The host decided whether a container was still the one declared by a digest
of its declaration, and the declaration names an env-file's path and a
mount's path — never what is in them. So when the store was given a new
port, the host rewrote the forge's and the analytics service's environment
files, correctly, and left both containers running with the old port in
their environment: a container reads its env-file when it is CREATED, and
`docker restart` hands it the same environment again. Both looked healthy
until they answered 502.
What a running container takes in at creation is now part of its spec, by
content: every env-file, a file bind-mounted into it, and every file this
host wrote at or under a directory bind-mounted into it — the secrets,
bindings and configs under a module's state directories. The digest is the
one the store already records for a file the host wrote (`wrote`), read
from the state as it stands when the container is reached, so a file
rewritten earlier in the same apply is already the new one; a file the host
has no record of — an env-file a predecessor left, the superuser secret
genesis writes before any declaration names it — is read from disk, which
is what keeps adopting a running store in place a reconcile and not a
recreate.
Deliberately not part of it: what else is in a bind-mounted directory,
which is the service's own data and changes while it runs; a named volume;
a seed created once, which digests as the seed the host wrote and not as
what has grown in it; and a step — a run-once or scheduled container reads
its files when it runs and runs fresh each time. On an adopted node a held
container is held before any of this is looked at.
The host records what each container was created reading, per file, so
the recreate can say which file changed — "recreated: <file> changed" in
the report and, now with its detail, in the log. A container made before
this record existed is recreated once and says so.
novox/hq 04-ISSUES/103
jschoubben
c60228e719