Refine platform evolution and engineering standards

PLATFORM_EVOLUTION.md: rewrite with convention-driven service
definitions (derived image names, service-level version, agent
defaults), mcdsl as a proper Go module (gap #1), multi-node
design considerations, and service discovery open question.

engineering-standards.md: add shared libraries section establishing
mcdsl as a normally-versioned Go module (no replace directives in
committed code), update service definition example to convention-
driven minimal format with route declarations.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-03-27 00:19:08 -07:00
parent 1146606208
commit 1def85f1eb
2 changed files with 196 additions and 90 deletions

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@@ -28,9 +28,12 @@ But the wiring between services is manual:
placed in `/srv/mc-proxy/certs/`, and referenced by path in the
mc-proxy config.
- **DNS**: records are manually configured in MCNS zone files.
- **Container networking**: operators specify `network`, `user`, and
`restart` policy per component, even though these are almost always
the same values.
- **Container config boilerplate**: operators specify `network`, `user`,
`restart`, full image URLs, and port mappings per component, even
though these are almost always the same values.
- **mcdsl build wiring**: the shared library requires `replace`
directives or sibling directory tricks in Docker builds. It should
be a normally-versioned Go module fetched by the toolchain.
Each new service requires touching 4-5 files across 3-4 repos. The
process works but doesn't scale and is error-prone.
@@ -43,11 +46,7 @@ want, not **how** to wire it:
```toml
name = "metacrypt"
node = "rift"
active = true
path = "metacrypt"
[build]
uses_mcdsl = false
version = "v1.0.0"
[build.images]
metacrypt = "Dockerfile.api"
@@ -55,9 +54,6 @@ metacrypt-web = "Dockerfile.web"
[[components]]
name = "api"
image = "mcr.svc.mcp.metacircular.net:8443/metacrypt:v1.0.0"
volumes = ["/srv/metacrypt:/srv/metacrypt"]
cmd = ["server", "--config", "/srv/metacrypt/metacrypt.toml"]
[[components.routes]]
name = "rest"
@@ -71,20 +67,30 @@ mode = "l4"
[[components]]
name = "web"
image = "mcr.svc.mcp.metacircular.net:8443/metacrypt-web:v1.0.0"
volumes = ["/srv/metacrypt:/srv/metacrypt"]
cmd = ["server", "--config", "/srv/metacrypt/metacrypt.toml"]
[[components.routes]]
name = "web"
port = 443
mode = "l7"
```
Everything else is derived from conventions:
- **Image name**: `<service>` for the first/api component,
`<service>-<component>` for others. Resolved against the registry
URL from global MCP config (`~/.config/mcp/mcp.toml`).
- **Version**: the service-level `version` field applies to all
components. Can be overridden per-component when needed.
- **Volumes**: `/srv/<service>:/srv/<service>` is the agent default.
Only declare additional mounts.
- **Network, user, restart**: agent defaults (`mcpnet`, `0:0`,
`unless-stopped`). Override only when needed.
- **Source path**: defaults to `<service>` relative to the workspace
root. Override with `path` if different.
`mcp deploy metacrypt` does the rest:
1. Agent assigns a free host port per route (random, check availability,
retry on collision).
1. Agent assigns a free host port per route (random, check
availability, retry on collision).
2. Agent requests TLS certs from Metacrypt CA for
`metacrypt.svc.mcp.metacircular.net`.
3. Agent registers routes with mc-proxy via gRPC (mc-proxy persists
@@ -128,16 +134,27 @@ hostname = "docs.metacircular.net" # optional, public DNS
If `hostname` is omitted, the route uses the default
`<service>.svc.mcp.metacircular.net`.
### Fields Removed from Service Definitions
### Multi-Node Considerations
These become agent-level defaults or are derived automatically:
This design targets single-node (rift) but should not prevent
multi-node operation. Key design decisions that keep the door open:
| Field | Current | Target |
|-------|---------|--------|
| `ports` | Manual port mapping | Agent-assigned via routes |
| `network` | Per-component | Agent default (`mcpnet`) |
| `user` | Per-component | Agent default (`0:0`) |
| `restart` | Per-component | Agent default (`unless-stopped`) |
- **Port assignment is per-agent.** Each node's agent manages its own
port space. No cross-node coordination needed.
- **Route registration uses the node's address, not `127.0.0.1`.**
When mc-proxy and the service are on the same host, the backend is
loopback. When they're on different hosts, the backend is the node's
network address. The agent registers the appropriate address for its
node. The mc-proxy route API already accepts arbitrary backend
addresses.
- **DNS can have multiple A records.** MCNS can return multiple records
for the same hostname (one per node) for simple load distribution.
- **The CLI routes to the correct agent via the `node` field.** Adding
a second node is `mcp node add orion <address>` and then services
can target `node = "orion"`.
Nothing in the single-node implementation should hardcode assumptions
about one node, one mc-proxy, or loopback-only backends.
---
@@ -157,11 +174,30 @@ These become agent-level defaults or are derived automatically:
| MCNS DNS serving | Working |
| MCR container registry | Working |
| Service definitions in ~/.config/mcp/services/ | Working |
| Image build pipeline (mcdeploy.toml, being folded into MCP) | Working |
| Image build pipeline (being folded into MCP) | Working |
### What needs to change
#### 1. MCP Agent: Port Assignment
#### 1. mcdsl: Proper Module Versioning
**Gap**: mcdsl is used via `replace` directives and sibling directory
hacks. Docker builds require the source tree to be adjacent. This is
fragile and violates normal Go module conventions.
**Work**:
- Tag mcdsl releases with semver (e.g., `v1.0.0`, `v1.1.0`).
- Remove all `replace` directives from consuming services' `go.mod`
files. Services import mcdsl by URL and version like any other
dependency.
- Docker builds fetch mcdsl via the Go module proxy / Gitea — no local
source tree required.
- `uses_mcdsl` is eliminated from service definitions and build config.
**Depends on**: Gitea module hosting working correctly for
`git.wntrmute.dev/kyle/mcdsl` (it should already — Go modules over
git are standard).
#### 2. MCP Agent: Port Assignment
**Gap**: agent doesn't manage host ports. Service definitions specify
them manually.
@@ -177,19 +213,20 @@ them manually.
**Depends on**: nothing (can be developed standalone).
#### 2. MCP Agent: mc-proxy Route Registration
#### 3. MCP Agent: mc-proxy Route Registration
**Gap**: mc-proxy routes are static TOML. The gRPC admin API exists but
MCP doesn't use it.
**Work**:
- Agent calls mc-proxy gRPC API to register/remove routes on deploy/stop.
- Route registration includes: hostname, host port (agent-assigned),
mode (l4/l7), TLS cert paths.
- Agent calls mc-proxy gRPC API to register/remove routes on
deploy/stop.
- Route registration includes: hostname, backend address (node address
+ assigned port), mode (l4/l7), TLS cert paths.
**Depends on**: port assignment (#1), mc-proxy route persistence (#4).
**Depends on**: port assignment (#2), mc-proxy route persistence (#5).
#### 3. MCP Agent: TLS Cert Provisioning
#### 4. MCP Agent: TLS Cert Provisioning
**Gap**: certs are manually provisioned and placed on disk. There is no
automated issuance flow.
@@ -200,9 +237,9 @@ automated issuance flow.
(`/srv/mc-proxy/certs/<service>.pem`).
- Cert renewal is handled automatically before expiry.
**Depends on**: Metacrypt cert issuance policy (#6).
**Depends on**: Metacrypt cert issuance policy (#7).
#### 4. mc-proxy: Route Persistence
#### 5. mc-proxy: Route Persistence
**Gap**: mc-proxy loads routes from TOML on startup. Routes added via
gRPC are lost on restart.
@@ -210,13 +247,13 @@ gRPC are lost on restart.
**Work**:
- mc-proxy persists gRPC-managed routes in its SQLite database.
- On startup, mc-proxy loads routes from the database.
- TOML route config is deprecated (kept for bootstrapping only, e.g.,
mc-proxy's own routes before MCP is fully operational).
- mcproxyctl becomes the primary route management interface.
- TOML route config is vestigial — kept only for mc-proxy's own
bootstrap before MCP is operational. The gRPC API and mcproxyctl
are the primary route management interfaces going forward.
**Depends on**: nothing (mc-proxy already has SQLite and gRPC API).
#### 5. MCP Agent: DNS Registration
#### 6. MCP Agent: DNS Registration
**Gap**: DNS records are manually configured in MCNS zone files.
@@ -225,9 +262,9 @@ gRPC are lost on restart.
`<service>.svc.mcp.metacircular.net`.
- Agent removes records on service teardown.
**Depends on**: MCNS record management API (#7).
**Depends on**: MCNS record management API (#8).
#### 6. Metacrypt: Automated Cert Issuance Policy
#### 7. Metacrypt: Automated Cert Issuance Policy
**Gap**: no policy exists for automated cert issuance. The MCP agent
doesn't have a Metacrypt identity or permissions.
@@ -235,13 +272,14 @@ doesn't have a Metacrypt identity or permissions.
**Work**:
- MCP agent gets an MCIAS service account.
- Metacrypt policy allows this account to issue certs scoped to
`*.svc.mcp.metacircular.net` (and explicitly listed public hostnames).
`*.svc.mcp.metacircular.net` (and explicitly listed public
hostnames).
- No wildcard certs — one cert per hostname per service.
**Depends on**: MCIAS service account provisioning (exists today, just
needs the account created).
#### 7. MCNS: Record Management API
#### 8. MCNS: Record Management API
**Gap**: MCNS is a CoreDNS precursor serving static zone files. There
is no API for dynamic record management.
@@ -257,7 +295,7 @@ is no API for dynamic record management.
wrapper, not a full service. This may be the right time to build the
real MCNS.
#### 8. Application $PORT Convention
#### 9. Application $PORT Convention
**Gap**: applications read listen addresses from their config files.
They don't check `$PORT` env vars.
@@ -279,32 +317,38 @@ The dependencies form a rough order:
```
Phase A — Independent groundwork (parallel):
#1 MCP agent port assignment
#4 mc-proxy route persistence
#8 $PORT convention in applications
#1 mcdsl proper module versioning
#2 MCP agent port assignment
#5 mc-proxy route persistence
#9 $PORT convention in applications
Phase B — MCP route registration:
#2 Agent registers routes with mc-proxy
(depends on #1 + #4)
#3 Agent registers routes with mc-proxy
(depends on #2 + #5)
Phase C — Automated TLS:
#6 Metacrypt cert issuance policy
#3 Agent provisions certs
(depends on #6)
#7 Metacrypt cert issuance policy
#4 Agent provisions certs
(depends on #7)
Phase D — DNS:
#7 MCNS record management API
#5 Agent registers DNS
(depends on #7)
#8 MCNS record management API
#6 Agent registers DNS
(depends on #8)
```
After Phase B, the manual steps are: cert provisioning and DNS. After
Phase C, only DNS remains manual. After Phase D, `mcp deploy` is fully
declarative.
After Phase A, mcdsl builds are clean and services can be deployed
with agent-assigned ports (manually registered in mc-proxy).
Each phase is independently useful. Phase A + B alone eliminates the
most common source of manual wiring errors (port assignment and mc-proxy
config).
After Phase B, the manual steps are: cert provisioning and DNS. This
is the biggest quality-of-life improvement — no more manual port
picking or mc-proxy TOML editing.
After Phase C, only DNS remains manual.
After Phase D, `mcp deploy` is fully declarative.
Each phase is independently useful and deployable.
---
@@ -317,14 +361,16 @@ config).
in addition to the `.svc.mcp.metacircular.net` name. Public DNS is
managed outside MCNS (Cloudflare? registrar?). How does the agent
handle the split between internal and external DNS?
- **mc-proxy bootstrap**: mc-proxy itself needs routes to be reachable.
If routes are in SQLite, how does mc-proxy start before MCP configures
it? A small set of static bootstrap routes (or self-configuration) may
be needed.
- **Multi-node**: this design assumes single-node (rift). When a second
node is added, port assignment is still per-agent, but mc-proxy
routing, cert provisioning, and DNS need to account for multiple
backends. Not a v1 concern, but worth keeping in mind.
- **mc-proxy bootstrap**: mc-proxy itself is a service that needs to be
running before other services can be routed. Its own routes (if any)
may need to be self-configured or seeded from a minimal static config
at first start. Once operational, all route management goes through
the gRPC API.
- **Rollback**: if cert provisioning fails mid-deploy, does the agent
roll back the port assignment and mc-proxy route? What's the failure
mode — partial deploy, full rollback, or best-effort?
- **Service discovery between components**: currently, components find
each other via config (e.g., mcr-web knows mcr-api's gRPC address).
With agent-assigned ports, components within a service need to
discover each other's ports. The agent could set additional env vars
(`$PEER_API_GRPC=127.0.0.1:9217`) or services could query the agent.

View File

@@ -143,6 +143,40 @@ Services hosted on `git.wntrmute.dev` use:
git.wntrmute.dev/kyle/<service>
```
### Shared Libraries (mcdsl)
The `mcdsl` module (`git.wntrmute.dev/kyle/mcdsl`) is the platform's
standard library — shared packages for auth, database, config,
HTTP/gRPC servers, CSRF, snapshots, and other cross-cutting concerns.
mcdsl is a normal Go module, versioned and tagged per standard SDLC
conventions. Services import it like any other dependency:
```go
import "git.wntrmute.dev/kyle/mcdsl/auth"
```
And reference it in `go.mod` with a tagged version:
```
require git.wntrmute.dev/kyle/mcdsl v1.2.0
```
**Rules:**
- mcdsl follows semver. Breaking changes require a major version bump.
- Services pin to a specific mcdsl version and upgrade deliberately.
- `replace` directives in `go.mod` are not permitted in committed code.
They are acceptable only during local development when iterating on
mcdsl and a consuming service simultaneously — they must be removed
before committing.
- Docker builds must not require the mcdsl source tree to be present.
The Go toolchain fetches the tagged module from Gitea like any other
dependency.
- When releasing a new mcdsl version, update consuming services in a
follow-up change — not atomically. Each service upgrades on its own
schedule.
---
## Build System
@@ -635,11 +669,7 @@ file defines a service with one or more container components:
```toml
name = "metacrypt"
node = "rift"
active = true
path = "metacrypt"
[build]
uses_mcdsl = false
version = "v1.0.0"
[build.images]
metacrypt = "Dockerfile.api"
@@ -647,29 +677,53 @@ metacrypt-web = "Dockerfile.web"
[[components]]
name = "api"
image = "mcr.svc.mcp.metacircular.net:8443/metacrypt:v1.0.0"
network = "mcpnet"
user = "0:0"
restart = "unless-stopped"
ports = ["127.0.0.1:18443:8443", "127.0.0.1:19443:9443"]
volumes = ["/srv/metacrypt:/srv/metacrypt"]
cmd = ["server", "--config", "/srv/metacrypt/metacrypt.toml"]
[[components.routes]]
name = "rest"
port = 8443
mode = "l4"
[[components.routes]]
name = "grpc"
port = 9443
mode = "l4"
[[components]]
name = "web"
volumes = ["/srv/metacrypt:/srv/metacrypt"]
[[components.routes]]
port = 443
mode = "l7"
```
The service definition is intentionally minimal. Most fields are
derived from conventions:
- **Image name**: `<service>` for api components, `<service>-<component>`
for others. The registry URL comes from global MCP config.
- **Version**: service-level `version` applies to all components unless
overridden per-component.
- **Volumes**: `/srv/<service>:/srv/<service>` is the default; only
declare additional mounts.
- **Network, user, restart**: agent defaults (`mcpnet`, `0:0`,
`unless-stopped`); override only when needed.
Top-level fields:
| Field | Purpose |
|-------|---------|
| `name` | Service name (matches the project name) |
| `node` | Target host to deploy to |
| `active` | Whether MCP should keep this service running |
| `path` | Source directory relative to the workspace (for builds) |
| `version` | Image version tag (applies to all components) |
| `active` | Whether MCP should keep this service running (default: true) |
| `path` | Source directory relative to workspace (default: same as `name`) |
Build fields:
| Field | Purpose |
|-------|---------|
| `build.uses_mcdsl` | Whether the build requires the mcdsl module |
| `build.images.<name>` | Maps image name to its Dockerfile path |
Component fields:
@@ -677,13 +731,19 @@ Component fields:
| Field | Purpose |
|-------|---------|
| `name` | Component name within the service (e.g. `api`, `web`) |
| `image` | Full image reference including MCR registry and version tag |
| `network` | Podman network to attach to |
| `user` | Container user:group |
| `restart` | Restart policy |
| `ports` | Host-to-container port mappings |
| `volumes` | Host-to-container volume mounts |
| `cmd` | Command and arguments passed to the entrypoint |
| `image` | Image name override (default: derived from service/component name) |
| `version` | Version override for this component |
| `volumes` | Host-to-container volume mounts (in addition to default) |
| `cmd` | Command override (default: Dockerfile CMD) |
Route fields:
| Field | Purpose |
|-------|---------|
| `name` | Route name (used for `$PORT_<NAME>` env var) |
| `port` | External port on mc-proxy |
| `mode` | `l4` (TLS passthrough) or `l7` (TLS termination) |
| `hostname` | Public hostname override (default: `<service>.svc.mcp.metacircular.net`) |
#### Convention