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author | John Ericson <John.Ericson@Obsidian.Systems> | 2021-02-25 20:35:11 +0000 |
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committer | John Ericson <John.Ericson@Obsidian.Systems> | 2021-02-25 21:51:05 +0000 |
commit | ca0994819d68aee26a2906c37a47ae609ac46c4c (patch) | |
tree | c96805c008c22926b1eaadc340a99323d53be532 /src/nix/make-content-addressable.md | |
parent | 10e81bf871551901ff0383bdede0f79325e93867 (diff) | |
parent | c189031e8be0530d73a817571ad7f81ad5eedce6 (diff) |
Merge remote-tracking branch 'upstream/master' into path-info
Diffstat (limited to 'src/nix/make-content-addressable.md')
-rw-r--r-- | src/nix/make-content-addressable.md | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/src/nix/make-content-addressable.md b/src/nix/make-content-addressable.md new file mode 100644 index 000000000..3dd847edc --- /dev/null +++ b/src/nix/make-content-addressable.md @@ -0,0 +1,59 @@ +R""( + +# Examples + +* Create a content-addressed representation of the closure of GNU Hello: + + ```console + # nix store make-content-addressable -r nixpkgs#hello + … + rewrote '/nix/store/v5sv61sszx301i0x6xysaqzla09nksnd-hello-2.10' to '/nix/store/5skmmcb9svys5lj3kbsrjg7vf2irid63-hello-2.10' + ``` + + Since the resulting paths are content-addressed, they are always + trusted and don't need signatures to copied to another store: + + ```console + # nix copy --to /tmp/nix --trusted-public-keys '' /nix/store/5skmmcb9svys5lj3kbsrjg7vf2irid63-hello-2.10 + ``` + + By contrast, the original closure is input-addressed, so it does + need signatures to be trusted: + + ```console + # nix copy --to /tmp/nix --trusted-public-keys '' nixpkgs#hello + cannot add path '/nix/store/zy9wbxwcygrwnh8n2w9qbbcr6zk87m26-libunistring-0.9.10' because it lacks a valid signature + ``` + +* Create a content-addressed representation of the current NixOS + system closure: + + ```console + # nix store make-content-addressable -r /run/current-system + ``` + +# Description + +This command converts the closure of the store paths specified by +*installables* to content-addressed form. Nix store paths are usually +*input-addressed*, meaning that the hash part of the store path is +computed from the contents of the derivation (i.e., the build-time +dependency graph). Input-addressed paths need to be signed by a +trusted key if you want to import them into a store, because we need +to trust that the contents of the path were actually built by the +derivation. + +By contrast, in a *content-addressed* path, the hash part is computed +from the contents of the path. This allows the contents of the path to +be verified without any additional information such as +signatures. This means that a command like + +```console +# nix store build /nix/store/5skmmcb9svys5lj3kbsrjg7vf2irid63-hello-2.10 \ + --substituters https://my-cache.example.org +``` + +will succeed even if the binary cache `https://my-cache.example.org` +doesn't present any signatures. + +)"" |