dockerTools.examples: explicitly set image tag to fix docker-tools tests

docker-tools tests load images without specifying any tag
value. Docker then uses the image with tag "latest" which doesn't
exist anymore since commit 39e678e24e38f1f374eaf5463b424ebdf75df9af.

+5
+5
pkgs/build-support/docker/examples.nix
··· 13 # 1. basic example 14 bash = buildImage { 15 name = "bash"; 16 contents = pkgs.bashInteractive; 17 }; 18 ··· 65 in 66 buildImage { 67 name = "nginx-container"; 68 contents = pkgs.nginx; 69 70 runAsRoot = '' ··· 106 # docker run -it --rm nix nix-store -qR $(nix-build '<nixpkgs>' -A nix) 107 nix = buildImageWithNixDb { 108 name = "nix"; 109 contents = [ 110 # nix-store uses cat program to display results as specified by 111 # the image env variable NIX_PAGER. ··· 121 # dockerTools chain. 122 onTopOfPulledImage = buildImage { 123 name = "onTopOfPulledImage"; 124 fromImage = nixFromDockerHub; 125 contents = [ pkgs.hello ]; 126 }; ··· 129 # See issue #34779 and PR #40947 for details. 130 runAsRootExtraCommands = pkgs.dockerTools.buildImage { 131 name = "runAsRootExtraCommands"; 132 contents = [ pkgs.coreutils ]; 133 # The parens here are to create problematic bash to embed and eval. In case 134 # this is *embedded* into the script (with nix expansion) the initial quotes
··· 13 # 1. basic example 14 bash = buildImage { 15 name = "bash"; 16 + tag = "latest"; 17 contents = pkgs.bashInteractive; 18 }; 19 ··· 66 in 67 buildImage { 68 name = "nginx-container"; 69 + tag = "latest"; 70 contents = pkgs.nginx; 71 72 runAsRoot = '' ··· 108 # docker run -it --rm nix nix-store -qR $(nix-build '<nixpkgs>' -A nix) 109 nix = buildImageWithNixDb { 110 name = "nix"; 111 + tag = "latest"; 112 contents = [ 113 # nix-store uses cat program to display results as specified by 114 # the image env variable NIX_PAGER. ··· 124 # dockerTools chain. 125 onTopOfPulledImage = buildImage { 126 name = "onTopOfPulledImage"; 127 + tag = "latest"; 128 fromImage = nixFromDockerHub; 129 contents = [ pkgs.hello ]; 130 }; ··· 133 # See issue #34779 and PR #40947 for details. 134 runAsRootExtraCommands = pkgs.dockerTools.buildImage { 135 name = "runAsRootExtraCommands"; 136 + tag = "latest"; 137 contents = [ pkgs.coreutils ]; 138 # The parens here are to create problematic bash to embed and eval. In case 139 # this is *embedded* into the script (with nix expansion) the initial quotes