chore: baseline container POC and atomic foundation plan

- Containerized Pi hello-world proof (image mosaic-poc-agent:0.84.4, non-root)
- Four immutable contract fixtures loaded into a generated system prompt
- build/hello/verify/reset scripts with exact-match gating and reset safety
- Documented Pi discovery (v0.84.4, -p mode, --system-prompt, container auth)
- Append-only BUILD-LOG with corrections; deferred layers in LAYERS.md
- Architecture plan: docs/plans/2026-09-02_atomic-mosaic-foundation.md
This commit is contained in:
2026-09-02 18:24:36 -05:00
commit c2365ae519
23 changed files with 3051 additions and 0 deletions
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#!/usr/bin/env bash
# Build the mosaic-agent container image using Docker Compose.
set -euo pipefail
cd "$(dirname "$0")/.."
# shellcheck source=common.sh
source scripts/common.sh
bootstrap_runtime_dir
docker compose build
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# Shared helpers for the POC host scripts. Not a documented entry point.
MOSAIC_DEV_DIR="/home/jwoltje/.mosaic-dev"
POC_ROOT_MARKER=".mosaic-poc-root"
# Ensure the runtime state directory exists and carries this project's
# ownership marker. The marker is what scripts/reset.sh requires before
# it will delete anything.
bootstrap_runtime_dir() {
if [ ! -d "$MOSAIC_DEV_DIR" ]; then
mkdir -p "$MOSAIC_DEV_DIR"
echo "bootstrap: created $MOSAIC_DEV_DIR"
fi
touch "$MOSAIC_DEV_DIR/$POC_ROOT_MARKER"
}
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#!/usr/bin/env node
/**
* Repository-local Git credential helper for git.mosaicstack.dev.
*
* Git invokes this helper with "get", "store", or "erase" and consumes its
* stdout directly. Never invoke it manually, enable shell tracing around it,
* or add credential values to logs.
*
* The credential file is intentionally not part of Git and must remain mode
* 0600. Override its location with MOSAIC_GITEA_CREDENTIAL_FILE if needed.
*/
import fs from "node:fs";
import os from "node:os";
import path from "node:path";
import process from "node:process";
const operation = process.argv[2] ?? "";
// Git may offer credentials back through stdin for store/erase. This helper is
// read-only: ignore those operations and never persist or print their input.
if (operation !== "get") {
process.exit(0);
}
const defaultCredentialFile = path.join(
os.homedir(),
"secrets",
"mosaic.gitea.json",
);
const credentialFile =
process.env.MOSAIC_GITEA_CREDENTIAL_FILE ?? defaultCredentialFile;
function fail(message) {
process.stderr.write(`git-credential-mosaic: ${message}\n`);
process.exit(1);
}
let stat;
try {
stat = fs.lstatSync(credentialFile);
} catch {
fail("credential file is unavailable");
}
if (!stat.isFile() || stat.isSymbolicLink()) {
fail("credential path must be a regular, non-symbolic-link file");
}
if ((stat.mode & 0o077) !== 0) {
fail("credential file permissions must be 0600 or stricter");
}
if (typeof process.getuid === "function" && stat.uid !== process.getuid()) {
fail("credential file must be owned by the current user");
}
let document;
try {
document = JSON.parse(fs.readFileSync(credentialFile, "utf8"));
} catch {
fail("credential file is not valid JSON");
}
const entry = document?.mosaicstack;
const configuredUrl = entry?.url;
const username = entry?.user;
const token = entry?.api_token;
if (
typeof configuredUrl !== "string" ||
typeof username !== "string" ||
typeof token !== "string" ||
username.length === 0 ||
token.length === 0 ||
/[\r\n]/.test(username) ||
/[\r\n]/.test(token)
) {
fail("credential file is missing valid mosaicstack url/user/api_token fields");
}
let credentialUrl;
try {
credentialUrl = new URL(configuredUrl);
} catch {
fail("configured credential URL is invalid");
}
if (
credentialUrl.protocol !== "https:" ||
credentialUrl.hostname !== "git.mosaicstack.dev"
) {
fail("credential URL is not the approved HTTPS Gitea host");
}
const request = {};
for (const line of fs.readFileSync(0, "utf8").split("\n")) {
const separator = line.indexOf("=");
if (separator > 0) {
request[line.slice(0, separator)] = line.slice(separator + 1);
}
}
// Fail closed: emit credentials only for the approved HTTPS host. A host may
// include an explicit port; it must match the configured URL exactly.
if (
request.protocol !== "https" ||
request.host !== credentialUrl.host
) {
process.exit(0);
}
// stdout is the Git credential-helper protocol channel, consumed directly by
// Git. Do not add status messages here.
process.stdout.write(`username=${username}\npassword=${token}\n`);
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#!/usr/bin/env bash
# Run the mosaic-agent service as a one-shot container and print the
# model response for the exact startup verification request.
#
# The request deliberately does NOT contain the expected marker
# MOSAIC_HELLO_OK. Only the model response is printed to stdout; no
# credentials or unrelated runtime data are printed.
set -euo pipefail
cd "$(dirname "$0")/.."
# shellcheck source=common.sh
source scripts/common.sh
bootstrap_runtime_dir
# -T: no pseudo-TTY, so stdout is clean model output.
# Errors, if any, go to stderr for diagnostics.
docker compose run --rm -T mosaic-agent
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#!/usr/bin/env bash
# Delete the generated POC runtime state at /home/jwoltje/.mosaic-dev,
# but ONLY when every safety check passes:
# 1. The resolved path is exactly /home/jwoltje/.mosaic-dev.
# 2. The path is not a symbolic link.
# 3. The directory contains the .mosaic-poc-root ownership marker
# created by this project.
# Any failed check aborts with nothing deleted.
set -euo pipefail
TARGET="/home/jwoltje/.mosaic-dev"
MARKER=".mosaic-poc-root"
fail() {
echo "reset: refusing to delete: $*" >&2
exit 1
}
# Nothing to do when the directory does not exist.
if [ ! -e "$TARGET" ]; then
echo "reset: $TARGET does not exist; nothing to remove"
exit 0
fi
# Check 2 (before resolution): the path itself must not be a symlink.
if [ -L "$TARGET" ]; then
fail "$TARGET is a symbolic link"
fi
# Check 1: resolved path must be exactly the POC runtime directory.
RESOLVED="$(realpath "$TARGET")"
if [ "$RESOLVED" != "$TARGET" ]; then
fail "resolved path $RESOLVED is not $TARGET"
fi
# Check 3: ownership marker created by this project must be present.
if [ ! -f "$TARGET/$MARKER" ]; then
fail "missing $MARKER ownership marker in $TARGET"
fi
rm -rf -- "$TARGET"
echo "reset: removed $TARGET"
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#!/usr/bin/env bash
# Complete verification test:
# 1. Build or confirm the image is built.
# 2. Run the agent request.
# 3. Remove surrounding whitespace from the response.
# 4. Compare with the expected marker (default MOSAIC_HELLO_OK).
# 5. Exit 0 only on exact match; nonzero otherwise.
#
# EXPECTED_MARKER may be overridden to prove the failure path
# (acceptance criterion 9), e.g.:
# EXPECTED_MARKER=MOSAIC_NOT_OK scripts/verify.sh
set -euo pipefail
cd "$(dirname "$0")/.."
# shellcheck source=common.sh
source scripts/common.sh
IMAGE="mosaic-poc-agent:0.84.4"
EXPECTED="${EXPECTED_MARKER:-MOSAIC_HELLO_OK}"
# 1. Build the image only if it is not already present.
if ! docker image inspect "$IMAGE" >/dev/null 2>&1; then
echo "verify: image $IMAGE not found, building..." >&2
bootstrap_runtime_dir
docker compose build
fi
# 2. Run the agent request (stdout only = model response).
set +e
RESPONSE="$(docker compose run --rm -T mosaic-agent 2>/tmp/mosaic-poc-stderr.$$)"
RC=$?
set -e
STDERR_FILE="/tmp/mosaic-poc-stderr.$$"
if [ $RC -ne 0 ]; then
echo "verify: agent run failed (exit $RC):" >&2
cat "$STDERR_FILE" >&2
rm -f "$STDERR_FILE"
exit 1
fi
rm -f "$STDERR_FILE"
# 3. Remove surrounding whitespace.
TRIMMED="$(printf '%s' "$RESPONSE" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')"
# 4-6. Exact comparison gate.
if [ "$TRIMMED" = "$EXPECTED" ]; then
echo "PASS: response matches expected marker"
exit 0
fi
echo "FAIL: response does not match expected marker" >&2
printf 'expected: %s\n' "$EXPECTED" >&2
printf 'actual : %s\n' "$TRIMMED" >&2
exit 1