Templates

Tera template engine reference — variables, filters, and GoReleaser compatibility

Anodizer uses the Tera template engine (Jinja2/Django-like syntax). Templates can be used in most string fields throughout the configuration: name templates, tag templates, message templates, signing arguments, and more.

Two syntaxes, one engine

Anodizer accepts both template dialects and renders them on the same Tera engine:

• Tera-native, no-dot — the canonical, recommended form. Reference fields by bare name ({{ Version }}), use Tera operators (==, !=, and, or, not), pipe through filters ({{ Tag | trimprefix(prefix="v") }}), and write control flow with {% %}.
• GoReleaser / Go text/template — paste a snippet straight out of a .goreleaser.yaml and it runs unchanged. Anodizer auto-translates Go idioms before rendering, so migrating costs nothing.

# Both forms are equivalent — pick either, mix freely:
name_template: "{{ ProjectName }}-{{ Version }}"     # Tera-native (recommended)
name_template: "{{ .ProjectName }}-{{ .Version }}"   # GoReleaser/Go (auto-translated)

The docs throughout this site use the Tera-native no-dot form as the canonical idiom; the Go form is documented here for painless migration.

Syntax

Templates use {{ "{{ }}" }} for variable interpolation and {{ "{% %}" }} for control flow:

name_template: "{{ ProjectName }}-{{ Version }}-{{ Os }}-{{ Arch }}"

GoReleaser compatibility

Anodizer auto-translates Go text/template syntax to its Tera equivalent before rendering, so a template copied verbatim from a .goreleaser.yaml works without edits. The translation covers:

• Leading dots — {{ "{{ .Field }}" }} → {{ "{{ Field }}" }} (and {{ "{{ .Env.FOO }}" }} → {{ "{{ Env.FOO }}" }}).
• Go statement blocks — {{ "{{ if }}" }} / {{ "{{ range }}" }} / {{ "{{ with }}" }} / {{ "{{ end }}" }} become Tera's {{ "{% if %}" }} / {{ "{% for %}" }} / {{ "{% endif %}" }} / {{ "{% endfor %}" }}.
• $ variables — $myvar Go locals are accepted.
• Comparison & logic functions — eq ne gt lt ge le and or not map to Tera operators (== != > < >= <= and or not).
• len — {{ "{{ len .Tags }}" }} becomes {{ "{{ Tags | length }}" }}.
• Positional function calls — Go-style positional arguments for replace split contains in reReplaceAll map slice time printf print println are mapped to Tera's named-argument form.

# Both forms are equivalent:
name_template: "{{ .ProjectName }}-{{ .Version }}"   # Go-style (compat)
name_template: "{{ ProjectName }}-{{ Version }}"       # Tera-style (native)

You can freely mix both styles in the same config file. The leading dot is stripped before the template is rendered.

Common GoReleaser idiom → Tera mapping

Anodizer preprocesses most Go-template constructs into their Tera equivalents, but a handful of idioms copied verbatim from a .goreleaser.yaml will produce confusing errors. Use this table when migrating.

If you hit a construct not covered here, open an issue with the failing template and the intended output.

Template variables

Project and version

Git information

Build context

Release state

The Is* flags (IsSnapshot, IsNightly, IsHarness, IsDraft, IsRelease, IsSingleTarget, IsMerging, IsGitDirty, IsGitClean, IsPrepare) are real booleans, and NightlyBuild is a real number — use them directly:

if: "{{ not IsSnapshot }}"            # skip on snapshots
if: "{{ IsHarness }}"                 # only inside the determinism harness
if: "{% if NightlyBuild > 0 %}true{% endif %}"

Comparing them to quoted strings (IsSnapshot == "false") never matches — Tera does not coerce booleans to strings — so anodizer rejects such conditions with a hard error instead of silently skipping the stage.

Time

Environment variables

Access environment variables via Env:

name_template: "{{ ProjectName }}-{{ Env.CUSTOM_SUFFIX }}"

You can define custom environment variables in the config:

env:
  CUSTOM_SUFFIX: "special"
  BUILD_MODE: "production"

Pipeline outputs

Stages can write values to the Outputs map, and templates can read them:

# Tera-style
body_template: "Build ID: {{ Outputs.build_id }}"
# Go-style (also supported)
body_template: "Build ID: {{ .Outputs.build_id }}"

Similar to Var.* but for pipeline outputs rather than user config values.

Note: Only reference keys that are actually set by stages. For optional keys, use the | default guard:

body_template: "Build: {{ Outputs.build_id | default(value=\"unknown\") }}"

Functions and filters

Tera provides many built-in filters (lower, upper, title, trim, length, default, …). On top of those, anodizer registers a full set of release-oriented helpers. Most are available in both forms — as a filter ({{ "{{ X | fn(...) }}" }}) and as a function ({{ "{{ fn(s=X, ...) }}" }}) — so the GoReleaser positional form ({{ "{{ fn X ... }}" }}) auto-translates onto them.

Examples below use the Tera-native no-dot idiom.

String

Formatting

printf implements the Go verb subset %s %d %v %x %X %o %b %c %q %f %e %E %g %G %t %% with flags, width, and precision (Go-style exponents). print follows Go's Sprint spacing rule (a space is inserted between two adjacent operands only when neither is a string).

Path

List and map

Semver

Environment

File

Time

Hashing

Fourteen hash functions take a file path argument (s=) and return the lowercase hex digest of that file's contents:

md5 · crc32 · sha1 · sha224 · sha256 · sha384 · sha512 · sha3_224 · sha3_256 · sha3_384 · sha3_512 · blake2b · blake2s · blake3

body_template: "checksum: {{ sha256(s=ArtifactPath) }}"

Not supported (intentionally): Go's html, js, urlquery, and call builtins are web-escaping / reflection helpers with no role in release templating, so they are not registered. Everything else from GoReleaser's function set — plus the Go text/template builtins that matter — is present.

Control flow

Tera supports conditionals and loops:

header: |
  {% if IsSnapshot %}
  **This is a snapshot build — not for production use.**
  {% else %}
  ## {{ ProjectName }} {{ Version }}
  {% endif %}

# Loops (less common in config, but available)
message_template: |
  New release: {{ Tag }}
  {% for crate in crates %}
  - {{ crate.name }}: {{ crate.version }}
  {% endfor %}