIs and features Interacting with etcd Set up a local cluster System limits Why gRPC gateway etcd API Reference etcd concurrency API Reference gRPC naming and discovery Learning etcd client architecture Client feature matrix Data model Glossary KV API guarantees Learner etcd v3 authentication design etcd versus other key-value stores etcd3 API Operations guide Clustering Guide Configuration flags Design of runtime reconfiguration Disaster recovery Failure modes Hardware recommendations Maintenance Migrate applications from using API v2 to API v3 Monitoring etcd Performance Role-based access control Run etcd clusters inside containers Runtime reconfiguration Supported systems Transport security model Versioning etcd gateway gRPC proxy Platforms Amazon Web Services Container Linux with systemd FreeBSD Upgrading Upgrade etcd from 2.3 to 3.0 Upgrade etcd from 3.0 to 3.1 Upgrade etcd from 3.1 to 3.2 Upgrade etcd from 3.2 to 3.3 Upgrade etcd from 3.3 to 3.4 Upgrade etcd from 3.4 to 3.5 Upgrading etcd clusters and applications etcd v3 API

Container Linux with systemd



The following guide shows how to run etcd with systemd under Container Linux.

Provisioning an etcd cluster

Cluster bootstrapping in Container Linux is simplest with Ignition; coreos-metadata.service dynamically fetches the machine’s IP for discovery. Note that etcd’s discovery service protocol is only meant for bootstrapping, and cannot be used with runtime reconfiguration or cluster monitoring.

The Container Linux Config Transpiler compiles etcd configuration files into Ignition configuration files:

  version: 3.2.0
  name: s1
  data_dir: /var/lib/etcd
  advertise_client_urls:       http://{PUBLIC_IPV4}:2379
  initial_advertise_peer_urls: http://{PRIVATE_IPV4}:2380
  listen_peer_urls:            http://{PRIVATE_IPV4}:2380
  discovery:         <token>

ct would produce the following Ignition Config:

$ ct --platform=gce --in-file /tmp/ct-etcd.cnf
        "contents":"[Unit]\nRequires=coreos-metadata.service\nAfter=coreos-metadata.service\n\n[Service]\nEnvironmentFile=/run/metadata/coreos\nEnvironment=\"ETCD_IMAGE_TAG=v3.1.8\"\nExecStart=\nExecStart=/usr/lib/coreos/etcd-wrapper $ETCD_OPTS \\\n  --name=\"s1\" \\\n  --data-dir=\"/var/lib/etcd\" \\\n  --listen-peer-urls=\"http://${COREOS_GCE_IP_LOCAL_0}:2380\" \\\n  --listen-client-urls=\"\" \\\n  --initial-advertise-peer-urls=\"http://${COREOS_GCE_IP_LOCAL_0}:2380\" \\\n  --advertise-client-urls=\"http://${COREOS_GCE_IP_EXTERNAL_0}:2379\" \\\n  --discovery=\"\u003ctoken\u003e\""}]}]},

To avoid accidental misconfiguration, the transpiler helpfully verifies etcd configurations when generating Ignition files:

  version: 3.2.0
  name: s1
  data_dir_x: /var/lib/etcd
  advertise_client_urls:       http://{PUBLIC_IPV4}:2379
  initial_advertise_peer_urls: http://{PRIVATE_IPV4}:2380
  listen_peer_urls:            http://{PRIVATE_IPV4}:2380
  discovery:         <token>
$ ct --platform=gce --in-file /tmp/ct-etcd.cnf
warning at line 3, column 2
Config has unrecognized key: data_dir_x

See Container Linux Provisioning for more details.

etcd 3.x service

Container Linux does not include etcd 3.x binaries by default. Different versions of etcd 3.x can be fetched via etcd-member.service.

Confirm unit file exists:

systemctl cat etcd-member.service

Check if the etcd service is running:

systemctl status etcd-member.service

Example systemd drop-in unit to override the default service settings:

cat > /tmp/20-cl-etcd-member.conf <<EOF
Environment="ETCD_OPTS=--name s1 \
  --listen-client-urls \
  --advertise-client-urls \
  --listen-peer-urls \
  --initial-advertise-peer-urls \
  --initial-cluster s1=,s2=,s3= \
  --initial-cluster-token mytoken \
  --initial-cluster-state new \
  --client-cert-auth \
  --trusted-ca-file /etc/ssl/certs/etcd-root-ca.pem \
  --cert-file /etc/ssl/certs/s1.pem \
  --key-file /etc/ssl/certs/s1-key.pem \
  --peer-client-cert-auth \
  --peer-trusted-ca-file /etc/ssl/certs/etcd-root-ca.pem \
  --peer-cert-file /etc/ssl/certs/s1.pem \
  --peer-key-file /etc/ssl/certs/s1-key.pem \
  --auto-compaction-retention 1"
mv /tmp/20-cl-etcd-member.conf /etc/systemd/system/etcd-member.service.d/20-cl-etcd-member.conf

Or use a Container Linux Config:

    - name: etcd-member.service
        - name: conf1.conf
          contents: |

  version: 3.2.0
  name: s1
  data_dir: /var/lib/etcd
  advertise_client_urls:       https://{PUBLIC_IPV4}:2379
  listen_peer_urls:            https://{PRIVATE_IPV4}:2380
  initial_advertise_peer_urls: https://{PRIVATE_IPV4}:2380
  initial_cluster:             s1=https://{PRIVATE_IPV4}:2380,s2=,s3=
  initial_cluster_token:       mytoken
  initial_cluster_state:       new
  client_cert_auth:            true
  trusted_ca_file:             /etc/ssl/certs/etcd-root-ca.pem
  cert_file:                   /etc/ssl/certs/s1.pem
  key_file:                    /etc/ssl/certs/s1-key.pem
  peer_client_cert_auth:       true
  peer_trusted_ca_file:        /etc/ssl/certs/etcd-root-ca.pem
  peer_cert_file:              /etc/ssl/certs/s1.pem
  peer_key_file:               /etc/ssl/certs/s1-key.pem
  auto_compaction_retention:   1
$ ct --platform=gce --in-file /tmp/ct-etcd.cnf

To see all runtime drop-in changes for system units:

systemd-delta --type=extended

To enable and start:

systemctl daemon-reload
systemctl enable --now etcd-member.service

To see the logs:

journalctl --unit etcd-member.service --lines 10

To stop and disable the service:

systemctl disable --now etcd-member.service

etcd 2.x service

Container Linux includes a unit file etcd2.service for etcd 2.x, which will be removed in the near future. See Container Linux FAQ for more details.

Confirm unit file is installed:

systemctl cat etcd2.service

Check if the etcd service is running:

systemctl status etcd2.service

To stop and disable:

systemctl disable --now etcd2.service

© 2019 The etcd authors

Container Linux with systemd