Configuration

Vela reads two files. Vela.toml lives in your project and describes one app. server.toml lives on the server and describes the machine.

Vela.toml

Read by vela deploy and the other client commands, from your project root.

[app]
name = "my-app"           # required: used in paths, logs and commands
domain = "my-app.com"     # required: the domain that routes to this app

[deploy]
server = "[email protected]"   # SSH target, user@host
type = "binary"           # "binary" or "beam" (default "binary")
binary = "my-app"         # entrypoint inside the release directory
health = "/health"        # GET this path, expect 200
drain = 5                 # seconds the old instance keeps its connections (default 5)
strategy = "blue-green"   # "blue-green" or "sequential" (default "blue-green")
pre_start = "bin/migrate" # runs before the app starts; failure aborts the deploy
post_deploy = "bin/notify"# runs after traffic swaps; failure is only logged

[env]
DATABASE_PATH = "${data_dir}/my-app.db"
RUST_LOG = "info"

App types

binary runs a compiled program directly: Rust, Go, C, anything that builds to an executable.

beam runs an Elixir/Phoenix release from mix release, with bin/server start unless you set binary. The release carries its own BEAM runtime, so the server needs no Erlang or Elixir.

Strategies

blue-green starts the new instance next to the old one. Once the health check passes, traffic swaps and the old instance drains. No request ever finds nothing listening. Use it when your state lives outside the process.

sequential stops the old instance before starting the new one, a gap of well under a second. Use it for SQLite, so two processes never write the same database file.

Hooks

pre_start runs inside the new release directory after it is unpacked and before the app starts. A non-zero exit aborts the deploy and leaves the old instance running. Put migrations here.

post_deploy runs after the health check has passed and traffic has moved. A failure is logged and does not roll anything back. Use it for cache warming or notifications.

Both hooks see the same environment as the app: secrets, [env], PORT and VELA_DATA_DIR.

Environment

Values in [env] can use two substitutions:

The server stores the resolved [env] with the app, so when the daemon restarts, every app comes back with the same environment.

Resources

[resources] accepts memory (for example "512M") and cpu_weight. They are not enforced yet; limits arrive with process isolation.

Secrets

Secrets stay on the server, never in your repository. Each app’s secrets live in a file readable only by Vela (mode 0600).

vela secret set my-app SECRET_KEY_BASE=...   # set or replace
vela secret list my-app                      # keys only, never values
vela secret remove my-app SECRET_KEY_BASE

They reach the app as environment variables. Refer to them in [env] as ${secret:KEY} when the app expects a different name.

Services

Declare what your app depends on. Vela provisions it on the first deploy and injects the connection details.

Postgres

[services.postgres]
version = "17"               # default "17"
databases = ["myapp_prod"]

Vela installs PostgreSQL with apt if it is missing, creates a user and database with a generated password, and sets DATABASE_URL to postgres://<db>:<password>@localhost/<db>. The credentials are kept in /var/vela/services/postgres/state.toml and reused on every deploy.

NATS

[services.nats]
version = "2.10"     # default "2.10"
jetstream = true     # default false

Vela downloads the NATS server from its GitHub releases, writes a config, supervises it, and sets NATS_URL to nats://localhost:4222. NATS listens on localhost only: 4222 for clients, 8222 for monitoring.

Remote builds

Build on the server instead of your laptop, for Elixir releases or whenever cross-compiling is more trouble than it is worth.

[build]
remote = true
command = "mix release"

[build.env]
MIX_ENV = "prod"

vela deploy then needs no artifact. It uploads your committed source with git archive HEAD, runs the command on the server, and activates the result like any other deploy. Uncommitted changes are not included.

server.toml

Lives at /etc/vela/server.toml and is read by vela serve. The commands your laptop runs over SSH read the same path, so keep it there.

data_dir = "/var/vela"        # apps, releases and state (default /var/vela)

[proxy]
http_port = 80                # default 80
https_port = 443              # default 443

[tls]
acme_email = "[email protected]"  # register with Let's Encrypt
staging = false                 # use Let's Encrypt staging while testing
# cert = "/etc/vela/tls/origin.pem"          # a static certificate instead of ACME
# key = "/etc/vela/tls/origin-key.pem"
# client_ca = "/etc/vela/tls/client-ca.pem"  # require client certificates (mTLS)

Without a config file, Vela uses /var/vela, listens on 80 and 443, and serves no TLS until acme_email is set.

TLS

With acme_email, Vela gets certificates from Let’s Encrypt over HTTP-01, picks them by SNI, checks them daily and renews 30 days before they expire. Plain HTTP redirects to HTTPS, except for the ACME challenge itself.

With cert and key, Vela serves that certificate instead, for example a Cloudflare Origin certificate. Add client_ca and the HTTPS listener refuses any connection without a client certificate signed by that CA; with Cloudflare’s Authenticated Origin Pulls, only Cloudflare can reach your server. The Cloudflare guide walks through it.

Backups

[backup]
schedule = "daily"                 # "hourly", "daily" or an interval like "12h"
retain = 7                         # how many backups to keep
destination = "/var/backups/vela"  # a local path or "s3://bucket/prefix"

[backup.include]
app_data = true    # app data directories; SQLite is checkpointed first
secrets = true     # each app's secrets and app.toml
postgres = true    # pg_dump of every provisioned database, gzipped

S3 destinations need the aws CLI installed and configured on the server. Run vela backup from your laptop to take one now.

Commands

vela status --json asks the daemon for live process details and probes each health path with a 3-second timeout; health is healthy, unhealthy, or unknown when no health path is set.