GitHub associates a unique resource ID (or "database ID" or just "ID") with each
API-accessible resource. For example, each issue,
repository, and user has a global ID. In my limited
experience with it, GitHub's REST API generally does not expose endpoints by
which resources can be queried by ID (though it does have some undocumented
endpoints). These resource IDs have been superseded by distinct
global node IDs (node_id
). GitHub's GraphQL API allows retrieval
of a node by its ID, called a "direct node lookup".
As you can tell, you likely don't have much reason to interact with the older identifiers directly. I encountered this case when using the ZenHub API, which interfaces with repositories only by resource ID. In my case, I wanted to retrieve a list of recently-closed issues from a set of repositories identified only by their resource ID (and without their owner or name).
This would be possible using the undocumented repository information REST endpoint I mentioned above, but I wanted to use the GraphQL API due to the amount of repositories I was interested in. GitHub's GraphQL API does not expose a means of querying repositories (or any object, to my understanding) by these resource IDs, so we need to manually convert them.
It turns out that the global node IDs are base64 encodings of a human-readable format. Take, for example, DataBiosphere/azul:
query {
azul: repository(owner:"DataBiosphere", name:"azul") {
id
databaseId
}
}
{
"data": {
"azul": {
"id": "MDEwOlJlcG9zaXRvcnkxMzkwOTU1Mzc=",
"databaseId": 139095537
}
}
}
If we decode the global node ID, we can see the pattern:
$ echo "MDEwOlJlcG9zaXRvcnkxMzkwOTU1Mzc=" | base64 --decode
010:Repository139095537
which we can infer is roughly equivalent to
{type_id}:{type_name}{resource_id}
. I'm pretty new to GraphQL, so I may have
butchered some of the terminology.
In any case, we can reverse this operation to calculate a global node ID from some resource identified only by resource ID:
$ echo -n "010:Repository139095537" | base64
MDEwOlJlcG9zaXRvcnkxMzkwOTU1Mzc=
query {
node(id:"MDEwOlJlcG9zaXRvcnkxMzkwOTU1MzcK") {
... on Repository {
nameWithOwner
}
}
}
{
"data": {
"node": {
"nameWithOwner": "DataBiosphere/azul"
}
}
}
Interestingly, this will work even with the trailing newline (i.e., calling
echo
in the above example without the -n
flag).
This trick is cool. Any idea how the new global node ids will work? You can see some community questions about this here.
An example (for a random new repo is)
The issue I am currently facing is that there used to be this mapping (the one you point out above) from
node_id
-->database_id
(and back again), but with the newnode_ids
this does not seem to be possible...Any thoughts?